Screening of Fungi Isolates for C-4 Hydroxylation of R-2-Phenoxypropionic Acid Based on a Novel 96-Well Microplate Assay Method.

Screening of Fungi Isolates for C-4 Hydroxylation of R-2-Phenoxypropionic Acid Based on a Novel 96-Well Microplate Assay Method. Appl Biochem Biotechnol. 2020 Mar 25;: Authors: Zhou HY, Jiang R, Li YZ, Xu W, Wang YS, Xue YP, Zheng YG Abstract R-2-(4-Hydroxyphenoxy)propionic acid (R-HPPA) is a pivotal intermediate for the synthesis of aryloxyphenoxypropionate (APP) herbicide. To rapidly screen microbial isolates with the capacity of hydroxylating R-2-phenoxypropionic acid to R-HPPA from various environmental samples, a convenient and safe 96-well microplate assay method with sodium nitrite (NaNO2) as chromogenic reagent was proposed and optimized. The optimum assay conditions were as follows: the detection wavelength was 420 nm, the concentration of NaNO2 solution was 6.0 g/L, color reaction temperature was 60 °C, the pH of the NaNO2 solution was 2.4, and the reaction time was 40 min. With the aid of this method, screening for microorganisms with C-4-specific hydroxylation activity of R-PPA was conducted. As a result, 23 strains among 3744 single colonies isolated from various samples exhibited the hydroxylation activity. Among these strains, the highest bioconversion rate was achieved by Penicillium oxalicum A5 and Aspergillus versicolor A12, respectively. After 72-h cultivation in shake flask, their conversion rates of R-HPPA from 10 g/L R-PPA reached 21.18% and 40.24%, respectively. The established method was effective in rap...
Source: Applied Biochemistry and Biotechnology - Category: Biochemistry Authors: Tags: Appl Biochem Biotechnol Source Type: research