Microbial ecology controls the establishment of fecal bacteria in tropical soil environment

Abstract

Fecal indicator bacteria, such as E. coli and enterococci are consistently present in Hawaii's streams in concentrations exceeding recreational water quality standards. The chapter tests two hypotheses by which these fecal indicator bacteria can become established populations in the soil environment of Hawaii. The first hypothesis states that the soil environment is unfavorable for the growth of fecal indicator bacteria but a small subpopulation of these fecal bacteria with metabolic characteristics suitable for growth in this restrictive environment will be selected to establish a population in the soil environment. The second hypothesis states that the soil environment of Hawaii is permissive and provides for sufficient conditions to accommodate the metabolic potential of most fecal bacteria to grow in its soil environment. The source of these fecal indicator bacteria has been determined to be the soil where these bacteria are able to multiply and have become a part of the soil microflora. The metabolic profile of the soil isolates of 48 E. coli and 30 enterococci is determined based on their ability to metabolize 95 different carbon sources using the biolog System.