It is reported that "Probiotic Lactic Acid Bacteria (LAB)" has various physiological effects for a host. To demonstrate those various actions, an adhesion of probiotic LAB to human intestinal tract is very important. We recently discovered 'blood group recognizing LAB' and identified SlpA as lectin-like protein recognizing A type antigen. Pathogens such as Helicobacter pylori are reported to recognized human blood group antigens. The blood group antigen sugar chain of mucin may play an essential role for bacterial colonization.
Lactobacillus plantarum LA 318 is a potential probiotic bacterium isolated from normal human intestinal tissue and shows high adhesion to human colonic mucin (HCM) mediated by the bacterial cell surface glyceraldehyde-3-phosphate dehydrogenase (GAPDH). After periodate oxidation of the HCM, the adhesion of LA 318 bacterial cells significantly decreased compared to the normal HCM. A BIACORE adhesion assay of the GAPDH to the blood group antigens was then performed. High adhesion was observed binding the A and B group antigens while adhesion to the H group antigen was lower. No interaction was observed between GAPDH and various monosaccharides. Further, the GAPDH adhesion to B-trisaccharide biotinyl polymer (BP)-probe [Galα1-3 (Fucα1-2) Gal-] was significantly higher as compared to B-disaccharide, Lewis D-trisaccharide, 3-fucosyl-N-acetylglucosamine and α-N-acetylneuraminic acid BP-probes. The data suggests the trisaccharide structure is important in binding to the blood group antigens. The adhesion of GAPDH to HCM significantly decreased after incubation with NAD⁺. This suggests the NAD binding domain on GAPDH may be related to the adhesion to the HCM. Thus, because strain LA 318 and some pathogens recognize the same receptor, strain LA 318 may competitively inhibit pathogenic infections, and therefore may be useful in the development of new anti-infectional foods.

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A total of 388 acid-producing bacterial strains were isolated from 11 samples of 7 kinds of Thai fermented foods. Thirty-one isolates produced bacteriocin-like inhibitory substances (BLISs) against the indicator strain, Lactobacillus sakei subsp. sakei JCM 1157^T. These 31 isolates were classified and identified with 16S rDNA RFLPs and 16S rDNA sequencing analysis as 20 Lactobacillus fermentum, 10 Lactobacillus plantarum, and 1 Weissella cibaria strains. Two strains, Lactobacillus plantarum TS220 and Weissella cibaria 110, were selected and their BLISs were partially purified. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the antibacterial substances produced by these strains were approximately 3.0 and 2.5 kDa in size.

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Several lactic acid bacteria such as Lactobacillus and Lactococcus produce type II restriction endonucleases. Type II restriction endonucleases were searched for in more than 200 lactic acid bacteria isolated from tide areas of the Ariake Sea. Leuconostoc mesenteroides isolated from the Ariake Sea produced a novel type II restriction endonuclease designated LmsRI. This enzyme was found to cleave several DNAs; however, it had no cleavage site for φX174 DNA. This study is the first to report the production of type II restriction endonuclease by Leuconostoc.

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