Spatiotemporal Characteristics of Air Microbial Community Structure in Daqu Manufacture Environment Explored by Culture-dependent and Culture-independent Methods

The change trend of the microbial community structure and diversity, in the air around new and old Daqu production factories used for 2 and 25 years, respectively, with the seasons were investigated by both culture-dependent and culture-independent methods. The results showed that the constituents and diversities significantly shifted with seasons, and the number of species and α-diversity indexes were the highest in spring, respectively, and both of them increased first and then decreased with seasons. 301 isolates were obtained by culture-dependent method, which belonged to the same category as that obtained by the culture-independent method, the bacterial flora was composed of five phyla, such as Acfinobacteria, etc., in which Pseudomonas, Staphylococcus, Bacillus, were dominant. The fungal flora was composed of three phyla, including Ascomycota., Phialemoniopsis and Aspergillus, etc. were dominant. Among these dominant species, Pseudomonas et al. 8 bacterial genera of Proteobacteria and Saccharomycopsis et al. 10 fungi genera of Ascomycota in the strong-flavor Daqu might be originated from the air. Compared with facilities used for 2 years, the quantity and diversity indexes in the air around the facilities used for 25 years were richer and more stable. Correlation analysis showed that the temperature and humidity of the air were the key factors affecting the quantity of microorganisms, while the change of the intensity of air pollution resulted in the community structure became unstabitily. These results revealed the spatiotemporal feature of the microbial community in the Daqu manufacturing niche and laid a methodological foundation for the study of the relationship and traceability between Daqu and environmental microorganisms.