Probiotic Bacillus Subtilis Research Articles

Untargeted metabolomics and PacBio analysis on bioactive components and microbial community in co-fermentation of black soldier fly larva

Fermentation can enhance nutritional value and safety of insect protein, this study utilized probiotic Bacillus subtilis (B. subtilis) and complex enzyme containing chitinase and protease to ferment the paste of Black Soldier Fly larva (BSFL), decomposing anti-nutritional factor chitin and protein in paste while inhibiting the proliferation of harmful microorganisms. The result indicated a 40 % degradation of chitin after fermentation, accompanied by an increase in the variety and quantity of amino acids and peptides, functional substances such as raffinose and cucurbitacin significantly increased, while the levels of antibiotics such as erythromycin and ofloxacin had decreased; after fermentation, there is a significant difference in the microbial distribution between bacteria, co-fermentation and CK, the indigenous microbiota of BSF and pathogenic bacteria such as Klebsiella pneumoniae and Clostridiaceae bacteria were significantly inhibited, anaerobic bacteria, including Anaerosalibacter, Caldicoprobacter and Tissierella, exhibit a marked increase; significant changes are detected in the carbon sources, amino acids, and key enzymes related to other metabolic pathways of B. subtilis during the fermentation process. Overall, we have developed a method for fermenting BSFL paste, aiming at enhance its probiotic properties, nutritional value, and safety. This study provided groundwork for utilizing fermented insects as a novel protein source for food and fodder.

Effect of Probiotic Supplementation in Diet on Egg Production, Egg Quality, Intestinal Morphology and Bacterial Population in Caecum of Laying Hens

The objective of this study was to study the effect of probiotic supplementation in diet on egg production, egg quality, intestinal morphology, and bacterial population in caecum of laying hens. A total of 768 Lohmann Brown-Classic laying hens, aged 42 - 54 weeks, were used. The laying hens were divided into 3 groups, each with 8 subgroups of 32 birds each. The experiment was planned to use a completely randomized design method. The 3 experimental groups were classified based on their dietary treatment as follows: 1) Basal diet (without probiotic supplementation), 2) Basal diet with probiotic 0.01 and 0.02 % in 3, respectively. Data was collected for 12 weeks. Adding probiotic in the diet was no significant difference on egg production, egg quality, and bacterial population in caecum. However, probiotic supplementation in the diet increased villi height of the duodenum significantly improved (p < 0.02), villi height per depth crypt of the duodenum significantly improved (p < 0.05), villi height per depth crypt of the jejunum significantly improved (p < 0.01), and villi height per depth crypt of the ileum significantly improved (p < 0.02). Therefore, studies have shown that dietary probiotic supplementation can improved small intestinal morphology are the most important indexes for measuring the digestive and absorption function of the small intestine are more efficient. HIGHLIGHTS Probiotic (Bacillus subtilis) is a gram-positive, non-pathogenic bacterium that can inhibit digestive enzymes such as protease, amylase, and lipase. These enzymes help increase the efficiency of digestion and absorption of nutrients. As a result of the working mechanism of Bacillus subtilis, it helps strengthen the intestinal wall, eliminates pathogenic microorganisms, reduces damaged intestinal mucosal cells, and improves intestinal absorption, resulting in increased production. Effect of probiotic (Bacillus subtilis) supplementation in laying hen diets on total bacterial load in appendix. No difference was found in the load of total bacteria and Escherichia coli (P > 0.05). Its beneficial properties stimulate the growth of beneficial bacteria in the intestines, such as Bifidobacteria sp. and Lactobacillus sp., causing the production of lactic acid, which makes the colon more acidic, resulting in inhibition of the growth of pathogenic microorganisms. GRAPHICAL ABSTRACT

Safety Evaluation and antioxidant potential of new probiotic strain Bacillus subtilis (NMCC-path-14) in Balb/c mice by sub-acute repeated dose toxicity

Probiotics have recently gained significant interest for their possible therapeutic effects in treating numerous health conditions. Probiotics containing Bacillus subtilis have been shown to have several health benefits, most notably in preventing diarrhea and gastrointestinal problems. A novel probiotic strain, Bacillus subtilis (NMCC-path-14), isolated from the rumen of a Nilli Ravi Buffalo, was evaluated for 28-day repeated dose toxicity in Balb/c mice. The NMCC-path-14 in low dose (1 × 108 CFU/ml) and high dose (1 × 1010 CFU/ml) was administered to the mice through gavage regularly. After 28 days of treatment, it was discovered that the no-observed-adverse-effect level (NOAEL) for NMCC-path-14 wasgreater than 1 × 1010 CFU/animal/day. This study also revealed no treatment-related changes in clinical parameters, body weight, gross pathology, or histology. Food consumption, hemoglobin, hematocrit, red blood cell counts, and colon length increased, while total/differential leukocyte count and platelets remained unchanged. The administration of NMCC-path-14 also resulted in decreased bilirubin and creatinine levels. Furthermore, NMCC-path-14 also displayed a promising antioxidant potential by increasing the antioxidant enzymes (GST, GSH, and CAT) and decreasing oxidant enzyme (MDA and NO) levels in vital organs like the liver, kidneys, spleen, and colon. TheNMCC-path-14also decreased the pathogenic bacterial population while increasing the beneficial population. Given the lack of adverse effects observed after NMCC-path-14 treatment, this strain is safe and must be considered as a potential probiotic in humans.

Evaluation of the potential probiotic Bacillus subtilis isolated from darkbarbel catfish (Pelteobagrus fulvidraco) on growth performance, serum immunity, and disease resistance of Aeromonas hydrophila.

This study aimed to identify potential probiotic strains of Bacillus subtilis from healthy fish gut microbiota for application in aquaculture. The effects of dietary B. subtilis administration on growth performance, serum enzyme activity, immune gene expression, and disease resistance in darkbarbel catfish (Pelteobagrus fulvidraco) were investigated. The isolate, identified through gene sequencing and biochemical tests, demonstrated resilience to pH 3.0% and 6.0% bile, and exhibited extracellular protease, cellulose, lipase, and amylase production. Darkbarbel catfish were fed diets with varying B. subtilis concentrations (0 CFU/kg [T0], 107 CFU/kg [T1], 108 CFU/kg [T2], and 109 CFU/kg [T3]). After 8 weeks, significant increases (p < 0.05) were observed in final body weight, weight gain rate, specific growth rate, serum lysozyme, serum superoxide dismutase, alkaline phosphatase, and total antioxidant capacity, whereas malondialdehyde levels significantly decreased. Feeding darkbarbel catfish with B. subtilis diets increased immunoglobulin M (IgM) and C3 gene expression (p < 0.05), indicating a positive impact on the fish's immune system. The strain upregulated interleukin 10 (IL-10) and transforming growth factor-β (TGF-β) expression and downregulated TNF-α and IL-1β, suggesting potential anti-inflammatory effects. Following a 7-day challenge with Aeromonas hydrophila, fish fed with B. subtilis exhibited lower mortality, with higher survival rates in the T2 and T3 groups. In conclusion, supplementing darkbarbel catfish diets with B. subtilis effectively enhances growth performance, immune response, and disease resistance.

Effects of dietary administration of probiotic (Bacillus subtilis) and iron oxide nanoparticles on the growth parameters of the fish Labeo rohita

Effects of dietary administration of probiotic (Bacillus subtilis) and iron oxide nanoparticles on the growth parameters of the fish Labeo rohita

The effects of using hydrolyzed feather meal, amino acids, and probiotics in the diet of juvenile rainbow trout on growth, digestibility, and expression of growth-related genes

The study investigated the effect of replacing fishmeal by varying levels of hydrolyzed feather meal (HFM) as well as dietary probiotic supplementation on growth performance, digestibility, histology, and gene expression of juvenile rainbow trout (Oncorhynchus mykiss). Five iso-nitrogenous (average of 50.60% crude protein), iso-energetic (average of 21.79 kJ/g), and iso-lipidic (average of 21.86% crude lipid) diets were formulated and fed to triplicate groups of juvenile rainbow trout weighing 29.65 ± 0.39 g (mean ± SD) for 75 days. Dietary treatments included one control (50% fishmeal) and four experimental diets, each containing 2 g/kg probiotics (Lactobacillus plantarum and Bacillus subtilis). The experimental diets included HFM30 (150 g/kg HFM, 9 g/kg lysine, and 4 g/kg methionine), HFM35 (175 g/kg HFM, 11 g/kg lysine, and 5 g/kg methionine), HFM40 (200 g/kg HFM, 13 g/kg lysine, and 6 g/kg methionine), and HFM45 (225 g/kg HFM, 15 g/kg lysine, and 7 g/kg methionine). Up to 40% replacement of fishmeal with HFM showed no significant difference compared to control group in growth performance (P > 0.05). Feed utilization of HFM45 was slightly lower than control and all the other experimental groups. There was no statistically significant difference in FCR value between HFM40 and control groups (P > 0.05). The apparent digestibility coefficients (ADCs) for protein and amino acids were very high in all groups (P < 0.05). Intestinal mucosa and sub‐mucosa layers of experimental fish showed general tissue integrity with no signs of tissue necrosis. For intestinal morphology, where 45% HFM replacement was applied, villus length to crypt depth (VL to CD) and villus surface area (SA) decreased by 46.01% and 44.44%, respectively, compared to the control group (P < 0.05). This situation shows that intestinal morphology can be damaged when the highest level (HFM45) of feather meal is used. Dietary HFM upregulated growth-related genes such as IGF-II, IGFBP-1b, IGFr1a, GDF9, and FGF2 and downregulated GHR-I and IGF-I. Overall, inclusion of HFM at 40% showed similar results to control group in juvenile rainbow trout feeding.

Bacillus subtilis 2118 exhibits bactericidal activity due to an inserted fish cDNA library

The probiotic Bacillus subtilis represents an efficient, environmentally friendly biocontrol agent to address the problem of evolving, mutation, and dissemination of multidrug-resistant bacteria. In the current study, B. subtilis 2118 strain was screened based on an insert fragment from a large yellow croaker cDNA library damage effect on the B. subtilis host. The supernatant of B. subtilis 2118 displayed a wide-spectrum antibacterial activity against one Gram+ and five Gram- bacteria, including Staphylococcus aureus, Aeromonas hydrophila, A. veronii, Escherichia coli, Vibrio alginolyticus, and V. parahemolyticus. It was further found that B. subtilis 2118 crude protein displayed bactericidal activity against indicator bacteria S. aureus and A. hydrophila with MIC of 187.50 μg/mL and 375.00 μg/mL, and MBC of both 375.00 μg/mL. The mechanism studies indicated that B. subtilis 2118 crude protein was mainly involved in collapse of cell membrane, cytoplasm agglutinating and outflow, and increasing membrane permeability. Besides these, the crude protein has potential of binding bacterial DNA, and probably interfering protein synthesis or degrading protein. Furthermore, B. subtilis 2118 crude protein maintains stable antibacterial activity even when pH 3–11, temperature 25–100 °C, UV radiation 0–60 min, and different proteases handling. In addition, B. subtilis 2118 crude protein has scarce hemolysis and less cytotoxicity towards 293 T and PCK cells. Taken together, B. subtilis 2118 strain and its crude protein have strong potential as alternative agents for antibiotics in aquaculture.

Whole Genome Sequencing-based Genetic Characterization and Safety Assessment of Probiotic Bacillus subtilis strain PLSSC

Whole Genome Sequencing-based Genetic Characterization and Safety Assessment of Probiotic Bacillus subtilis strain PLSSC

Potential of Liquid Probiotics Bacillus subtilis and Bacillus coagulans on Broiler Chicken Carcas Percentage and Business Analysis

The aim of this research was to find out liquid probiotic Bacillus subtilis and Bacillus coagulans as feed aditive to carcass percentage and economic analysis in broiler. This research used 24 broiler aged 20 day. P0 (control group) was given 2 ml of aquadest. P1, P2, and P3 were given liquid probiotic Bacillus subtilis and Bacillus coagulans with different dosage respectively (2 ml, 4 ml, and 6 ml). The sample of data was taken by weighing broiler manually. The data of carcass percentageanalyzed using one way Analysis of Variance (ANOVA) and if showed significant difference, continue by Duncan test as post-hoc test. The data of business analysis analyzed by descriptive. The result of this research was indicate that all doses 2 ml, 4 ml and 6 ml of liquid probiotic were significnat difference (p&lt;0.05) in carcass percentage. The result of doses 4 ml of liquid probiotic was most higher than doses 2 ml and 6 ml in carcass percentage. Business analysis in this research gave effect in contribution margin and value &gt; 1 of the revenue cost ratio which could be stated that the broiler business was feasible.

Immunomodulatory properties of Bacillus subtilis extracellular vesicles on rainbow trout intestinal cells and splenic leukocytes.

Extracellular vesicles (EVs) are cell-derived membrane-surrounded vesicles that carry bioactive molecules. Among EVs, outer membrane vesicles (OMVs), specifically produced by Gram-negative bacteria, have been extensively characterized and their potential as vaccines, adjuvants or immunotherapeutic agents, broadly explored in mammals. Nonetheless, Gram-positive bacteria can also produce bilayered spherical structures from 20 to 400 nm involved in pathogenesis, antibiotic resistance, nutrient uptake and nucleic acid transfer. However, information regarding their immunomodulatory potential is very scarce, both in mammals and fish. In the current study, we have produced EVs from the Gram-positive probiotic Bacillus subtilis and evaluated their immunomodulatory capacities using a rainbow trout intestinal epithelial cell line (RTgutGC) and splenic leukocytes. B. subtilis EVs significantly up-regulated the transcription of several pro-inflammatory and antimicrobial genes in both RTgutGC cells and splenocytes, while also up-regulating many genes associated with B cell differentiation in the later. In concordance, B. subtilis EVs increased the number of IgM-secreting cells in splenocyte cultures, while at the same time increased the MHC II surface levels and antigen-processing capacities of splenic IgM+ B cells. Interestingly, some of these experiments were repeated comparing the effects of B. subtilis EVs to EVs obtained from another Bacillus species, Bacillus megaterium, identifying important differences. The data presented provides evidence of the immunomodulatory capacities of Gram-positive EVs, pointing to the potential of B. subtilis EVs as adjuvants or immunostimulants for aquaculture.

Prebiotic, probiotic and marine algae suplementation in juvenile tilapia diet

This study evaluated the probiotic mannan oligosaccharide (MOS), and marine algae for Nile tilapia (Oreochromis niloticus) feeding. The parameters analyzed were fish-growth rate, hematological and immunological parameters, and intestinal microbiota. Also, fish were submitted to experimental infection challenge with Aeromonas hydrophila to evaluate the immune response. Nile tilapia juveniles (weight 8.86 ± 3.22 g) were used in the six treatments with four replicates, for 63 days. The treatments were: control basal diet; PAS-TR: basal diet plus 0.04 g·kg-1 of the probiotic (Bacillus cereus and Bacillus subtilis); MOS: basal diet plus 4 g·kg-1 of the prebiotic mannooligosaccharide, 4 g·kg-1 of the prebiotic Kappaphycus alvarezii. Two more diets were formulated by a combination of PAS-TR + MOS (4 +4 g·kg-1), and PAS-TR + KAP (4 +4 g·kg-1). For the challenge experiment, the fish were fed for 21 days, infected via intraperitoneal injection with A. hydrophila (1 x 106 UFC·mL-1), and the mortality rate was registered for 15 days post-infection. Results indicated the capacity of probiotic to remain in the gut for 63 days, and it was inhibited neither by autochthonous microbiota nor by prebiotics used. The feed additives tested for Nile tilapia did not cause a beneficial or adverse effect on growth or hematological variables. However, these treatments protected the fish from A. hydrophyla infection, proved by higher survival rate, and relative protection levels. We concluded that probiotic PAS-TR and prebiotics MOS and KAP, combined or not as symbiotics, may promote immune protection and reduce the mortality rate of A. hydrophyla infection.

Efficacy of Saccharomyces cerevisiae Fermentation Product and Probiotic Supplementation on Growth Performance, Gut Microflora and Immunity of Broiler Chickens.

Concern for global health security and the environment due to the emergence of antibiotic-resistant bacteria and antibiotic residues in meat and other livestock products has led many countries to restrict the use of antibiotics in animal feed. This experiment was performed to assess the impact of dietary supplementation of a probiotic (Bacillus subtilis) and a postbiotic (Saccharomyces cerevisiae fermentation product) on growth performance, carcass traits, blood haemato-biochemical profile, gut microflora, gut morphology, and immune response in broilers as an alternative to antimicrobials in poultry production system to minimize the effect on global health security. A total of 324 one-day-old Ven Cobb 400 broiler chicks were randomly divided into three dietary groups, each containing 12 replicated pens, and each replicate contained nine chickens. The dietary groups consisted of (1) a basal diet without any growth promoters (T1), (2) the basal diet augmented with Bacillus subtilis at 200 g/MT feed (T2), and (3) the basal diet supplemented with Saccharomyces cerevisiae fermentation product at 1.25 kg/MT feed (T3). To calculate body weight gain, all birds and residual feed were weighed on a replicated basis on days 0, 7, 14, 21, 28, 35, and 42; mortality was recorded daily. At the end of the trial (42 d), two chickens from each replicate were slaughtered for carcass traits, gut microflora, and morphology measurements. Blood samples were collected for the haemato-biochemical profile on 35 d and antibody titer on 28 d and 35 d. Feeding with SCFP (T3 group) significantly improved average daily feed intake (ADFI) and average daily gain (ADG) of chickens compared to the T1 (control) and T2 (probiotic) groups from 1 to 14 days of age. Feed conversion ratio (FCR) was significantly improved in SCFP-fed birds (T3) relative to the control (T1) over the entire experimental period. Carcass traits and blood haemato-biochemical parameters remained unaffected by any diets. However, cholesterol levels and concentrations of corticosterone were significantly lower in T3 compared to T2 and T1 groups. Total E. coli, Enterohaemorrhagic E. coli, ESBL-producing Enterobacteriaceae, and Salmonella counts were significantly lower in T2 and T3 groups compared to T1 group and Salmonella counts were lower in T3 when compared to T2. However, there was no significant difference in Lactobacillus count among treatment groups. A significant increase in villi height and villi-height-to-crypt-depth ratio (VH: CD) was observed in both T3 and T2 groups. On day 28, the T3 and T2 groups exhibited a significant increase in antibody titers against Newcastle disease virus and infectious bursal disease virus. It can be concluded that Saccharomyces cerevisiae fermentation product and Bacillus subtilis probiotic could be viable alternatives to antimicrobials in poultry production considering beneficial impacts in broilers fed an antibiotic-free diet.

Investigating antibiotic free feed additives for growth promotion in poultry: effects on performance and microbiota

The poultry industry is evolving towards antibiotic-free production to meet market demands and decelerate the increasing spread of the antimicrobial resistance. The growing need for antibiotic free products has challenged producers to decrease or completely stop using antimicrobials as feed supplements in broiler diet to improve feed efficiency, growth rate, and intestinal health. Natural feed additives (e.g., probiotics and phytobiotics) are promising alternatives to substitute antimicrobial growth promoters. The goal of our study was to characterize the effects of a Probiotic and an Essential Oils blend on broilers' performance and perform a time-series analysis to describe their excreta microbiome. A total of 320 Cobb 500 (1-day-old) chicks were raised for 21 d in 32 randomly allocated cages. Treatments consisted of 4 experimental diets: a basal diet, and a basal diet mixed with an Antibiotic (bacitracin methylene disalicylate), an essential oils blend (oregano oil, rosemary, and red pepper), or a Probiotic (Bacillus subtilis). Body weight (on 1, 10, and 21d), and feed intake (10d and 21d) were recorded and feed conversion ratio was calculated. Droppings were collected daily (1-21d) to characterize broilers' excreta microbiota by targeted sequencing of the bacterial 16S rRNA gene. The Probiotic significantly improved feed conversion ratio for starter phase 1 to 10d (P = 0.03), grower phase 10 to 21d (P = 0.05), and total period 1 to 21d (P = 0.01) compared to the Antibiotic. Feed supplements did not affect alpha diversity but did impact microbial beta diversity (P < 0.01). Age also impacted microbiome turnover as differences in alpha and beta diversity were detected. Furthermore, when compared to the basal diet, the probiotic and antibiotic significantly impacted relative abundance of Bifidobacterium (log2 fold change -1.44, P = 0.03), Intestinimonas (log2 fold change 0.560, P < 0.01) and Ligilactobacillus (log2 fold change -1.600, P < 0.01). Overall, Probiotic supplementation but not essential oils supplementation positively impacted broilers' growth performance by directly causing directional shifts in broilers' excreta microbiota structure.

Different levels of single-strain probiotic (Bacillus subtilis) with proteolytic enzyme (serratiopeptidase) can be used as an alternative to antibiotic growth promoters in broiler

In the current study, the proteolytic enzyme (serratiopeptidase) was used to enhance the efficacy of Bacillus subtilis (B. subtilis) probiotic as a growth promotor in broiler chicken. The effects of serratiopeptidase on the efficacy of different levels of B. subtilis as a growth promotor in broiler chicks were evaluated regarding growth performance traits, villus histomorphometric characterization, and intestinal microbiota count. Day-old broiler chicks (n=120) were allocated into four groups having three replicates/group. In the control group (C), the basal diet was kept without supplementation. In treatment groups (P100, P150, and P200), the basal diet was supplemented with 100, 150, and 200 mg probiotics, respectively besides 30mg proteolytic enzyme in the three treated groups for 4 weeks. The performance parameters were significantly affected by the supplementation of serratiopeptidase to the B. subtilis treatment groups. Feed intake (FI), body weight gain (WG), feed conversion ratio (FCR), and dressing percent were significantly improved in the treatment groups as compared to the control group. Significantly, the lowest feed intake was recorded for the P200 group. The highest body weight gain and dressing percent were recorded for the P200 group. Improved FCR was recorded in the P200 group (1.7) as compared to the control group. The different levels of B. subtilis supplemented with serratiopeptidase revealed significant improvements (P<0.05) in the morphology of the intestine by showing increases in villus height and width and crypt depth of the small intestine. The microbial count revealed that E. coli and salmonella colonies were significantly reduced in the P200 group as compared to the control and other treatment groups. In conclusion, the supplementation of B. subtilis with serratiopeptidase as a growth promoter in broiler chicks significantly improved the overall performance, and intestinal health and reduced microbial load contributing to optimizing the performance of broiler chickens. The greatest improvement was observed in the P200 group fed with B. subtilis as a probiotic and serratiopeptidase enzyme (200mg:30mg).

Effects of Bacillus subtilis on the immune parameters, intestinal morphology and mucin gene expression in broilers exposed to Salmonella enterica challenge

The objective of this study was to evaluate the effect of the probiotic Bacillus subtilis supplementation on bacterial population, morphometry and mucin gene expression of intestine, and on immune response in Salmonella challenged broilers. Treatments were: 1) negative control (no probiotic- no challenging); 2) probiotic treated (no challenging); 3) positive control (no probiotic-salmonella challenging), and 4) Salmonella challenged chicks fed probiotic. Salmonella infection resulted in significant decrease in the relative weight of thymus. In challenged birds, dietary addition of probiotic increased (P&lt;0.0.5) the relative weights of bursa and thymus. Population of lactic acid bacteria was significantly higher in probiotic treated groups as compared to negative control or challenged chickens. Challenged chickens had the lowest count of goblet cells and those received probiotic had the highest goblet cells count. The expression of mucin 2 gene was higher in group received dietary probiotic as compared with other treatments. Difference for gene expression was not found in challenged chickens and the negative control (P&gt;0.05). In conclusion, the dietary inclusion of Bacillus subtilis could alleviate the negative effects of Salmonella infection on intestinal cells and bacterial population and could improve the growth and development of immune organs and function in infected broilers.&#x0D;

Effects of a novel synbiotics-enzyme complex as a replacement for antibiotics on growth performance, slaughter and meat characteristics, immune organ index, and intestinal morphology of broilers.

Antibiotic use in broilers is being discouraged globally due to the challenges it poses. This study was conducted to assess the effects of supplementing broilers with a Symbiotic-Enzyme complex (SEC) containing prebiotics (mannose oligosaccharides), probiotics (Clostridium butyricum and Bacillus subtilis), and enzymes (glucose oxidase, and α-galactosidase) as an alternative to antibiotics on growth performance, carcass and meat quality traits, mortality, linear body measurements, intestinal morphology and immune organ indexes. A total of 864 mixed-sex 1-day-old arbor acres (AA+) broilers were allocated to 8 experimental groups replicated 9 times with 12 chickens per replicate. These included 6 treatment groups with SEC inclusion levels of 0.025, 0.04, 0.05, 0.06, 0.08, and 0.10%, respectively, and two control groups: a negative control group containing a basal diet only and the positive control group (Antibiotics group) containing a basal diet and antibiotic oxytetracycline added at 0.2%. Growth performance was measured on day 21 and 42, and the mortality, carcass, meat quality traits, linear body measurements, intestinal morphology, and organ size indexes were measured on day 42. The results indicated that supplementing broilers with 0.1% SEC resulted in insignificant (P > 0.05) increases in average daily feed intake (ADFI), significant (P < 0.05) increases in the average daily gains (ADG), and significant (P < 0.05) reduction in a feed-to-gain ratio (F/G) in all the phases compared to the control and antibiotics groups. Supplementation of broilers with 0.1% SEC inclusion levels also significantly (P < 0.05) increased the body slope length, chest width, chest depth, keel length, and shank circumference. Furthermore, broilers on diets containing 0.1% SEC inclusion level also had significantly (P < 0.05) higher dressed, semi-evisceration, evisceration, and breast muscle percentages. Including SEC at 0.1% also significantly (P < 0.05) increased villus height and villus-to-crypt ratio (V/C) but reduced crypt depth in the duodenum, jejunum, and ileum compared to the control groups. SEC inclusion at 0.1% significantly (P < 0.05) increased the spleen, bursal, and thymus indexes, respectively. Supplementation of broilers with 0.1% SEC can be used as an antibiotic alternative because it increases the F/G, improves the carcass and meat quality, increases the body conformation, improves the small intestines' functions, and immune organ size.

Engineering a probiotic Bacillus subtilis for acetaldehyde removal: A hag locus integration to robustly express acetaldehyde dehydrogenase.

We have addressed critical challenges in probiotic design to develop a commercially viable bacterial strain capable of removing the intestinal toxin, acetaldehyde. In this study, we report the engineering of the hag locus, a σD-dependent flagellin expression site, as a stable location for robust enzyme production. We demonstrate constitutive gene expression in relevant conditions driven by the endogenous hag promoter, following a deletion of the gene encoding a post-translational regulator of σD, FlgM, and a point mutation to abrogate the binding of the translational inhibitor CsrA. Reporter constructs demonstrate activity at the hag locus after germination, with a steady increase in heterologous expression throughout outgrowth and vegetative growth. To evaluate the chassis as a spore-based probiotic solution, we identified the physiologically relevant ethanol metabolic pathway and the subsequent accumulation of gut-derived acetaldehyde following alcohol consumption. We integrated a Cupriavidus necator aldehyde dehydrogenase gene (acoD) into the hag locus under the control of the flagellin promoter and observed a rapid reduction in acetaldehyde levels in gut-simulated conditions post-germination. This work demonstrates a promising approach for the development of genetically engineered spore-based probiotics.

Changes in gene expression in the intestinal mucus of broilers with woody breast myopathy

Previous work has shown that dietary treatments affect woody breast (WB) incidence differently, which indicates that gut conditions such as gut barrier function, inflammation, and oxidative stress are likely related to WB. In this study, dietary supplementation with antibiotics (bacitracin) or probiotics (Bacillus subtilis) was investigated for their effects on the expression of transcripts related to gut barrier function, inflammation, and oxidative stress in the mucus lining of the jejunum from broilers with or without WB. A split-plot experimental design was used in this study. The dietary treatments served as the main plot factor and the breast muscle condition was the subplot factor. On d 41, jejunum mucus was collected from 1 bird from each of 3 replicate pens in each 3 dietary treatment groups that exhibited WB and an additional bird that contained a normal breast (3 biological replicates/treatment/phenotype; 3 × 3 × 2, total N = 18). Total RNA was extracted using a commercial RNA extraction kit. The expression levels of CLDN1, MUC6, TLR2A, TLR2B, TLR4, IFN-γ, IL-1β, IL-8L1, IL-10, NOS2, and SOD were determined using 2-step RT-qPCR analysis. The gene expression difference in ΔCt values was determined after normalizing with the chicken 18S rRNA gene. When the significant differences occurred between treatments, the relative fold change was calculated using the ΔΔCt method and the significance level was calculated. The PROC GLM procedure of SAS 9.4 was used, and the level of significance was set at P ≤ 0.05. There were no significant interactive effects between diet and the breast muscle condition on the expression of any of the genes tested. However, birds with WB exhibited higher MUC6 (P < 0.0001) gene expression levels than birds with normal breast muscles. In addition, the expression of SOD decreased in birds that were fed the antibiotic diet when compared to birds that were fed the probiotic diet (P = 0.014). In conclusion, WB identified in broilers tested in the current study is attributed to increased expression of mucin, indicating a correlation between WB incidence and gel-forming mucin secretion and pathogen signaling.

Natural resistance and immunological response of young Volyn meat breed to the action of probiotics

To investigate the response of natural resistance and immunological reactions of newborn young animals of the Volyn beef breed to the use of probiotic preparations. To conduct experimental research, three groups were formed from young Volyn meat breeds: the control group was fed only on mother's milk, the first group received a probiotic preparation with Bacillus Subtilis strain in addition to cow's milk, the second experimental group –– Lactobacillus spp. The activity of natural resistance and the body's immune response were studied on the 5th, 10th, and 30th day of the experiment. The level of nonspecific natural resistance was determined by indicators of bactericidal, lysozyme, phagocytic, and complementary activity of blood serum, and the immunological response was determined by the concentration of immunoglobulins of classes G, M, and A in the blood. It was established that starting from the 5th day of life, a difference in the nonspecific resistance of control and experimental animals was noted groups In separate age periods, probiotic supplements had a different degree of influence on the natural resistance of young animals. The greatest difference in the direction of growth in such indicators of non-specific resistance as bactericidal and complementary activity of blood serum was noted under the influence of the probiotic supplement Bacillus Subtilis (I experimental group), and indicators of lysozyme and phagocytic activity of blood serum were greater under the action of Lactobacillus spp. (II experimental group). The difference between indicators of bactericidal activity of blood under the action of Lactobacillus spp. in comparison with the control was at the age of 30 days (16.85 %, Р&lt;0.01), and under the action of Bacillus Subtilis –– at the age of 60 days (25.49 %, Р&lt;0.001). The level of phagocytic and complementary blood activity was the highest at the age of 60 days in the I experimental group –– by 17.17 % (Р&lt;0.001) and 32.57 % (Р&lt;0.001), in the II experimental group –– by 23.20 % (Р &lt;0.001) and 36.34 % (Р&lt;0.001), respectively. Regarding the concentration of immunoglobulins, the largest changes in their indicators were noted in the group that received Lactobacillus spp. Addition of probiotic strains of bacteria to the diet of young animals has a positive effect on the natural resistance and immune response of the body, which in the future will contribute to reducing the level of morbidity in young animals. Key words: calves, probiotics, bacterial strains, microorganisms, immunoglobulins, non-specific resistance of the organism, T-lymphocytes, phagocytic activity, bactericidal activity of blood serum.

Isolation and Evaluation of the Probiotic Activity of Lactic Acid Bacteria Isolated from Pickled Brassica juncea (L.) Czern. et Coss.

The naturally occurring lactic acid bacteria can be isolated from various sources. Pickled Brassica juncea (L.) Czern. et Coss. was used to isolate lactic acid bacteria (LAB). This study was conducted to compare the probiotic properties of probiotics isolated from pickled Vietnamese cabbage with some commercial strains of probiotics available on the Vietnamese market. The results showed that two strains (Lactobacillus fermentum and Lactiplantibacillus plantarum) isolated from pickled Vietnamese cabbage and three commercial strains of probiotics (Bacillus subtilis, Bacillus clausii, Lactobacillus acidophilus) all showed probiotic properties. Probiotic properties were evaluated through the ability to survive in low pH, pepsin, pancreatin, and bile salt media, the hydrophobicity of the bacteria, the antibiotic resistance, and the resistance to pathogenic bacteria. The isolated strain Lactiplantibacillus plantarum had fewer probiotic properties than Bacillus subtilis but more than the two commercial strains Bacillus clausii and Lactobacillus acidophilus, and the isolated Lactobacillus fermentum showed the fewest probiotic properties of the five strains.