高盐废水盐度对中度嗜盐菌生长动力学的影响

Effect of salinity on moderate halophilic bacteria growth kinetics in high salinity wastewater

高盐废水盐度变化是影响微生物生长的重要因素之一。研究以中度嗜盐菌Halomonassp．STSY．3为例，测定其在不同盐度下生长对数期末OD600,并以葡萄糖为限制性基质，利用Monod方程，对菌株进行生长动力学拟合。结果表明，Halomonassp．STSY-3的最适生长盐度为7％（以NaCl计），此盐度下其OD600 为2．56，而0%和34％盐度下OD600分别为0．47和0．06；Halomonassp．STSY-3的生长动力学模型与实验数据能较好地拟合，在最适生长盐度下动力学模型参数μmax 为2．257h-1，Ks为0．0082g／L。比较不同盐度下STSY-3生长动力学参数，得出中度嗜盐菌STSY-3的生长存在3个明显分区：最适盐度区（盐度2％～9％）、嗜盐过渡区（盐度9％～20％和0．68％～1．76％）及生长抑制区（盐度≤2％或≥20％）。其中嗜盐过渡区0．68％～1．76％由于范围较小，实际意义小，忽略不计。

Salinity changes seriously affect the growth of microorganism in high salinity wastewater. The study took a moderate halophilic bacteria Halomonas sp. STSY-3 as an example, tested its OD600 in the end of logarithmic phase under different salinities, and took glucose as the restrictive substance, utilized the Monod e- quation to fit the growth kinetics. The results show that the optimal growth salinity of Halomonas sp. STSY-3 is 7% （in NaCl meter） , under which its ODs00 is 2.56, the OD600under 0% salinity and 34% salinity is only 0.47 and 0.06, respectively. The growth kinetics model of Halomonas sp. STSY-3 and the experimental data can be well fitted. Under the optimal salinity, its kinetics model parameter μmax is 2. 257 h-1, Ks is 0. 0082 g/L. Com- paring the kinetics parameters under different salinities, the conclusion is that the growth of moderate halophilic bacterium STSY-3 has three obvious regions： optimum salinity region （salinity 2% -9% ）, halophilic transition region （salinity 9% - 20% and 0.68% - 1.76% ） and growth inhibition region （salinity below 2% or above 20% ）. The range of halophilic transition region （ salinity 0.68% - 1.76% ） is short and its practical significance is small, so it can be negligible.