Investigating the variation of dissolved organic matters and the evolution of autotrophic microbial community in composting with organic and inorganic carbon sources

Abstract

The main purpose of this study was to analyze the effects of different carbon source (Na2CO3, NC; sugarcane molasses, SM) additives on dissolved organic matter (DOM), cbbL-containing autotrophic microbes (CCAM), and the relationship among physico-chemical parameters, DOM and CCAM to better understand carbon transformation in composting. The results showed that SM or NC additive could promote the degradation and transformation of OM and DOM. After adding SM or NC, the Simpson index decreased by 2.03% and 0.51%, respectively, and Luteimonas and Thermomonspora were detected using high throughput sequencing, indicating that SM and NC increased the diversity of CCAM community. Additionally, both NC and SM contributed to improve the abundance of cbbL gene (45.91% and 2.15%) based on fluorescence quantitative PCR (qPCR) analysis at the cooling phase of composting. Pearson correlation analysis revealed that Proteoobacteria, Firmicutes, Acidobacteria and Nematoda were positively related with C/N, OM and DOM (0.5 < R < 0.9, P < 0.05).