Rice bran is a nutrient-rich agricultural by-product, and most of the bioactive compounds in it are bound and thus have poor bioavailability. Research has demonstrated that targeted microbial fermentation is a high-efficiency bioprocess for the degradation and modification of complex macromolecules to release phenolic compounds, flavonoids, dietary fibre derivatives and other new biologically active substances. Fermentation can be used to increase the antioxidant, anti-inflammatory and metabolically regulatory effects of rice bran more efficiently by changing its structure and increasing the content of active components compared with the conventional extraction method. Although some studies have investigated how to obtain suitable microbial strains and substrates, optimisation of the processing conditions for improving metabolic and functional performance has not been achieved; otherwise, other problems will still arise in the event of industrial-scale application, such as fluctuations in raw material supply, process instability, and high production costs. In the future, the integration of process analytical technology (PAT), artificial intelligence and microbial engineering will build a large-scale intelligent and controllable fermentation system. Therefore, the specific route of fermentation for valorising rice bran into high-value functional ingredients has been identified, and the scientific foundation for developing sustainable foods and nutraceuticals has been established.

Prometryn, a methylthio-s-triazine herbicide, persists widely in agricultural soils after long-term application, causing crop phytotoxicity and potential human health risks, and microbial degradation offers an eco-friendly, cost-effective strategy for remediation. In this study, three prometryn-degrading bacterial strains were isolated from long-term contaminated cornfield soil in Harbin, China, and identified as Pseudomonas sp. ZM-1, Achromobacter sp. ZM-2 and Stenotrophomonas sp. ZM-3 based on morphological, biochemical and 16S rDNA sequence analysis; strain ZM-3 is, to the best of our knowledge, the first reported pure-culture Stenotrophomonas isolate with confirmed prometryn-degrading capability. The three strains degraded 97.3%, 85.1% and 92.8% of 100 mg·L⁻¹ prometryn within 48 h respectively. The 1:1:1 synthetic consortium removed 96.8% of prometryn in 15 h, showing markedly superior degradation efficiency compared with single strains, and its 12-h degradation rate reached 96.87% with a half-life of 2.2 h following response surface optimization. In soil microcosms spiked with 20 mg·kg⁻¹ prometryn, the consortium reduced the pollutant half-life from 58.2 days to 7.8 days and achieved 96.3% removal after 30 days, alongside enhanced soil dehydrogenase, catalase and urease activities. High-throughput 16S rRNA gene sequencing revealed directional succession of the soil bacterial community, enrichment of core degrading taxa, and predicted enrichment of xenobiotic biodegradation pathways during remediation. Maize pot experiments confirmed that the consortium significantly alleviated prometryn phytotoxicity at the tested concentration, restoring plant growth parameters to 95–97% of the uncontaminated control. This study provides an efficient synthetic microbial consortium for bioremediation of prometryn-contaminated agricultural soils.