title: Enhanced growth and bioconversion of isoflavones in prebiotic-soymilk fermented by UV-treated lactobacilli and bifidobacteria.
abstract: The aim of this study was to evaluate the effects of ultraviolet (UV) radiation (ultraviolet A (UVA), ultraviolet B (UVB) and ultraviolet C (UVC) at 30-90 J/m²) on the membrane properties of lactobacilli and bifidobacteria, and their bioconversion of isoflavones in prebiotic-soymilk. UV treatment caused membrane permeabilization and alteration at the acyl chain, polar head and interface region of membrane bilayers via lipid peroxidation. Such alteration subsequently led to decreased (p < 0.05) viability of lactobacilli and bifidobacteria immediately after the treatment. However, the effect was transient where cells treated with UV, particularly UVA, grew better in prebiotic-soymilk than the control upon fermentation at 37°C for 24 h (p < 0.05). In addition, UV treatment also increased (p < 0.05) the intracellular and extracellular β-glucosidase activity of lactobacilli and bifidobacteria. This was accompanied by an increased (p < 0.05) bioconversion of glucosides to bioactive aglycones in prebiotic-soymilk. Our present study illustrated that treatment of lactobacilli and bifidobacteria with UV could develop a fermented prebiotic-soymilk with enhanced bioactivity.
authors: Bioprocess Technology Division, School of Industrial Technology, Universiti Sains Malaysia, Penang, Malaysia.
authors: Siok-Koon
authors: SK
authors: Yeo
authors: Min-Tze
authors: MT
authors: Liong
mesh_terms: D001644:Bifidobacterium / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects*; D002462:Cell Membrane / Q000737:chemistry / Q000528:radiation effects*; D005960:Glucosides / Q000378:metabolism; D007529:Isoflavones / Q000378:metabolism*; D007778:Lactobacillus / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects*; D008051:Lipid Bilayers / Q000378:metabolism / Q000528:radiation effects; D015227:Lipid Peroxidation / Q000528:radiation effects; D050296:Microbial Viability; D010539:Permeability; D056692:Prebiotics; D019936:Probiotics / Q000528:radiation effects*; D045730:Soy Foods / Q000382:microbiology; D041942:Soy Milk / Q000378:metabolism*; D014466:Ultraviolet Rays; D001617:beta-Glucosidase / Q000378:metabolism
chemical_list: D005960:Glucosides; D007529:Isoflavones; D008051:Lipid Bilayers; D056692:Prebiotics; D001617:beta-Glucosidase