Development And Evaluation Of A Mixed Microbial Inoculant For Mink Manure Composting

With the development of economy and society, the number of farms has been increasing sharply. Followed by a huge amount of animal manure wastes, which has caused serious environmental problems. Compost is a good way to deal with these organic waste which can be harmless and recycling. But it takes so much time of traditional compost and the waste can not be treated completely. Therefore, inoculating mixed microbial inoculant during the process of composting to promoting its situation has so important practical significances.This thesis focuses on developing a mixed microbial inoculant to deal with mink manure more quickly. The main finding in this study are as follows:Firstly, Replicate compost piles were built and sampled in each stage. Twenty kinds of microorganisms were separated from these samples. After that, we merged them into 8 kinds based on the colony morphology.These 8 kinds of microorganisms were identified by 16S rDNA, the results showed that they belong to the kind of Bacillus amyloliquefaciens, Bacillus flexus, Bacillus subtilis, Ureibacillus thermosphaericus, Geobacillus sp., Geobacillus pallidus, Bacillus licheniformis, Ureibacillus sp.. They all have their distinctive functions. Next, we combined these microorganisms with medium to make mixed microbial inoculant named ABTNLⅡ.Two compost piles were built using mink manure. And mixed microbial inoculant was inoculated into one of them. In order to evaluate how the mixed microbial inoculants influence composting process, we examined temperature, pH value, moisture, carbon-nitrogen ratio, E4/E6 and so on. The results showed that experimental group with the mixed inoculant was 2 days shorter to get to the stage of high temperature and maintain 7 days longer than control group. Besides, the highest temperature of experimental group was 64.1 ℃, which was much higher than 59.0℃ of control group. The experimental group generated an earthy and humic acid odor after 23 days composting, while the control group showed a hint of ammonia and unpleasant odor when it was over. During the mink composting, the results of chemical indexs such as pH, C/N, EC, E4/E6、water soluble ammonia nitrogen and nitrate nitrogen showed that the experimental group is much better than control group. The seed germination index (GI) for compost contained the mixed microbial inoculant has increased to over 80% after 10 days composting and even to 95% when over, while in control group it was still under 80% when the composting process was over. In general, the mixed inoculant accelerated the decomposition of toxic and hazardous substances and promoted the process of composting. The manure waste composting product could be used as organic fertilizer, in result of the mink manure waste is treated in a harmless and recycling way.