Сравнение методов выявления экзополисахарид-продуцирующих бактерий и обоснование выбора метода скрининга для почвенных изолятов

Abstract

To select exopolysaccharide (EPS)-producing bacteria from soil samples, several methods were compared: visual assessment of mucoid colonies, screening on Congo red medium, scanning electron microscopy, and EPS isolation via ethanol precipitation followed by quantification. The Congo red agar method — specifically the variant described by the Korean research group Shaffique et al. (2023) — was selected for primary screening; this involves using LB medium supplemented with 5% sucrose and 0.8 g/L Congo red, with incubation for 5 days at 30-35°C. This method is simple, suitable for high-throughput colony screening, and compatible with the conditions of our isolation protocol. Its main limitation is that it yields qualitative results; therefore, selected isolates require further verification through EPS isolation and quantification.