强天气干扰条件下粤西凡纳滨对虾养殖池塘细菌群落动态特征

于暴雨频发的华南雨季（2009年5月-8月）对粤西凡纳滨对虾（Litopenaeus vannamei）养殖池塘水体和底泥进行调查，研究在强天气干扰条件下养殖池塘细菌数量动态及多样性指数变化情况。结果发现，水体异养细菌在104-106 cfu？mL-1间波动，弧菌数量在养殖初期高达105 cfu？mL-1， 虾池301# 和404# 自6月18日开始施用芽孢杆菌（Bacillus subtilis）等微生态制剂后，其弧菌（Vibrio sp.）数量维持在104 cfu？mL-1以下，403# 和305# 波动较大且多次超过105 cfu？mL-1；4口虾池水体弧菌与异养细菌的数量比值在养殖初期均超过20%，之后301# 和404# 保持在12%以下,403#和305# 在养殖后期分别达到21%和33%。底泥异养细菌先升高后稳定,弧菌数量除305# 较稳定外，其他虾池波动较大（103-107 cfu？g-1）。施用微生态制剂池塘301#和404#水体微生物群落多样性较前期降低，305#和403#较前期升高；底泥微生物群落多样性则呈现相同的变化规律，群落的丰富度、常见种的优势度和群落均度较前期有所降低。结果表明，施用微生态制剂的虾池可在气候多变的情况下保持养殖水体细菌群落的相对稳定，抑制弧菌滋生，降低微生态环境风险。

Dynamic characteristics of bacterial community in culture ponds for Litopenaeus vannamei in western Guangdong under influence of severe weather

We observed the water and sediment in culture ponds for Litopenaeus vannamei in western Guangdong during the rainy season in South China （May~August, 2009） to study the changes of bacterial quantity and microbial diversity index under the influence of severe weather. The results show that the amount of heterotrophic bacteria in water was 104~106 cfu·mL-1. The amounts of Vibrio exceeded 105 cfu·mL-1 in the early period, and those were less than 104 cfu·mL-1 in No.301 and No.404 ponds which were added with probiotics （Bacillus subtilis, etc.） since June 18, while those in No.403 and No.305 ponds often exceeded 105 cfu·mL-1. In the early period, the ratios of Vibrio to heterotrophic bacteria in water were more than 20% in the 4 ponds, and those were less than 12% in No.301 and No.404 ponds later; in later period, the ratios were 21% and 33% in No.403 and No. 305 ponds, respectively. The amount of heterotrophic bacteria in sediment increased first and then stabilized. The amount of Vibrio in the ponds fluctuated （103~107 cfu·g-1） except No.305 pond. The microbial community functional diversity index decreased in No.301 and No.404 ponds which were added with probiotics, while that in No.305 and No.403 ponds increased. The diversity index in sediment showed a similar variation, in other words, microbial community richness, dominance of common species and community evenness decreased. The results indicate that applying probiotics periodically in shrimp ponds can stabilize bacterial communities, inhibit growth of Vibrio and reduce risk of micro-ecological environment in case of changeable weather.