Inoculation of phosphate-solubilizing bacteria (Bacillus) regulates microbial interaction to improve phosphorus fractions mobilization during kitchen waste composting

• Published in: Bioresource technology 2021-11, Vol.340, p.125714-125714, Article 125714
• Main Authors: Zhang, Xinjun, Zhan, Yabin, Zhang, Hao, Wang, Ruihong, Tao, Xingling, Zhang, Liping, Zuo, Yilin, Zhang, Lei, Wei, Yuquan, Li, Ji
• Format: Article
• Language: English
• Subjects: Bacillus; Bacterial co-occurrence network; Compost; P fractions; PSB inoculant
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2021.125714

[Display omitted] •Role of Bacillus as PSB inoculant in KW composting was revealed.•Bacillus inoculation increased OM degradation and 14% available P content.•Adding Bacillus changed indigenous bacterial community composition and diversity.•pH was the main factor affecting the dynamics of P fractions and bacterial taxa.•Bacillus indirectly improved P mobilization by intensifying microbial interactions. Bacillus presents in most composts as core microbial taxa and is widely used as inoculant in composting. However, the role of Bacillus as phosphate-solubilizing bacteria (PSB) inoculant in composting and the response of indigenous bacterial community are unclear. This study used redundancy analysis (RDA), network analysis and structural equation model (SEM) to investigate the dynamics of phosphorus (P) fractions, bacterial community, and microbial interaction in composting with PSB (Bacillus sp. P6) inoculation. Results indicated that Bacillus inoculation increased Olsen P content, organic matter degradation, and bacterial diversity, benefiting P fractions mobilization during composting. RDA showed that pH was the main factor influencing P fractions transformation and bacterial taxa. Network analysis and SEM revealed that Bacillus indirectly improved the contribution of bacterial community on P mobilization by enhancing microbial interactions. Therefore, Bacillus with P solubilizing function may be a potential inoculant to regulate the biotic process of P transformation.