抗烟草黑胫病菌的菌株ZY-19-2的鉴定及发酵条件研究

Study on Identification and Fermentation Condition of the Strain ZY-19-2 which Inhibit to Tobacco Black Shank

烟草黑胫病是烟草上重要毁灭性病害之一,生产上主要采取综合防治措施,包括种植抗病品种、农业防治、病害发生期的药剂防治,以及生物防治和植物诱导抗性的利用等,后两者已成为当前综合防治的研究重点。生物防治是烟草黑胫病防治最主要的手段之一。从烟草根际土样中分离、筛选得到一株对烟草黑胫病菌有抑制作用的菌株ZY-19-2,为了评价该菌株利用价值,对菌株ZY-19-2进行了鉴定及不同培养条件下该菌株产几丁质酶的活力。结果表明:该菌株为淡紫拟青霉(Paecilomyces lilacinus);该菌株的最佳发酵条件以1.2%胶体几丁质为碳源,发酵液初始pH为6.0,以1%蛋白胨为氮源,0.1%吐温80作为表面活性剂,发酵时间为60h,接种量为1%,摇床转速为120r/min,最高酶活达到0.216U/mL。通过对菌株ZY-19-2发酵条件的优化,为应用该菌株规模化生产高效廉价的几丁质酶、几丁质寡糖及对烟草黑胫病防治奠定基础。

Tobacco black shank is one of the most serious diseases of tobacco.People mainly adopt integrated management to the disease like,breeding for resistance varieties,agro-protection,chemical control,biological control and plant induced resistance in production of tobacco.Biological control is the best way against the disease for tobacco.The strain ZY-19-2 was isolated and screened from rhizosphere of tobacco,which demonstrated high inhibitory to tobacco black shank.In order to appraise its value,we identified the strain and studied its activity of Chitinase in different culture conditions.The results indicated that the stain ZY-19-2 was Paecilomyces lilacinus,which showed strongly inhibition action to parasitica Phytophthroa Dast var.nicotianae and the highest activity of Chitinase was 0.216 U/mL using 1.2% chitin as carbons source in the medium and the initial pH of fermentation fluid was 6.0,with 1% peptone as nitrogen,0.1% Tween-80 as a surfactant,fermentation time being 60 h,rotation speed of 120 min.The strain ZY-19-2 was optimized in culture different conditions,which established foundation on producing highly effective Chitinase and chitooligosaccarides and controlling tobacco black shank.