Lactic Acid Bacteria In Combination Research Articles

The effect of seed germination and Bacillus spp. on the ripening of plant cheese analogs.

The development of novel plant-based fermented food products for which no traditional templates exist requires the development of starter cultures. Although the principles of microbial flavor formation in plant-based analogs partially overlap with dairy fermentations, the composition of the raw materials and thus likely the selective pressure on the activity of starter cultures differs. Experiments that are described in this study explored the use of seed germination, the use of lactic acid bacteria, and the use of bacilli to reduce hygienic risks, to acidify plant milk, and to generate taste-active compounds through proteolysis and fermentative conversion of carbohydrates. The characterization of fermentation microbiota by culture-dependent and culture-independent methods also confirmed that the starter cultures used were able to control microbial communities throughout 90 d of ripening. Taken together, the results provide novel tools for the development of plant-based analogs of fermented dairy products.

Enhancement of Biomass Conservation and Bioethanol Production of Sweet Sorghum Silage by Constructing Synergistic Microbial Consortia.

The efficient storage of materials before bioethanol production could be key to improving pretreatment protocol and facilitating biodegradation, in turn improving the cost-effectiveness of biomass utilization. Biological inoculants were investigated for their effects on ensiling performance, biodegradability of silage materials, and final bioethanol yield from sweet sorghum. Two cellulolytic microbial consortia (CF and PY) were used to inoculate silages of sweet sorghum, with and without combined lactic acid bacteria (Xa), for up to 60 days of ensiling. We found that the consortia notably decreased pH and ammonia nitrogen content while increasing lactic acid/acetic acid ratios. The microbes also functioned in synergy with Xa, significantly reducing lignocellulose content and improving biomass preservation. First-order exponential decay models captured the kinetics of nonstructural carbohydrates and suggested high water-soluble carbohydrate (grams per kilogram dry matter [DM]) preservation potential in PY-Xa (33.48), followed by CF-Xa (30.51). Combined addition efficiently improved enzymatic hydrolysis and enhanced bioethanol yield, and sweet sorghum treated with PY-Xa had the highest ethanol yield (28.42 g L-1). Thus, combined bioaugmentation of synergistic microbes provides an effective method of improving biomass preservation and bioethanol production from sweet sorghum silages. IMPORTANCE Ensiling is an effective storage approach to ensure stable year-round supply for downstream biofuel production; it offers combined facilities of storage and pretreatment. There are challenges in ensiling sweet sorghum due to its coarse structure and high fiber content. This study provides a meaningful evaluation of the effects of adding microbial consortia, with and without lactic acid bacteria, on changes in key properties of sweet sorghum. This study highlighted the bioaugmented ensiling using cellulolytic synergistic microbes to outline a cost-effective strategy to store and pretreat sweet sorghum for bioethanol production.

Bacillus coagulans in Combination with Chitooligosaccharides Regulates Gut Microbiota and Ameliorates the DSS-Induced Colitis in Mice.

ABSTRACTUlcerative colitis (UC) are chronic inflammatory disorders, which may be caused by intestinal barrier dysfunction, immune system disorders and intestinal microbiota dysbiosis. Synbiotic, the combination of probiotics and prebiotics, is thought to be a pragmatic approach in mitigating inflammation in UC. Bacillus coagulans has been recognized as a potential probiotic for treating intestinal diseases because of its favorable industrial and probiotic properties, including sporulation and lactic acid production. In this study, we evaluated the treatment effects of the B. coagulans FCYS01 spores with or without the chitooligosaccharides (COSs) on UC generated using dextran sulfate sodium (DSS) in mice. Supplementation of B. coagulans spores, prebiotic COSs or the synbiotic (the spores + COSs) had a significant positive effect on DSS-induced UC. The disease activity index and histological damage score were significantly reduced after these supplementations. Compared to DSS group, these supplementations also significantly modulated the cytokines IL-4, IL-6, IL-8, IL-10, and C-reactive protein (CRP) levels and significantly maintained expressions of tight junction proteins and mucin protein and promotes recovery of the intestinal barrier. In addition, these supplementations regulate the composition of gut microbiota and improve the production of short-chain fatty acids (SCFAs), through enrichment of SCFA-producing bacteria, such as Akkermansia and Ruminococcus species. In summary, the synbiotic ameliorated the overall inflammatory status of the experimental UC model and showed a better treatment effect than B. coagulans or COSs did alone as revealed by the markers such as, colon length, IL-4 and Occludin levels.IMPORTANCE Probiotic and prebiotic are believed to be useful in alleviating the inflammatory, thereby resolving or preventing the severity of UC. Spore-forming bacteria Bacillus coagulans show advantages of stability and probiotic effects, being suggested as the important probiotics for UC treatment. Here, we demonstrate that administration of B. coagulans spores, chitooligosaccharides (COSs), or the synbiotic attenuates DSS-induced colitis and significantly correlates with altered gut immune responses. The treatment effect of the synbiotic is inferred to be relied on the enrichment of probiotic bacteria, such as Akkermansia and Ruminococcaceae species, which are reported to be crucial important for gut health. Our findings facilitate the development of therapeutic and preventive strategies for UC using spore-forming lactic acid bacteria in combination with COSs.

Antagonistic Activity of Lactic Acid Bacteria and Rosa rugosa Thunb. Pseudo-Fruit Extracts against Staphylococcus spp. Strains

Staphylococcus bacteria are ubiquitous microorganisms. They occur in practically all environments. They also show the ability to colonize the skin and mucous membranes of humans and animals. The current trend is to look for new natural factors (e.g., plant extracts rich in polyphenols) limiting the growth of undesirable bacteria in food and cosmetics or use as an adjunct in antibiotic therapy. The aim of this study was to evaluate the effect of extracts from Rosa rugosa Thunb. on the antagonistic properties of selected lactic acid bacteria strains in relation to Staphylococcus spp. isolates. The biological material consisted of seven strains of lactic acid bacteria (LAB) and seven strains of bacteria of the Staphylococcus genus. The anti-staphylococcal properties of the Rosa rugosa Thunb. pomace extracts (the tested extracts were characterized by a high content of polyphenols, namely 8–34 g/100 g DM/dm) were tested using the well method. The conducted research showed that the pomace extracts of the pseudo-fruit (Rosa rugosa Thunb.) had the ability to inhibit the growth of Staphylococcus spp. bacteria. The minimum concentration of polyphenols inhibiting the growth of staphylococci was in the range of 0.156–0.625 mg/mL. The conducted research showed that combined lactic acid bacteria and extracts from the pomace from the pseudo-fruit Rosa rugosa Thunb. (LR systems) may be factors limiting the growth of Staphylococcus spp. bacteria. As a result of the research, two-component antagonist systems consisting of LAB cultures and extracts from Rosa rugosa Thunb. pomace were developed, which effectively limited the growth of the test strains of Staphylococcus spp. In 41% of all tested cases, the zone of inhibition of growth of bacteria of the genus Staphylococcus spp. after the use of two-component antagonist systems was higher than that as a result of the control culture (without the addition of extracts).

The fermented soy whey produced by a combined lactic acid bacteria starter shows improved flavor and the function in alleviating dextran sulphate sodium induced colitis in mice

ABSTRACT In this study, Lactiplantibacillus plantarum BC299, Lactobacillus delbrueckii subsp. bulgaricus 717 and Streptococcus thermophilus 176 were used as combined starter cultures to produce a fermented soy whey beverage. The results showed that the fermentation of the combined starter cultures increased the content of lactic acid, acetic acid, succinic acid, and malic acid, while decreased the content of citric acid, fumaric acid and propionic acid. Meanwhile, the fermentation also effectively changed the proportion of volatile flavor substances. The higher sensory score of the fermented soy whey also confirmed the flavor improvement effect of the combined starter cultures. In addition, the in vivo results of animal experiments showed that the fermented soy whey could significantly improve the disease activity index (DAI) and colon morphology in dextran sulfate sodium (DSS) induced colitis mice. This study showed that the combined lactic acid bacteria starter cultures had important value-added relevance on the effective reuse of the soy whey by-product.

Effects of Lactic Acid Bacteria and Molasses Additives on Dynamic Fermentation Quality and Microbial Community of Native Grass Silage.

Ensiling native grass is an effective method to protect the nutritional quality of forage and alleviate feed shortages in the cold winter of the Inner Mongolian Plateau. To improve the usability of native grass resources as feed in China, the effects of lactic acid bacteria and molasses additions on the microbial population, fermentation quality, and nutritional quality of native grass during silage were investigated. Treatments were a control treatment with no additive (CK), lactic acid bacteria (L), molasses (M), and lactic acid bacteria in combination with molasses (L+M), all of which were stored at ambient temperature (17–28°C) for 7, 14, 30, and 60 days. The results showed that all additives improved nutritional value and fermentation quality with low pH and ammonia nitrogen (NH3–N) and high crude protein (CP) and water soluble carbohydrate (WSC) than control silage over the ensiling period. Compared with L or M silage, the L+M silage combination improved fermentability, as evidenced by higher LA content and a faster pH drop during the first 7 days of ensiling. With prolonged ensiling time, the combined addition of L and M could increase the count of desirable Lactobacillus, decrease microbial diversity, and inhibit the growth of undesirable microorganism, such as Clostridia, Escherichia, and Enterobacter abundance compared with silage treated with CK, L. or M. Application of L together with M could further improve the silage quality of native grass by altering bacterial community structure. In summary, the addition of lactic acid bacteria and molasses increased the relative abundance of Lactobacillus of native grass silage and improved fermentation quality.

Characterization and identification of a novel microbial consortium M2 and its effect on fermentation quality and enzymatic hydrolysis of sterile rice straw.

To isolate and enrich lignocellulolytic microbial consortia from yak (Bos grunniens) rumen and evaluate their effects on the fermentation characteristics and enzymatic hydrolysis in rice straw silage. A novel microbial consortium M2 with high CMCase and xylanase activities was enriched and observed to be prone to use natural carbon sources. Its predominant genus was Enterococcus, and most carbohydrate-active enzyme (CAZyme) genes belonged to the glycosyl hydrolases class. The consortium M2 was introduced with or without combined lactic acid bacteria (XA) to rice straw silage for 60days. Inoculating the consortium M2 notably decreased the structural carbohydrate contents and pH of rice straw silages. Treatment that combines consortium M2 and XA resulted in the highest levels of lactic acid and lignocellulose degradation. The consortium M2 alone or combined with XA significantly (p<0.01) increased water-soluble carbohydrates (WSCs), mono- and disaccharides contents compared with the XA silage. Combined addition obviously improved the enzymatic conversion efficiency of rice straw silage with higher glucose and xylose yields (23.39 and 12.91 w/w% DM, respectively). Ensiling pretreatment with the microbial consortium M2 in sterile rice straw improved fermentation characteristics. The combined application of consortium M2 with XA had synergistic effects on promoting the degradation of structural carbohydrates and enzymatic hydrolysis. Rice straw is difficult to ensile because of its low WSC and high structural carbohydrate contents. The microbial consortium M2 identified herein exhibits great potential for degrading fibrous substrates, and their combination with XA provides a faster and more effective synergistic strategy for biorefinery of lignocellulosic biomass.

Ensiling pretreatment with two novel microbial consortia enhances bioethanol production in sterile rice straw

The present study extracts and enriches cellulolytic microbial consortia from yak (Bos grunniens) and evaluates their effects on the fermentation profile and bioethanol yield in rice straw silage. Two microbial consortia (CF and PY) with high cellulolytic activity were isolated and observed to be prone to utilize natural carbon sources. Two consortia were introduced with and without combined lactic acid bacteria (CLAB) to rice straw for up to 60 days of ensiling, and their application notably decreased the levels of structural carbohydrates and pH values of rice straw silages. Treatments that combining microbial consortia and CLAB resulted in the highest levels of lactic acid, water soluble carbohydrates, mono- and disaccharides, and lignocellulose degradation, with PY + CLAB group yielding the highest bioethanol production. The microbial consortia identified herein exhibit great potential for degrading fibrous substrates, and their combination with CLAB provides a feasible way to efficiently use rice straw for bioethanol production.

Improvement of the antimicrobial activity of lactic acid bacteria in combination with berries/fruits and dairy industry by-products.

By-products from berries/fruits (B/F) and the dairy industry (DI) are an important environmental issue in many countries. In the present study, the concept of an improvement of the antimicrobial activity of lactic acid bacteria (LAB) in combination with B/F (raspberries, blackcurrants, apples, rowanberries) and DI by-products was analysed. Antimicrobial activities of the B/F by-products and LAB (13 LAB strains were estimated against 15 pathogenic strains) were evaluated, with whey substrate being used for the selected and the highest antimicrobial activities showing LAB cultivation. The broadest spectrum of pathogenic bacteria inhibition was shown by lyophilised blackcurrant and apple by-products, which inhibited 13 and 12 pathogenic strains of the 15 strains analysed, respectively. The strongest inhibition of the tested pathogens were shown by the Lactobacillus uvarum LUHS245 and Lactobacillus casei LUHS210 and, for the abovementioned LAB biomass preparation, whey enriched with 2.5 g 100 g-1 glucose, 2.0 g 100 g-1 yeast extract and 0.5 g 100 g-1 saccharose is a suitable and sustainable substrate. The B/F by-product's antimicrobial activity can be enhanced in combination with the LUHS245 and LUHS210 strains. LAB, B/F and DI by-products can be used for preparation of antimicrobial products because the combination of compounds from different origins showed higher antimicrobial properties. © 2019 Society of Chemical Industry.

Effects of CFSs produced by lactic acid bacteria in combination with grape seed extract on the microbial quality of ready-to-eat baby leaf vegetables

AbstractThe effects of the combined use of cell-free supernatant (CFS) and grape seed extract (GSE) in inhibiting the growth of pre-existing and inoculated foodborne bacteria on mixed, ready-to-eat (RTE) baby leaf vegetables were examined. Lactobacillus brevis WK12 and Leuconostoc mesenteroides WK32 produced significantly more acetic and lactic acid than citric, malic, succinic, or fumaric acids after 24 h of fermentation. The inhibition zone sizes observed when Lactobacillus brevis WK12 and Leuconostoc mesenteroides WK32 CFSs and 0.1% GSE were used in combination were much greater than those observed when either of the CFSs alone was used on agar plates. The application of 5% CFS from Lactobacillus brevis WK12 or Leuconostoc mesenteroides WK32 in combination with 0.1% GSE reduced the total counts of aerobic mesophilic bacteria, coliforms, and yeasts/molds in RTE baby leaf vegetable samples by 2.01, 1.74, and 1.87 log CFU/g, respectively, compared with those determined in the control. Combined CFS and GSE...

Effects of ensiling treatments on lactic acid production and supplementary methane formation of maize and amaranth – An advanced green biorefining approach

A green biorefinery enables the material and energetic use of biomass via lactic acid and methane production. Different ensiling techniques were applied to maize and amaranth with the aim to increase the amount of lactic acid in the silage. In addition the methane formation potential of the ensiled samples and the remaining solid residues after separating the organic juice were assessed. Treating maize with homofermentative lactic acid bacteria in combination with carbonated lime increased the amount of lactic acid about 91.9%. For amaranth no additional lactic acid production was obtained by treating the raw material. Specific methane yields for the solid residues of amaranth were significantly lower in comparison to the corresponding silages. The most promising treatment resulted in a production of 127.9±4.1gkg−1 DM lactic acid and a specific methane yield for the solid residue of 349.5±6.6lNkg−1 ODM.

Effect of lactic acid bacteria in combination with yeast on fermentation of wort

Eight Lactobacillus, five Saccharomyces and one Streptococcus strains were chosen to perform mono and mixed culture fermentations, focusing on interaction investigation via agar diffusion and analysis of cell growth kinetics, both serving as selection criteria. Mixed culture fermentations with four lactic acid bacteria (Lb. bulgaricus, Lb. paracasei SF1, Lb. plantarum 2142, and Lb. casei Shirota) and four yeast strains (S. cerevisiae W66, S. cerevisiae WS34/70, S. cerevisiae W120, and S. carlsbergensis 843) were performed in wort with initial cell ratio of 1:1. It was determined that during fermentations, cell concentration of lactic acid bacteria exceeded that of yeasts by one order of magnitude. Three strain combinations (S. carlsbergensis with Lb. bulgaricus, Lb. 2142, and Lb. Shirota) were chosen for further fermentations. Basic behaviour of them in wort was studied in mono culture, which helped to determine interaction type between bacteria and yeast in mixed culture. It resulted in higher Lactobacillus cell concentration in mono cultural than in mixed culture fermentation, which refers to competition. Cell ratio was changed to 1:10 (lactobacilli:yeasts), to favour growth of yeast and avoid lower pH. Despite the higher initial concentration of yeast, results turned in favour of lactobacillus already at the 24th hour.

EFFECT OF MICROORGANISMS ON THE FERMENTATION OF FUSARIUM SPP. CONTAMINATED BARLEY AND ITS DETOXIFICATION

The work is dedicated to increase the efficiency of the processing of Fusarium contaminated barley biomass by using pretreatment of grains with antimicrobial lactic acid bacteria in combination with special selected strains of yeast for alcoholic fermentation. Bacteriocins producing lactic acid bacteria (LAB) have been isolated from Lithuanian spontanious rye sourdoughs. These LAB’s were attributing to Lactobacillus and Pediococcus genotypes and Lactobacillus sakei KTU05-06, Pediococcus acidilactici KTU05-07 and P. pentosaceus KTU05-08 species, PCR detection of LAB structural genes has been carried out. The contamination of barley with Fusarium spp. decrease the amount of ethanol during fermentation processes (R2 = 0.868) and, contrary, increase the concentrations of higher alkohols (R2 = 0.867). The efficiency of fermentation process could be increased by selecting yeast strains: a higher ethanol yield and a lower amount of higher alkohols was observed by using K. marxianus var. Bulgaricus. Other yeast strains – K. Marxianus show the same effect on fermentation processes as S. cerevisae. The treatment of contaminated barley with selected LAB has not a significant influence on bioethanol yield. But by using some LAB strains such as P. acidilactici and P. pentosaceus a higher amount of higher alkohols has been developed. Furthermore in all cases this biotechnological solution has positive influence on dried grains with solubles (DDGS) detoxification by decreasing the amount of DON in important raw material for feed production. The best detoxification effect has been achieved by using P. acidilactici or L. sakei for contaminated barley treatment and S. cerevisiae – for fermentation processes. So, by selecting LAB with antimicrobial activity in combiantion with yeast, the efficiency of the processing of Fusarium cantaminated barley can be significantly increased: biomass could be used for bioethanol production and DDGS – for feed.DOI: http://dx.doi.org/10.5755/j01.ct.60.2.1617

Study on the reduction of acrylamide in mixed rye bread by fermentation with bacteriocin-like inhibitory substances producing lactic acid bacteria in combination with Aspergillus niger glucoamylase

This study mainly focuses on a strategy for reducing of acrylamide in cereal products, predominantly in bakery products. The effect of mesophilic lactic acid bacteria (LAB) strains as well as a novel fermentation media on the bases of extruded rye wholemeal on the acrylamide formation in mixed rye bread of different weight of loaf was studied. The LC–MS/MS method for acrylamide determination in bread crumb has been applied. Addition of 15% low pH (pH 3.4–4.3) fermented product to bread dough, which were produced by using commercial strain Lactobacillus casei and bacteriocin-like inhibitory substances (BLIS) producing strains Lactobacillus sakei KTU05-6, Pediococcus acidilactici KTU05-7 and Pediococcus pentosaceus KTU05-8 separately, caused significant reduction of acrylamide in mixed rye bread. All bread loafs of 1000 g contained less by 27% acrylamide concentrations versus loafs of 500 g. Acrylamide formation was affected (r2 = 0.7193) by total reducing sugar content in bread and slightly correlated (r2 = 0.5587) with reducing sugar content in sourdough. The treatment of extruded rye wholemeal with Aspergillus niger glucoamylase as compared to the control sample was found to have a positive effect on the acidification process lowering the acrylamide formation on an average by 59.4% and 40% in 500 g and 1000 g loafs of bread, respectively. This study demonstrates that acrylamide content could be reduced by using LAB excreting lower amylolytic activity in the medium, while the higher proteolytic activity is preferred.

The effect of additives in silages of pure timothy and timothy mixed with red clover on chemical composition and in vitro rumen fermentation characteristics

AbstractThe aim was to compare the effects of additives on direct cut silages of pure timothy and timothy mixed with tetraploid red clover. First and second growth cuts were ensiled during three consecutive years, 1994, 1995 and 1996, either without any additive or with the addition of formic acid, or lactic acid bacteria in combination with molasses. Effects of the additives on the degradation characteristics of the herbage and the silages were analysed using an automatic in vitro gas production (GP) technique. At the end of the in vitro procedures, organic matter and neutral‐detergent fibre (NDF) degradabilities were determined.The tetraploid red clover persisted in the leys during the 3 years and was the dominant species at the second growth in the mixed leys. The herbage from the mixed crops had lower dry‐matter contents, higher crude protein concentrations and higher buffering capacity compared with the pure timothy at both cuts. In general, the additives reduced pH, and the concentrations of ammonium‐N and acetic acid in the silages. The treated silages had a more rapid faster GP in both crops.The silages from the mixed crop benefited more from the additives compared with the grass silages. The additives affected the soluble fractions as well as the NDF degradability of the silages of the mixed crop more than those fractions of the grass silages. The addition of molasses in combination with a commercial inocula resulted in increased production of lactic acid and ethanol in silages from both crops. The silages without additives could not meet the requirements for good silages according to the standards of the Swedish dairy industry.

Bacteriocins of Lactic Acid Bacteria in Combination Have Greater Antibacterial Activity

Antibacterial efficiency of two bacteriocins from lactic acid bacteria, pediocin AcH, and nisin was tested individually and in combination against several gram-positive bacterial strains including some involved in food spoilage and foodborne diseases. Pediocin AcH and nisin were more antibacterial in combination than when they were used alone. The principles of this greater antibacterial spectrum have been proposed. Bacteriocins in combinations can be used advantageously to design efficient natural food biopreservative(s).