The production of butyric acid by Clostridium butyricum ZJUCB at various pH values was investigated. In order to study the effect of pH on cell growth, butyric acid biosynthesis and reducing sugar consumption, differe...The production of butyric acid by Clostridium butyricum ZJUCB at various pH values was investigated. In order to study the effect of pH on cell growth, butyric acid biosynthesis and reducing sugar consumption, different cultivation pH values ranging from 6.0 to 7.5 were evaluated in 5-L bioreactor. In controlled pH batch fermentation, the optimum pH for cell growth and butyric acid production was 6.5 with a cell yield of 3.65 g/L and butyric acid yield of 12.25 g/L. Based on these results, this study then compared batch and fed-batch fermentation of butyric acid production at pH 6.5. Maximum value (16.74 g/L) of butyric acid concentration was obtained in fed-batch fermentation compared to 12.25 g/L in batch fermentation. It was concluded that culti- vation under fed-batch fermentation mode could enhance butyric acid production significantly (P<0.01) by C. butyricum ZJUCB.展开更多
Acid production with flue gas is a complex nonlinear process with multiple variables and strong coupling.The operation data is an important basis for state monitoring,optimal control,and fault diagnosis.However,the op...Acid production with flue gas is a complex nonlinear process with multiple variables and strong coupling.The operation data is an important basis for state monitoring,optimal control,and fault diagnosis.However,the operating environment of acid production with flue gas is complex and there is much equipment.The data obtained by the detection equipment is seriously polluted and prone to abnormal phenomena such as data loss and outliers.Therefore,to solve the problem of abnormal data in the process of acid production with flue gas,a data cleaning method based on improved random forest is proposed.Firstly,an outlier data recognition model based on isolation forest is designed to identify and eliminate the outliers in the dataset.Secondly,an improved random forest regression model is established.Genetic algorithm is used to optimize the hyperparameters of the random forest regression model.Then the optimal parameter combination is found in the search space and the trend of data is predicted.Finally,the improved random forest data cleaning method is used to compensate for the missing data after eliminating abnormal data and the data cleaning is realized.Results show that the proposed method can accurately eliminate and compensate for the abnormal data in the process of acid production with flue gas.The method improves the accuracy of compensation for missing data.With the data after cleaning,a more accurate model can be established,which is significant to the subsequent temperature control.The conversion rate of SO_(2) can be further improved,thereby improving the yield of sulfuric acid and economic benefits.展开更多
Gastric ulcer is a chronic disease featured with unexpected complications, including bleeding, stenosis and perforation, as well as a high incidence of recurrence. Clinical treatments for gastric ulcer have allowed th...Gastric ulcer is a chronic disease featured with unexpected complications, including bleeding, stenosis and perforation, as well as a high incidence of recurrence. Clinical treatments for gastric ulcer have allowed the rapid development of potent anti-ulcer drugs during the last several decades. Gastric ulcer healing is successful with conventional treatments including H2-receptor antagonists, and proton pump inhibitors(PPIs) have been essential for ulcer healing and prevention of complications. Additionally, Helicobacter pylori eradication therapy is effective in reducing ulcer recurrence and leads to physiological changes in the gastric mucosa which affect the ulcer healing process. However, in spite of these advancements, some patients have suf-fered from recurrence or intractability in spite of continuous anti-ulcer therapy. A new concept of the quality of ulcer healing(QOUH) was initiated that considers the reconstruction of the mucosal structure and its function for preventing ulcer recurrence. Although several gastroprotection provided these achievements of the QOUH, which PPI or other acid suppressants did not accomplish, we found that gastroprotection that originated from natural products, such as a newer formulation from either Artemisia or S-allyl cysteine from garlic, were very effective in the QOUH, as well as improving clinical symptoms with fewer side effects. In this review, we will introduce the importance of the QOUH in ulcer healing and the achievements from natural products.展开更多
[ Objectives ] To study the effects of low-protein diets supplemented with amino acids on the production performance, carcass quality and input-output ratio of fattening pigs and growing-finishing pigs. [ Methods] Two...[ Objectives ] To study the effects of low-protein diets supplemented with amino acids on the production performance, carcass quality and input-output ratio of fattening pigs and growing-finishing pigs. [ Methods] Two studies were conducted on fattening pigs and growing pigs respectively. Pigs in two experimental groupswere fed with low-protein diets supplemented with amino acids and normal diets respectively, and the initial weight, final weight, feed consumption and car- cass index of the tested pigs were measured. [ Results] The average final weight of fattening pigs in test group was 2.4 kg lower than that in control group, while the difference was not significant (P 〉 0.05 ). The average daily gain of fattening pigs in test group was 60 g lower than that in control group, indicating that low protein diets had a tendency to decrease the growth rate (P 〉 0.05 ), and reduction of daily weight gain in low protein diet pigs reached 7.6%. The development of pigs in low protein diet group was poor, however, the difference was not significant. Carcass backfat thickness in low-protein diet group was slightly higher than that in control group, the difference was significant ( P 〈 0.05 ). There was no significant difference in input-output ratio between low-protein diet group and control group. Finalweight of growing-finishing pigs in low-protein diet group was 3.22 % lower than that in control group, the average daily weight gainwas 6.91% lower than that in control group, feed intake in test group was 5.48% lower than that in control group, and difference between the two treatments was significant (P 〈 0.05 ). Feed meat ratio in low-protein diet group improved, however, the difference was not significant(P 〉0.05). [ Conclusions] Production performance of the pigs would be decreasedand the input-output ratio could not be improvedwhen the adding contents of crude protein in diets was reduced 3% -4%. Therefore, it is recommended that the crude protein level should be enough when pigs were fed with low-protein diets.展开更多
The absorption process in acrylic acid production was water-intensive.The concentration of acrylic acid before distillation process was low,which induced to large amount of wastewater and enormous energy consumption.I...The absorption process in acrylic acid production was water-intensive.The concentration of acrylic acid before distillation process was low,which induced to large amount of wastewater and enormous energy consumption.In this work,a new method was proposed to concentrate the side stream of absorption column and thus increase the concentration in bottom product by electrodialysis.The influence of operating conditions on concentration rate and specific energy consumption were investigated by a laboratory-scale device.When the voltage drop was 1 V·cP^(-1)(1 cP=10^(-3) Pa·s),flow velocity was 3 cm·s^(-1) and the temperature was 35℃,the concentration rates of acrylic acid and acetic acid could be 203.3%and 156.6%in the continual-ED process.Based on the experimental data,the absorption process combined with ED was simulated,in which the diluted solution from ED process was used as spray water and the concentrated solution was feed back to the absorption column.The results shown that the flow rate of spray water was decreased by 37.1%,and the acrylic acid concentration at the bottom of the tower was increased by 4.56%.The ions exchange membranes before and after use 1200 h were tested by membrane surface morphology(scanning electron microscope),membrane chemical groups(infrared spectra),ion exchange capacity,and membrane area resistance,which indicated the membrane were stable in the acid system.This method provides new method for energy conservation and emission reduction in the traditional chemical industry.展开更多
Eight types of spongy sheet were prepared by freeze-drying aqueous solutions of hyaluronic acid (HA) and poly(γ-glutamic acid) (PGA) with or without bioactive components including vitamin C derivative (VC), glucosylc...Eight types of spongy sheet were prepared by freeze-drying aqueous solutions of hyaluronic acid (HA) and poly(γ-glutamic acid) (PGA) with or without bioactive components including vitamin C derivative (VC), glucosylceramide (GC), and epidermal growth factor (EGF). Spongy sheets were categorized into the following groups: Group I (HA/PGA), Group II (HA/PGA + VC), Group III (HA/PGA + GC), Group IV (HA/PGA + VC, GC), Group V (HA/PGA + EGF), Group VI (HA/PGA + VC, EGF), Group VII (HA/PGA + GC, EGF), and Group VIII (HA/PGA + VC, GC, EGF). In the first experiment, we examined fibroblast proliferation in conditioned medium that had been prepared by immersing each spongy sheet in a conventional culture medium. EGF-incorporating spongy sheets (Groups V-VIII) enhanced fibroblast proliferation more than EGF-free spongy sheets (Groups I-IV). In the second experiment, cytokine production by fibroblasts was evaluated using a wound surface model. This involved elevation of fibroblasts-incorporating collagen gel sheets to the air-liquid interface, on which a spongy sheet (Groups I, IV, V and VIII) was placed and cultured for 1 week. EGF-incorporating spongy sheets (Groups V and VIII) enhanced the production of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) by fibroblasts more than EGF-free spongy sheets (Groups I and IV). The effect of these four types of spongy sheet on wounds was investigated in animal experiments. Chemical peel was performed by contacting 50% trichloroacetic acid (TCA) on the dorsal region of mice, after which a spongy sheet was placed, and the wound condition was then observed in a two-week period. Angiogenesis was facilitated to a greater degree in Group VIII compared with Groups I, IV and V. This finding indicates that Group VIII spongy sheet is a promising aid for skin recovery after chemical peel.展开更多
Palmitoleic acid(POA)can be naturally found only in few oil seeds and has significant applications in pharmaceutical industry.Recently,the isolated oleaginous yeast Scheffersomyces segobiensis DSM 27193 was identified...Palmitoleic acid(POA)can be naturally found only in few oil seeds and has significant applications in pharmaceutical industry.Recently,the isolated oleaginous yeast Scheffersomyces segobiensis DSM 27193 was identified with high content of POA in its intracellular lipid(13.80%).In this study,process optimization focused on dissolved oxygen regulation to improve POA production was conducted.Dynamic agitation was found to do significant enhancement on POA-rich lipid production than aeration regulation.Under the best condition of 1000 r·min^(-1)of agitation and 1 vvm(airvolume/culture volume/min)of aeration,no ethanol was detected during the whole fermentation process,while a dry biomass concentration of 44.80 g·L^(-1)with 13.43 g·L^(-1)of lipid and 2.93 g·L^(-1)of POA was achieved.Transcription analysis revealed that the ethanol synthetic pathway was downregulated under the condition of high agitation,while the expression of the key enzymes responsible for lipid and POA accumulation were enhanced.展开更多
Thermotolerant microorganisms were collected, identified and characterized under different physiological conditions from various rotten fruits in Bangladesh for vinegar production. Among the 15-isolates characterized ...Thermotolerant microorganisms were collected, identified and characterized under different physiological conditions from various rotten fruits in Bangladesh for vinegar production. Among the 15-isolates characterized previously, the strains F-1, F-3 and F-10 represented Staphylococcus, Bacillus and Acetobacter spp., respectively. After checking various parameters for growth, acetic acid production rate was optimized further. Among the 3-starins analyzed here, the strain F-10 gave maximum acetic acid (7.0 g/100 ml) at 37°C in 2% ethanol concentration. The strain F-10 is capable of producing high yield of acetic acid at relatively high temperature, which is an ideal condition for vinegar production, which may reduce the water cooling expenses as well as the risk of contamination.展开更多
Objective To develop an analytical method for simultaneously qualitative and quantitative determination of melamine and triazine-related by-products including ammelide, ammeline, and cyanuric acid in milk and milk pro...Objective To develop an analytical method for simultaneously qualitative and quantitative determination of melamine and triazine-related by-products including ammelide, ammeline, and cyanuric acid in milk and milk products by gas chromatography- tandem mass spectrometry (GC-MS/MS). Methods Melamine and triazine-related by-products namely ammelide, ammeline and cyanuric acid in the samples were extracted in a solvent mixture of diethylamine, water, and acetonitrile (10:40:50, V/V/V). After centrifugation, an aliquot of the supernatant was evaporated to dryness under a gentle stream of nitrogen gas, and then melamine and triazine-related by-products were derivatized using BSTFA with 1% TMCS. The derivatives of melamine and its analogues were determined by gas chromatography/tandem mass spectrometry using multiple reactional monitoring (MRM) with 2, 6-Diamino-4-chloropyrimidine (DACP) being used as an internal standard. Results The linear detectable ranges were from 0.004 mg/kg to 1.6 mg/kg for melamine, ammelide, ammeline, and cyanuric acid with a correlation coefficient no less than 0.999. The recovery rates of the tour compounds in spiked blank milk powder at concentrations 0.5, 1, 2 mg/kg were between 61.4%-117.2%, and the relative standard deviation was no more than 11.5% (n=6). The detection limits of melamine, ammelide, ammeline and cyanuric acid in milk powder were 0.002 mg/kg with a ratio of signal to noise of 3. Conclusion This GC-MS/MS method for simultaneous determination of melamine, ammelide, ammeline, and cyanuric acid in milk and milk products is sensitive and specific.展开更多
Production of ursolic acid, the anti-hepatitis effective composition from natural plant,Sambucus chinensis Lindl.was carried out and the scale-up preparation technology was studied.Extraction of the herb Sambucus chin...Production of ursolic acid, the anti-hepatitis effective composition from natural plant,Sambucus chinensis Lindl.was carried out and the scale-up preparation technology was studied.Extraction of the herb Sambucus chinensis Lindl.was extracted in reflux with 7 volume times of refluxing ethanol at 80℃ for 1 h for two times.The extract was purified with a selt-made specific impurity remover “YCXY-1” to yield ursolic acid of high purity.A new “Extraction/Gelation” technology for the production of ursolic acid was developed. The specific impurity remover “YCXY-1” showed high effectiveness in purification. The purity of the mass-produced ursolic acid was up to 99.8%. The chemical structure of the product was confirmed by the physicochemical constants and spectroscopic identification. The production of high-purity ursolic acid was optimized with natural plant as raw material and with only ethanol as extracting solvent. The difficulties such as isolation and impurity removal were addressed effectively. The novel technology is reasonable, convenient, practical, low-cost, high-yield, suitable for mass production.展开更多
In accordance with principles and methods of ecology, the effects of acidic deposition on productivity and volume increment of masson pine and Cinnamomum campora forest which are widely distributed in southern sub...In accordance with principles and methods of ecology, the effects of acidic deposition on productivity and volume increment of masson pine and Cinnamomum campora forest which are widely distributed in southern suburbs of Chongqing, China were studied. Based on the field data and measurements, a multivariable stepwise regression model was established to analyze the effects of multiple environmental factors on the productivity of the forest ecosystems. This model was used to assess the volume and economic losses of these two forest ecosystems caused by acidic deposition. The result showed that, among the environmental factors, pH value of precipitation, soil depth, soil organic contents and slope are the dominant ones influencing the growth of masson pine forest. It was also shown that the acidic deposition has no clear relation to the growth of C.Campora forest, so development of such broad leaved forest is suitable in the area.展开更多
[Objective] More accurate, rapid and sensitive method of melamine and cyanuricacid residue in dairy products and feedstuff were re- viewed. [ Method] Physicochemical properties, metabolism, uses, harm and detection me...[Objective] More accurate, rapid and sensitive method of melamine and cyanuricacid residue in dairy products and feedstuff were re- viewed. [ Method] Physicochemical properties, metabolism, uses, harm and detection methods of melamine and cyanuric acid were analyzed and described. [ Result] Melamine and cyanuric acid, when used alone, were slightly toxic, but long -term intake could lead to animal reproductive and urinary system damage. [ Condusion] Establishing a more sensitive, fast and easy to popularize detection method for elarnine and cyanuricacid res- idue in dairy products and feedstuff was necessary.展开更多
Industrial production process including nitric acid production is an important greenhouse gas emission source. Although IPCC guidelines have given calculation methods and emission factors for N2O emission from nitric ...Industrial production process including nitric acid production is an important greenhouse gas emission source. Although IPCC guidelines have given calculation methods and emission factors for N2O emission from nitric acid production, emission factors of nitric acid production in China are not given. And it can be seen from the comparison of the guidelines and registered CDM projects in China that the N2O emission factors given in the IPCC guidelines and actual N2O emission from nitric acid production in China differ greatly while measured N2O emission data is not available, so determination of emission factors for N2O emission from nitric acid production is an important basic research for N2O emission calculation in China. The method that calculate N2O emission factors from nitric acid production in China is studied with baseline emission factors based on actual measurement of registered CDM projects and the calculated emission factor is compared with that given in the IPCC guidelines in the text.展开更多
The popularization of <i>Dioscorea dumetorum</i> (Dioscoreaceae), a nutritious yam species is still marginal due to constraints such as the low interest of research, poor cultural practices, insufficient a...The popularization of <i>Dioscorea dumetorum</i> (Dioscoreaceae), a nutritious yam species is still marginal due to constraints such as the low interest of research, poor cultural practices, insufficient and expensive seeds, pests, and diseases. The latter pushes producers to use about 50% of their harvest as seed for the next planting season. The lack of a specific fertilizer formulation for yam production on the oxysols of Cameroon is another constraint. This study was aimed at enhancing the availability of quality seeds through the characterization of five yam accessions. One experiment was performed to determine the effect of cultivar and origin of tuber sets on their germination rate. The <span>second concerned the evaluation of cultivars and soil treatment effects on ag</span>ronomic parameters of yam seedlings. Yam cultivars were subjected to nine fertilizer formulations as follows: T0: no fertilizer;T1: mycorrhizal fungi (MF) + 150 g manure + peanut waste;T2: 25 g chemical fertilizer (20.10.10);T3: MF + peanut waste;T4: 16 g chemical fertilizer (12.6.20);T5: 25 g (20.10.10) +100 g CaO + 150 g manure;T6: 100 g CaO + 150 g manure;T7: 20 g tropicote + 2 g DAP (Diammonium phosphate, a reference starter fertilizer coded N18P46) + 100 g CaO + 150 g manure;and T8: mycorrhiza. These treatments were tested in a factorial design. Results show that Ibo sweet 3 and Mabondji sweet white 1 yam accessions were less affected by anthracnose disease on the aerial parts. Guzang 1 showed the best germination rate and yield, making it appropriate for cultivation in the region. Soil treatments, T2, T5, T7 and T8 significantly increased the yield of yam cultivars. Mycorrhiza treatment alone gave a better response to seed weight, indicating the interest of this biofertilizer as a solution for good seedling production. These fertilizer treatments can be recommended to farmers for more seed production with optimum seed weight (300 g).展开更多
Land conversion is considered an effective measure to ensure national food security in China, but little information is available on the quality of low productivity soils, in particular those in acid sulfate soil regi...Land conversion is considered an effective measure to ensure national food security in China, but little information is available on the quality of low productivity soils, in particular those in acid sulfate soil regions. In our study, acid sulfate paddy soils were divided into soils with high, medium and low levels based on local rice productivity, and 60 soil samples were collected for analysis. Twenty soil variables including physical, chemical and biochemical properties were determined. Those variables that were significantly different between the high, medium and low productivity soils were selected for principal component analysis, and microbial biomass carbon (MBC), total nitrogen (TN), available silicon (ASi), pH and available zinc (AZn) were retained in the minimum data set (MDS). After scoring the MDS variables, they were integrated to calculate a soil quality index (SQI), and the high, medium and low productivity paddy soils received mean SQI scores of 0.95, 0.83 and 0.60, respectively. Low productivity paddy soils showed worse soil quality, and a large discrepancy was observed between the low and high productivity paddy soils. Lower MBC, TN, ASi, pH and available K (AK) were considered as the primary limiting factors. Additionally, all the soil samples collected were rich in available P and AZn, but deficient in AK and ASi. The results suggest that soil AK and ASi deficiencies were the main limiting factors for all the studied acid sulfate paddy soil regions. The application of K and Si on a national basis and other sustainable management approaches are suggested to improve rice productivity, especially for low productivity paddy soils. Our results indicated that there is a large potential for increasing productivity and producing more cereals in acid sulfate paddy soil regions.展开更多
<strong>Background:</strong> <span><span style="font-family:Verdana;">Omega-3 polyunsaturated fatty acids (PUFAs) have some protective benefits for patients with coronary artery and c...<strong>Background:</strong> <span><span style="font-family:Verdana;">Omega-3 polyunsaturated fatty acids (PUFAs) have some protective benefits for patients with coronary artery and cerebrovascular diseases. Eicosapentaenoic acid (EPA) drugs are prescribed as branded (B: EPADEL</span><sup><span style="font-family:Verdana;"><span style="color:#4F4F4F;font-family:-apple-system, " font-size:14px;white-space:normal;background-color:#ffffff;"="">?</span></span></sup><span style="font-family:Verdana;">) or generic products but no data exist concerning the differences in treatment outcomes between these products. </span><b><span style="font-family:Verdana;">Methods and Results: </span></b><span style="font-family:Verdana;">We investigated the differences in the serum levels of EPA, docosahexaenoic acid (DHA) and arachidonic acid (AA), and the EPA/AA ratios through blood sampling six months after daily administration of 1800 mg of EPADEL</span><sup><span style="font-family:Verdana;"><span style="color:#4F4F4F;font-family:-apple-system, " font-size:14px;white-space:normal;background-color:#ffffff;"="">?</span></span></sup><span style="font-family:Verdana;"> and a generic EPA drug was initiated for 96 patients with cardiovascular diseases. All patients received these PUFA treatments while continuing with baseline therapy. After 6 months of administration, EPADEL</span><sup><span style="font-family:Verdana;"><span style="color:#4F4F4F;font-family:-apple-system, " font-size:14px;white-space:normal;background-color:#ffffff;"="">?</span></span></sup><span style="font-family:Verdana;"> produced better results than the generic (G) product (EPA;baseline: 59.4 ± 25.5 </span><span style="font-family:Verdana;">μ</span><span style="font-family:Verdana;">g, B: 215.5 ± 58.8 </span><span style="font-family:Verdana;">μ</span><span style="font-family:Verdana;">g, G: 199.7 ± 63.8 </span><span style="font-family:Verdana;">μ</span><span style="font-family:Verdana;">g, B vs G, p < 0.0005;AA;baseline: 197.4 ± 44.6 </span><span style="font-family:Verdana;">μ</span><span style="font-family:Verdana;">g, B: 158.3 ± 36.3 </span><span style="font-family:Verdana;">μ</span><span style="font-family:Verdana;">g, G: 163.6 ± 38.9 </span><span style="font-family:Verdana;">μ</span><span style="font-family:Verdana;">g, B vs G, p < 0.02, as mean ± SD). </span><b><span style="font-family:Verdana;">Conclusions</span></b></span><b><span style="font-family:Verdana;">:</span></b><span style="font-family:Verdana;"> There were clear differences between EPA branded and the generic products. Further study is required to determine whether the benefits from the branded product justify the higher price compared to the generic drug cost.</span>展开更多
Acetohydroxamic acid(AHA) is a novel saltfree reagent used for the separation of Pu and Np from U in the advanced Purex process. This paper reports the c-ray damage of AHA in HNO_3 and its radiolytic product. For 0.2 ...Acetohydroxamic acid(AHA) is a novel saltfree reagent used for the separation of Pu and Np from U in the advanced Purex process. This paper reports the c-ray damage of AHA in HNO_3 and its radiolytic product. For 0.2 mol L^(-1) AHA in 0.2–2.0 mol L^(-1) HNO_3 irradiated at a dose of 5–25 kGy, the radiolytic rate of AHA is6.63–77.5%, and it increases with the HNO_3 concentration and absorbed dose. The main radiolytic gases are N_2O and H_2, with volume fractions of(0.500–16.2) 9 10^(-2) and(1.30–11.8) 9 10^(-3), respectively, and they increase with the absorbed dose; the H_2 volume fraction decreases with increasing HNO_3 concentration. The main liquid radiolytic products are CH_3 COOH and HNO_2, and their concentrations are(3.40–19.7) 9 10^(-2) and(0.200–4.80) 9 10^(-3)-mol L^(-1), respectively, which increase with the HNO_3 concentration. Since a significant concentration of HNO_2 is present in the irradiated AHA-HNO_3 solution, a holding reductant must be used to destroy HNO_2 and stabilize Pu(Ⅲ) and Np(Ⅴ) when AHA is applied for the separation of Pu and Np from U.展开更多
Alpha linolenic acid ( ALA), a kind of polyunsaturated fatty acid extracted from plants and fruits, has a variety of biological functions. In recent years, ALA has attracted much attention as a natural green feed ad...Alpha linolenic acid ( ALA), a kind of polyunsaturated fatty acid extracted from plants and fruits, has a variety of biological functions. In recent years, ALA has attracted much attention as a natural green feed additive. The physical and chemical properties, metabolic process, physiological function of ALA as well as its application and mechanisms in livestock and poultry production are summarized in the paper.展开更多
Probiotics have become essential in food safety and health discourse with interest in their availability, stability, nutrition, and health implications. In this paper, an overview of probiotics of yeast and lactic aci...Probiotics have become essential in food safety and health discourse with interest in their availability, stability, nutrition, and health implications. In this paper, an overview of probiotics of yeast and lactic acid, bacterial fermented food is presented. Probiotics of <i>Lactobacillus spp.</i> and <i>Bifidobacterium spp</i>.’s activities and processes within the human intestinal system are examined. Yeast and lactic acid bacterial (LAB) fermented foods from classified food groups such as vegetables, cereals, and grains, soybean, milk, fish, meat, and beverages are examined. This paper focuses on probiotic (microorganism) strains identified with food and their potential health and nutrition benefits. Finally, the impact of processing parameters and non-process factors on probiotics potential in fermented food is investigated.展开更多
Bauxite residue deposit area(BRDA)is a typical abandoned mining wasteland representing extreme hostile environment with increased alkalinity.Microbially-driven neutralization of bauxite residue,based on the microbial ...Bauxite residue deposit area(BRDA)is a typical abandoned mining wasteland representing extreme hostile environment with increased alkalinity.Microbially-driven neutralization of bauxite residue,based on the microbial acid producing metabolisms,is a novel strategy for achieving rapid pH neutralization and thus improving its environmental outcomes.The hypothesis was that these extreme conditions promote microbial communities which are capable of novel ecologically relevant functions.Several alkaliphilic acid producing bacteria were isolated in this study.One strain was selected for its superior growth pattern and acid metabolism(termed EEEL02).Based on the phylogenetic analysis,this strain was identified as Bacillus thuringiensis.The optimized fermentation conditions were as follows:pH 10;NaCl concentration 5%;temperature 25℃;EEEL02 preferred glucose and peptone as carbon and nitrogen sources,respectively.Based on optimal fermentation conditions,EEEL02 induced a significant pH reduction from 10.26 to 5.62 in 5-day incubation test.Acetic acid,propionic acid and CO2(g)were the major acid metabolites of fermentation,suggesting that the pH reduction in bauxite residue may be caused by acid neutralization derived from microbial metabolism.This finding provided the basis of a novel strategy for achieving rapid pH neutralization of bauxite residue.展开更多
文摘The production of butyric acid by Clostridium butyricum ZJUCB at various pH values was investigated. In order to study the effect of pH on cell growth, butyric acid biosynthesis and reducing sugar consumption, different cultivation pH values ranging from 6.0 to 7.5 were evaluated in 5-L bioreactor. In controlled pH batch fermentation, the optimum pH for cell growth and butyric acid production was 6.5 with a cell yield of 3.65 g/L and butyric acid yield of 12.25 g/L. Based on these results, this study then compared batch and fed-batch fermentation of butyric acid production at pH 6.5. Maximum value (16.74 g/L) of butyric acid concentration was obtained in fed-batch fermentation compared to 12.25 g/L in batch fermentation. It was concluded that culti- vation under fed-batch fermentation mode could enhance butyric acid production significantly (P<0.01) by C. butyricum ZJUCB.
基金supported by the National Natural Science Foundation of China(61873006)Beijing Natural Science Foundation(4204087,4212040).
文摘Acid production with flue gas is a complex nonlinear process with multiple variables and strong coupling.The operation data is an important basis for state monitoring,optimal control,and fault diagnosis.However,the operating environment of acid production with flue gas is complex and there is much equipment.The data obtained by the detection equipment is seriously polluted and prone to abnormal phenomena such as data loss and outliers.Therefore,to solve the problem of abnormal data in the process of acid production with flue gas,a data cleaning method based on improved random forest is proposed.Firstly,an outlier data recognition model based on isolation forest is designed to identify and eliminate the outliers in the dataset.Secondly,an improved random forest regression model is established.Genetic algorithm is used to optimize the hyperparameters of the random forest regression model.Then the optimal parameter combination is found in the search space and the trend of data is predicted.Finally,the improved random forest data cleaning method is used to compensate for the missing data after eliminating abnormal data and the data cleaning is realized.Results show that the proposed method can accurately eliminate and compensate for the abnormal data in the process of acid production with flue gas.The method improves the accuracy of compensation for missing data.With the data after cleaning,a more accurate model can be established,which is significant to the subsequent temperature control.The conversion rate of SO_(2) can be further improved,thereby improving the yield of sulfuric acid and economic benefits.
基金Supported by The National Center of Efficacy Evaluation for the Development of Health Products Targeting Digestive Disorders (NCEED) Grant (A102063) from the Ministry of Health and Welfare, South Korea
文摘Gastric ulcer is a chronic disease featured with unexpected complications, including bleeding, stenosis and perforation, as well as a high incidence of recurrence. Clinical treatments for gastric ulcer have allowed the rapid development of potent anti-ulcer drugs during the last several decades. Gastric ulcer healing is successful with conventional treatments including H2-receptor antagonists, and proton pump inhibitors(PPIs) have been essential for ulcer healing and prevention of complications. Additionally, Helicobacter pylori eradication therapy is effective in reducing ulcer recurrence and leads to physiological changes in the gastric mucosa which affect the ulcer healing process. However, in spite of these advancements, some patients have suf-fered from recurrence or intractability in spite of continuous anti-ulcer therapy. A new concept of the quality of ulcer healing(QOUH) was initiated that considers the reconstruction of the mucosal structure and its function for preventing ulcer recurrence. Although several gastroprotection provided these achievements of the QOUH, which PPI or other acid suppressants did not accomplish, we found that gastroprotection that originated from natural products, such as a newer formulation from either Artemisia or S-allyl cysteine from garlic, were very effective in the QOUH, as well as improving clinical symptoms with fewer side effects. In this review, we will introduce the importance of the QOUH in ulcer healing and the achievements from natural products.
基金Supported by"Pig-based Eco-friendly Feed Research and Demonstration"of Science and Technology Department in Hebei Province(11220422)Technology Research on Application of"Animal-derived Active Red Gold Protein Peptide"in Pig Breeding(16226601D)
文摘[ Objectives ] To study the effects of low-protein diets supplemented with amino acids on the production performance, carcass quality and input-output ratio of fattening pigs and growing-finishing pigs. [ Methods] Two studies were conducted on fattening pigs and growing pigs respectively. Pigs in two experimental groupswere fed with low-protein diets supplemented with amino acids and normal diets respectively, and the initial weight, final weight, feed consumption and car- cass index of the tested pigs were measured. [ Results] The average final weight of fattening pigs in test group was 2.4 kg lower than that in control group, while the difference was not significant (P 〉 0.05 ). The average daily gain of fattening pigs in test group was 60 g lower than that in control group, indicating that low protein diets had a tendency to decrease the growth rate (P 〉 0.05 ), and reduction of daily weight gain in low protein diet pigs reached 7.6%. The development of pigs in low protein diet group was poor, however, the difference was not significant. Carcass backfat thickness in low-protein diet group was slightly higher than that in control group, the difference was significant ( P 〈 0.05 ). There was no significant difference in input-output ratio between low-protein diet group and control group. Finalweight of growing-finishing pigs in low-protein diet group was 3.22 % lower than that in control group, the average daily weight gainwas 6.91% lower than that in control group, feed intake in test group was 5.48% lower than that in control group, and difference between the two treatments was significant (P 〈 0.05 ). Feed meat ratio in low-protein diet group improved, however, the difference was not significant(P 〉0.05). [ Conclusions] Production performance of the pigs would be decreasedand the input-output ratio could not be improvedwhen the adding contents of crude protein in diets was reduced 3% -4%. Therefore, it is recommended that the crude protein level should be enough when pigs were fed with low-protein diets.
基金supported by the National Key Research and Development Program of China(2016YFC0401202)Key Research and Development Program of Hebei Province(18394008D)。
文摘The absorption process in acrylic acid production was water-intensive.The concentration of acrylic acid before distillation process was low,which induced to large amount of wastewater and enormous energy consumption.In this work,a new method was proposed to concentrate the side stream of absorption column and thus increase the concentration in bottom product by electrodialysis.The influence of operating conditions on concentration rate and specific energy consumption were investigated by a laboratory-scale device.When the voltage drop was 1 V·cP^(-1)(1 cP=10^(-3) Pa·s),flow velocity was 3 cm·s^(-1) and the temperature was 35℃,the concentration rates of acrylic acid and acetic acid could be 203.3%and 156.6%in the continual-ED process.Based on the experimental data,the absorption process combined with ED was simulated,in which the diluted solution from ED process was used as spray water and the concentrated solution was feed back to the absorption column.The results shown that the flow rate of spray water was decreased by 37.1%,and the acrylic acid concentration at the bottom of the tower was increased by 4.56%.The ions exchange membranes before and after use 1200 h were tested by membrane surface morphology(scanning electron microscope),membrane chemical groups(infrared spectra),ion exchange capacity,and membrane area resistance,which indicated the membrane were stable in the acid system.This method provides new method for energy conservation and emission reduction in the traditional chemical industry.
文摘Eight types of spongy sheet were prepared by freeze-drying aqueous solutions of hyaluronic acid (HA) and poly(γ-glutamic acid) (PGA) with or without bioactive components including vitamin C derivative (VC), glucosylceramide (GC), and epidermal growth factor (EGF). Spongy sheets were categorized into the following groups: Group I (HA/PGA), Group II (HA/PGA + VC), Group III (HA/PGA + GC), Group IV (HA/PGA + VC, GC), Group V (HA/PGA + EGF), Group VI (HA/PGA + VC, EGF), Group VII (HA/PGA + GC, EGF), and Group VIII (HA/PGA + VC, GC, EGF). In the first experiment, we examined fibroblast proliferation in conditioned medium that had been prepared by immersing each spongy sheet in a conventional culture medium. EGF-incorporating spongy sheets (Groups V-VIII) enhanced fibroblast proliferation more than EGF-free spongy sheets (Groups I-IV). In the second experiment, cytokine production by fibroblasts was evaluated using a wound surface model. This involved elevation of fibroblasts-incorporating collagen gel sheets to the air-liquid interface, on which a spongy sheet (Groups I, IV, V and VIII) was placed and cultured for 1 week. EGF-incorporating spongy sheets (Groups V and VIII) enhanced the production of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) by fibroblasts more than EGF-free spongy sheets (Groups I and IV). The effect of these four types of spongy sheet on wounds was investigated in animal experiments. Chemical peel was performed by contacting 50% trichloroacetic acid (TCA) on the dorsal region of mice, after which a spongy sheet was placed, and the wound condition was then observed in a two-week period. Angiogenesis was facilitated to a greater degree in Group VIII compared with Groups I, IV and V. This finding indicates that Group VIII spongy sheet is a promising aid for skin recovery after chemical peel.
基金supported by the National Key Research & Development Program of China (2021YFC2101500, 2018YFA0902200)National Natural Science Foundation of China (22008115, 21978130)+4 种基金Jiangsu Province Natural Science Foundation for Youths (SBK2020044721)Jiangsu Provincial Agricultural Science and Technology Independent Innovation Fund Project (CX(21)3120)Jiangsu Planned Projects for Postdoctoral Research Funds (2021K085A)China Postdoctoral Science Foundation (2020M671467)Postdoctoral Research Funding Program of Jiangsu Province (2021K085A)
文摘Palmitoleic acid(POA)can be naturally found only in few oil seeds and has significant applications in pharmaceutical industry.Recently,the isolated oleaginous yeast Scheffersomyces segobiensis DSM 27193 was identified with high content of POA in its intracellular lipid(13.80%).In this study,process optimization focused on dissolved oxygen regulation to improve POA production was conducted.Dynamic agitation was found to do significant enhancement on POA-rich lipid production than aeration regulation.Under the best condition of 1000 r·min^(-1)of agitation and 1 vvm(airvolume/culture volume/min)of aeration,no ethanol was detected during the whole fermentation process,while a dry biomass concentration of 44.80 g·L^(-1)with 13.43 g·L^(-1)of lipid and 2.93 g·L^(-1)of POA was achieved.Transcription analysis revealed that the ethanol synthetic pathway was downregulated under the condition of high agitation,while the expression of the key enzymes responsible for lipid and POA accumulation were enhanced.
文摘Thermotolerant microorganisms were collected, identified and characterized under different physiological conditions from various rotten fruits in Bangladesh for vinegar production. Among the 15-isolates characterized previously, the strains F-1, F-3 and F-10 represented Staphylococcus, Bacillus and Acetobacter spp., respectively. After checking various parameters for growth, acetic acid production rate was optimized further. Among the 3-starins analyzed here, the strain F-10 gave maximum acetic acid (7.0 g/100 ml) at 37°C in 2% ethanol concentration. The strain F-10 is capable of producing high yield of acetic acid at relatively high temperature, which is an ideal condition for vinegar production, which may reduce the water cooling expenses as well as the risk of contamination.
文摘Objective To develop an analytical method for simultaneously qualitative and quantitative determination of melamine and triazine-related by-products including ammelide, ammeline, and cyanuric acid in milk and milk products by gas chromatography- tandem mass spectrometry (GC-MS/MS). Methods Melamine and triazine-related by-products namely ammelide, ammeline and cyanuric acid in the samples were extracted in a solvent mixture of diethylamine, water, and acetonitrile (10:40:50, V/V/V). After centrifugation, an aliquot of the supernatant was evaporated to dryness under a gentle stream of nitrogen gas, and then melamine and triazine-related by-products were derivatized using BSTFA with 1% TMCS. The derivatives of melamine and its analogues were determined by gas chromatography/tandem mass spectrometry using multiple reactional monitoring (MRM) with 2, 6-Diamino-4-chloropyrimidine (DACP) being used as an internal standard. Results The linear detectable ranges were from 0.004 mg/kg to 1.6 mg/kg for melamine, ammelide, ammeline, and cyanuric acid with a correlation coefficient no less than 0.999. The recovery rates of the tour compounds in spiked blank milk powder at concentrations 0.5, 1, 2 mg/kg were between 61.4%-117.2%, and the relative standard deviation was no more than 11.5% (n=6). The detection limits of melamine, ammelide, ammeline and cyanuric acid in milk powder were 0.002 mg/kg with a ratio of signal to noise of 3. Conclusion This GC-MS/MS method for simultaneous determination of melamine, ammelide, ammeline, and cyanuric acid in milk and milk products is sensitive and specific.
文摘Production of ursolic acid, the anti-hepatitis effective composition from natural plant,Sambucus chinensis Lindl.was carried out and the scale-up preparation technology was studied.Extraction of the herb Sambucus chinensis Lindl.was extracted in reflux with 7 volume times of refluxing ethanol at 80℃ for 1 h for two times.The extract was purified with a selt-made specific impurity remover “YCXY-1” to yield ursolic acid of high purity.A new “Extraction/Gelation” technology for the production of ursolic acid was developed. The specific impurity remover “YCXY-1” showed high effectiveness in purification. The purity of the mass-produced ursolic acid was up to 99.8%. The chemical structure of the product was confirmed by the physicochemical constants and spectroscopic identification. The production of high-purity ursolic acid was optimized with natural plant as raw material and with only ethanol as extracting solvent. The difficulties such as isolation and impurity removal were addressed effectively. The novel technology is reasonable, convenient, practical, low-cost, high-yield, suitable for mass production.
文摘In accordance with principles and methods of ecology, the effects of acidic deposition on productivity and volume increment of masson pine and Cinnamomum campora forest which are widely distributed in southern suburbs of Chongqing, China were studied. Based on the field data and measurements, a multivariable stepwise regression model was established to analyze the effects of multiple environmental factors on the productivity of the forest ecosystems. This model was used to assess the volume and economic losses of these two forest ecosystems caused by acidic deposition. The result showed that, among the environmental factors, pH value of precipitation, soil depth, soil organic contents and slope are the dominant ones influencing the growth of masson pine forest. It was also shown that the acidic deposition has no clear relation to the growth of C.Campora forest, so development of such broad leaved forest is suitable in the area.
文摘[Objective] More accurate, rapid and sensitive method of melamine and cyanuricacid residue in dairy products and feedstuff were re- viewed. [ Method] Physicochemical properties, metabolism, uses, harm and detection methods of melamine and cyanuric acid were analyzed and described. [ Result] Melamine and cyanuric acid, when used alone, were slightly toxic, but long -term intake could lead to animal reproductive and urinary system damage. [ Condusion] Establishing a more sensitive, fast and easy to popularize detection method for elarnine and cyanuricacid res- idue in dairy products and feedstuff was necessary.
文摘Industrial production process including nitric acid production is an important greenhouse gas emission source. Although IPCC guidelines have given calculation methods and emission factors for N2O emission from nitric acid production, emission factors of nitric acid production in China are not given. And it can be seen from the comparison of the guidelines and registered CDM projects in China that the N2O emission factors given in the IPCC guidelines and actual N2O emission from nitric acid production in China differ greatly while measured N2O emission data is not available, so determination of emission factors for N2O emission from nitric acid production is an important basic research for N2O emission calculation in China. The method that calculate N2O emission factors from nitric acid production in China is studied with baseline emission factors based on actual measurement of registered CDM projects and the calculated emission factor is compared with that given in the IPCC guidelines in the text.
文摘The popularization of <i>Dioscorea dumetorum</i> (Dioscoreaceae), a nutritious yam species is still marginal due to constraints such as the low interest of research, poor cultural practices, insufficient and expensive seeds, pests, and diseases. The latter pushes producers to use about 50% of their harvest as seed for the next planting season. The lack of a specific fertilizer formulation for yam production on the oxysols of Cameroon is another constraint. This study was aimed at enhancing the availability of quality seeds through the characterization of five yam accessions. One experiment was performed to determine the effect of cultivar and origin of tuber sets on their germination rate. The <span>second concerned the evaluation of cultivars and soil treatment effects on ag</span>ronomic parameters of yam seedlings. Yam cultivars were subjected to nine fertilizer formulations as follows: T0: no fertilizer;T1: mycorrhizal fungi (MF) + 150 g manure + peanut waste;T2: 25 g chemical fertilizer (20.10.10);T3: MF + peanut waste;T4: 16 g chemical fertilizer (12.6.20);T5: 25 g (20.10.10) +100 g CaO + 150 g manure;T6: 100 g CaO + 150 g manure;T7: 20 g tropicote + 2 g DAP (Diammonium phosphate, a reference starter fertilizer coded N18P46) + 100 g CaO + 150 g manure;and T8: mycorrhiza. These treatments were tested in a factorial design. Results show that Ibo sweet 3 and Mabondji sweet white 1 yam accessions were less affected by anthracnose disease on the aerial parts. Guzang 1 showed the best germination rate and yield, making it appropriate for cultivation in the region. Soil treatments, T2, T5, T7 and T8 significantly increased the yield of yam cultivars. Mycorrhiza treatment alone gave a better response to seed weight, indicating the interest of this biofertilizer as a solution for good seedling production. These fertilizer treatments can be recommended to farmers for more seed production with optimum seed weight (300 g).
基金supported by the Special Fund for Agroscientific Research in the Public Interest,China(201003016)the earmarked fund for China Agriculture Research System(CARS-01-31)the National Basic Research Program of China(2013CB127405)
文摘Land conversion is considered an effective measure to ensure national food security in China, but little information is available on the quality of low productivity soils, in particular those in acid sulfate soil regions. In our study, acid sulfate paddy soils were divided into soils with high, medium and low levels based on local rice productivity, and 60 soil samples were collected for analysis. Twenty soil variables including physical, chemical and biochemical properties were determined. Those variables that were significantly different between the high, medium and low productivity soils were selected for principal component analysis, and microbial biomass carbon (MBC), total nitrogen (TN), available silicon (ASi), pH and available zinc (AZn) were retained in the minimum data set (MDS). After scoring the MDS variables, they were integrated to calculate a soil quality index (SQI), and the high, medium and low productivity paddy soils received mean SQI scores of 0.95, 0.83 and 0.60, respectively. Low productivity paddy soils showed worse soil quality, and a large discrepancy was observed between the low and high productivity paddy soils. Lower MBC, TN, ASi, pH and available K (AK) were considered as the primary limiting factors. Additionally, all the soil samples collected were rich in available P and AZn, but deficient in AK and ASi. The results suggest that soil AK and ASi deficiencies were the main limiting factors for all the studied acid sulfate paddy soil regions. The application of K and Si on a national basis and other sustainable management approaches are suggested to improve rice productivity, especially for low productivity paddy soils. Our results indicated that there is a large potential for increasing productivity and producing more cereals in acid sulfate paddy soil regions.
文摘<strong>Background:</strong> <span><span style="font-family:Verdana;">Omega-3 polyunsaturated fatty acids (PUFAs) have some protective benefits for patients with coronary artery and cerebrovascular diseases. Eicosapentaenoic acid (EPA) drugs are prescribed as branded (B: EPADEL</span><sup><span style="font-family:Verdana;"><span style="color:#4F4F4F;font-family:-apple-system, " font-size:14px;white-space:normal;background-color:#ffffff;"="">?</span></span></sup><span style="font-family:Verdana;">) or generic products but no data exist concerning the differences in treatment outcomes between these products. </span><b><span style="font-family:Verdana;">Methods and Results: </span></b><span style="font-family:Verdana;">We investigated the differences in the serum levels of EPA, docosahexaenoic acid (DHA) and arachidonic acid (AA), and the EPA/AA ratios through blood sampling six months after daily administration of 1800 mg of EPADEL</span><sup><span style="font-family:Verdana;"><span style="color:#4F4F4F;font-family:-apple-system, " font-size:14px;white-space:normal;background-color:#ffffff;"="">?</span></span></sup><span style="font-family:Verdana;"> and a generic EPA drug was initiated for 96 patients with cardiovascular diseases. All patients received these PUFA treatments while continuing with baseline therapy. After 6 months of administration, EPADEL</span><sup><span style="font-family:Verdana;"><span style="color:#4F4F4F;font-family:-apple-system, " font-size:14px;white-space:normal;background-color:#ffffff;"="">?</span></span></sup><span style="font-family:Verdana;"> produced better results than the generic (G) product (EPA;baseline: 59.4 ± 25.5 </span><span style="font-family:Verdana;">μ</span><span style="font-family:Verdana;">g, B: 215.5 ± 58.8 </span><span style="font-family:Verdana;">μ</span><span style="font-family:Verdana;">g, G: 199.7 ± 63.8 </span><span style="font-family:Verdana;">μ</span><span style="font-family:Verdana;">g, B vs G, p < 0.0005;AA;baseline: 197.4 ± 44.6 </span><span style="font-family:Verdana;">μ</span><span style="font-family:Verdana;">g, B: 158.3 ± 36.3 </span><span style="font-family:Verdana;">μ</span><span style="font-family:Verdana;">g, G: 163.6 ± 38.9 </span><span style="font-family:Verdana;">μ</span><span style="font-family:Verdana;">g, B vs G, p < 0.02, as mean ± SD). </span><b><span style="font-family:Verdana;">Conclusions</span></b></span><b><span style="font-family:Verdana;">:</span></b><span style="font-family:Verdana;"> There were clear differences between EPA branded and the generic products. Further study is required to determine whether the benefits from the branded product justify the higher price compared to the generic drug cost.</span>
文摘Acetohydroxamic acid(AHA) is a novel saltfree reagent used for the separation of Pu and Np from U in the advanced Purex process. This paper reports the c-ray damage of AHA in HNO_3 and its radiolytic product. For 0.2 mol L^(-1) AHA in 0.2–2.0 mol L^(-1) HNO_3 irradiated at a dose of 5–25 kGy, the radiolytic rate of AHA is6.63–77.5%, and it increases with the HNO_3 concentration and absorbed dose. The main radiolytic gases are N_2O and H_2, with volume fractions of(0.500–16.2) 9 10^(-2) and(1.30–11.8) 9 10^(-3), respectively, and they increase with the absorbed dose; the H_2 volume fraction decreases with increasing HNO_3 concentration. The main liquid radiolytic products are CH_3 COOH and HNO_2, and their concentrations are(3.40–19.7) 9 10^(-2) and(0.200–4.80) 9 10^(-3)-mol L^(-1), respectively, which increase with the HNO_3 concentration. Since a significant concentration of HNO_2 is present in the irradiated AHA-HNO_3 solution, a holding reductant must be used to destroy HNO_2 and stabilize Pu(Ⅲ) and Np(Ⅴ) when AHA is applied for the separation of Pu and Np from U.
基金Supported by Key Scientific Research Project of Colleges and Universities in Henan Province(15A230012)
文摘Alpha linolenic acid ( ALA), a kind of polyunsaturated fatty acid extracted from plants and fruits, has a variety of biological functions. In recent years, ALA has attracted much attention as a natural green feed additive. The physical and chemical properties, metabolic process, physiological function of ALA as well as its application and mechanisms in livestock and poultry production are summarized in the paper.
文摘Probiotics have become essential in food safety and health discourse with interest in their availability, stability, nutrition, and health implications. In this paper, an overview of probiotics of yeast and lactic acid, bacterial fermented food is presented. Probiotics of <i>Lactobacillus spp.</i> and <i>Bifidobacterium spp</i>.’s activities and processes within the human intestinal system are examined. Yeast and lactic acid bacterial (LAB) fermented foods from classified food groups such as vegetables, cereals, and grains, soybean, milk, fish, meat, and beverages are examined. This paper focuses on probiotic (microorganism) strains identified with food and their potential health and nutrition benefits. Finally, the impact of processing parameters and non-process factors on probiotics potential in fermented food is investigated.
基金Projects(41877511,41842020)supported by the National Natural Science Foundation of ChinaProject(502221703)supported by the Innovative Project of Independent Exploration of Central South University,China
文摘Bauxite residue deposit area(BRDA)is a typical abandoned mining wasteland representing extreme hostile environment with increased alkalinity.Microbially-driven neutralization of bauxite residue,based on the microbial acid producing metabolisms,is a novel strategy for achieving rapid pH neutralization and thus improving its environmental outcomes.The hypothesis was that these extreme conditions promote microbial communities which are capable of novel ecologically relevant functions.Several alkaliphilic acid producing bacteria were isolated in this study.One strain was selected for its superior growth pattern and acid metabolism(termed EEEL02).Based on the phylogenetic analysis,this strain was identified as Bacillus thuringiensis.The optimized fermentation conditions were as follows:pH 10;NaCl concentration 5%;temperature 25℃;EEEL02 preferred glucose and peptone as carbon and nitrogen sources,respectively.Based on optimal fermentation conditions,EEEL02 induced a significant pH reduction from 10.26 to 5.62 in 5-day incubation test.Acetic acid,propionic acid and CO2(g)were the major acid metabolites of fermentation,suggesting that the pH reduction in bauxite residue may be caused by acid neutralization derived from microbial metabolism.This finding provided the basis of a novel strategy for achieving rapid pH neutralization of bauxite residue.