Distributions of DNA and RNA Hydrolyzing Bacteria in Lakes and Their Extracellular Nuclease Production

Abstract

The number of DNA and RNA hydrolyzing bacteria in the water of six lakes was found to range from 102 to 104 N•ml-1. They accounted for 8% to 67% of heterotrophic bacteria in the lake water. While the number of DNA and RNA hydrolyzing bacteria in the sediment of six lakes was found to range from 104 to 106 N•ml-1 and from 103 to 106 N•ml-1, respectively. They accounted for 6% to 50% of heterotrophic bacteria in the sediment. The distribution of both bacteria was correlated with the amount of chlorophyll a. The vertical distribution of DNA and RNA hydrolyzing bacteria in Lake Shinseiko reached maxima at a depth of 2m during the circulation period, and a maximum at a depth of 2m and at the surface layer for DNA and RNA hydrolyzing bacteria, respectively, during the stagnation period. © 1993, The Japanese Society of Limnology. All rights reserved.