The Driving Mechanism Of The Spatial Distribution Of Bacterial And Fungal Communities Within A Pile During Agricultural Waste Composting

Composting has been widely used as a major process of stabilizing agriculturalorganic wastes through the degradation of biodegradable components by microbialcommunities under controlled conditions. Bacteria and fungi species play significantroles in the decomposition and mineralization of agricultural organic wastes. Theircommunity compositions are likely to be influenced by several physico-chemicalparameters in composting systems. In most cases, the effects of pile temperature andwater soluble carbon (WSC) were greater than that of others. So far, thephysico-chemical parameters have not been evaluated simultaneously with thebacterial and fungal composition changes to separate out their relative importance. Itis of interest to conduct such research to determine to what extent of differences inbacterial and fungal communities are influenced by these parameters, respectively.The goal of this study was to identify and prioritize some of the physico-chemicalparameters that contributed to bacterial and fungal community compositions duringagricultural waste composting. Relationships between those parameters and microbialcommunity compositions determined by PCR-DGGE were simultaneously evaluatedby redundancy analysis (RDA). This study was to identify the predominant factorsamong six physico-chemical parameters on bacterial and fungal community structureand assess the impacts of growth position and growth stage on bacterial and fungalcommunity composition during agriculture waste composting.Results of bacterial RDA with physico-chemical parameters indicated that piletemperature and pH were the predominant factors which had explained17.2%(P=0.0340) and12.0%(P=0.0480) of the variation of the bacterial community structure;Results of bacterial RDA with growth position and growth stage showed highlysignificance (P <0.0500), growth stage was more pronounced than growth position ashad explained31.2%(P=0.0400), against18.1%(P=0.0300) of the variation.Results of fungal RDA with physico-chemical parameters indicated that moisturecontent and pile temperature were the predominant factors which had explained34.1%(P=0.00020) and9.7%(P=0.0260) of the variation of the fungal communitystructure; Results of fungal RDA with growth position and growth stage showedhighly significance (P <0.0500), growth stage was more pronounced than growthposition as had explained53.4%(P=0.0060), against8.9%(P=0.0386) of the variation.