A novel fungal and bacterial consortium promotes the degradation of rice straw: Conditions optimization and degradation properties

Abstract

The rapid development of agriculture has led to the production of a large amount of crop straw, necessitating effective strategies for its management. Microbial degradation offers a promising method. In this study, a novel microbial consortium composed of Phanerochaete chrysosporium, Aspergillus niger, and Streptomyces griseorubens, known for their robust lignocellulose degradation capabilities, was constructed for rice straw degradation. The establishment of this microbial consortium was based on the growth curve and antagonistic tests. Orthogonal optimization revealed that Streptomyces griseorubens played a predominant role in the degradation of rice straw. The optimal degradation conditions were determined as follows: nitrogen source concentration of 2.5 gL⁻¹, material-liquid ratio of 40 g L⁻¹, inoculum size of 3%, and pH value of 9. Under these conditions, the degradation efficiency reached 42% within 15 days. The decomposition of lignocellulosic components in the straw was confirmed through various characterization methods. Additionally, as the degradation process progressed, there was a noticeable decrease in protein-like substances and an increase in humic acid-like substances in the degradation solution.