Can Community Level Physiological Profiles Be Used For Compost Maturity Testing?

Community level physiological profiling utilizing Biolog plates was evaluated as an assay for testing the maturity of composts. Compost samples of different maturity stages were collected from a forced-aeration open windrow biowaste composting site. Several approaches of data analysis were used. They included single-point readings at certain well color densities, estimation of the area under activity curves, calculations of kinetic parameters and, finally, estimates of functional diversity. The capacity of community level physiological profiles to characterize compost maturity was evaluated in reference to several other physicochemical and biological (respiration, microbial biomass) maturity indices. Methods of optical density transformation and analytical procedures had little effect on the quality of information derived from principal component analysis. Except for a difference in resolution, both physicochemical parameters and community level physiological profiles were suitable for identifying different stages of compost maturity. The data suggested that community level physiological profiles may be a promising tool for evaluation of compost maturity.