产梓醇地黄内生菌的分离鉴定及遗传稳定性研究

通过组织分离法从野生地黄组织中分离得到24株内生菌,采用2,4-二硝基苯肼显色法对所分离的菌株进行产梓醇性能的测定,筛选得到一株产梓醇性能较好的菌株BLCC1-0148,研究其10代内培养物产梓醇性能的遗传稳定性,结合菌落形态特征及菌株特异性序列分析等手段,最终将BLCC1-0148鉴定为蜡样芽孢杆菌(Bacillus Cereus)。利用正交设计试验对高产菌株BLCC1-0148进行发酵条件的优化,最佳发酵培养基如下:葡萄糖0.5%、蛋白胨0.5%、酵母膏0.75%、氯化钠1%;发酵温度37℃,摇床转数180 rpm,发酵时间3 d,梓醇产量达到839μg·mL-1;

Isolation and identification of endophytic bacteria produced catalpol from rehmannia and studies on genetic stability

24 strains of entophyte were isolated from Rehmannia by tissue isolation. The 2,4 - dinitrobenzene hydrazine chromogenic method were used to determing the performance of catalpa alcohol from separated strains. The strain BLCC1 -0148 with better performance production of catalpol and good genetic stability were screened and had been identified as Ba-cillus Cereus by based on physiological,biochemical characteristics and 16S rDNA sequence phylogeny analysis. The cultur-al conditions of BLCC1 - 0148 strain was optimized by the orthogonal design experiment. The optimum medium composition of fermentation conditions was as follows：glucose 0. 5% ,tryptone 0. 5% ,yeast extract 0. 75% ,NaCl 1% . The fermentation conditions included cultural temperature 37 ℃,rotational speed of rocking bed 180 rpm,fermentation time 3d. The produc-tion of catalpol reached 839 μg·mL - 1.