51 / 2021-06-29 22:27:18

Inoculation of phosphate-solubilizing bacteria regulates microbial interaction to improve phosphorus fractions transformation during kitchen waste composting

Phosphate-solubilizing bacteria, Inoculation, Composting, Phosphorus fractions transformation, Microbial interaction.

Phosphate-solubilizing bacteria have been widely used in aerobic composting of organic wastes to improve phosphorus availability. Our previous study suggested that Bacillus sp. P6. (MW513386.1) had a good effect on phosphate solubilization in shake flask culture; However, the effect of PSB inoculant made by Bacillus sp. P6 on the transformation of phosphorus fractions and the dynamic change of bacterial community in compost is not clear. In this study, two composts including non-inoculated compost (CK) and PSB-inoculated compost (PSB) were compared for evaluating the role of inoculant (Bacillus sp. P6) in the bacterial interaction and P dynamics during composting by high-throughput sequencing and network analysis. The results indicated that the abundance of Bacillus in PSB was always higher than that of CK during the whole composting process. In addition, inoculation of PSB increased12.25% of NaHCO₃-P _{(i, o)} of P fractions. Inoculation of PSB was beneficial to improve bacterial diversity and the richness of bacterial species. Based on Redundancy analysis, Bacillus, Enterobacter, Thermobifida, Oceanobacillus, Pseudomonas, Domibacillus, Staphylococcus were positively correlated (p < 0.05) with NaHCO₃-Po, NaOH-Pi, in KW composting of PSB. Based on the analysis of microbial networks, Bacillaceae and Lactobacillceae are the main factors affecting phosphorus fractions transformation during KW composting.