The Influence of Compound Microbial System and Mineral Elements on the Degradation Efficiency of Corn Stalks

Zhang Junwei¹, Liu Xuechun¹, Zhang Pengzhen¹, Xue Linlin¹, Zhao Longmei¹, Cao Pinghua¹, Fan Shouwu², Li Wang¹
1.College of Animal Science and Technology, Henan University of Science and Technology
2.Luoyang Ouke Biotechnology Co., Ltd.

Abstract: [Methods] Air-dried and pulverized corn starch passed through a 2mm sieve was used as the test sample. Formaldehyde-modified mold strains *Bacillus velezensis* and *Bacillus amyloliquefaciens*, and fungal spores *Aspergillus aculeatus* and *Aspergillus niger* (named HL-1, HM-6, MN-1, and M1-2, respectively) selected in pre-tests were used as test strains. Based on strain diversity and abundance, 15 degradation combinations were constructed using these 4 strains. Pollutant analysis was used to determine the 4... The contribution of each strain in the compound bacterial system was determined. Based on the determination of the optimal compound bacterial system, the effects of different contents of P, N, and Ca on the degradation of CF were observed through single-component experiments and orthogonal experiments. Finally, the optimal combination of mineral elements was determined with CF mass fraction as the main indicator and viable cell count and the activities of methyl cellulase (CMCase) and filter paper enzyme (FPAase) as auxiliary indicators. [Results] (1) According to the results of diversity and toxicity effect analysis, the compound bacterial system J (HL-1+HM-6+M1-2) had the best degradation effect. After the degradation was improved, the CF mass fraction was 31.59%, which was 3.06 fractions lower than the original formaldehyde degradation CF mass fraction (34.65%), and the CF degradation rate reached 8.83%. (2) Single-component calculations and orthogonal experiments showed that adding 0.7 g/kg P, 0.7 g/kg N, and 0.5 g/kg Ca to the composite bacterial strain J resulted in a viable bacterial count of 10.73 × 10⁻⁸ CFU/mL after 6 days of degradation. The activities of CMCase and FPAase were 8.12 and 2.51 U/g, respectively, and the CF mass fraction was 27.49%, which was 7.16 percentage points higher than that of the original composite maize recovery strain. The CF recovery rate reached 20.66%. [Conclusion] Under the experimental conditions, adding mineral elements P, N, and Ca to the selected optimal bacterial strain J (HL-1+HM-6+M1-2) is beneficial to the degradation of maize recovery strain.