Screening for Raw Starch Digesting Bacteria

Abstract

Screening for raw starch digesting bacteria revealed that bacteria producing amylase, which hydrolyzes raw starch, are widely distributed in nature. From among 155 raw starch digesting bacterial isolates, 20 strains were selected and examined as to both the characteristics of their enzymes and some bacteriological properties. According to the action patterns of their enzymes on starch, these strains could be divided into two groups, i.e., exolytic and endolytic amylase producers. The phenotypic properties of a representative bacterial isolate belonging to each group were examined. One of them (isolate TB1012) was assigned to Bacillus polymyxa (Prazmowski) Mace, which produced an exolytic β-amylase. The other (isolate B1018) was identified as Bacillus sp., which produced an endolytic amylase giving a single activity band corresponding to an approximate molecular weight of 75,000 on SDS-polyacrylamide gel electrophoresis. © 1989, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.