Wheat, along with maize and rice, is one of the world’s three major cereals, and its straw is a by-product with an estimated global annual yield exceeding 550 million tons. Although straw can serve as livestock feed, composting material, bio-based growth substrate or household fuel, large amounts are still returned directly to fields or burned openly, causing biomass loss and environmental pollution. Developing technologies for the effective utilization of wheat straw biomass is therefore important for mitigating greenhouse gas emissions and supporting sustainable agriculture. In wheat-peanut rotation systems in particular, converting straw into organic fertilizer or growth substrate could increase peanut yield while reducing fertilizer inputs.
To enhance the efficient utilization of wheat straw biomass, the researchers isolated 2,102 Bacillus strains between 2018 and 2023 from diverse sources including crop residues, fermented feed, human and livestock manure, compost and soils. From this collection they selected a multifunctional strain, Bacillus amyloliquefaciens SQ1, and evaluated it from screening through to crop-relevant application: effects on wheat straw decomposition, inhibition of A. flavus, fungal transcriptional responses, mycotoxin reduction, microbial community structure and peanut seedling growth.
During straw decomposition, SQ1 accelerated the loss of cellulose and hemicellulose, decreased the C/N and lignin/N ratios and rapidly shifted the pH toward neutrality, all indicators of faster and more mature decomposition. It also suppressed fungal proliferation: cryo-SEM imaging revealed fractured and collapsed A. flavus hyphae with markedly reduced spore adhesion. Transcriptomic profiling of A. flavus under SQ1 exposure revealed coordinated repression spanning cell-envelope biogenesis and sterol synthesis, with down-regulation of fks1, aflY, erg2 and erg11, diminished developmental competence through ligA, and attenuated toxin regulation through aflR. Straw amended with SQ1 showed a reduced relative abundance of Aspergillus and lower aflatoxin B1 content.
Using the SQ1-amended decomposed straw as a substrate improved peanut seedling survival, plant height and leaf chlorophyll, indicating that the treatment benefits early crop growth as well as the decomposition process itself. The authors conclude that SQ1 functions as a dual-purpose biocatalyst, breaking down cellulose while inhibiting fungal growth, thereby enhancing straw biotransformation, mitigating mycotoxin risk and supporting early crop growth. The findings highlight a sustainable, value-added approach to wheat straw utilization with practical implications for improved substrate management and cleaner production in crop systems.
The work entitled “Direct screening of multifunctional Bacillus amyloliquefaciens for fiber degradation, antifungal activity, and its role in promoting wheat straw decomposition and peanut seedling growth” was published in Systems Microbiology and Biomanufacturing (published on Aug. 12, 2026).
DOI：10.1007/s43393-026-00538-5