利用枯草芽孢杆菌和EM菌剂复合的尾菜液态发酵工艺研究OA

To address the challenges of low degradation efficiency and poor fermentation stability in the resource utilization of agricul-tural vegetable waste,this study developed a"hydrolysis-acidification"temporal inoculation submerged fermentation process using a composite microbial agent consisting of Bacillus subtilis(Bs,4.1×108 CFU·mL-1)and effective microorganisms(EM,1.2×108 CFU·mL-1).A mixture of Chinese cabbage,carrot,sweet potato peel,and watermelon rind at a fresh weight ratio of 2∶2∶3∶3 was used as the sub-strate.Through optimization of the microbial agent ratio,single-factor tests,and response surface methodology,the optimal conditions were determined as follows:Bs∶EM=1∶2(V/V),sequential inoculation with Bs followed by EM after a 15 h interval,fermentation tem-perature of 31 ℃,and a total inoculum size of 4.0%.Validation experiments conducted in a 5 L fermenter revealed that the organic matter degradation rate reached 44.21%,the total acid content was 30.15 g·L-1,and the system pH remained stable at 3.6.Mechanis-tic analysis indicated that Bacillus subtilis first secretes cellulase and other enzymes to degrade macromolecular organic matter into fermentable sugars,which are subsequently converted into organic acids by EM,thereby establishing a"hydrolysis-acidification"metabolic cascade.This cascade effectively avoids substrate competition and inhibits the growth of spoilage microorganisms.The pro-posed process significantly enhances the degradation efficiency and acidification stability of vegetable waste,shortens the fermentation period,and reduces water consumption,providing an engineering-oriented technical reference for the resource utilization of agricultur-al waste in arid regions of Northwest China.