Abstract:The effect of a single microorganism in degrading rice straw is not apparent. The microbial flora, combined with multiple microorganisms, can effectively degrade rice straw, which is currently the primary choice for straw waste degradation.[Objective] To explore the interspecies coordination mechanism, the microbial flora can transform rice straw more efficiently than a single strain and provide a theoretical reference for improving the biodegradation process of straw materials.[Methods] A microbial population combination with a degradation effect better than monoculture was constructed artificially through the combination of strains and the weight loss of rice straw as an indicator. The experimental strains were identified by molecular biology methods. Combined with cellulase activity and GC-MS analysis of fermentation products revealed the interspecies coordination mechanism of microbial populations during rice straw degradation.[Results] Strain B (Bacillus cereus) cultured at 30℃ for 8 days, the degradation rate of rice straw was 50.9%. The combination of strain B and strain D2 (Bacillus amyloliquefaciens), W1 (Ochrobactrum intermedium), and G1 (Bacillus licheniformis) constituted 4 strains of BD2W1G1. For the composite flora, rice straw's degradation rate by culturing at 30℃ for 8 days is 73.3%, 22.4% higher than that of single strain B. The fermentation product analysis showed that strain B produced a large amount of acid, phenol, and other substances in a single culture. B+D2 co-culture, the degradation rate of rice straw is 64.6%, the acid in the fermentation broth is relatively reduced by 87.4%, and the phenol is reduced by 61.9% (pentadecanoic acid, n-hexadecanoic acid, 2,4 Di-tert-butylphenol, and 6-tert-butyl p-cresol is significantly reduced). When B+D2+W1 is co-cultured, the fermentation broth phenols are further reduced by 15.7% (6-tert-butyl-p-cresol is significantly reduced), and rice straw is degraded by 71.0%. When B+D2+W1+G1 is co-cultured, phenols and acids continue to decrease by 10.7%, and rice straw is degraded by 73.3%.[Conclusion] Pentadecanoic acid, n-hexadecanoic acid, 2,4-di-tert-butylphenol and 6-tert-butyl-p-cresol, and other acids phenols can inhibit the efficiency of strain B in decomposing rice straw. Strain D2, W1, and G1 can reduce the content of acids and phenols, including the four substances (A total of 82.9% reduction in acids and 88.2% reduction in phenols), improve the decomposition efficiency (A total of 22.4% increase in decomposition effect). The composition of rice straw is complex, and the bacteria with different functions are combined into a compound inoculum, which reduces feedback inhibition and forms metabolic complementarity, which can effectively improve the biodegradation effect of rice straw.