title: Enhanced growth of lactobacilli and bioconversion of isoflavones in biotin-supplemented soymilk by electroporation.
abstract: This study aimed at utilizing electroporation to further enhance the growth of lactobacilli and their isoflavone bioconversion activities in biotin-supplemented soymilk. Strains of lactobacilli were treated with different pulsed electric field strength (2.5, 5.0 and 7.5 kV/cm) for 3, 3.5 and 4 ms prior to inoculation and fermentation in biotin-soymilk at 37°C for 24 h. Electroporation triggered structural changes within the cellular membrane of lactobacilli that caused lipid peroxidation (p < 0.05) and alteration of membrane fluidity (p < 0.05). This was due to the application of electric potential difference across membrane that induced pores formation and subsequently increased membrane permeability. Reversible permeabilized cells resumed growth to >9 log CFU/ml after fermentation in biotin-soymilk (p < 0.05). Lactobacilli cells treated at electric field strength of 7.5 kV/cm for 3.5 ms also showed enhanced β-glucosidase activity (p < 0.05) compared to lower doses and control, leading to increased bioconversion of isoflavones glucosides to aglycones in biotin-soymilk (p < 0.05). Results from this study show that electroporation could be used to produce biotin-soymilk with increased bioactive aglycones.
authors.affiliation: School of Industrial Technology, Universiti Sains Malaysia, Penang, Malaysia.
authors.forename: Joo-Ann
authors.initials: JA
authors.lastname: Ewe
authors.forename: Wan-Nadiah
authors.initials: WN
authors.lastname: Wan-Abdullah
authors.forename: Abdul Karim
authors.initials: AK
authors.lastname: Alias
authors.forename: Min-Tze
authors.initials: MT
authors.lastname: Liong
mesh_terms: D001710:Biotin / Q000378:metabolism*; D002462:Cell Membrane / Q000648:ultrastructure*; D019587:Dietary Supplements; D004560:Electricity; D018274:Electroporation / Q000379:methods*; D005285:Fermentation; D005960:Glucosides / Q000378:metabolism; D007529:Isoflavones / Q000378:metabolism*; D007778:Lactobacillus / Q000254:growth & development* / Q000378:metabolism; D015227:Lipid Peroxidation; D008560:Membrane Fluidity; D010539:Permeability; D019936:Probiotics; D045730:Soy Foods / Q000382:microbiology; D041942:Soy Milk / Q000378:metabolism*; D001617:beta-Glucosidase / Q000378:metabolism
chemical_list: D005960:Glucosides; D007529:Isoflavones; D001710:Biotin; D001617:beta-Glucosidase