The functional capacity of plantaricin-producing Lactobacillus plantarum SF9C and S-layer-carrying Lactobacillus brevis SF9B to withstand gastrointestinal transit

Abstract

Background: We evaluated the functional capacity of plantaricin-producing Lactobacillus plantarum SF9C and S-layer-carrying Lactobacillus brevis SF9B to withstand gastrointestinal transit and to compete among the gut microbiota in vivo. Considering the probiotic potential of Lb. brevis SF9B, this study aims to investigate the antibacterial activity of Lb. plantarum SF9C and their potential for in vivo colonisation in rats, which could be the basis for the investigation of their synergistic functionality. Results: A plantaricin-encoding cluster was identified in Lb. plantarum SF9C, a strain which efficiently inhibited the growth of Listeria monocytogenes ATCC ® 19111 ™ and Staphylococcus aureus 3048. Homology-based three-dimensional (3D) structures of SF9C plantaricins PlnJK and PlnEF were predicted using SWISS-MODEL workspace and the helical wheel representations of the plantaricin peptide helices were generated by HELIQUEST. Contrary to the plantaricin-producing SF9C strain, the S-layer-carrying SF9B strain excluded Escherichia coli 3014 and Salmonella enterica serovar Typhimurium FP1 from the adhesion to Caco-2 cells. Finally, PCR-DGGE analysis of the V2-V3 regions of the 16S rRNA gene confirmed the transit of the two selected lactobacilli through the gastrointestinal tract (GIT). Microbiome profiling via the Illumina MiSeq platform revealed the prevalence of Lactobacillus spp. in the gut microbiota of the Lactobacillus-treated rats, even on the 10th day after the Lactobacillus application, compared to the microbiota of the healthy and AlCl 3-exposed rats before Lactobacillus treatment. Conclusion: The combined application of Lb. plantarum SF9C and Lb. brevis SF9B was able to influence the intestinal microbiota composition in rats, which was reflected in the increased abundance of Lactobacillus genus, but also in the altered abundances of other bacterial genera, either in the model of healthy or aberrant gut microbiota of rats. The antibacterial activity and capacity to withstand in GIT conditions contributed to the functional aspects of SF9C and SF9B strains that could be incorporated in the probiotic-containing functional foods with a possibility to positively modulate the gut microbiota composition.

Lyophilized alginate-based microspheres containing Lactobacillus fermentum D12, an exopolysaccharides producer, contribute to the strain’s functionality in vitro

“…Adhesion ability to intestinal cells can be associated with the potential to exclude pathogen species. Lactobacillus strains display a wide spectrum of antimicrobial activities established through the inhibitory action of the range of metabolites, including lactic acid, but also specific biomolecules like bacteriocins [ 26 ]. Therefore, in order to evaluate the potential to antagonize the infection of undesirable bacteria in the gut, the antimicrobial activity of L. fermentum D12 expressed as an effective inhibition ratio (EIR), against Listeria monocytogenes ATCC ® 19111™ and Staphylococcus aureus 3048 was tested.…”

A Lactic Acid Bacteria Consortium Impacted the Content of Casein-Derived Biopeptides in Dried Fresh Cheese

“…In this study, LAB strains with the highest caseinolytic activity were further characterized. This included L. brevis D6, L. fermentum D12 and L. plantarum D13 previously identified by WGS and with characterised probiotic specificities [ 10 , 12 , 20 ]. We previously demonstrated that the EPS producing D12 strain inhibited enteropathogenic bacteria, survived simulated GIT conditions and adhered to Caco-2 cells in vitro [ 12 ].…”

“…Mucedola, Settimo Milanese, Italy) and tap water ad libitum. Feeding with LAB consortium was defined according to Butorac et al [ 20 ]. Animal experiments were carried out in accordance with the EU Directive 2010/63/EU [ 40 ] for animal experiments, including approval by local authorities and an animal ethics committee (Law on the Welfare of Animals.…”

Quality of traditionally produced Istrian sausage and identification of autochthonous lactic acid bacteria strains as potential functional starter cultures

“…The nondissociated form of lactic acid induces intracellular pH decrease, thus causing collapse of the proton electrochemical gradient in susceptible bacteria, resulting in its bacteriostatic or bactericidal action. In addition, antimicrobial peptides bacteriocins are also commonly produced among Lactobacillus species with the antagonistic activity, mostly against phylogenetically related bacteria [11,[53][54][55][56]. Casaburi et al [57] isolated the bacteriocin-producing L. curvatus 54M16 strain considered to be an appropriate starter culture during fermented sausage ripening to improve the quality and safety of traditional fermented sausages prepared without the addition of antimicrobials.…”