Isolation and characterization of novel peptides from fermented products of Lactobacillus for ulcerative colitis prevention and treatment

Ulcerative colitis(UC)is an incurable and highly complex digestive disease affecting millions of people worldwide.Compared to the current therapeutic drugs,bioactive peptides are more promising and safe substances as functional foods or drugs for the prevention and treatment of UC.The alcohol-soluble components from fermentation broth by fresh wheat germ and apple(AC-WGAF)were found to be effective in UC prevention in dextran sulfate sodium-induced mice in vivo.Herein,4 novel peptides are identifi ed from AC-WGAF by membrane ultrafi ltration,recycling preparative high-performance liquid chromatography,and matrix-assisted laser desorption–ionization time-of-fl ight/time-of-fl ight mass spectrometry,possessing anticolitis activity via using an in vitro model.One of those peptides named T24(PVLGPVRGPFPLL)exhibited the most remarkable anti-colitis activity by preventing tight junction protein loss,maintaining epithelial barrier integrity,and promoting cell proliferation during in vitro and in vivo studies by regulating mitogen-activated protein kinase signaling pathways.Thus,T24 is a promising peptide as a functional food or novel drug for UC prevention and treatment.

Pressure relief-dipping-microwave assisted polymerization of melamine-L-aspartic acid resin at activated carbon for purification of L-threonine fermented crude product

L-threonine(L-Thr) obtained by fermentation often contains vestigial hydrosoluble Pb(Ⅱ), Fe(Ⅱ), L-glutamic acid(L-Glu) etc., which affect the product quality. Poly melamine and L-aspartic acid(L-Asp) resin functional coconut shell activated carbon composite(PMA/AC) was prepared by a pressure relief-dipping-microwave assisted polymerization method for the simultaneous removals. The adsorption capacities of Pb(Ⅱ), Fe(Ⅱ) and L-Glu could reach to 82.34 mg·g^(-1), 57.82 mg·g^(-1) and 102.58 mg·g^(-1) at conditions of pH 5.0, 45 °C and 4 h with an initial concentration of 0.01 mol·L^(-1), respectively. The present PMA/AC was successfully used to the simultaneous removals of vestigial Pb(Ⅱ), Fe(Ⅱ) and L-Glu from the fermented crude product solution of L-Thr. Moreover, the PMA/AC was carefully characterized by FE-SEM, IR et al. analysis techniques, the results show that abundant PMA particles evenly distributed at the inner and outside surface of AC with a size of(50 ± 20) nm.

Effect of Fermented Plant Products on Alkaline-Saline Soil and the Growth of Alfalfa Seedlings

A pot experiment was conducted by putting ameliorants,the products of plants fermented by lactobacillus,and sandy soil into alkaline-saline soil. After such blending,the soil physicochemical properties and the growth index of Alfalfa seedlings were measured in order to explore the influence of the blending on alkaline-saline soil and the growth of alfalfa seedlings. The results showed that soil p H decreased significantly after adding ameliorant; mixing ameliorant and sandy soil into alkaline-saline soil reduced soil evaporation and increased the germination rate of alfalfa seeds and their chlorophyll content as well as the seedling height,root length of alfalfa seedlings,but it had no significant effect on alfalfa seedlings' biomass and leaf number; besides,excessive ameliorant would inhibit the growth of alfalfa seedlings.

Effects of Dilute Acid-intensified Hydrolysis on Fermentative Biohydrogen Production Capacity of Maize Stalk

[Objective] This study was to explore the effects of dilute acid hydrolysis on fermentative biohydrogen production capacity of maize stalk. [Method] Using maize stalks subjected to mechanical disintegration,steam explosion and dilute acid hydrolysis as experimental materials,we measured and analyzed the effects of different treatments and particle size of maize stalk were analyzed. [Result] The optimal fermentative biohydrogen production was found under following parameters：pretreatment of 0.8% dilute H2SO4 following steam explosion,particle size of maize stalk of 0.425-0.850 mm,liquid-solid ratio [0.8% H2SO4 （M）：stalk （W）] of 10：1. [Conclusion] Post steam explosion,dilute 0.8% dilute H2SO4 intensified hydrolysis on maize stalk could produce fermentative biohydrogen production capacity.

Postbiotics from Saccharomyces cerevisiae fermentation stabilize microbiota in rumen liquid digesta during grain-based subacute ruminal acidosis(SARA) in lactating dairy cows

Background Subacute ruminal acidosis(SARA)is a common metabolic disorder of high yielding dairy cows,and it is associated with dysbiosis of the rumen and gut microbiome and host inflammation.This study evaluated the impact of two postbiotics from Saccharomyces cerevisiae fermentation products(SCFP)on rumen liquid associated microbiota of lactating dairy cows subjected to repeated grain-based SARA challenges.A total of 32 rumen cannulated cows were randomly assigned to 4 treatments from 4 weeks before until 12 weeks after parturition.Treatment groups included a Control diet or diets supplemented with postbiotics(SCFPa,14 g/d Original XPC;SCFPb-1X,19 g/d Nutri Tek;SCFPb-2X,38 g/d Nutri Tek,Diamond V,Cedar Rapids,IA,USA).Grain-based SARA challenges were conducted during week 5(SARA1)and week 8(SARA2)after parturition by replacing 20%DM of the base total mixed ration(TMR)with pellets containing 50%ground barley and 50%ground wheat.Total DNA from rumen liquid samples was subjected to V3–V416S r RNA gene amplicon sequencing.Characteristics of rumen microbiota were compared among treatments and SARA stages.Results Both SARA challenges reduced the diversity and richness of rumen liquid microbiota,altered the overall composition(β-diversity),and its predicted functionality including carbohydrates and amino acids metabolic pathways.The SARA challenges also reduced the number of significant associations among different taxa,number of hub taxa and their composition in the microbial co-occurrence networks.Supplementation with SCFP postbiotics,in particular SCFPb-2X,enhanced the robustness of the rumen microbiota.The SCFP supplemented cows had less fluctuation in relative abundances of community members when exposed to SARA challenges.The SCFP supplementation promoted the populations of lactate utilizing and fibrolytic bacteria,including members of Ruminococcaceae and Lachnospiraceae,and also increased the numbers of hub taxa during non-SARA and SARA stages.Supplementation with SCFPb-2X prevented the fluctuations in the abundances of hub taxa that were positively correlated with the acetate concentration,andα-andβ-diversity metrics in rumen liquid digesta.Conclusions Induction of SARA challenges reduced microbiota richness and diversity and caused fluctuations in major bacterial phyla in rumen liquid microbiota in lactating dairy cows.Supplementation of SCFP postbiotics could attenuate adverse effects of SARA on rumen liquid microbiota.

Feeding a Saccharomyces cerevisiae fermentation product improves udder health and immune response to a Streptococcus uberis mastitis challenge in mid-lactation dairy cows

Background:We aimed to characterize the protective effects and the molecular mechanisms of action of a Saccharomyces cerevisiae fermentation product(NTK)in response to a mastitis challenge.Eighteen mid-lactation multiparous Holstein cows(n=9/group)were fed the control diet(CON)or CON supplemented with 19 g/d NTK for 45 d(phase 1,P1)and then infected in the right rear quarter with 2500 CFU of Streptococcus uberis(phase 2,P2).After 36-h,mammary gland and liver biopsies were collected and antibiotic treatment started until the end of P2(9 d post challenge).Cows were then followed until day 75(phase 3,P3).Milk yield(MY)and dry matter intake(DMI)were recorded daily.Milk samples for somatic cell score were collected,and rectal and udder temperature,heart and respiration rate were recorded during the challenge period(P2)together with blood samples for metabolite and immune function analyses.Data were analyzed by phase using the PROC MIXED procedure in SAS.Biopsies were used for transcriptomic analysis via RNA-sequencing,followed by pathway analysis.Results:DMI and MY were not affected by diet in P1,but an interaction with time was recorded in P2 indicating a better recovery from the challenge in NTK compared with CON.NTK reduced rectal temperature,somatic cell score,and temperature of the infected quarter during the challenge.Transcriptome data supported these findings,as NTK supplementation upregulated mammary genes related to immune cell antibacterial function(e.g.,CATHL4,NOS2),epithelial tissue protection(e.g.IL17C),and anti-inflammatory activity(e.g.,ATF3,BAG3,IER3,G-CSF,GRO1,ZFAND2A).Pathway analysis indicated upregulation of tumor necrosis factorα,heat shock protein response,and p21 related pathways in the response to mastitis in NTK cows.Other pathways for detoxification and cytoprotection functions along with the tight junction pathway were also upregulated in NTK-fed cows.Conclusions:Overall,results highlighted molecular networks involved in the protective effect of NTK prophylactic supplementation on udder health during a subclinical mastitic event.

Effects of Fermentation Product Containing Phytase on Productive Performance,Egg Quality,and Phosphorous Apparent Metabolism of Laying Hens Fed Different Levels of Phosphorus

This study investigated the effects of fermentation product containing phytase （FPP） that was fermented using waste vinegar residue （WVR） as substrate from Aspergillusficuum NTG-23 on productive performance, egg quality, and phosphorus apparent metabolism of laying hens. First, 375 22-wk-old Jinghong hens were allocated into 5 treatments （5 replicates of 15 hens each） in an 8-wk experiment for evaluating the parameters of productive performance, egg quality, serum, and tibia. Experimental diets contained 4% FPP and 96% corn-soybean diet. The levels of dicalciurn phosphate （DCP） were 1.34, 1.01, 0.67, 0.34 and 0%. Next, thirty 31-wk-old Jinghong hens were fed 5 types of diets for evaluating phosphorous apparent metabolism rate. Egg productive rate, egg weight, feed conversion ratio, Haugh unit, egg albumen height, serum calcium, tibia ash, tibia ash calcium and tibia breaking strength were not different significantly among 5 treatments. The significant difference of average daily feed intake was not appeared when the DCP content of corn-soybean-FPP diet was reduced to 0.67%; the eggshell hardness, eggshell thickness and serum phosphorus were not reduced significantly until the DCP content of corn-soybean-FPP diet was reduced to 0.34%. The yolk color was improved when the laying hens fed deficient DCP corn-soybean-FPP diet. A 22.14% reduction in excreta phosphorus was observed when the laying hens fed low phosphorus （0.67% DCP） corn-soybean-FPP diet. A 30% elevation of phosphorus apparent metabolism rate was obtained when the DCP content of corn-soybean-FPP diet was decreased from 1.34 to 1.01%. The reducing cost of layer diet was totalized about 120 CNY 1000 kg1 diet when the content of DCP was 0.67% in corn-soybean-FPP diet. These results indicated that FPP could be applied in laying hen as a potential, cost-effective and rational application of WVR.

Effects of Saccharomyces cerevisiae fermentation products on performance and rumen fermentation and microbiota in dairy cows fed a diet containing low quality forage

Background： A possible option to meet the increased demand of forage for dairy industry is to use the agricultural byproducts, such as corn stover. However, nutritional value of crop residues is low and we have been seeking technologies to improve the value. A feeding trial was performed to evaluate the effects of four levels of Saccharomyces cerevisiae fermentation product（SCFP; Original XP; Diamond V） on lactation performance and rumen fermentation in mid-lactation Holstein dairy cows fed a diet containing low-quality forage. Eighty dairy cows were randomly assigned into one of four treatments： basal diet supplemented with 0, 60, 120, or 180 g/d of SCFP per head mixed with 180, 120, 60, or 0 g of corn meal, respectively. The experiment lasted for 10 wks, with the first 2 weeks for adaptation.Results： Dry matter intake was found to be similar（P 〉 0.05） among the treatments. There was an increasing trend in milk production（linear, P ≤ 0.10） with the increasing level of SCFP supplementation, with no effects on contents of milk components（P 〉 0.05）. Supplementation of SCFP linearly increased（P 〈 0.05） the N conversion, without affecting rumen pH and ammonia-N（P 〉 0.05）. Increasing level of SCFP linearly increased（P 〈 0.05） concentrations of ruminal total volatile fatty acids, acetate, propionate, and butyrate, with no difference in molar proportion of individual acids（P 〉 0.05）. The population of fungi and certain cel ulolytic bacteria（Ruminococcus albus, R. flavefaciens and Fibrobacter succinogenes）increased linearly（P 〈 0.05） but those of lactate-utilizing（Selenomonas ruminantium and Megasphaera elsdeni） and lactate-producing bacteria（Streptococcus bovis） decreased linearly（P ≤ 0.01） with increasing level of SCFP. The urinary purine derivatives increased linearly（P 〈 0.05） in response to SCFP supplementation, indicating that SCFP supplementation may benefit for microbial protein synthesis in the rumen.Conclusions： The SCFP supplementation was effective in maintaining milk persistency of mid-lactation cows receiving diets containing low-quality forage. The beneficial effect of SCFP could be attributed to improved rumen function; 1）microbial population shift toward greater rumen fermentation efficiency indicated by higher rumen fungi and cel ulolytic bacteria and lower lactate producing bacteria, and 2） rumen microbial fermentation toward greater supply of energy and protein indicated by greater ruminal VFA concentration and increased N conversion. Effects of SCFP were dose-depended and greater effects being observed with higher levels of supplementation and the effect was more noticeable during the high THI environment.

Effect of lactic acid bacteria inoculants on alfalfa(Medicago sativa L.) silage quality:assessment of degradation(in situ) and gas production(in vitro)

Alfalfa （Medicago sativa） is difficult to ensile successfully because of the low content of moisture and water-soluble carbohydrates （WSC） in fresh alfalfa and the high buffering capacity in fresh alfalfa. Here, we conducted a study to evaluate the effects of three lactic acid bacteria （LAB） inoculants （Lactobacillus case/, lactobacillus plantarum, and Pediococcus pentosaceus） on silage quality, in sitE/ruminal degradability, and in vitro fermentation of alfalfa silage. The first cut of alfalfa was wilted, chopped, and randomly divided into four groups： the control （CON） and control mixed with three separate LAB inoculants （106 cfu g-1）. Simmental steers with a body weight of （452±18） kg and with installed rumen fistulas were prepared for in situ degradation and for in vitro gas production. LAB inoculants had a lower （P〈0.05） content of butyric acid than the CON group. Among them, the L. casei inoculated silage had a higher （P〈0.05） content of water-soluble carbohydrate （WSC） and a lower （P〈0.05） NH3-H content. The effective degradation （ED） of crude protein in LAB inoculation decreased （P〈0.05）, while the ED of acid detergent fiber increased （P〈0.05） in situ fermentation. The alfalfa silage with LAB inoculants produced more carbon dioxide （P〈0.05）. The NH3-H content of mixed incubation fluid in L. casei inoculated silage was lower （P〈0.05） compared with other groups. Therefore, this study showed that LAB inoculants could improve both ensiling quality and degradation. In particular, the L. casei inoculations exhibited better performance by limiting proteolysis during ensiling.

Effects of Selenium on Fusarium Growth and Associated Fermentation Products and the Relationship with Chondrocyte Viability

This study determined the effects of selenium on the growth of Fusorium strains and the effects of products extracted from the fungal cultures on relevant indicators of chondrocytes injury.

Rumen methane output and fermentation characteristics of gramineous forage and leguminous forage at differing harvest dates determined using an in vitro gas production technique

An in vitro rumen gas production technique was employed to determine the methane production and fermentation characteristics of Leymus chinensis and Medicago ruthenica at differing harvest dates（May 15,May 30,June 30,July 30,August 30 and September 30）,which are sequential phases within a single continuous growth of two 10-year-old pastures.To quantify the rate of degradation and compare in vitro rumen fermentation characteristic,a logistic-exponential model,where initial gas volume was zero（LE_0）,was used to fit gas production and methane output results.Dried,milled forage samples were incubated in vitro for 72 h at 39℃ and gas production was recorded intermittently throughout the incubation and gas samples were collected to measure methane production.Results showed that there were significant interactions between species and harvest for all chemical composition variables（P〈0.001） and condensed tannin content（P〈0.001）.L.chinensis produced more total gas and methane than M.ruthenica（P〈0.001）.Both total gas and methane production decreased lineally（P〈0.001） with advancing harvest date.The degradation rates of L.chinensis and M.ruthenica harvested on September 30 were lower than those on the other harvest dates（P〈0.01）.M.ruthenica fermented fluid had higher concentration of ammonia N（P〈0.05） and molar proportions of isobutyrate（P〈0.01）,valerate（P〈0.001） and isovalerate（P〈0.01） in total volatile fatty acids than L chinensis.Furthermore,concentration of isovalerate decreased cubically with advancing harvest date（P〈0.05）.In conclusion,M.ruthenica produced less methane than L.chinensis and the total gas and methane production decreased with advancing harvest date for both species,which may be due to the changes in contents of chemical compositions and condensed tannin in forages.

Effect of initial substrate and biomass concentrations on anaerobic fermentative hydrogen production in batch reactors

The effects of initial substrate (5-60 g /L) and biomass concentration (0.5-3 g /L) on fermentative hydrogen production by mixed cultures were investigated in batch tests using glucose as substrate.The experimental results showed that the hydrogen production increases as the initial substrate concentration increases from 0 to 25 g /L.It indicated that the shift in the metabolic pathway or in the composition of the bacterial flora occurs.The maximum hydrogen yield of 1.78 mol /mol-glucose is obtained at the substrate concentration of 15 g /L.This study also shows that initial biomass concentration affects the hydrogen yield as the cumulative hydrogen production has been increased with the increase of initial cell concentration up to 1.5 g /L and reached the highest level.The maximum hydrogen yield is obtained at the cell concentration of 1.5 g /L.It indicated that the optimum biomass /substrate ratio,maximizing the hydrogen yield and the hydrogen production rate,is determined to be 0.1 g biomass /g glucose.

Mechanism and Clinical Observation of Effect of Growgx Yeast Fermentation Product Extract on Photo-aged HFF-1 Cells

[Objectives]To explore the effect of the extract of Growgx yeast fermentation product on ultraviolet A(UVA)-induced photo-aging of human skin fibroblasts(HFF-1)and its specific mechanisms from the level of cell biology,and discussed the application of the Growgx yeast fermentation product extract for skin aging.[Methods]A photo-aging model of HFF-1 cells was induced by UVA radiation meter,and it was given different concentrations of Growgx for intervention.The proliferation activity of the HFF-1 cells was detected with MTT method,and their migration and invasion ability was measured by scratch test.The SOD,HYP and MDA levels were detected with corresponding kits.After oxygen infusion apparatus assisted facial skin administration,the repair of the skin was observed through the VISIA skin tester.[Results]The survival rate of HFF-1 cells was reduced significantly by UVA with an irradiation dose of 10.8 J/cm2(P<0.05),while Growgx significantly increased their survival rate(P<0.001)and sped up the repair of damaged cells.Growgx promoted the production of SOD(P<0.05),reduced the level of MDA(P<0.05),and increased the level of HYP(P<0.05).Growgx effectively inhibited UVA-induced photo-aging of HFF-1 cells.The mechanism may be related to accelerating cell damage repair,up-regulating SOD and HYP expression levels,and reducing MDA expression level.The clinical observation showed that Growgx effectively improved skin spots and pores,making the skin smoother and more delicate.[Conclusions]Growgx can effectively fight against photo-aging caused by ultraviolet rays,and can significantly improve skin wrinkles.

Fermentative Biohydrogen Production with Enteric Bacteria Isolated from the Intestine of Wild Common Carp Dwelling in Tarim River Basin

The biological hydrogen generating from fermentation of low-cost lignocellulosic feedstocks by hydrogen-producing bacteria has attracted many attentions in recent years. In the present investigation, ten hydrogen-producing bacteria were newly isolated from the intestine of wild common carp (Cyprinus carpio L.), and identified belonging to the genera of Enterobacter and Klebsiella based on analysis of the 16S rDNA gene sequence and examination of the physiological and biochemical characteristics. All the isolates inherently owned the ability to metabolize xylose especially the cotton stalk hydrolysate for hydrogen production with hydrogen yield (HY) higher than 100 mL·L-1. In particular, two isolates, WL1306 and WL1305 obtained higher HY, hydrogen production rate (HPR), and hydrogen production potential (HPP) using cotton stalk hydrolysate as sugar substrate than the mixed sugar of glucose & xylose, which obtained the HY of 249.5 ± 29.0, 397.0 ± 36.7 mL·L-1, HPR of 10.4 ± 1.2, 16.5 ± 1.5 mL·L-1·h-1, HPP of 19.5 ± 2.3, 31.0 ± 2.8 mL·L-1·g-1sugar, separately. The generation of soluble metabolites, such as the lactate, formate, acetate, succinate and ethanol reflected the mixed acid fermentation properties of the hydrogen production pathway.

Methodological factors affecting gas and methane production during in vitro rumen fermentation evaluated by meta-analysis approach

Effects of some methodological factors on in vitro measures of gas production（GP, mL/g DM）, CH4production（mL/g DM） and proportion（% CH4 on total GP） were investigated by meta-analysis. These factors were considered：pressure in the GP equipment（0 = constant; 1 = increasing）, incubation time（0 = 24; 1 = ≥ 48 h）, time of rumen fluid collection（0 = before feeding; 1 = after feeding of donor animals）, donor species of rumen fluid（0 = sheep; 1 =bovine）, presence of N in the buffer solution（0 = presence; 1 = absence）, and ratio between amount of buffered rumen fluid and feed sample（BRF/FS; 0 = ≤ 130 mL/g DM; 1 = 130–140 mL/g DM; 2 = ≥ 140 mL/g DM）. The NDF content of feed sample incubated（NDF） was considered as a continuous variable. From an initial database of 105 papers, 58 were discarded because one of the above-mentioned factors was not stated. After discarding 17 papers,the final dataset comprised 30 papers（339 observations）. A preliminary mixed model analysis was carried out on experimental data considering the study as random factor. Variables adjusted for study effect were analyzed using a backward stepwise analysis including the above-mentioned variables. The analysis showed that the extension of incubation time and reduction of NDF increased GP and CH4 values. Values of GP and CH4 also increased when rumen fluid was collected after feeding compared to before feeding（＋26.4 and ＋9.0 mL/g DM, for GP and CH4）,from bovine compared to sheep（＋32.8 and ＋5.2 mL/g DM, for GP and CH4）, and when the buffer solution did not contain N（＋24.7 and ＋6.7 mL/g DM for GP and CH4）. The increase of BRF/FS ratio enhanced GP and CH4production（＋7.7 and ＋3.3 mL/g DM per each class of increase, respectively）. In vitro techniques for measuring GP and CH4 production are mostly used as screening methods, thus a full standardization of such techniques is not feasible. However, a greater harmonization of analytical procedures（i.e., a reduction in the number of available protocols） would be useful to facilitate comparison between results of different experiments.

Effects of solid-state fermentation product of yeast supplementation on liver and intestinal health,and resistance of common carp(Cyprinus carpio)against spring viraemia carp virus

This study aimed to investigate the effects of solid-state fermentation products of yeast(SFPY)on liver and intestinal health and disease resistance of common carp(Cyprinus carpio).A total of 200 common carp with an initial average weight of 2.55±0.004 g were divided into 5 groups(4 replications per group and 10 fish per replication),and were fed with one of five diets,including a control diet and 4 diets supplemented with 2‰(Y2),3‰(Y3),4‰(Y4),or 5‰(Y5)SFPY,respectively,for 8 weeks.Results indicated that,the addition of SFPY to the diet of common carp did not affect the growth performance or survival rate of fish(P=0.253).Interestingly,with the addition of SFPY,the triacylglycerol(TAG)content of the liver presented a linear decreasing tendency(P=0.004),with significantly decreased in Y4 and Y5 groups(P=0.035)compared with control.Serum lipopolysaccharide(LPS)content and diamine oxidase(DAO)activity presented a negative linear relationship with the addition of SFPY(P=0.015,P=0.030),while serum lipopolysaccharide binding protein(LBP)content first decreased and then increased(P<0.001).The total antioxidant capacity(T-AOC)in the intestine of fish increased continuously with increasing SFPY supplementation(P=0.026),reaching the highest level in Y5 group.The villus height in all experimental groups were significantly higher than that in the control group(P<0.001).Furthermore,compared to the control,adding 3‰SFPY to the control diet of common carp significantly increased the relative abundance of Fusobacteria(P=0.018)and decreased that of Proteobacteria(P=0.039)at phylum level,and increased the relative abundance of Cetobacterium(P=0.018)and decreased that of Shewanella(P=0.013)at genus level.Compared with the control,the relative mRNA expression level of spring viraemia of carp virus N protein(SVCV-n)in the kidney was lower than that of the control group without significance and bottomed out in Y4 group(P=0.138).In conclusion,dietary SFPY enhanced the SVCV resistance capacity of common carp by improving liver and intestinal health and modulating the gut microbiota.Thus,SFPY is a potential feed additive to be used in aquaculture to reduce the huge economic loss of common carp due to SVCV disease.Based on liver TAG content and intestinal villus height,the optimal addition level of SFPY was 3.02‰and 2.72‰,respectively.

Inhibitory Effect of Lactic Acid Bacteria on Salmonella

[Objectives]To explore the inhibitory effect of lactic acid bacteria(LAB)on the growth of Salmonella.[Methods]The inhibitory effect of lactic acid bacteria on Salmonella was investigated by Oxford cup agar diffusion test from the aspects of lactic acid bacteria body,metabolites,pH,thermal stability and acid resistance.[Results]The growth of Salmonella was disturbed by the inhibition of lactic acid bacteria.The mechanism of inhibitory effect may be:simple low pH and lactic acid bacteria have no inhibitory effect on Salmonella;however,there are active substances in the metabolites of lactic acid bacteria,which have high thermal stability and a wide range of acid resistance,and are effective substances for inhibiting the growth of Salmonella.[Conclusions]This study is helpful for screening more natural preservative substances,reducing the contamination rate of Salmonella to food,and is expected to provide a theoretical basis for the preservation and preservation of food.

Feeding of yeast(Candida spp.) improves in vitro ruminal fermentation of fibrous substrates

In vitro gas production technique（IVGPT） was used with the objective of determining the inclusion effect of live cells of two strains of Candida yeast on in vitro ruminal fermentation of two fibrous substrates. In order to achieve this, two experiments were performed： A） using oat straw（Avena sativa） as substrate; B） using alfalfa hay（Medicabo sativa） as substrate, comparing the effect of two different strains of Candida genre, both isolated from the rumen, on the mentioned substrates. Levica 25（Candida tropicalis） yeast belongs to the culture collection of the Institute of Animal Science, Cuba, and Levazoot 15（Candida norvegensis） yeast is part of the collection of the Faculty of Zootechnology and Ecology of the Autonomous University of Chihuahua, Mexico. Both strains demonstrated their potential in activating the ruminal fermentation. They stimulated（P〈0.0001） the ruminal fermentation of the substrates under study. However, the Levazoot strain stimulated the dry matter（DM） fermentation of alfalfa in 21.43%, more than Levica 25. It is concluded that there is an influence of yeast strain and diet on the rumen environment and, therefore, it is important to select the appropriate strain in every production condition.

Detection and Analysis of 1,2-propanediol Content in Whole-crop Silage Corn

[ Objective ] The paper was to investigate the content of 1,2-propanediol in silage feed. [ Method ] Whole-crop corn was stored in laboratory bag silos and outdoor bunker silos. Bag silos were stored for 3, 7, 14, 28, 56 and 120 d, respectively, and fermentation products were analyzed after opening; the fermentation products, which were from three 500 t above-ground outdoor bunker silos stored for 120 d, were detected. Eight sampling points were selected for each bunker silo. [ Result] No 1,2-propanediol was detected out in laboratory bag silos, and lactic acid was dominant in fermentation products. The acetic acid content significantly increased （ P 〈 0.05 ） with the extension of storage time, whereas the acetic acid content was kept below one-third of the lactic acid content ; 1,2-propanediol and a small amount of 1-propanol were detected out in three bunker silos, and lactic acid was dominant in fermentation products, whereas the content of acetic acid was slightly lower than that of lactic acid. The differences in fermentation products from different silos and different sites in silos presented heterogeneity; except to propanediol, lactic acid bacteria and yeast, there was no significant difference in fermentation products at the top and bottom layers of silos （ P 〉0.05 ） ; there were significant differences in contents of lactic acid, acetic acid, 1,2-propanediol, and yeast between the outer and inner parts of silos （P 〈 0.05 ） ; except to pH values and acetic acid, there were significant differences in fermentation products between hunker silos （P 〈0. 05）. [ Conclusion] No 1,2-propanediol is detected out in laboratory bag silos due to relatively simple fermentation products. However, 1,2-propanediol can be detected in the bunker silos due to complex outdoor environment for silage, and the microorganisms producing 1,2-propanediol exist in silos.

Development of Lactose Free Yogurt Technology for Personalized Nutrition

Due to the widespread use of antibiotics, the bad ecological situation, fermented milk drinks are gaining more and more popularity because of associating with an array of health benefits. Fermented milk products contain a unique in its kind disaccharide of animal origin lactose, which has the ability to stimulate the development of lactic acid microorganisms that suppress the vital activity of pathogenic microflora in the human intestine, promoting the absorption of calcium, magnesium and phosphorus. A significant part of the world’s population suffers from lactose intolerance, linked to a genetically determined deficiency of the β-galactosidase enzyme, which is one of the main reasons for the decrease in demand for dairy products among consumers suffering from primary or acquired intolerance to milk sugar. Lactose is a natural disaccharide contained in dairy products. Lactase deficiency is a variant of fermentopathy caused by the inability to break down lactose due to the activity decrease of lactase—the parietal digestion enzyme in the small intestine. Lactose intolerance in the gastrointestinal tract of a person suffering from hypo- and alactasia leads to dispersion, diarrhea and other undesirable phenomena. For the successful prevention and treatment of these diseases, it is necessary to reduce or completely eliminate the lactose intake. A technology for lactose-free milk production was developed using fermentation technology. On the basis of lactose-free milk, a range of lactose-free yoghurts was developed of animal origin of the following types: natural, enriched and fortified. Flax seeds, sesame seeds and chia seeds, which are rich in vitamins, were used to produce a range of enriched yogurts. To obtain fortified yoghurts, the mineral iron was used, which prevent the development of anemia and oncological pathologies. Experimental assortment of lactose-free yoghurts was assessed by physicochemical and organoleptic methods. All developed samples meet the standards of technical documentation for this type of food product. The organoleptic characteristics were highly appreciated. Developed lactose-free products are an opportunity for many people to return to a normal healthy diet.