摘要

 奶牛场产生大量的粪肥，用作肥料使用于农田。虽然使用粪肥作为肥料减少了化肥的施用，但与粪肥应用的主要问题是微生物污染。粪肥是包括病原体在内的各种微生物种群的贮藏库，有可能造成污染并对公众和动物健康构成危险。虽然广泛应用了有机肥，但不同处理工艺下粪肥微生物多样性的变化仍不清楚。我们推测，动物粪便的微生物群体随着农场环境中的粪便处理而变化。动物粪便引起的微生物风险可能取决于粪便处理方式。本研究通过对加州中部山谷地区的奶牛粪便取样调查，并对其进行16S rRNA含量和多样性分析，以了解不同处理工艺后粪便的微生物群落结构。粪肥的微生物群落分析表明，液体粪肥的群落结构不同于固体粪肥。例如，硫单胞菌属细菌是液体样品中的唯一的，而热水菌属细菌仅在固体样品中观察到。梭菌属细菌存在于固体和液体样品中。液体样品中的总体是可比的，固体样品中的总体也是相似的。这些结果表明，施用粪肥的方式(即液体与固体)可能对农作物肥料的农田微生物群产生潜在影响。

Dairy farms generate a considerable amount of manure, which is applied in cropland as fertilizer. While the use of manure as fertilizer reduces the application of chemical fertilizers, the main concern with regards to manure application is microbial pollution. Manure is a reservoir of a broad range of microbial populations, including pathogens, which have potential to cause contamination and pose risks to public and animal health. Despite the widespread use of manure fertilizer, the change in microbial diversity of manure under various treatment processes is still not well-understood. We hypothesize that the microbial population of animal waste changes with manure handling used in a farm environment. Consequential microbial risk caused by animal manure may depend on manure handling. In this study, a reconnaissance effort for sampling dairy manure in California Central Valley followed by 16S rRNA analysis of content and diversity was undertaken to understand the microbiome of manure after various handling processes. The microbial community analysis of manure revealed that the population in liquid manure differs from that in solid manure. For instance, the bacteria of genus Sulfuriomonas were unique in liquid samples, while the bacteria of genus Thermos were observed only in solid samples. Bacteria of genusClostridium were present in both solid and liquid samples. The population among liquid samples was comparable, as was the population among solid samples. These findings suggest that the mode of manure application (i.e., liquid versus solid) could have a potential impact on the microbiome of cropland receiving manure as fertilizers.

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0190126