奥托类芽孢杆菌NPDY05-8利用秸秆扩繁条件优化OA

Aiming at the promotion challenges of high dosage and high cost in the field application of Paenibacillus ottoensis NPDY05-8,the straw was proposed for the direct field propagation of this strain to reduce the cost of field application and improve the feasibility of its technological popularization.In this study,the broad-spectrum bacteriostatic Paenibacillus ottoensis NPDY05-8 was taken as the research object,and the whole-genome sequencing,cellulase gene analysis,morphological observation and cellulose utilization capacity determination were conducted on it.A systematic study on the technological optimization of its propagation in the field with straw as the sole nutrient source was carried out.The effects of culture temperature,initial pH value,inoculum size and straw content on the propagation of strains were investigated by single factor experiment,and the optimal propagation conditions were determined.The results showed that the whole-genome sequencing revealed that the strain NPDY05-8 contained four cellulase genes(GH51,GH94,GH56,GH74),which could be rapidly propagated by the straw as the sole nutrient source.The results of single-factor experiments showed that the optimal propagation conditions were as follows:daily average temperature of 20-30℃,initial pH of 6.5-7.0,inoculum size of more than 0.125%(v/v),and straw content of more than 5.0 g·L-1.Under these conditions,the biomass of the strain could reach more than 107 CFU·mL-1,which could meet the requirements of field irrigation application.The research results provided technical support for the large-scale field application of Paenibacillus ottoensis NPDY05-8,and also provided technical guarantee for the popularization of green prevention and control of maize stalk rot.