降雨对秦皇岛西浴场细菌总数和可培养菌群组成的影响

Effects of rainfall on the total number of bacteria and the composition of culturable bacteria in Qinhuangdao West Beach

摘要:

【目的】研究降雨条件对浴场细菌总数和优势菌群组成的影响。【方法】2014年8月强降雨前后采集秦皇岛西浴场3个站位的海水样品，采用荧光显微镜计数法和平板计数法分别对细菌总数和可培养细菌总数进行计数；对群落结构组成进行分析，并对可培养细菌进行鉴定。【结果】雨前3个站位细菌总数和可培养细菌总数平均值分别为5.6×109 cfu/L和8.3×107 cfu/L，雨后分别为9.2×109 cfu/L和2.1×108 cfu/L。在可培养菌群中，变形菌门(Proteobacteria，雨前占80%，雨后占73%)是主要的微生物类群，其次为拟杆菌门(Bacteroides，雨前占12%，雨后占13%)、厚壁菌门(Firmicutes，雨前占7%，雨后占11%)等；肠杆菌属(Enterobacter spp.，21株)、海杆菌属(Marinobacter spp.，13株)、弓形菌属(Arcobacter spp.，13株)、假单胞菌属(Pseudomonas spp.，10株)、芽孢杆菌属(Bacillus spp.，10株)和弧菌属(Vibrio spp.，6株)为雨前可培养细菌优势属，而雨后可培养细菌优势属为肠杆菌属(22株)、海杆菌属(21株)、芽孢杆菌属(14株)、不动杆菌属(Acinetobacter spp.，11株)、假单胞菌属(9株)和弓形菌属(5株)等。【结论】降雨对细菌总数有显著的影响，同时降雨后浴场微生物群落结构发生了改变。

Abstract:

[Objective] To analyze the influence of precipitation on the total bacteria and microbial community composition in coastal waters. [Methods] Water samples were collected from three stations in Qinhuang Dao west beach before and after rainfalls in August 2014. Total and culturable bacterial species were enumerated using fluorescence microscope and plate counting methods, respectively. Culturable bacterial species were identified using molecular approach and the microbial community structure was analyzed. [Results] Total and culturable bacterial species were 5.6×109 cfu/L and 8.3×107 cfu/L before rainfall, 9.2×109 cfu/L and 2.1×108 cfu/L after rainfalls. Among the culturable bacteria, Proteobacteria is the mostly dominant bacterial phylum (80% before rainfall, 73% after rainfall), followed by Bacteroides (12% before rainfall, 13% after rainfall) and Firmicute (7% before rainfall, 11% afer rainfall). Enterobacter spp. (21 strains), Marinobacter spp. (13 strains), Arcobacter spp. (13 strains), Pseudomonas spp. (10 strains), Bacillus spp. (10 strains) and Vibrio spp. (6 strains) were dominant species before rainfall. Enterobacter spp. (22 strains), Marinobacter spp. (21 strains), Bacillus spp. (14 strains), Acinetobacter spp. (11 strains), Pseudomonas spp. (9 strains) and Arcobacter spp. (5 strains) were dominant species after rainfall. [Conclusion] Precipitation has significant impact on total number of bacteria. Clearly, precipitation significantly shaped the bacterial community structure in the coastal waters.