为探讨拮抗菌GQ-17在植物真菌病害生物防治中的应用潜力,通过形态观察、生理生化测定、细胞成分分析以及16SrDNA序列分析确定其分类地位,采用牛津杯法测定其发酵液的理化性质,并采用单因素试验与正交设计方法筛选出该菌株的优化发酵配方和发酵条件.结果表明:GQ-17为龟裂链霉菌(Streptomyces rimosus),该菌株发酵液对番茄灰霉病菌、番茄叶霉病菌、水稻纹枯病菌、小麦赤霉病菌、玉米弯孢病菌、茄子黄萎病菌、黄瓜褐斑病菌、黄瓜枯萎病菌都有较高的抑制活性；对温度和酸碱度不明感,在100℃处理30min抑菌活性为对照的88.6％,pH值5～9之间抑菌活性无明显变化;对光照较敏感,日光照射6h,其活性降低51.5％.培养基优化组合为:玉米粉10g,黄豆粉10g,NaC1 4g,CaCO3 1g,去离子水1000mL;优化发酵条件为:初始pH值7.0,发酵温度31℃,发酵时间5d,接种量3％,250mL三角瓶装液量50mL,摇床转速120r·min-1.%The aim of this study was to evaluate the potential of an antagonism strain GQ-17 for biocontrol ability against plant fungus disease.Taxonomic identification based on morphology, physiological and biochemical characterization, cell components analysis together with 16S rDNA sequence analysis were conducted.The physical and chemical properties of the crude fermentation extract were measured with oxford cup method.In addition, the single factor test and orthogonal design experiments were also employed to screen out the optimal liquid fermentation compositions and the optimal fermentation conditions of the strain.The result showed that strain GQ-17 was identified as Streptomyces rimosus.Its crude fermentation extract had high inhibitory activities on Botrytis cinerea, Fulvia fulva, Rhizoctonia solani, Fusarium graminearum, Curvularia lunata, Verticillium dahliae, Corynespora cassiicola and Fusarium oxysporum f.sp.cucumerinum.It was thermostable with 88.6% remaining activities after heat threated at 100℃ for 30min.It was insensitive to pH and stable in the pH range of 5-9.Its activities reduced 51.5% under sunlight irradiation 6h.The best compositions of cultural medium were as follow: com meal 10g,soybean flour 10g, NaCl 4g,CaCO3 1g,deionized water 1000mL.The optimal fermentation conditions were as follow: initial pH7.0, temperature 31℃, fermentation time 5d, inoculation rate 3%, medium capacity 50mL/250mL and rotation speed 150r·min-1.
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