Fate of Escherichia coli and their antibiotic resistant pattern in food waste composting process

Abstract

This study was investigated a potential pathogenic bacteria and antibiotic resistant bacteria (ARB) from the food waste composting. Moreover, study on environment factors may effect to pathogenic bacteria and ARB persistence under food waste composting. Escherichia coli as a representative bacterial in this study. Investigated compost for 8 weeks in 150 L reactors in aerobic condition. The results of ARB from materials before composting indicated multiple antibiotic resistant (MAR) index of E. coli was 0.312. First phase of composting, temperature inside composts were increased to 37.0-57.0 ^OC. E. coli survival under high temperature condition had developed to high level of antibiotic resistant and decreased to low level depended on time period. The results of ARB development in 8 weeks of composting was decreased, MAR index of E. coli was 0.214. Most of E. coli survival classified as ARB which resisted to 1 antibiotic group (60%). Moreover, MAR index of E. coli (0.405) from leachate of food waste composting was higher than in compost and decreased depended on ferment time period (7^th week, MAR index = 0.150). Therefore, using of food waste compost should be needed more time for completely composting or prolonged compost using to reduced ARB contamination. To reduce the high level of ARB may contaminate in compost, there should be an appropriate leachate management system for protecting the widespread of ARB to the environment.