座壳孢菌对烟粉虱致病力的研究

座壳孢属(Aschersonia)是粉虱和介壳虫的一类重要病原真菌,可用于世界性害虫烟粉虱(Bemisiatabaci)的生物防治.本文对来自世界各地的15株座壳孢菌进行了产孢、萌发性状比较,在此基础上筛选出11株产孢、萌发能力较好的菌株测定其对烟粉虱的致病力.菌株Aa5、Ag1、Aa8、Aa7、Aa2和Aa1均表现出高致病性(＞60%),此外本研究还发现菌株的致病力与其萌发率成明显正相关(r=0.86),而与产孢量不相关.     

Effect of Different Energy Sources on Ochrobactrum anthropi Bacteria Chromium Reduction

Ochrobactrum anthropi CTS-325 isolated from a chromium-contaminated site had better resistance to Cr(Ⅵ) in LB medium under aerobic condition.Meanwhile,it was found that the reduction of Cr(Ⅵ) is not complete during the experimental process.Therefore,a series of small molecule energy sources including nitrogen and carbon sources were added into the LB medium in the bacterial stationary phase to promote the chromium reducibility.The result showed that the bacterial growth was positively correlated with the chromium reduction.SDS-PAGE analysis indicated that the protein groups were changed when the bacteria were stimulated by the chromium.Additionally,it was revealed that O.anthropi CTS-325 could utilize the cheaper alternative of sugar(sucrose residue leaching solution) well for further growth and restart the chromium reduction,which offered a new method for practical appli-cations.     

碳源、氮源、金属离子和维生素对虫生真菌粉虱座壳孢孢子萌发、菌丝生长和产孢的影响

研究了12种碳源、10种氮源、6种金属离子和6种维生素对粉虱座壳孢的孢子萌发率、菌丝生长和产孢量的影响.D-木糖、D-果糖、D-半乳糖对孢子萌发有极显着的抑制作用.最有利于菌丝生长的碳源为可溶性淀粉,其次为蔗糖、甘露醇和山梨醇.碳源极显着地抑制产孢,其中肌醇的抑制能力最强.酵母浸粉、胰蛋白胨、干酪素、蛋白胨和牛肉浸膏最能促进孢子萌发,可是硝酸钠、尿素和酵母浸膏明显抑制孢子萌发.胰蛋白胨、干酪素和牛肉浸膏最有利于菌丝生长.所有氮源均有利于增加产孢量,其中酵母浸粉、胰蛋白胨和酵母浸膏为最好的产孢氮源,而硫酸铵的作用最小.Zn2+能显著地促进孢子萌发,而Cu2+强烈地抑制菌丝生长.除了Fe2+极显着地促进产孢外,其它金属离子对产孢均表现出抑制作用.VB1、VB5、VC和VB6均促进萌发,其中VB5效果显著.这些维生素对菌丝生长均无显著影响,但极显着地抑制产孢,其中VB6的抑制效果最明显.