粘质沙雷氏菌(Serratia marcescens)发酵培养基优化的研究

Study on Optimization of Fermentative Culture Media of Serratia marcescens

采用单因素试验和正交试验，对从山东东营海岸湿地盐碱滩地土壤中筛选出的一株海洋菌种——粘质沙雷氏菌（Serratia marcescens）的发酵培养基进行优化，并进行100L发酵罐中试放大试验的研究。确定粘质沙雷氏菌的最佳培养基配方为葡萄糖10g／L，硫酸铵5g／L，麸皮50g／L，柠檬酸三钠1．0g／L，K2HPO4·3H2O0．3g／L，FeSO4·7H2O 0．05g／L，MgSO4·7H2O 0．5g／L，PH7．2～7．7。发酵最适温度为30℃。通过测定粘质沙雷氏菌在发酵罐中培养的生长曲线，确定发酵时间以28～30h为宜，发酵结束后发酵液中的活菌数约为50×10^8个／mL。将所筛选到的粘质沙雷氏菌应用于农作物的病害防治，效果非常显著，表明是一株高活性的生物防治拮抗菌。此研究结果为高效率、低成本和工业化生产具有生物防治作用的海洋菌种制剂提供了科学依据，也为海岸湿地盐碱土的可持续开发利用提供了技术支撑。

The single factor and orthogonal tests were used to optimize the fermentative culture media of Serratia marcescens screened from the saline-alkali soil in Dongying City, Shandong Province, and the study on pilot-plant test in 100 L fermentation tank was made. It is shown from the test results that the optimal culture medium ingredients are glucose 10 g/L, （NH4）2SO4 5 g/L, wheat bran 50 g/L, trisodium citrate 1.0 g/L, K2HPO4 · 3H2O 0.3 g/L, FeSO4 · 7H2O 0. 05 g/L, MgSO4 · 7H2O 0.5 g/L and pH 7.2 -7.7, and the optimal fermentation temperature is 30 ℃. The optimal fermentation periods is determined to be 28 to 30 hours based on the growth curve of Serratia marcescens in the fermentation tank, and the total number of live bacteria on completion of fermentation was 50 × 10^8 individuals/mL in the fermentation liquid. The application of Serratia marcescens to the biological control of plant disease has got good results, and Serratia marcescens has proven a highly active antagoristic bacterium for biological control. This research results provide scientific basis for efficiently and economically producing marine bacterial preparation for biological control and technical support for the sustainable development and utilization of saline-alkali soil in Chinese coastal wetland.