Microbial community changes during the composting of municipal solid waste

Phospholipid fatty acid (PLFA) analysis has been used to characterize microorganisms from a range of different environments, but has not been previously used in the assessment of compost organisms. Compost processing and maturity are assumed to be related to the microorganisms present, but methods to elucidate and evaluate these relationships are lacking. In this study, PLFA analysis was used to follow microbial community changes during the composting of municipal solid waste (MSW). Patterns of change were compared between pilot- and full-scale facilities and between varied feedstocks. At the pilot level, actual MSW and two synthetic MSW formulations (similar C:N, different available C) were composted. At the full-scale facilities, actual MSW was composted as was actual MSW amended with nitrogen. The PLFA data generated by all studies was analyzed using principal component and multivariate statistical methods. The PLFA profiles changed over the composting process in a consistent and predictable manner. PLFA profiles also proved to be characteristic of specific stages of composting and may, therefore, be useful in evaluating (and optimizing) the progress of material processing and product maturity.