Lactobacillus casei and Lactobacillus rhamnosus proteins P40 and P75 belong to a large family of secreted cell wall proteins that contain a carboxy(C)-terminal CHAP or NlpC/P60 superfamily domains. In addition to their peptidoglycan hydrolases activity, proteins in this family are specific antigens of pathogens, frequently responsible of interactions with the host. L. rhamnosus GG and L. casei BL23 purified P40 and P75 proteins have antiapoptotic activity by inducing the EGF/Akt pathway. The aim of this work was to study the genetics, phylogeny and dissemination of this family of proteins in the genus Lactobacillus as well as their characteristics and likely function. The scrutiny of their DNA encoding sequences revealed the presence of minisatellite DNA in the P75 encoding gene of L. casei/paracasei strains (cmuB) with intraspecific indels that gave raise to four different alleles (cmuB1–4), which are exclusive of this species. Phylogenic analyses suggest that both proteins are present mainly in the L. casei and Lactobacillus sakei phylogenomic groups. A P40 ancestral gene was possibly present in the common ancestor of Enterococcaceae, Lactobacillaceae and Streptococcaceae. P75 is also present in L. casei and L. sakei groups, but its evolution is difficult to explain only by vertical transmission. Antibodies raised against the N-terminal regions of P40 and P75 improved their immunological detection in culture supernatants as they recognized almost exclusively proteins of L. casei/paracasei/rhamnosus strains, highlighting their structural similarity, that allowed to detect them in different fermented dairy products that contained probiotic L. casei strains. Purified P40 and P75 proteins showed no evident lytic activity but they complemented L. casei BL23 cmuA and cmuB defective mutants, respectively, thus proving that they actively participate in cell division.

Adulteration of meat products, including illegal substitution and addition of ingredients, tampering, and the misrepresentation and labelling of food or food ingredients, is becoming a more serious problem globally. The consequences of such manipulations can pose various health risks for consumers, including food allergies and poisoning. This study investigates the problem of meat product adulteration, and detection of the same using real-time polymerase chain reaction (qPCR).

Background: This study was aimed at the development of a whey beverage enriched with a probiotic starter culture, prebiotics, vitamins, and minerals, and evaluation of microbiological, physico-chemical, and toxicological characteristics of the developed beverage. Methods: The beverage formulation was determined based on organoleptic analysis. The assessment of microbiological and physico-chemical parameters was carried out in accordance with regulatory standards. The safety assessment of the developed drink was carried out in vivo. Results:A beverage formulation based on whey enriched with probiotic bacteria Lactobacillus casei 1A, Lactobacillus paracasei 2A, Lactobacillus brevis 4 LB, prebiotic inulin, vitamins (A, C) and minerals (potassium iodide) was developed. The organoleptic, physico-chemical, and microbiological properties of the developed drink were determined. The quality of the beverage complied with food safety regulations, the viability of probiotic bacteria and the acidity of the beverage remained stable during storage. Acute score toxicity and allergenic properties in vivo did not reveal any physiological abnormalities and made it possible to classify the developed product as a low-hazard substance. Conclusion:The optimal composition of a probiotic whey beverage has been developed, which can be considered as a potential product for functional nutrition. Keywords: Whey beverage, Formulation, Probiotic, Functional, Safety Assessment, Toxicity, Allergenic properties, In vivo

In this study, we conducted a whole-genome analysis of the Lacticaseibacillus paracasei subsp. paracasei 2LB isolated from Kazakh traditional fermented milk (koumiss) to identify genes associated with the safety and probiotic potential of the strain. A comparative genomic analysis of the core and pan-genome of L. paracasei 2LB was performed. Functional annotation revealed the presence of genes putatively involved in metabolism, genetic information processing, and cellular processes. In terms of safety parameters, the stability of its genetic material, the absence of the ability to synthesize virulence factors, and genes responsible for antibiotic resistance were characterized. Also, in vitro studies of the L. paracasei 2LB strain showed resistance to stress factors and antimicrobial activity, and the presence of coding sequences encoding adhesion factors, bacteriocins, bile salts, pH, cold and heat shock, and osmotic stress was observed through genomic analysis. These results indicate that the L. paracasei 2LB strain is a potential probiotic candidate and demonstrate that whole-genome analysis is a useful method for assessing the quality and safety of probiotics.

This study presents the high-quality draft genome sequence of Levilactobacillus brevis 3LB (L. brevis 3LB), a strain derived from a fermented milk koumiss from the Akmola region of the Republic of Kazakhstan. This strain is stored in the National Depository of Kazakhstan, Republican Collection of Microorganisms LLP, under the identifier L. brevis 3LB B-RKM 0546. Genomic DNA sequencing was performed on the Illumina MiSeq platform, and de novo genome assembly was carried out using SPAdes Genome Assembler v3.15.5. The assembled draft genome was 2307,466 bp in size, with 150x coverage, a GC content of 46.01%, an L50 value of 7, and an N50 value of 168,338 bp. The genome consists of 63 contigs and contains 2260 coding genes, as well as 61 transfer RNA (tRNA) genes, 7 ribosomal RNA (rRNA) genes, and 2 CRISPR loci. Functional analysis of the 3LB strain genome revealed the dominance of genes related to metabolism, information storage and processing, and cellular processes, providing a comprehensive understanding of the biological potential of bacteria by elucidating their biochemical reactions, metabolic pathways, and mechanisms of adaptation to the environment. According to GO analysis, these categories contain the highest number of genes (786, 549, and 361, respectively). Among the COG functional categories, transcription (228), translation and ribosome biogenesis (166), and carbohydrate metabolism (166) stand out. Cellular motility was the least represented (8 genes). KEGG analysis also confirmed the dominance of metabolism (446) and genetic information processing (296). RAST annotation further emphasized the importance of carbohydrate metabolism (19.82%), protein synthesis (16.37%), and amino acid synthesis (9.85%). CAZymes analysis identified 52 genes encoding enzymes involved in carbohydrate modification, with glycoside hydrolases (26) and glycosyltransferases (20). A genomic safety analysis of the L. brevis 3LB strain revealed that it is not a human pathogen, as it does not contain virulence genes, and the probability of structural pathogenicity is extremely low (0.0314). Although three incomplete phage regions and genes with low identity to vanT and nimA (requiring further study) were detected in silico, no known antibiotic resistance genes were detected. The absence of plasmids also confirms its safety. Notably, the strain possesses two high-fidelity CRISPR arrays, providing protective mechanisms. Furthermore, three secondary metabolite regions capable of synthesizing compounds with potential antibacterial activity (a class IV lanthanide peptide, a terpene precursor, and a polyketide) were identified, giving the strain a competitive advantage. These genome mining results indicate the biotechnological significance, safety, and probiotic potential of the novel strain L. brevis 3LB. The data presented here provide a foundation for further research into the probiotic activity of strain 3LB, both in vitro and in vivo, as well as its potential applications in food industry and biomedicine.