除臭菌株组合强化猪粪堆沤细菌群落结构分析

Bacterial community structure in pig manure composted with a deodorizing strain combination

摘要:

【背景】 好氧堆肥是处理农业固体废弃物常用的资源化利用方式，但在此过程中会产生恶臭气体(NH₃和H₂S)，对人类和畜禽的健康造成威胁。微生物除臭技术成本低、效果好，但单菌株的环境适应性差、作用单一。【目的】 开发高效微生物除臭菌株组合，优化微生物除臭技术，解决堆肥恶臭问题。【方法】 通过筛选除臭微生物、控温模拟堆肥研究微生物除臭菌株组合对堆肥过程中细菌群落结构变化的影响，并对相关功能基因进行分析和注释。【结果】 添加微生物除臭菌株组合E的堆肥中，NH₃和H₂S的最高释放量仅有添加商用菌剂X组的40%左右。物种分类结果表明，堆肥过程中相对丰度较高的门包括变形菌门(Proteobacteria)、放线菌门(Actinomycetota)、厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidota)等，相较于X组和CK组，变形菌门(Proteobacteria)、放线菌门(Actinomycetota)在E组的样本中具有更高的相对丰度；优势菌属包括假单胞菌属(Pseudomonas)、棒杆菌属(Corynebacterium)、假纤细芽孢杆菌属(Pseudogracilibacillus)等，其中棒杆菌属在E组样本中一直占据优势。KEGG数据库注释结果表明，微生物除臭菌株组合E的添加促进了堆肥中微生物群落的氨基酸代谢水平；功能基因注释结果也表明氨同化相关基因(gs, gdh, asn,gln)和含硫氨基酸合成相关基因(cysC)的丰度较高，因此，组合E减少NH₃和H₂S排放的主要机制是促进了氮和硫元素转化为氨基酸等有机物。【结论】 微生物除臭菌株组合E能够在粪污堆肥过程中有效抑制NH₃和H₂S的释放，为粪污资源化利用过程中产生的臭气处理提供了微生物资源基础。

Abstract:

[Background] Aerobic composting is a common resource utilization method to treat agricultural solid waste, while odorous gases (NH₃ and H₂S) generated during the composting process pose a threat to the health of humans and animals. Microbial deodorization has low costs and good effects, while single strains have poor environmental adaptability and limited effects. [Objective] To develop a combination of efficient deodorizing strains and optimize microbial deodorization conditions to address the foul odor in composting. [Methods] The effects of the deodorizing strain combination on the changes of bacterial community structure during composting were studied by screening of deodorizing microbial strains and temperature-controlled simulated composting. Furthermore, the relevant functional genes were analyzed and annotated. [Results] The maximum release of NH₃ and H₂S from the compost supplemented with the deodorizing strain combination E was only about 40% of that from the compost treated with the commercial microbial agent X. The species classification results show that the phyla with relatively high abundance during composting include Proteobacteria, Actinomycetota, Firmicutes and Bacteroidota. Group E showed higher relative abundance of Proteobacteria and Actinomycetota than groups X and CK. The dominant genera included Pseudomonas, Corynebacterium, and Pseudogracilibacillus, among which Corynebacterium kept being dominant in group E. The annotation results from the KEGG database indicated that the addition of the deodorizing strain combination E promoted the amino acid metabolism in the microbial community during composting. Similarly, functional gene annotation results revealed higher abundance of ammonia assimilation-related genes (gs, gdh, asn, and gln) and the sulfur-containing amino acid synthesis-related gene (cysC), suggesting that the combination E reduced NH₃ and H₂S emissions by facilitating the conversion of nitrogen and sulfur into amino acids and other organic compounds. [Conclusion] The deodorizing strain combination E can effectively inhibit the release of NH₃ and H₂S in the manure composting process, providing microbial resources for the treatment of waste gases generated in the manure resource utilization process.