奶牛场厌氧发酵牛粪生产垫料工艺中菌群变化的研究

Study on Bacterial Flora Changes in Producing Bedding Process Using Cow Manure by Anaerobic Fermentation Technology in Dairy Farms

【目的】探究奶牛场粪污厌氧发酵生产垫料工艺过程中菌群的变化,为奶牛场牛粪垫料标准化生产和合理安全使用提供理论参考。【方法】采集4个规模化奶牛场中粪污厌氧发酵前牛粪、厌氧发酵固液分离后的牛粪及牛卧床上的牛粪垫料,提取菌体DNA进行16S rRNA高通量测序,对于不同阶段的微生物多样性、菌群组成及显著差异的特征菌群进行分析。【结果】与发酵前牛粪相比,经过厌氧发酵固液分离后的牛粪中菌群多样性和丰富度均降低,但与牛粪垫料菌群多样性和丰度相似。发酵前牛粪中丰度最高的菌门和菌属分别为厚壁菌门(Firmicutes,55.15%)和瘤胃菌科UCG-005菌属(UCG-005,16.68%),厌氧发酵固液分离后牛粪中丰度最高的菌门和菌属分别为厚壁菌门(48.12%)和芽孢杆菌属(Bacillus,12.16%),牛粪垫料中丰度最高的菌门和菌属分别为放线菌门(Actinobacteriota,37.02%)和谷氨酸杆菌(Glutamicibacter,11.65%)。通过LEfSe分析发现,发酵前牛粪、厌氧发酵固液分离后牛粪及垫料3组间存在显著差异的菌属共有14种。【结论】通过对奶牛场厌氧发酵牛粪生产垫料过程中菌群组成的研究,发现优势菌门和菌属均发生了较大改变,发酵处理后菌群多样性和丰富度均降低,该种生产工艺完全满足奶牛场对牛粪垫料安全性的需要。

【Objective】The changes of bacterial flora were investigated for producing bedding process using cow manure by anaerobic fermentation technology in dairy farms,in order to provide some theoretical references for standardized production,the reasonable and safe use of cow manure as bedding.【Method】Samples were collected from four large-scale dairy farms,including cow manure before anaerobic fermentation,cow manure after solid-liquid separation during anaerobic fermentation,and cow manure bedding on the bed.Bacterial DNA was extracted for high-throughput 16S rRNA sequencing,and the microbial diversity,composition,and significant differences in characteristic microbial communities at different stages were analyzed.【Result】Compared with cow manure before fermentation,the diversity and richness of microbial communities in cow manure after anaerobic fermentation solid-liquid separation were reduced,but were similar to those in cow manure substrate.The phyla and genus with the highest abundance in cow manure before fermentation were Firmicutes(55.15%)and UCG-005(16.68%),respectively.The phyla and genus with the highest abundance in cow manure after anaerobic fermentation solid-liquid separation were Firmicutes(48.12%)and Bacillus(12.16%),respectively.The phyla and genus with the highest abundance in cow manure bedding were Actinobacteriota(37.02%)and Glutamicibacter(11.65%),respectively.LEfSe analysis showed that there were a total of 14 bacterial genera with significant differences between the three groups of cow manure before fermentation,cow manure after anaerobic fermentation solid-liquid separation,and bedding.【Conclusion】Through the study of the microbial community composition during anaerobic fermentation of cow manure production in dairy farms,it was found that the dominant bacterial phyla and genus had undergone significant changes.After fermentation treatment,the diversity and richness of the microbial community had decreased.This production process could meet the safety requirements of dairy farms for cow manure production.