Influence of diets to Wistar rats supplemented with soya, flaxseed and lupine products treated by lactofermentation to improve their gut health.

The present study proposes the contribution of lactic acid bacteria and plants rich in bioactive substances and high-quality proteins as alternative products for human diets in improving the gut environment as potential against pathogenic bacteria. The effect of diets supplemented with soya, flaxseed and lupine flours fermented with a Pediococcus acidilactici KTU05-7 probiotic strain in the gastrointestinal tract (GIT) of Wistar rats were analyzed. In vivo experiments showed a positive effect of long time lactofermentation of plant material on the body weight of rats. Diets with fermented yellow lupine resulted in enhanced activities of α-glucosidase, ß-galactosidases, as well as high levels of lactic acid bacteria, bifidobacteria and enterococci in the GIT were determined. Lactofermentation of analyzed plant products had a significantly lowering effect on Escherichia coli compared with the control group. The dominant flora of large intestines like Bifidobacterium and anaerobic cocci were found in high levels after diets with fermented lupine.

Lactic acid bacteria isolated from rye sourdoughs produce bacteriocin-like inhibitory substances active against Bacillus subtilis and fungi.

AIM: To screen five strains of lactic acid bacteria (LAB) isolated from rye sourdoughs for the potential production of antimicrobial substances. METHODS AND RESULTS: Lactobacillus sakei KTU05-06, Pediococcus acidilactici KTU05-7, Pediococcus pentosaceus KTU05-8, KTU05-9 and KTU05-10 isolated from rye sourdoughs were investigated for the production of bacteriocin-like inhibitory substances (BLIS). The supernatants of analysed LAB inhibited growth of up to 15 out of 25 indicator bacteria strains as well as up to 25 out of 56 LAB strains isolated from rye sourdoughs. Moreover, these five LAB were active against ropes-producing Bacillus subtilis and the main bread mould spoilage causing fungi -Aspergillus, Fusarium, Mucor and Penicillium. Lactobacillus sakei KTU05-6 demonstrated the best antibacterial properties and is resistant towards heat treatment even at 100°C for 60 min. CONCLUSIONS: The use of LAB-producing antibacterial substances may be a good choice as a co-starter culture to ensure the stability of sourdoughs and to avoid the bacterial and fungi spoilage of the end product. SIGNIFICANCE AND IMPACT OF THE STUDY: The antimicrobial compounds designated as sakacin KTU05-6, pediocin KTU05-8 KTU05-9, KTU05-10 and AcKTU05-67 were not identical to any other known BLIS, and this finding leads up to the assumption that they might be the novel.

Influence of baking enzymes on antimicrobial activity of five bacteriocin-like inhibitory substances produced by lactic acid bacteria isolated from Lithuanian sourdoughs.

AIM: To evaluate the effect of four different baking enzymes on the inhibitory activity of five bacteriocin-like inhibitory substances (BLIS) produced by lactic acid bacteria (LAB) isolated from Lithuanian sourdoughs. METHODS AND RESULTS: The overlay assay and the Bioscreen methods revealed that the five BLIS exhibited an inhibitory effect against spore germination and vegetative outgrowth of Bacillus subtilis, the predominant species causing ropiness in bread. The possibility that the observed antibacterial activity of BLIS might be lost after treatment with enzymes used for baking purposes was also examined. CONCLUSIONS: The enzymes tested; hemicellulase, lipase, amyloglucosidase and amylase had little or no effect on the majority of the antimicrobial activities associated with the five BLIS studied. SIGNIFICANCE AND IMPACT OF THE STUDY: This study suggests a potential application in the sourdough baking industry for these antimicrobial producing LAB strains in the control of B. subtilis spore germination and vegetative outgrowth.