不同位置窖泥酶活力及其细菌群落结构相关性分析

Enzyme activity in pit mud with different position and its correlation with bacterial community structure

窖泥微生物对酒质的影响是通过多种酶促反应实现,目前对窖泥酶活的研究较少,缺乏关于窖泥中氮代谢功能酶的空间分布特征分析。该研究分析不同位置的窖泥理化因子和酶活力,采用高通量测序技术对窖泥细菌群落进行分析,通过聚类分析研究细菌群落的空间分布特点,并标记窖泥微生物的基因序列预测参与氮代谢功能酶的相对丰度。结果表明,铵态氮含量(1478.37 mg/kg)、过氧化氢酶活力[1.731 mg/(g·d)]、蛋白酶活力[1.107 mg/(g·d)]在窖底窖泥中最大,在窖池内自上而下呈增高趋势,而脱氢酶呈减小趋势。Firmicutes是窖泥的绝对优势菌门,Caproiciproduces、Lactobacillus、Fastidiosipila分别是窖底、窖壁中层和窖壁上层窖泥的第一优势菌属。铵态氮、蛋白酶与Aminobacterium呈显著的正相关(P<0.05);酸性磷酸酶与Lactobacillus呈显著负相关(P<0.05),脲酶与Syntrophaceticus呈显著的正相关(P<0.05)。PICRUSt2功能预测中,参与氮代谢的功能酶在不同位置窖泥中的相对丰度差异显著(P<0.05)。酶活性影响窖泥物质循环,物质交换是微生物相互作用的重要驱动力,功能酶活力可以衡量氮代谢的强度,由此可见,窖泥位置对氮代谢酶的分布产生重要影响,并影响着氮代谢,该研究为解析微生物参与窖泥中的物质循环过程提供理论基础。

The Baijiu quality was affected by the enzymatic reaction of pit mud microorganisms.At present,there was little research on pit mud enzyme activity and spatial distribution characteristics of nitrogen metabolism enzymes in pit mud.The study analyzed physicochemical indicators and enzyme activities of pit mud at different locations.High-throughput sequencing was used to elaborate the bacterial communities.Cluster analysis was used to explore the distribution characteristics of the bacterial community from the view of space-time.Gene sequence of pit mud microorganism was used to predict the relative abundance of enzymes which involved in nitrogen metabolism.The results showed that ammonium nitrogen content(1478.37 mg/kg),catalase activity[1.731 mg/(g·d)]and protease activity[1.107 mg/(g·d)]increased from top to bottom in the pit,while dehydrogenase activity decreased.Firmicutes was the absolute dominant bacteria of pit mud.Lactobacillus,Caproiciproduces,and Fastidiosipila were the first dominant bacteria in bottom pit mud,wall mezzanine pit mud,and wall top pit mud,respectively.Ammonium nitrogen,protease,and Aminobacterium showed significant positive correlation(P<0.05).Acid phosphatase was significantly negatively correlated with Lactobacillus(P<0.05),urease was significantly positively correlated with Synthephaceticus(P<0.05).In the function prediction of PICRUSt2,the relative abundance of functional enzymes that involves in nitrogen metabolism in pit mud is significantly different at different locations(P<0.05).Enzyme activity affected pit mud material circulation.Material exchange was an important driving force for microbial interaction.Functional enzyme activity could measure the intensity of nitrogen metabolism.It can be seen that pit mud location had an important impact on the distribution of nitrogen metabolizing enzymes and nitrogen metabolism.The study provides a theoretical basis for analyzing the participation of microorganisms in the material circulation process in pit mud.