发光酶基因lux AB标记硅酸盐细菌NBT菌株的研究

外源基因标记技术为研究土壤引入细菌的生态行为提供了有效的检测手段，通过选择不同的碳源和降低碳氮比筛选获得0．25％麦芽糖作为碳源的菌体制备培养基，对硅酸盐细菌BT菌株进行紫外诱变和抗生素抗性驯化获得—株抗利福平200μg·ml^-1的NBT-R200菌株，含发光酶基因luxAB的质粒pTR102：：luxAB在辅助质粒pRK2013的帮助下转入该菌株中，从而赋予NBT菌株以发光活性和利福平、卡那霉素、四环素三种抗生素抗性．以对数生长期的菌体制备受体细胞，发现对数生长前期的细胞转移频率最高，可达6．70×10^-5，杂交比例以1：1：1适宜．标记菌株RL85的释钾能力没有丧失且有提高，发光特性稳定，连续转接20次后仍具有发光活性和3种抗生素抗性，适用于根际微生态学研究。

Introduction of bioluminescence genes into silicate-dissolving bacteria strain NBT

In this study, silicate-dissolving bacteria NBT strain was grown with 0.25% maltose as carbon source, and the rifampicin-resistance was generated by ultraviolet mutagenesis and streak naturalized to 200 microg x ml(-1). Through triparental cross, the luxAB genes were introduced into NBT-R200 at the help of pRK2013. The luminescence activity of the hybrid strain was tested, which indicated that all colonies had a high luminescence activity and kanamycin-, tetracyctine-and rifampicin-resistance. The NBT-R200 cells prepared from initial logarithmic growth phage were more likely to be sensitive to foreign DNA, and the maximum translocation frequency was up to 6.70 x 10(-5). In addition, the optimal mating ratio was 1:1:1. The potassium release ability from feldspar and the luminescence of luxAB genes marked silicate-dissolving bacteria RL85 strain were stable, and hence, the RL85 was available to rhizosphere microecology researches.