Limosilactobacillus fermentum ING8, a Potential Multifunctional Non-Starter Strain with Relevant Technological Properties and Antimicrobial Activity

Exploring Technological, Safety and Probiotic Properties of Enterococcus Strains: Impact on Rheological Parameters in Fermented Milk

Enterococci, known for their resilience, are commonly found in food, the environment, and the gastrointestinal tracts of humans and animals. In recent research, six strains of enterococcus were isolated from bat guano. These include Enterococcus mundtii SRBG1, Enterococcus gallinarum SRBG3, Enterococcus faecium SRBG2, Enterococcus casseliflavus EC1, and Enterococcus devriesei CAU 1344. Identification was done using 16S DNA analysis. Each strain underwent evaluation for its technological properties (such as tolerances to various NaCl concentrations and temperatures, as well as amylolytic, β-galactosidase, lipolytic, and proteolytic activities, and EPS production) and selected probiotic properties (including safety profile, resistance to 0.3 percent bile salts and gastric juice with a pH of 2.5, lysozyme tolerance, and antibacterial and antibiofilm activities against four foodborne pathogens). The results were analyzed using Principal Component Analysis. This analysis revealed that E. mundtii SRBG1 and E. gallinarum SRBG3, followed by E. faecium SRBG2, were most closely associated with a broad range of technological characteristics and were subsequently used for fermenting skimmed milk. The rheological properties of the samples indicated a shear-thinning or non-Newtonian behavior. Furthermore, during storage of the fermented milk at 4 °C over periods of 1, 7, 14, and 21 days, there were no significant changes in bacterial count (at around 7 log10 CFU/mL) and pH when fermented with the three evaluated strains.

Significance of Limosilactobacillus fermentum and Saccharomyces cerevisiae on the Growth Performance, Haematological Traits, Serum Biochemistry, Faecal and Caeca Microbiota of Broiler Chickens

OBJECTIVE

The aim of the study was to supplement Lactobacillus and yeast in broiler feed by replacing immunomodulators to develop antibiotic free meat and egg production by analyzing broiler performance, haematological traits, serum biochemistry, histopathology, fecal bacterial count, and metagenomic analysis of broiler ceca.

METHOD

Two cultures i.e. KGL4 (Limosilactobacillus fermentum MTCC 25515) and WBS2A (Saccharomyces cerevisiae GI: MG101828) were considered for the evaluation of Broiler chicken's health and growth during 42 days study without supplementing immunomodulators and commercial probiotics in poultry feeds. The 96-day-old broiler chickens were grouped into: T1 [Control: basal diet + immunomodulatory factor and commercial probiotic], T2 [Basal diet without immunomodulatory factor and commercial probiotic + KGL4 (108 CFU/mL), T3 [Basal diet without immunomodulatory factor and commercial probiotic + WBS2A (107 CFU/mL), and T4 [Basal diet without immunomodulatory factor and commercial probiotic + KGL4 + WBS2A in a 1:1 ratio] (Institutional Animal Ethics Committee (IAEC) No. 365/PRS/2022). The following parameters, i.e., body weight gain, feed consumption ratio (FCR), white blood cell count (WBC), red blood cell count (RBC), hemoglobin content, platelet count, cholesterol content, triglycerides, high density lipoprotein (HDL), very low-density lipoprotein (VLDL), fecal counts and metagenomic analysis of broiler ceca samples, were measured.

RESULTS

In the study, amongst various traits, the overall performance of the group treated along with Limosilactobacillus fermentum (KGL4) showed improved results as compared to control group. Limosilactobacillus fermentum (KGL4) treated group had higher body weight gain (2583.04 ± 35.421 g), FCR (1.60 ± 0.019), WBC (235.60 ± 2.562 × 103/µL), hemoglobin content (14.10 ± 0.442 g/dl), and HDL (131.40 ± 11.400 mg/dl). The investigation did not show significant variations in the relative proportions of genus or phylum among various groups during metagenomic analysis of ceca samples. There was also an improvement in haematological traits; no evidence of necrosis in heart, intestine and liver tissues.

CONCLUSIONS

The present study conclude that it is safe to feed Limosilactobacillus fermentum and Saccharomyces cerevisiae to broilers as feed supplements and also supports the current knowledge regarding the use of yeast and lactic acid bacteria as an effective alternative stimulant for maintaining health and growth of broiler chickens.

Inhibition of Pathogenic Microbes by the Lactic Acid Bacteria Limosilactobacillus Fermentum Strain LAB-1 and Levilactobacillus Brevis Strain LAB-5 Isolated from the Dairy Beverage Borhani

Lactic acid bacteria (LAB) with prominent antimicrobial effects against pathogens have been reported in several milk-based and plant-based foods. Borhani is a popular beverage prepared from the ingredients of both dairy and plant origins and is believed to be highly beneficial for health. Herein, we report the pathogen-inhibitory activity of two borhani-associated lactic acid bacteria (LAB), Limosilactobacillus fermentum strain LAB-1 and Levilactobacillus brevis strain LAB-5. Their antimicrobial activity was primarily assessed using the cell free supernatant (CFS) by agar diffusion technique in which both strains showed strong antimicrobial effects against several pathogenic and spoilage microorganisms including Acinetobacter baumannii, Bacillus cereus, Bacillus subtilis, Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa, Salmonella abony, Salmonella typhi, Shigella flexneri, and Staphylococcus aureus. The L. fermentum strain with its ability to inhibit all the target pathogens appeared to be more effective with larger inhibition-zone formation as compared to the L. brevis strain which also successfully inhibited all pathogens but had relatively little effects on A. baumannii. The extent of their inhibitory effect was further assessed by co-culture inhibition assay in which growth of the test microbes was monitored for 24 hours in presence of the CFS. The CFS of both lactic acid bacteria could effectively inhibit growth of the pathogenic microbes for a significant period of time. While the L. fermentum strain could almost completely stop growth of all test organisms, the L. brevis strain was particularly effective against Shigella flexneri and the Salmonella species. Our study, therefore, suggests the presence of beneficial lactic acid bacteria in borhani which can be of important use as antimicrobial agents in functional foods and therapeutics to help acquire protection against drug resistant pathogens.

Functional genomics of the lactic acid bacterium Limosilactobacillus fermentum LAB-1: metabolic, probiotic and biotechnological perspectives

A genome-based systematic analysis was conducted to characterize the metabolic, probiotic, fitness, and safety properties of Limosilactobacillus fermentum LAB-1, a lactic acid bacterium demonstrating strong antimicrobial effects against clinical pathogens. Gene functional characterization revealed a large number of genes for carbohydrate metabolism and a heterofermentative system for carbon dissimilation. Genes for intact pyruvate oxidation, pentose phosphate, and PRPP biosynthetic pathways were identified. Substantial carbohydrate-active enzymes and transporters were also predicted. Metabolic reconstruction revealed complete sets of enzymes for arginine, lysine, methionine, threonine, proline, and ornithine biosynthesis. The bacterium harbors a diverse range of peptidases, and a large variety of peptide and amino acid uptake systems. It encodes restriction-modification and CRISPR-Cas systems for protection against phage infections and carries a wide spectrum of stress proteins for adaptation in the gut and industrial conditions. Genes related to the biosynthesis of B-group and K vitamins were identified allowing its application for novel bio-enriched food production. Other beneficial traits of probiotic and industrial importance such as production of flavor compounds, exopolysaccharide, acetoin, and butanediol were identified. Three antimicrobial peptides were predicted which showed >98% sequence-identity to experimentally validated bacteriocins. Negative traits such as transmissible antibiotic resistance, pathogenicity or virulence appeared to be absent suggesting the strain to be considered safe. The genome analysis will allow precisely targeted laboratory research and full exploitation of the probiotic potentials towards functional-food, biotechnology and health-related applications.