title: Growth, bioconversion of isoflavones and probiotic properties of parent and subsequent passages of Lactobacillus upon ultraviolet radiation.
abstract: The objective of this study was to evaluate the effects of ultraviolet (UV) radiation (UVB; 90 J/m²) on growth, bioconversion of isoflavones and probiotic properties of parent and subsequent passages of L. casei FTDC 2113. UV radiation significantly enhanced (P < 0.05) the growth of parent cells in mannitol-soymilk fermented at 37°C for 24 h. This had led to an enhanced intracellular and extracellular β-glucosidase activity with a subsequent increase in bioconversion of isoflavones in mannitol-soymilk (P < 0.05). UV radiation also promoted (P < 0.05) the tolerance of parent cells towards acidic condition (pH 2 and 3) and intestinal bile salts (oxgall, taurocholic and cholic acid). In addition, parent treated cells also exhibited better (P < 0.05) adhesion ability to mucin and antimicrobial activity compared to that of the control. All these positive effects of UV radiation were only prevalent in the parent cells without inheritance by first, second and third passage of cells. Although temporary, our results suggested that UV radiation could enhance the bioactive and probiotic potentials of L. casei FTDC 2113, and thus could be applied for the production of probiotic products with enhanced bioactivity.
authors.affiliation: Bioprocess Technology Division, School of Industrial Technology, Universiti Sains Malaysia, Penang, Malaysia.
authors.forename: Siok-Koon
authors.initials: SK
authors.lastname: Yeo
authors.forename: Min-Tze
authors.initials: MT
authors.lastname: Liong
mesh_terms: D000818:Animals; D000898:Antibiosis; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000378:metabolism; D001647:Bile Acids and Salts / Q000378:metabolism; D005517:Foodborne Diseases / Q000382:microbiology / Q000517:prevention & control; D005752:Gastric Mucins / Q000378:metabolism; D006090:Gram-Negative Bacteria / Q000254:growth & development; D006094:Gram-Positive Bacteria / Q000254:growth & development; D007529:Isoflavones / Q000032:analysis / Q000378:metabolism*; D007780:Lacticaseibacillus casei / Q000254:growth & development* / Q000378:metabolism / Q000528:radiation effects*; D008296:Malaysia; D008353:Mannitol / Q000378:metabolism; D050296:Microbial Viability / Q000528:radiation effects; D019936:Probiotics / Q000378:metabolism*; D041942:Soy Milk / Q000737:chemistry / Q000378:metabolism; D034421:Sus scrofa; D013997:Time Factors; D014466:Ultraviolet Rays; D001617:beta-Glucosidase / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D001647:Bile Acids and Salts; D005752:Gastric Mucins; D007529:Isoflavones; D008353:Mannitol; D001617:beta-Glucosidase