Cloning and Characterization of Gene Promoters from Bacillus pumilus

DNA fragments obtained from Sau3AI partially digested total DNA of Bacillus pumilus UN31-C-42 are first inserted into BamHI site of pSUPV4, a promoter-probe vector. The recombinant DNA molecules are transformed into Escherichia coli cells and eight-three Kanr clones (named pSUBp1-pSUBp83) are obtained. The inserted fragments in pSUBp53, pSUBp57, pSUBp21, which showed high level of kanamycin- resistance, are sequenced and analyzed, respectively. These fragments contain some con-served sequences of prokaryotic gene promoters, such as TATAAT and TIGACA box. The promoter frag-ment Bp53 could efficiently promote the alkaline protease gene of B. pumilus expression not only in E.coli but also in B. subtilis cells.     

生长条件影响新型隐球酵母漆酶表达的比较分析

对病原真菌新型隐球酵母致病因子漆酶的表达进行了分析.实验发现不同血清型菌株漆酶表达调控有所不同.高毒性血清型A型菌株H99在稳定期初期漆酶活性高于血清型D型菌株,但漆酶活性最终值远低于D型菌株JEC21.铜离子的对二者漆酶的诱导作用也不一致.血清型A型菌株H99,漆酶的表达量随培养基中的铜离子浓度的增加而增加;而对于血清型D型菌株JEC21,则是在低浓度铜离子(10μmol/L)诱导时漆酶活性达最大值,而当培养基中铜离子的浓度继续增大,漆酶的活性逐渐降低.与葡萄糖不同,培养基中氮源对漆酶的表达有一定抑制作用,但不同氮源对漆酶的表达抑制作用不同.培养温度升高使漆酶活性降低,铜离子可以在有高糖、高温等抑制条件下诱导漆酶表达,这些观察均未见报道,对研究漆酶的生产应用和揭示其生物学功能有一定参考价值.     

高产紫杉醇真菌的筛选

从广西大学、广西北海、青岛崂山、兰州五泉山、秦皇陵、长白山、神农架等地采回松柏科植物的树枝,利用无菌分离技术从树枝中分离得到植物内共生真菌,用土豆（PDA）培养基培养并发酵,发酵产物经过抽滤、旋转蒸发等处理后采用高效液相色谱法对提取物进行检测.最终分离得到147株菌种,并筛选得到产紫杉醇真菌QHL（秦皇陵）002a,产量为77.4μg/L.