Effects Of Lactic Acid Bacteria Research Articles

Effect of lactic acid bacterial starter KUB-G2 on grass silage quality and its microbial community performed using 140-ton plastic bag silos: a large-scale study

This study investigated the effectiveness of lactic acid bacteria (LAB) starters in 140 tons of signal grass silage. We compared a locally developed starter, a combination of Lactiplantibacillus plantarum KUB-SP1-3 and Pediococcus acidilactici KUB-M6 (KUB-G2) with a commercial starter. We monitored the chemical and microbiological properties of silage at ensiling (day 0) and after 21 days. The results indicated that KUB-G2 produced high-quality silage. There were no significant differences in total viable microbes, lactic acid, or propionic acid contents between the starters. However, the silage produced with KUB-G2 had a lower acetic acid content than that produced with the commercial starter. KUB-G2 also resulted in a narrower microbiome profile dominated by Pediococci whereas the control group displayed a broader range of bacterial taxa with colonization by Lactiplantibacillus and Lentilactobacillus. These findings suggested that KUB-G2, with its distinct microbial profile, is a suitable replacement for imported commercial starters in large-scale signal grass silage production.

Characterization and potential lipid-lowering effects of lactic acid bacteria isolated from cats.

This study aimed to study the characterization and the potential lipid-lowering effects of new isolated lactic acid bacteria from the feces of healthy adult cats. We collected 85 cat fecal samples, isolated, screening lactic acid bacteria strains from samples, and investigated their in vitro and in vivo biological properties. A total of 221 lactic acid bacteria strains were isolated from 85 cat fecal samples. Sixteen strains with calcium dissolution rings greater than 1 mm were identified and selected for further characterization. Three lactic acid bacteria strains, Lactobacillus plantarum L-27-2, Pediococcus lactis L-14-1, and Enterococcus faecium, were identified as showing the most promising rates of cholesterol degradation (greater than 20%) and bacteriostatic radius (over 15 mm). These three strains exhibited robust growth and adherence to epithelial cells, along with adaptability to low pH (greater than 70%) and high bile salt conditions (greater than 60%), and remarkable cholesterol degradation and anti-pathogen activity. Sixteen mice were fed a high-fat diet (HFD) from 4 to 8 weeks of age, while a control group of the same size received a normal diet (ND). At 8 weeks of age, serum, feces and adipose tissue were collected. The results showed that, compared with mice fed an HFD diet alone, all mice fed an HFD diet plus lactic acid bacteria could decrease weight gain. P < 0.05 and the pathological changes of adipose tissue were alleviated. In addition, mice fed L-14-1 and F203 showed abdominal fat accumulation decreased (P < 0.05). Mice fed L-27-2 showed serum and liver triglyceride (TG) decreased (P < 0.05) and mice fed F203 showed serum high density lipoprotein cholesterol (HDL-C) increased (P < 0.01). mice fed L-27-2 and L-14-1 showed inflammatory cytokines (IL-6) was decreased (P < 0.01) Analysis of the fecal microbiota of mice fed these three lactic acid bacteria strains revealed alterations in the gut microbial community. There were common changes in intestinal microbes in mice fed these three lactic acid bacteria: (1) Bacteroides decreased; (2) Myxococcus increased; (3) Lachnoclostridium decreased. The microbes mentioned are all part of the core intestinal flora. This study provided three potential lactic acid bacteria for alleviating animal obesity and inflammation.

Effects of lactic acid bacteria exposed to extreme conditions on yoghurt quality

In this study, two bacterial strains used in the production of yoghurt were subjected to three distinct stress conditions (low pressure, infrared light, and low pressure + infrared light) and then used as starter cultures for yoghurt production. The obtained results revealed that the bacterial stress response mechanisms, especially those of bacteria exposed to low pressure, positively affected the physicochemical, textural, and microbiological quality during storage of yoghurts produced with these bacteria. In addition, it was found that prolonging the exposure time to stress conditions increased this effect even more. The samples subjected to low pressure for 2 hours had the shortest fermentation time among all samples, while the samples subjected to infrared light for 2 hours had the longest fermentation time. Yoghurts produced with bacteria subjected to low pressure conditions had more organic acids and aroma components and less syneresis during storage compared to other samples. Furthermore, it was determined that yoghurt samples produced with bacteria exposed to stress conditions had higher L* and a* values, lower b* values, improved textural values, and higher bacterial counts during the 7-day storage period compared to control samples.

Effects of Lactic Acid Bacteria on The Quality of Steamed Bread and Its Process Transformation

The starter culture of traditional steamed buns is composed of a variety of microorganisms, among which lactic acid bacteria are the main source of fermentation. The quality of the product is directly affected by the diversity and abundance of lactic acid bacteria. As a probiotic that plays an important role in many fields, lactic acid bacteria have an important impact on the quality of steamed buns. These effects include enhanced nutritional value, improved flavor, altered texture, extended shelf life, production of antioxidants, etc. The dough fermentation method in which lactic acid bacteria play a major role is called sourdough. It has better technological value than ordinary dough and is one of the research focuses of the food industry. This study explores the natural link between lactic acid bacteria and the flavor, texture, antioxidant activity, and nutritional value of steamed bun dough. At the same time, the effects of process improvement and the addition of new raw materials on the quality and nutritional properties of steamed buns fermented by lactic acid bacteria were explored.

The Health Regulatory Effect of Lactic Acid Bacteria on Human Body

Probiotics are a kind of active microorganisms that are beneficial to the host by colonizing in the human body and changing the composition of the flora in a certain part of the host. The organic acids, special enzymes and actinomycin’s produced by lactic acid bacteria (LAB) have special physiological functions. LAB can regulate the normal flora of gastrointestinal tract and maintain the microecological balance, so as to improve gastrointestinal function, increase food digestibility and biotiter, reduce serum cholesterol, control endotoxin, inhibit the growth of spoilage bacteria in intestinal tract, and improve body immunity. This paper studied the existence mode and influencing factors of probiotics and took LAB as an example to mainly describe the research progress of LAB in probiotics, discussed the mechanism of probiotics to maintain the ecological balance of intestinal flora, summarized the impact of probiotics on human body, and aimed at various problems and deficiencies faced by the probiotic industry at present. Some suggestions on the future research direction are put forward.

The Potential Teeth Bleaching and Halitosis Prevention Effects of Pediococcus inopinatus THK-30, a Kimchi-Derived Lactic Acid Bacterium: In Vitro Study.

Recent developments in addressing dental aesthetic concerns, encompassing issues like teeth discoloration and halitosis, underscore the demand for safer alternative solutions. This study aims to confirm the effects of lactic acid bacteria (LAB) from kimchi on artificial teeth bleaching and their potential impact in terms of preventing halitosis-related bacteria. To evaluate the antimicrobial effects against oral pathogens, disc diffusion tests and broth microdilution methods were used. Additionally, crystal violet analysis was performed to confirm the biofilm inhibition effect. The bleaching effects on stained artificial teeth were analyzed using the CIEDE2000 colorimetric method. Statistical analyses were performed using GraphPad Prism 9 with one-way and two-way ANOVA, with the significance level set at α < 0.05. The strain THK-30, isolated from kimchi, exhibited antibacterial activity against Streptococcus mutans, Porphyromonas gingivalis, and Fusobacterium nucleatum, and was identified as Pediococcus inopinatus. Moreover, THK-30 showed a synergistic antibacterial effect against Gram-negative oral pathogens with 8% sodium hexametaphosphate (SHMP). In the stained artificial teeth bleaching test and artificial teeth biofilm inhibition test, the cell-free supernatant of THK-30 displayed significant teeth bleaching effects and caused the inhibition of biofilm formation, both independently and in combination with SHMP 8%. This study has demonstrated the potential applicability of LAB in teeth discoloration and halitosis. These findings are poised to provide a foundation for the development of research pertaining to the control of oral bacteria.

Antagonistic Effects of Lactic Acid Bacteria Isolated from Ethiopian Traditional Fermented Foods and Beverages Against Foodborne Pathogens.

Lactic acid bacteria (LAB) found in Ethiopian traditional fermented foods and beverages have potential antagonistic effects against foodborne pathogens due to their capacity to produce various antimicrobial metabolites. This study evaluated the antagonistic activity of LAB isolated from Ethiopian traditional fermented foods and beverages against foodborne pathogens and characterized their antimicrobial substances. A total of 180 traditional fermented foods and beverages were collected, and the antagonistic activities of LAB were evaluated against selected foodborne pathogens. The effects of pH, temperature, enzymes, and food additives on the antagonistic effects of cell-free supernatant produced by LAB were investigated. LAB identification and characterization were conducted using an integrated phenotypic approach and MALDI TOF MS spectrum analysis, and data were analyzed using one-way ANOVA and Tukey post hoc analysis. A total of 956 LAB were isolated, of which seventeen (17 LAB) isolates of Pediococcus pentosaceus (Pc. pentosaceus (n = 7)), Pediococcus acidilactici (Pc. acidilactici (n = 2)), Enterococcus faecium (Ec. faecium (n = 6)), and Lactococcus lactis (Lc. lactis (n = 2)) were screened for antagonistic activity based on their ability to produce bacteriocins, probiotic activity, and preservative potential. Pc. pentosaceus JULABB16, Pc. pentosaceus JULABB01, and Ec. faecium JULABBr39 showed strong antagonistic activity against all pathogens, with mean inhibition zone diameters ranging from 23.50 to 35.50mm. Lc. lactis, Pc. pentosaceus, Pc. acidilactici, and Ec. faecium produced bioactive metabolites that were sensitive to proteolytic enzymes and capable of withstanding high temperatures (80-100°C) and acid concentrations (pH 2-10). The CFS produced by Lc. lactis, Pc. pentosaceus, Pc. acidilactici, and Ec. faecium showed the most impending antagonistic activity against all pathogens. The bioactive substances produced by LAB isolates had promising effects against food spoilage and pathogenic bacteria, making them potential natural food preservatives.

Effects of lactic acid bacteria on protein metabolism of Sunit lamb

To investigate the effect of adding lactic acid bacteria (LAB) to Sunit lambs’ diet on their protein metabolism, 18 3-month-old Sunit sheep were randomly divided into two groups (Group C (non-feeding of LAB) and Group L (feeding of LAB)) for a 90 d feeding trial. After the animals were slaughtered, we measured several key factors, including basal indices, amino acid composition, protein metabolism enzyme activity, and protein metabolism-related gene expression. There were nine replications of each group. The data show that LAB had a significant effect on the intramuscular fat (IMF) content (P<0.001). The composition of amino acids in the serum and mutton was improved by the addition of LAB. The addition of LAB led to a significant increase in the expression of genes related to AKT serine/threonine kinase 1 (Akt1), mammalian target of rapamycin (mTOR), p70 ribosomal protein S6 kinase (p70S6K1), and eukaryotic initiation factor 4E (eIF4E) protein synthesis (P<0.05), while the expression of all genes related to protein catabolism was reduced. Thus, dietary LAB can increase IMF content, improve amino acid composition, regulate protein metabolism in lambs, and provide a new way and theoretical basis for dietary management to improve meat quality in housed sheep.

Effectiveness of LAB filtrate of shrimp pastes products on quality characteristics of fresh stingray (Dasyatis kuhlii)

Stingray (Dasyatis kuhlii) is a type of by-catch fish that is widely used as a product with economic value, but the handling on board is not paid attention to so that when it is landed the condition of the fish is not fresh. This study aims to determine the effect of lactic acid bacteria (LAB) of shrimp paste products in maintaining the quality characteristics of stingrays by chemical testing, namely pH and TVBN, and microbiological testing, namely TPC. This research was conducted from August to October 2022. In this study, BAL was used which was isolated from shrimp paste and stored for 7 days at a temperature of 25-27 °C and the observation time was on the 2nd, 4th, and 7th day. The results of the pH test showed varied results. 7.99 – 9.17. TVBN test results in 627.33 mgN/100 to 1052.16 mgN/100. The TPC value shows a result of 3.86 x 107 cfu/ml – 6.788 x 108 cfu/ml. The effect of LAB of shrimp paste products in maintaining the quality characteristics of stingrays is less effective at room temperature.

모싯잎 에탄올 추출물을 첨가한 산업용 배지에서 배양한 유산균 발효물의 항비만 효과

This study investigated the anti-obesity effects of lactic acid bacteria ferments cultured in industrial medium with ethanol extract of ramie leaf (Boehmeria nivea L.). On the 4th day of fermentation, the maximum live cell counts were 8.75-8.85 log CFU/mL, pH was 3.74-3.79, and total acidity was 2.07-2.19%. The fermentation of lactic acid bacteria on the fourth day resulted in the amount of lactic acid reaching 1,676.03-1,910.12 mg%. The lipase inhibitory activities of Lactiplantibacillus plantarum (L. plantarum) JBLAB0101 (FRLPLA) and Lactobacillus rhamnosus GG (LGG, (FRLLGG)) ferments were 30.10%, and 25.63%, respectively, at a concentration of 0.5 mg/mL. The lipid accumulation, leptin production, PPAR-γ and SREBP-1c mRNA levels were decreased to 37.54%, 54.64%, 24.18%, and 31.32%, respectively, at 200 μg/mL concentration of FRLPLA. These results suggest that anti-obesity effect could be increased by lactic acid bacteria in industrial medium with extract of ramie leaf.

Exploring Anti-Breast Cancer Effects of Live Pediococcus acidilactici and Its Cell-Free Supernatant Isolated from Human Breast Milk.

Current breast cancer treatment options are limited by drug resistance and adverse side effects, which calls for the need for alternatives or complementary remedies. Probiotic bacteria isolated from human breast milk have been shown to possess proapoptotic and anti-inflammatory properties against breast mastitis in breastfeeding mothers and are being studied as possible anticancer regimens. Thus, this study aimed at exploring the effect of lactic acid bacteria isolated from human breast milk on MDA-MB 231 breast cancer cells. A total of twenty-two bacteria were isolated from four human breast milk samples. The isolates were characterized and identified using biochemical tests and Sanger sequencing, respectively. For in vitro experiments, we used isolated P. acidilactici to treat MDA-MB-231 cells, and an MTT assay was used to detect proliferation. RT-qPCR and wound healing assays were performed to determine the effect of the isolated P. acidilactici on breast cancer cytokine expression and migration. Exposure of MDA-MB 231 breast cancer cells to live P. acidilactici and its cell-free supernatant (CFS) for 24 h resulted in a reduction in cancer cell viability. Also, the expression of the cytokines IL-6, IL-8, and IL-10 in the breast cancer cells increased following exposure to P. acidilactici and its CFS for 24 and 72 h. Additionally, the levels of the SLUG gene remained unchanged while the TWIST1 gene was upregulated following exposure of the cancer cells to bacteria, indicating that P. acidilactici may promote epithelial-mesenchymal transition in breast cancer. Finally, the CFS significantly inhibited cancer cell mobility. These findings serve as a foundation to further investigate the usefulness of P. acidilactici as a potential therapeutic agent in breast cancer therapy.

Effect of Lactic Acid Bacteria Fermentation on Plant-Based Products

Lactic acid bacteria effectively utilize the nutrients and active compounds in plant-based materials via their powerful metabolic pathways and enzyme systems, achieving a combination of nutrition, functionality, and deliciousness. Currently, the majority of review articles predominantly concentrate on summarizing the fermentation of fruits and vegetables by lactic acid bacteria, devoting comparatively less attention to researching other plant species varieties and plant-based by-products. Furthermore, the summary of the research on the active substances and functional properties lacks sufficient depth. This review provides a comprehensive overview of the status of and technological progress in lactic acid bacteria fermentation of various plant species and plant-based by-products, and the effects of lactic acid bacteria on the active substances and functional properties are emphasized. In addition, this review emphasizes that active substances give products more functionality. The aim of this review is to emphasize the significant contribution of lactic acid bacteria to the active substances and functional properties of plant-based products, which will assist researchers in better comprehending the application value of lactic acid bacteria in the plant-based domain and direct attention towards the interaction mechanisms between active substances and product functionality. Concurrently, this review provides a certain theoretical foundation and reference for the application of fermented functional products in promoting health and preventing diseases.

Cholesterol lowering in diet-induced hypercholesterolemic mice using Lactobacillus bile salt hydrolases with different substrate specificities.

The cholesterol-lowering effect of lactic acid bacteria with high activity of bile salt hydrolase (BSH) is unclear. We believe that distinguishing BSH substrate specificity is necessary to study the effect of various BSH enzymes. We engineered a BSH mutant enzyme recombinant strain named F67A, which exclusively hydrolyzes taurocholic acid (TCA) using site-directed mutagenesis, and a previously lab-constructed BSH recombinant strain, YB81 that exclusively hydrolyzes glycocholic acid (GCA). We also constructed the recombinant strain named NB5462, which carries the empty pSIP411 plasmid and was used as a blank control strain. The intestinal flora in pseudo-germ-free (PGF) mice in which intestinal flora were eliminated via antibiotics, and F67A successfully reduced serum cholesterol levels in high-cholesterol diet-fed mice, whereas YB81 did not yield the same results. However, YB81 regained its cholesterol-lowering capacity in specific pathogen-free (SPF) mice with intact intestinal flora. The cholesterol-lowering mechanism of F67A involved modifying the bile acid pool through BSH enzyme activity. This adjustment regulated the expression of intestinal farnesoid X receptor and subsequently elevated hepatic cholesterol 7α-hydroxylase (CYP7A1), effectively reducing cholesterol levels. Conversely, GCA, the substrate of YB81, was found in minimal quantities in mice, preventing it from inducing changes in bile acid pools. In the presence of intestinal flora, the YB81 BSH enzyme induced notable alterations in bile acids by regulating changes in the intestinal flora and BSH within the flora, ultimately resulting in cholesterol reduction. This is the first study investigating the substrate specificity of BSH, demonstrating that different substrate-specific BSH enzymes exhibit cholesterol-lowering properties. Additionally, we elaborate on the mechanism of BSH-mediated enterohepatic axis regulation.

Efficacy of Lactic Acid Bacteria Probiotics on Feed Efficiency and Carcass Weight in Kampung Unggul Balitbangtan (KUB) Chicken

This study aimed to determine the effect of lactic acid bacteria probiotics on the performance of Kampung Unggul Balitbangtan (KUB) chicken. A total of 48 KUB chickens aged 2 weeks were randomized into 4 treatments and each treatment consisted of 12 chickens. This study was conducted for 8 weeks. This study used 4 different treatments including (P0) not using probiotics, (P1) using probiotics of 1 mL/L drinking water, (P2) using probiotics of 2 mL/L drinking water, and (P3) using probiotics of 3 mL/L drinking water. The data were analyzed using ANOVA continued with Duncan’s Multiple distance test. As a result, reported that the data had a significant difference in the increase in feed efficiency and carcass weight. In conclusion, the administration of probiotics of 3 mL/L of drinking water can increase feed efficiency and carcass weight in KUB chickens.

MICROBIOLOGICAL PROCESSES IN THE LUCERNE HAYLAGE UNDER INOCULATION WITH LACTIC ACID BACTERIA

Objective. To characterize the effect of lactic acid bacteria (LAB) on the quantitative and qualitative composition of the groups of microorganisms in the lucerne haylage after their introduction. Methods. Microbiological (cultivation of microorganisms on various media, determination of their viability, measurement of osmotolerance, determination of the amount of lactic acid during cultivation on skimmed sterile milk), microscopic, laboratory experiments on the lucerne haying with a dry matter (DM) content of 46 % and 37 % with and without inoculation with LAB strains, statistical. Results. Lucerne was inoculated with monocultures of Lactobacillus sp. LH42, Lactobacillus sp. LH43, Lactobacillus sp. LH47, L. plantarum КТ-L18/1 osmotolerant strains, which showed tolerance to 2 %, 4 %, 6.5 % sodium chloride in 100 % of cases. The best indicators in terms of active and titrated acidity were found in cultures of Lactobacillus sp. LН47, L. plantarum КТ-L18/1. The inoculation of LAB into the haylage ecosystem at Day 15 of fermentation resulted in an increase in the number of LAB compared to the untreated control. At Day 45 of lucerne haying, the number of LAB decreased and was registered at the level from 1 to 100 billion CFU/g at a 46 % DM content and at the level from 0.01 to 10 billion CFU/g at a 37 % DM content. The greatest development of clostridia in the lucerne haylage in experiments was reported at Day 3 with a sharp decrease in their number at Day 45. The influence of Lactobacillus sp. LH 43, Lactobacillus sp. LH 47, L. plantarum KT-L18/1 on the reduction of the growth of the number of clostridia both at a 46 % and 37 % DM content at the end of the fermentation period was shown. A higher number of yeasts was established at a lower (37 %) content of DM in the haylage. A fungistatic effect was established in variants with LAB inoculation versus the control variant. The relationship between the dynamics of decreasing active acidity (pH) and the dynamics of microbiota development has been shown. Conclusion. Inoculation of the studied strains of lactic acid bacteria into high-protein lucerne haylage mass contributed to an order of magnitude increase in the number of LAB versus the control variant, suppression of the development of clostridia, yeasts and a rapid decrease in active acidity, which confirms data about the effect of LAB-based inoculants on the fermentation of plant raw materials by adjusting the composition of groups of microorganisms

Implications and Mechanisms of Antiviral Effects of Lactic Acid Bacteria: A Systematic Review.

Lactic acid bacteria (LAB) are among the most important strains of probiotics. Some are normal flora of human mucous membranes in the gastrointestinal system, skin, urinary tract, and genitalia. There is evidence suggesting that LAB has an antiviral effect on viral infections. However, these studies are still controversial; a systematic review was conducted to evaluate the antiviral effects of LAB on viral infections. The systematic search was conducted until the end of December 17, 2022, using international databases such as Scopus, Web of Science, and Medline (via PubMed). The keywords of our search were lactic acid bacteria, Lactobacillales, Lactobacillus (as well as its species), probiotics, antiviral, inhibitory effect, and virus. Of 15.408 potentially relevant articles obtained, 45 eligible in-vivo human studies were selected for inclusion in the study from databases, registers, and citation searching. We conducted a systematic review of the antiviral effects of the LAB based on the included articles. The most commonly investigated lactobacillus specie were Lactobacillus rhamnosus GG and Lactobacillus casei. Our study indicates that 40 of the selected 45 of the included articles support the positive effect of LAB on viral infections, although some studies showed no significant positive effect of LABs on some viral infections.

Effects of lactic acid bacteria on antioxidant activity in vitro and aroma component of Eucommia ulmoides tea.

Eucommia ulmoides tea is a popular functional health drink in Asian countries, but its unique herbal aroma is difficult for consumers to accept. The effects of four lactic acid bacteria strains (Lactobacillus plantarium, Lactobacillus bulgaricus, Lactobacillus acidophilus and Streptococcus thermophilus) fermentation on the physicochemical property, antioxidant activity in vitro and aroma component of E. ulmoides leaves were studied. Within the four strains, the sample by L. bulgaricus fermentation showed the higher concentrations of chlorogenic acid, geniposidic acid and stronger antioxidant activity in vitro. Moreover, the sample by L. bulgaricus fermentation produced a stronger fruity and floral flavor. These results suggested that L. bulgaricus was the best strain for fermentation E. ulmoides tea. The differences between different strains should be considered when selecting lactic acid bacteria for raw material fermentation of fruits and vegetables.

Effect of lactic acid bacteria and Bacillus on anthracnose disease in postharvest papaya fruit

Abstract. Thi QVC, Dung TQ, Huynh NTN, Truc NT, Thuy NP. 2023. Effect of lactic acid bacteria and Bacillus on anthracnose disease in postharvest papaya fruit. Biodiversitas 24: 5883-5894. Anthracnose disease of papaya fruit caused by Colletotrichum (isolate TD1), identified by 5.8S rRNA sequence homology, is a main obstacle in papaya fruit, influencing fruit quality and minimizing shelf life. Therefore, to diminish the disease and sustain the fruit quality, the impact of Lactic Acid Bacteria (LAB) and Bacillus on the growth of anthracnose disease and fruit quality was investigated in vitro and in vivo. Furthermore, 13 LAB and 12 Bacillus isolates were collected from traditional fermented vegetables and papaya rhizospheric soils. The results showed that 13 LAB isolates and 6 isolates of Bacillus were inhibitory against Colletotrichum in an in vitro test. Two isolates of LDC11 and BHL21 with the highest antifungal activity were selected to evaluate their effect on Colletotrichum growth and papaya fruit quality under in vivo conditions. These findings indicated that the isolates LDC11 and BHL21 at a density of 106 CFU/mL reduced the disease incidence and severity. The LAB and Bacillus treated papaya fruit increased a number of parameters, such as weight loss, TSS, and L*, a*, and b* values. However, vitamin C content, TA, and fruit firmness were reduced compared to the control. The research shows a potential applications of LAB and Bacillus in the postharvest preservation of papaya fruit. To our knowledge, this is the first study to apply Bacillus and LAB bacteria to control diseases in postharvest papaya in Vietnam.

Effect of lactic acid bacteria and wheat bran on the fermentation quality and bacterial community of Broussonetia papyrifera silage

BackgroundPaper mulberry has been considered as a high-quality protein feedstuff to cope with the shortage of feed and the development of livestock. In addition, the features of high moisture and low water-soluble carbohydrate concentration in fresh paper mulberry make it difficult to ensile. Therefore, it is important to find an optimal way to improve the paper mulberry silage quality. In this study, we aimed to investigate the application of Lactobacillus plantarum (LP) and wheat bran (WB) on the fermentation characteristics, chemical composition and microbial community of paper mulberry silage.ResultsThe objective of this study was to evaluate the effects of Lactobacillus plantarum and wheat bran alone or combination (LP + WB) addition on the fermentation quality and bacterial community of paper mulberry silage. After 60 days of ensiling, the employed three treatments had higher crude protein contents compared with control (P < 0.05). More importantly, WB and LP + WB treatments significantly reduced the pH value and NH3-N concentration, and increased lactic acid content (P < 0.05). Microbial analysis indicated that the bacterial community in WB and LP + WB treatments showed distinct difference with LP and control. Lactobacillus was the dominant genera in all treatments. However, at the species level, Lactobacillus farciminis became the most dominant bacteria in control and LP treatments while the dominant bacteria in WB and LP + WB were Lactobacillus brevis and Lactobacillus farciminis. In addition, Lactobacillus brevis was positively correlated to crude protein and lactic acid and negatively correlated to pH and NH3-N. Overall, this study revealed that ensiling paper mulberry with WB or combination LP could improve silage quality through altering microbial community, which provided a practical approach for enhancing paper mulberry silage quality.ConclusionWheat bran and combinations of Lactobacillus plantarum and wheat bran additions could reduce pH, NH3-N and increase LA content. The application of WB and LP + WB shifted the dominant bacteria species to Lactobacillus brevis. In summary, the addition of wheat bran and combinations of lactic acid bacteria and wheat bran were effective ways to enhance paper mulberry silage fermentation.Graphical

Antioxidant effect of lactic acid bacteria in human bronchial epithelial cells exposed to cigarette smoke.

Chronic lung diseases are a major and increasing global health problem, commonly caused by cigarette smoke. We aimed to explore the antioxidant effects of lactic acid bacteria (LAB) against cigarette smoke in bronchial epithelial cells. The antioxidant effects of 21 heat-killed (HK) LAB strains were tested in cigarette smoke stimulated BEAS-2B cells and 3-D bronchospheres organoids. We showed that HK Lactiplantibacillus plantarum BGPKM22 possesses antioxidant activity against cigarette smoke, resistance to hydrogen peroxide, and free radical neutralizing activity. We demonstrated that HK BGPKM22 inhibited cigarette smoke induced expression of the Aryl hydrocarbon receptor (AhR) and Nuclear factor erythroid 2 related factor 2 (Nrf2) genes. The cell-free supernatant (SN) of BGPKM22 fully confirmed the effects of HK BGPKM22. For the first time, we revealed that HK and SN of L. plantarum BGPKM22 possess antioxidant activity and modulate AhR and Nrf2 gene expression in bronchial epithelial cells exposed to cigarette smoke.