Weizmannia coagulans:an ideal probiotic for gut health

Weizmannia coagulans(formerly Bacillus coagulans)is a spore-forming and lactic acid-producing bacterium.It has recently attracted much attention from researchers and food manufacturers due to its probiotic functions and stability in processing and storage.W.coagulans is capable of improving gut health through the regulation of gut microbiota,modulation of immunity,and improving digestibility and metabolism.Spores,germinated cells and metabolites of W.coagulans modulate the gut micro-environment and further affect other organs.W.coagulans is an environment-friendly probiotic since it can contribute to the host by reconstructing the balance of gut microbiota and only temporarily resides in the intestine after administration.W.coagulans has been generally recognized as safe(GRAS)by the US Food and Drug Administration(FDA),thus it is an ideal probiotic for improving gut health.The merit of its stability in processing and storage provides W.coagulans spores many possibilities for its use in various types of functional foods.This review presents an overview of the characteristics of W.coagulans that make it an ideal probiotic candidate and highlights the proposed health benefits with scientific evidence conferred by the administration of W.coagulans.

Alleviative effects of Bacillus coagulans strains on irritable bowel syndrome-unraveling strain specificity through physiological and genomic analysis

The high intraspecies heterogeneity of Baciillus coagulans leads to significant phenotypic differences among different strains.Thus,6 B.coagulans strains were tested in the present study using an irritable bowel syndrome(IBS)animal model to determine whether the IBS-alleviating effects of B.coagulans strains are strain-specific.The results of this study showed that the ingestion of B.coagulans GBI-30,6086,and B.coagulans CCFM1041 significantly alleviated IBS symptoms in mice.In contrast,other B.coagulans strains showed no or limited alleviating effects on IBS symptoms.According to our experimental results,the two main common features of these strains were as follows:1)The resistance of vegetative cells to bile salts,and 2)ability to synthesize specific lipids and secondary metabolites.Screening strains based on these two indicators may greatly reduce costs and provide a basis for mining new functional B.coagulans strains.Our results also suggest that administration of B.coagulans could significantly regulate microbiota dysbiosis in animal models.Moreover,the close relationships between the gut microbiota,gut microbiota metabolites,and IBS were further confirmed in this study.

Oral administration of Bacillus coagulans TQ-35 alleviates allergic responses in OVA-sensitive BALB/c mice

Bacillus coagulans has been extensively studied so far,but there has been a lack of research on its usage in allergy.In this study,we designed to assess the effect of different concentrations of B.coagulans on food allergy in a BALB/c mouse model of ovalbumin(OVA)-induced food allergy and its effect on gut microbes.The assessment of symptoms,specific immunoglobulin E(IgE),T-cell differentiation,and related gene expression levels in sensitized mice by assay indicated that high doses of oral B.coagulans could alleviate allergic symptoms.Treatment with B.coagulans,in the high-dose group,significantly reduced IgE and IgG1 levels and modulated the balance of T helper type 1 cell(Th1)and Th2 and the expression of relevant genes in the spleen.16S rRNA analysis showed that probiotics improved the structure of the microbiota,in particular by boosting the percentage of Clostridia,Bacteroides vulgatus and Enterococcus faecium,and by increasing the abundance of microbial species,thereby modulating the immune system.Therefore,this study can provide insights into the practical application of B.coagulans doses to alleviate OVA allergy.

The synbiotic mixture of lactulose and Bacillus coagulans protects intestinal barrier dysfunction and apoptosis in weaned piglets challenged with lipopolysaccharide

Background Lactulose as an effective prebiotic protects intestinal mucosal injury.Bacillus coagulans is widely used in feed additives because of its ability to promote intestinal health.Our previous study suggests that the combination of lactulose and Bacillus coagulans may be a good candidate as alternative for antibiotic growth promoters.However,the in vivo effects of lactulose and Bacillus coagulans on growth and intestinal health under immune challenge in piglets remains unclear.The objective of this study is to explore the protective effects of synbiotic containing lactu-lose and Bacillus coagulans on the intestinal mucosal injury and barrier dysfunction under immune challenge in weaned piglets.Methods Twenty four weaned piglets were assigned to 4 groups.Piglets in the CON-_(saline)and LPS-_(LPS)group were fed the basal diet,while others were fed either with chlortetracycline(CTC)or synbiotic mixture of lactulose and Bacillus coagulans for 32 d before injection of saline or lipopolysaccharide(LPS).Piglets were sacrificed 4 h after LPS injection to collect samples to determine intestinal morphology,integrity and barrier functions as well as relative genes and proteins.Results Our data showed that no differences were observed in the growth performance of the four test groups.LPS injection induced higher serum diamine oxidase activities,D-lactic acid levels,and endotoxin status,lower villus height and ratio of villus height to crypt depth,greater mRNA and lower protein expression related tight junction in both jejunum and ileum.In addition,a higher apoptosis index,and protein expression of Bax and caspase-3 were also observed in the LPS challenge group.Interestingly,dietary synbiotic mixture with lactulose and Bacillus coagulans protected against LPS-induced intestinal damage,barrier dysfunction and higher apoptosis as well as CTC.Conclusions Our data suggest that dietary supplementation of synbiotic mixture with lactulose and Bacillus coagu-lans showed resilience to LPS-induced intestinal morphological damage,barrier dysfunction and aggressive apoptosis in piglets as well as the protective effects of CTC.These results indicate that synbiotic mixture of lactulose and Bacillus coagulans showed beneficial effects on performance and resilience to acute immune stress in weaned piglets.

Effects of Bacillus coagulans supplementation on the growth performance and gut health of broiler chickens with Clostridium perfringens-induced necrotic enteritis

Background: The poultry industry is in need of effective antibiotic alternatives to control outbreaks of necrotic enteritis(NE) due to Clostridium perfringens.Methods: This study was conducted to investigate the effects of feeding Bacil us coagulans on the growth performance and gut health of broiler chickens with C. perfringens-induced NE. Two hundred and forty 1-day-old broiler chicks were randomly assigned to a 2 × 2 factorial arrangement with two dietary B. coagulans levels(0 or 4 × 109 CFU/kg of diet) and two disease chal enge statuses(control or NE chal enged).Results: NE-induced reduction in body weight gain was relieved by the addition of B. coagulans into broiler diets compared with the NE-infected birds. NE infection damaged intestinal morphological structure, promoted intestinal C.perfringens growth and liver invasion, and enhanced anti-C. perfringens specific sI gA concentrations in the gut and specific IgG levels in serum compared with the uninfected birds. NE infection significantly(P < 0.05) decreased mucin-2(at 14 d post-infection(DPI), tol-like receptor 2(TLR2, at 7 and 14 DPI), TLR4(at 7 and 14 DPI), tumor necrosis factor super family15(TNFSF15, at 7 and 14 DPI), lysozyme(LYZ, at 14 DPI) and fowlicidin-2(at 7 and 14 DPI) mR NA levels, whereas it dramatical y(P = 0.001) increased IFN-γ mR NA levels at 7 DPI. However, chal enged birds fed diets supplemented with B.coagulans showed a significant(P < 0.01) decrease in gut lesion scores, decreased C. perfringens numbers in the cecum and liver, and an increase in fowlicidin-2 mR NA levels in compared with the uninfected birds. In addition, compared with the non-supplemented group, dietary inclusion of B. coagulans improved intestinal barrier structure, further increased specific sI gA levels and alkaline phosphatase(IAP) activity in the jejunum, enhanced the expression of jejunum lysozyme mR NA, and inhibited the growth, colonization, and invasion of C. perfringens; in contrast, it reduced serum-specific IgG concentrations and jejunum IFN-γ mR NA levels.Conclusion: These results indicated that dietary B. coagulans supplementation appeared to be effective in preventing the occurrence and reducing the severity of C. perfringens-induced NE in broiler chickens.

Mechanism of the Effect of Bacillus coagulans on Production Performance of Laying Hens in Late Laying Period

[Objective]The paper was to investigate the mechanism of Bacillus coagulans preparation in improving production performance of laying hens in late period of laying.[Method]A total of 648 individuals of"Jingfen 1"laying hens(66 weeks of age)in late period of laying were randomly divided into four groups,six replicates each group,and each group had 27 individuals of laying hens.The laying hens in control group were fed with basal diet,and those in experimental groupsⅠ,Ⅱ and Ⅲ were fed with the basal diets added with 3.33×10^6,1×10^7,3.33×10^7 CFU/g B.coagulans,respectively.The pretrial lasted one week,and the formal test lasted eight weeks.[Result]Compared with the control group,the laying rate in group Ⅰ increased significantly,and the feed-gain ratio in experimental group Ⅱ decreased noticeably while the spleen index increased remarkably;the alkaline phosphatase activities and blood calcium content in experimental groups Ⅰ,Ⅱ and Ⅲ increased significantly(P<0.05),while the triglyceride content decreased remarkably(P<0.05);the urea content in experimental groups Ⅰ and Ⅱ decreased obviously(P<0.05).Adding B.coagulans significantly increased the specific activity of amylase,lipase and protease in various intestinal mucosa of small intestine(P<0.05);adding B.coagulans significantly increased the content of follicle-stimulating hormone(FSH)and estradiol(E2),and significantly increased the mRNA expression of follicle stimulating hormone receptor gene(FSHR).[Conclusion]B.coagulans preparation could significantly improve the production performance of laying hens in late period of laying;appropriately enhance the immune capacity of laying hens;improve the serum biochemical indicators;increase the activity of digestive enzymes in the small intestine;and promote the release of gonadal hormone and the mRNA expression of FSHR gene in the ovary.

MLST analysis of genetic diversity of Bacillus coagulans strains to evaluate effects on constipation model

Bacillus coagulans can help ameliorate or prevent gastrointestinal diseases, but the genetic relationships among B. coagulans isolates are not well studied. Multilocus sequence typing analysis was conducted on 57 isolates of B. coagulans from 22 provinces or autonomous regions in China. B. coagulans isolates were highly diverse and a total of 33(sequence typings) STs were found. These isolates had a weak clonal population structure and strong indications of intraspecies recombination. The evolution direction of B. coagulans was not correlated with geography or isolation source. Fifteen strains were selected for further analysis based on proximity relationships from the phylogenetic tree. Five isolates(B. coagulans-1, B. coagulans-10, B. coagulans-39, B. coagulans-70 and B. coagulans-71) with good spore-forming ability relative to the rest of the isolates were evaluated for constipation relief. B. coagulans-39 significantly relieved constipation symptoms in mice by regulating intestinal flora, increasing the production of short-chain fatty acids and restoring the level of gastrointestinal regulatory peptides. Comparative genomic analysis showed the beneficial effects of B. coagulans-39 might be associated with specific functional genes that are involved in the utilization of various carbohydrates as primary substrates and short-chain fatty acid production.

Alleviative effects of a novel strain Bacillus coagulans XY2 on copper-induced toxicity in zebrafish larvae

Copper (Cu) is a kind of micronutrient element that is essential for human metabolism.However,it is also considered as an environmental pollutant which is toxic to organisms at a high concentration level.Probiotics,regarded as beneficial microorganisms for promoting human health,have functions of antioxidant capacity,immune-enhancing properties,intestinal barrier protection and regulation.Several studies have reported that probiotics show positive effects on alleviating and intervening heavy metals toxicity.However,evidence for relieving copper-induced toxicity by probiotics is still limited.In this study,we firstly conducted a zebrafish larvae model to screen out microorganisms which are helpful for CuSO_(4)toxicity resistance and one novel strain named as Bacillus coagulans XY2 was discovered with the best protective activity.B.coagulans XY2 significantly reduced the mortality of zebrafish larvae exposed to 10μmol/L CuSO_(4)for 96 hr,as well as alleviated the neutrophils infiltration in the larvae lateral line under a 2 hr exposure.B.coagulans XY2 exhibited a high in vitro antioxidant activity and against CuSO_(4)-induced oxidative stress in zebrafish larvae by up-regulating sod1,gstp1 and cat gene transcriptional levels and relevant enzymatic activities.CuSO_(4)stimulated the inflammation process resulting in obvious increases of gene il-1βand il-10 transcription,which were suppressed by B.coagulans XY2 intervention.Overall,our results underline the bio-function of B.coagulans XY2 on protecting zebrafish larvae from copper toxicity,suggesting the potential application values of probiotics in copper toxicity alleviation on human and the environment.

凝结芽胞杆菌发酵优化工艺

为提高凝结芽胞杆菌(Bacillus coagulans)的生长效率,在摇瓶、发酵罐水平考察了最适的碳源、温度、维生素添加量、pH以及发酵过程存在的氧化胁迫对凝结芽胞杆菌生长代谢的影响,获得了发酵培养基配方,并确定了30 L发酵罐最适培养条件:培养温度为40℃,初始pH为6.2~6.5,培养过程中9~14 h用氨水溶液控pH=5.5,pH大于5.5后停止控制,全程以4.1 mg/(L·h)速率流加半胱氨酸。优化条件下,发酵13 h细胞生物量达1.9×10^(10)CFU/mL,较对照提高363.4%,细胞生长效率为1.5×10^(9) CFU/(mL·h),较对照提高305.4%。显著提高了生物量、缩短了发酵周期,为凝结芽胞杆菌工业化生产提供了重要参考。

Effect of dietary supplementation of Bacillus coagulans or yeast hydrolysates on growth performance,antioxidant activity,cytokines and intestinal microflora of growing-finishing pigs

This study was to investigate the effects of dietary supplementation of Bacillus coagulans(BC) and yeast hydrolysates(YH) on growth performance,antioxidant activity,cytokines and intestinal microflora of growing-finishing pigs.Thirty-six barrows(initial BW=26.87±2.65 kg) were assigned randomly to 3 treatments with 4 replicates,3 pigs per replicate.Pigs in the control group(CON) were fed a basal diet,and the diets for the other 2 groups were the basal diet plus BC at 200 mg/kg and the basal diet plus YH at 3,000 mg/kg.The trial lasted for 104 d.Compared with CON,YH treatment significantly increased average daily gain(ADG) and average daily feed intake(ADFI) during the finishing phase(P <0.05),and significantly enhanced ADG during the overall period(P <0.05).Dietary inclusion of BC tended to increase ADFI during the finishing period(P=0.08).Compared with CON,BC treatment imp roved lysozyme(LZM),complement 3(C3),complement 4(C4),interlenkin-10(IL-10) and total antioxidant capacity(T-AOC) level in serum(P <0.05).Dietary inclusion of YH enhanced the serum IL-10 level(P <0.05) and tended to increase T-AOC level(P=0.06).Dietary inclusion of YH elevated(P <0.05) the number of Lactobacillus and Bacillus in cecal contents of pigs,promoted the populations of Bifidobacterium and Bacillus in colonic contents.Moreover,the BC diet increased(P <0.05) the count of Bifidobacterium in colonic contents.These results indicated that dietary BC supplementation is beneficial to improve the immunity.Dietary YH supplementation promoted the growth performance and the populations of beneficial bacteria in the hindgut of the growing-finishing pigs.

Effects of benzoic acid,Bacillus coagulans and oregano oil combined supplementation on growth performance,immune status and intestinal barrier integrity of weaned piglets

This experiment was conducted to investigate the effects of benzoic acid,Bacillus coagulans and oregano oil combined supplementation on growth performance,immune status and intestinal barrier integrity of piglets.In a 26-d experiment,25 piglets were randomly assigned to 5 treatments:1)a basal diet,negative control(NC),2)NC added with antibiotics,positive control(PC);3)NC added with benzoic acid at 3,000 g/t and Bacillus coagulans at 400 g/t(AB);4)NC added with benzoic acid at 3,000 g/t and o regano oil at 400 g/t(AO);5)NC added with 3,000 g/t benzoic acid and Bacillus coagulans at 400 g/t and oregano oil at 400 g/t(ABO);On d 27,all piglets were euthanized to obtain jejunal mucosa to measure immune status and intestinal barrier integrity.Results showed that pigs fed AB diet increased the final body weight and average daily body weight gain and decreased the ratio of feed to gain co mpared with NC group(P<0.05).Co mpared with NC group,AB,AO and ABO decreased serum tumor necrosis factor-a concentration and ABO decreased interleukin-1βconcentration in serum and jejunal mucosa(P<0.05).Compared with NC group,AB upregulated mRNA expressions of sodium-glucose cotransportel,claudin-1,occludin and mucin2 in jejunal mucosa and the populations of Bifidobacterium and Bacillus in cecal digesta(P<0.05).Compared with NC group,ABO increased jejunal mucosal occludin mRNA abundance and Bifidobacterium population in cecal digesta,and decreased Escherichia coli population in cecal digesta(P<0.05).Furthermore,AB and ABO increased Bacillus population in cecal digesta compared with PC group(P<0.05).These results indicated that dietary AB supplementation could improve growth performance and intestinal barrier integrity of piglets when fed antibiotic-free diets,which was possibly associated with the improvement of immune status and intestinal microflora.Dietary ABO supplementation is also beneficial to improve immune status and intestinal barrier integrity and micro flora of piglets.

Use of dry yeast cells as a cheap nitrogen source for lactic acid production by thermophilic Bacillus coagulans WCPIO-4

Dry yeast cells （DYC） were used as a cheap nitrogen source to replace expensive yeast extract （YE） for L-lactic acid production by thermophilic Bacillus coagulans. Cassava starch （200 g. L1） was converted to L-lactic acid by simultaneous saccharification and fermentation using Bacillus coagulans WCP10-4 at 50℃ in the presence of 20g·L-1 of DYC, giving 148.1 g·L-1 of L- lactic acid at 27 h with a productivity of 5.5 g·L-1·h-1 and a yield of 92%. In contrast, 154.4 g·L-1 of lactic acid was produced at 24 h with a productivity of 6.4 g·L-1. hl and a yield of 96% when equal amount of YE was used under the same conditions. Use of pre-autolyzed DYC at 50℃ for overnight slightly improved the lactic acid titer （154.5g·L-1） and productivity （7.7g·L-1·h-1） but gave the same yield （96%）.

Chemical constituents of Solanum coagulans and their antimicrobial activities

The present study aimed at determining the chemical constituents of Solanum coagulans and their antimicrobial activities. The compounds were isolated by various chromatographic techniques and their structures were elucidated on the basis of extensive spectroscopic analysis, chemical methods, and comparison with reported spectroscopic data. One new phenolic glycoside, methyl salicylate 2-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside(1), together with 12 known compounds(2–13), were isolated from the aerial parts of Solanum coagulans. Compound 1 was a new phenolic glycoside, and 2–6 were isolated from Solanum genus for the first time. The antimicrobial activities of the isolated compounds were also evaluated. Compound 7 showed remarkable antifungal activity against T. mentagrophytes, M. gypseum and E. floccosum with MIC values being 3.13, 1.56 and 3.13 μg·m L^(-1), respectively.

凝结芽孢杆菌BC320对南美白对虾生长和血液免疫指标的影响

为验证一株分离自南美白对虾体内的凝结芽孢杆菌(Bacillus coagulans)BC320对南美白对虾(Penaeus vannamei)生长性能和非特异性免疫指标的影响,将1200尾南美白对虾(平均体重3.24 g±0.2 g)随机分成4组,分别添加0‰、0.5‰、1‰、1.5‰的BC320,每组300尾,3个重复,每个重复100尾。经40 d养殖后,检测平均增重率(AWG)、特定生长率(SGR)、饲料系数(FC)和成活率(SR)等生长指标和超氧化物歧化酶(SOD)、酸性磷酸酶(ACP)、碱性磷酸酶(ALP)、溶菌酶(LSM)、过氧化物酶(POD)等免疫指标。结果显示,终末体重、增重率和特定生长率指标,各处理组与对照组相比均有显著增加,但在添加1‰和1.5‰之间没有显著性差异;当添加量为1‰时,试验组的SOD、ACP、ALP和POD与对照组均有显著差异,LSM与对照组之间没有显著差异。本试验结果表明,凝结芽孢杆菌BC320可促进南美白对虾生长,提高其非特异性免疫水平。

凝结芽孢杆菌对奥尼罗非鱼消化酶活性、消化率及生长性能的影响

在基础饲料中分别添加不同剂量的凝结芽孢杆菌(Ⅰ:1.0×1011cfu/kg饲料,Ⅱ:3.0×1011cfu/kg饲料,Ⅲ:6.0×1011cfu/kg),室外水族箱中饲养奥尼罗非鱼(Oreochromis niloticus×O.aureus)(34.50±0.25 g),用基础饲料投喂作为对照,每饲料组设三个重复,每水族箱随机放养16尾鱼,投喂率为3%。采用静水饲养以避免各箱之间水的交换。56 d后测定鱼体的生长和消化酶活性。结果显示:不同添加量的凝结芽孢杆菌均能显著提高奥尼罗非鱼胃、肝胰脏和肠道蛋白酶活性(P<0.05),但酶的活性随添加量的提高呈下降趋势。凝结芽孢杆菌的添加对胃、肝胰脏和肠道淀粉酶及脂肪酶活性没有显著影响(P>0.05)。Ⅰ组和Ⅱ组的干物质表观消化率、蛋白质消化率、相对增重率、饵料系数和蛋白质效率均显著高于对照组(P<0.05),而Ⅲ组和对照组之间差异不显著(P>0.05)。结果提示,饲料中添加1.0×1011cfu/kg饲料的凝结芽孢杆菌就能显著促进奥尼罗非鱼的生长和饲料营养物质的利用,满足最佳生长。

益生凝结芽孢杆菌发酵培养基的优化

对益生凝结芽孢杆菌(Bacillus coagulans)发酵培养基进行优化,试验考察了不同碳源、氮源、无机盐对芽孢形成和抑菌率的影响。在单因素试验基础上进行了研究,结合Plackett-Burman设计结果,选取葡萄糖、蛋白胨、酵母膏、Mn2+、Ca2+五个因素。结果表明,葡萄糖、蛋白胨、酵母膏对凝结芽孢形成和抑菌率影响显著。

不同来源寡聚-1,6-葡糖苷酶异源表达及酶学特性

寡聚-1,6-葡糖苷酶(EC 3.2.1.10)对于乳酸发酵液残糖中含量较高的异麦芽糖有较高的利用活性。基于前期研究工作基础并经BRENDA数据库搜索挑选了5个可能耐高温、耐酸的寡聚-1,6-葡糖苷酶基因(Bacillus coagulans ATCC 7050的malL BF292011(BC1)和malL BF292004(BC2)、Bacillus subtilis 168的malL yvdL BSU34560(BS1)和yugT BSU31290(BS2)以及Bacillus thermoglucosidasius KP 1006的malL(KP)),首次利用pET表达系统在大肠杆菌中进行重组表达、纯化及酶学性质的系统研究。结果显示:BC1、BC2、KP的最适pH为5.0,BS1、BS2的最适pH为6.0。最适温度分别为:KP(60℃),BC1(56℃),BC2(56℃),BS1(43℃),BS2(43℃)。Mg^(2+)、NH_(4)^(+)对于BC1的酶催化活性具有激活作用,Co^(2+)、K+、NH_(4)^(+)对于KP有激活作用,但这些离子对于BC2、BS1和BS2都没有明显的激活作用。Zn^(2+)、Cu^(2+)、Ni^(+)对这5种寡聚-1,6-葡糖苷酶都有明显的抑制作用。以对硝基苯-α-D-葡萄糖苷(pNPG)为底物时,酶的转换数和催化效率从高到低依次为:KP>BC1>BS1>BS2>BC2。以乳酸发酵液中的残糖成分作为参考,在以麦芽糖、异麦芽糖、蔗糖、乳糖、海藻糖以及可溶性直链淀粉作为底物测定酶活时,BC1、BC2、KP、BS1的最适底物都是异麦芽糖,BS2的最适底物为麦芽糖。

凝结芽孢杆菌、粪肠球菌对樱桃谷肉鸭生长性能的影响

选取405羽1日龄樱桃谷肉鸭,对照组饲喂基础日粮,试验组分别在基础日粮中添加凝结芽孢杆菌(Bacillus coagulans)和粪肠球菌(Enterococcus faecalis),研究凝结芽孢杆菌、粪肠球菌对樱桃谷肉鸭生长性能的影响。结果表明,1周龄时,凝结芽孢杆菌组体重极显著低于粪肠球菌组及对照组(P<0.01),日采食量显著高于对照组(P<0.05)。6周龄时,凝结芽孢杆菌组及粪肠球菌组日采食量极显著低于对照组(P<0.01);凝结芽孢杆菌组与粪肠球菌组的平均成活率显著高于对照组(P<0.05);凝结芽孢杆菌组与粪肠球菌组的平均日采食量、平均料重比有低于对照组的趋势,但差异不显著(P>0.05)。由此可见,在樱桃谷肉鸭饲粮中添加凝结芽孢杆菌和粪肠球菌能有效减少日采食量,降低料重比,提高成活率,具有一定的经济效益。

Combination eect of pH and acetate on enzymatic cellulose hydrolysis

The productivity and efficiency of cellulase are significant in cellulose hydrolysis. With the accumulation of volatile fatty acids （VFAs）, the pH value in anaerobic digestion system is reduced. Therefore, this study will find out how the pH and the amount of acetate influence the enzymatic hydrolysis of cellulose. The effects of pH and acetate on cellulase produced from Bacillus coagulans were studied at various pH 5-8, and acetate concentrations （0-60 mmol/L）. A batch kinetic model for enzymatic cellulose hydrolysis was constructed from experimental data and performed. The base hypothesis was as follows： the rates of enzymatic cellulose hydrolysis rely on pH and acetate concentration. The results showed that the suitable pH range for cellulase production and cellulose hydrolysis （represents efficiency of cellulase） was 2.6-7.5, and 5.3-8.3, respectively. Moreover, acetate in the culture medium had an effect on cellulase production （KI = 49.50 mmol/L, n = 1.7） less than cellulose hydrolysis （/（＇i = 37.85 mmol/L, n = 2.0）. The results indicated that both the pH of suspension and acidogenic products influence the enzymatic hydrolysis of cellulose in an anaerobic environment. To enhance the cellulose hydrolysis rate, the accumulated acetate concentration should be lower than 25 mmol/L, and pH should be maintained at 7.

一株具有降解玉米赤霉烯酮能力的凝结芽孢杆菌的分离、鉴定及其发酵条件的确定

从池塘养殖鲤鱼中分离出一株具有降解玉米赤霉烯酮能力的芽孢杆菌,经16SrDNA比对鉴定为凝结芽孢杆菌(Bacillus coagulans)。经液相色谱方法检测其发酵上清液对玉米赤霉烯酮的24、48h降解能力分别为62%和84%。经发酵实验得到此株凝结芽孢杆菌的最适生长条件为:40℃,pH值6.4,经36h好氧液体发酵可得25.9亿个/mL的活菌数,最佳液体培养基为:蛋白胨15‰,酵母粉5‰,玉米粉15‰,葡萄糖20‰,麸皮10‰。综合实验结果,此株凝结芽孢杆菌可作为饲料添加剂用于饲料中霉菌毒素的降解和提高动物抗病能力。