title: Applicability of a colorimetric method for evaluation of lactic acid bacteria with probiotic properties.
abstract: Rapid colorimetric methods using various indicator reagents have been developed to monitor bacterial viability. Here, we examined the applicability of a method based on the reduction of resazurin or water-soluble tetrazolium salt-8 (WST-8) to screen lactic acid bacteria (LAB) for growth, tolerance against bile acid and low pH. The resazurin reduction test proved unsuitable for screening LAB such as Lactobacillus plantarum and Leuconostoc mesenteroides since it reacted with acid present in the cultures. LAB growth could be indirectly quantified by measuring WST-8 reduction. This method proved more sensitive and quickly results than counting bacterial colony forming units and turbidity at 600 nm in the presence of bile and acid. Our results suggested that the WST-8-based method could be useful for the characterization of growth and tolerance of the lactic acid producing bacteria.
authors.affiliation: World Institute of Kimchi, Gwangju 61755, Republic of Korea.
authors.forename: Min Young
authors.initials: MY
authors.lastname: Jung
authors.affiliation: World Institute of Kimchi, Gwangju 61755, Republic of Korea.
authors.forename: Jina
authors.initials: J
authors.lastname: Lee
authors.affiliation: World Institute of Kimchi, Gwangju 61755, Republic of Korea.
authors.forename: Boyeon
authors.initials: B
authors.lastname: Park
authors.affiliation: World Institute of Kimchi, Gwangju 61755, Republic of Korea.
authors.forename: Hyelyeon
authors.initials: H
authors.lastname: Hwang
authors.affiliation: World Institute of Kimchi, Gwangju 61755, Republic of Korea.
authors.forename: Sung-Oh
authors.initials: SO
authors.lastname: Sohn
authors.affiliation: World Institute of Kimchi, Gwangju 61755, Republic of Korea.
authors.forename: Se Hee
authors.initials: SH
authors.lastname: Lee
authors.affiliation: World Institute of Kimchi, Gwangju 61755, Republic of Korea.
authors.forename: Hyeong In
authors.initials: HI
authors.lastname: Lim
authors.affiliation: World Institute of Kimchi, Gwangju 61755, Republic of Korea.
authors.forename: Hae Woong
authors.initials: HW
authors.lastname: Park
authors.affiliation: World Institute of Kimchi, Gwangju 61755, Republic of Korea. Electronic address: leejonghee@wikim.re.kr.
authors.forename: Jong-Hee
authors.initials: JH
authors.lastname: Lee
mesh_terms: D001647:Bile Acids and Salts / Q000378:metabolism; D015169:Colony Count, Microbial; D003124:Colorimetry / Q000379:methods*; D056546:Lactobacillales / Q000254:growth & development* / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D048191:Lactiplantibacillus plantarum / Q000302:isolation & purification / Q000378:metabolism; D050296:Microbial Viability; D010078:Oxazines / Q000378:metabolism; D010084:Oxidation-Reduction; D019936:Probiotics / Q000302:isolation & purification / Q000378:metabolism*; D012680:Sensitivity and Specificity; D013778:Tetrazolium Salts / Q000378:metabolism; D014966:Xanthenes / Q000378:metabolism
chemical_list: C476329:2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H tetrazolium monosodium salt; D001647:Bile Acids and Salts; D010078:Oxazines; D013778:Tetrazolium Salts; D014966:Xanthenes; C005843:resazurin
keywords: Colorimetric assay; LAB; Lactobacillus plantarum; Probiotics