防治设施蔬菜土传病害生防菌株B1619生物学特性的研究

Study on Biological Characteristics of B1619 Preventing Soil-borne Diseases of Facility Vegetable

【目的】生防菌株B1619是一株能够防控设施蔬菜土传病害的生防菌株。本文从分泌代谢物种类、生物膜形态、最佳碳源、氮源、无机盐、微量元素、p H和温度方面研究生防菌株B1619的生物学特性。【方法】最佳碳氮源、无机盐、微量元素、p H和温度的研究稀释平板法进行;生物膜通过Msgg培养基培养。【结果】生防菌株B1619可产生蛋白酶、纤维素酶和嗜铁素蛋白酶培养基、嗜铁素培养基和纤维素酶培养基上产生晕圈,几丁质酶培养基上未产生分解晕圈;可形成致密、厚实的生物膜;最适生长温度为27℃,最适p H为5.9,最佳碳源为甘露醇,最佳氮源为牛肉膏,微量元素丙氨酸、VB1能促进B1619的生长,其中丙氨酸有显著促进作用;无机盐Ca Cl2和Mg SO4促进B1619生长。生防菌株B1619在24 h前处于对数生长期,24 h生长数量最大,24 48 h之后,菌体生长基本达到稳定;24 h主要以菌体形式存在,24 h之后,开始出现芽孢,到72 h达到90%以上的芽孢率。【结论】B1619可以产生蛋白酶、纤维素酶和嗜铁素,但不分泌几丁质酶;B1619在大多数速效碳源下生长良好,在无机氮源中的生长优于有机氮源;适宜的温度、p H、微量元素和无机盐可以促进B1619的生长;B1619的生长在48 h后基本达到稳定。此外,电镜观察了B1619 24、48、72 h生长过程中的菌体形态变化。

[ Objective ] Strain B 1619 can prevent soil-borne diseases of facility vegetables. In this article, we studied its biological character-istics in respects of metabolite species, biofilm morphology, temperature, pH, carbon nitrogen sources, trace elements, inorganic salt andgrowth curve. [ Method] Dilution-plate method was used to find out the best culture conditions and Msgg medium was used for the observationof its biofilm. [ Result ] Results showed there were halos in the protease medium, siderophore medium and cellulase medium, but no the phe-nomenon in the chitinase medium;B1619 can produce protease, cellulose and iron, B1619it also can form a dense and thick biofilm, at thesame time, 27 ℃, pH 5.9, mannitol, beef extract, Ala, CaC12 and MgSO4 were optimum for its growth. Logarithmic growth was at the first24 hours, the cell number reach maximum at 24 h and its growth keep stable after 24 48 hours, it mainly keeps thalli before 24 hours whileproducing spores after 24 hours, the spore number reach maximum at 72 hours and its sporulation rate was high, even over 90 %. [ Conclu-sion] B1619 can produce eellulase, siderophorc and protease. Inorganic nitrogen , available carbon source and suitable trace elements arebeneficial to the growth of B1619, suitable temperature, pH also make difference. The growth of B1619 reach the dynamic balance after 48hours. In addition, we observe the cell morphology changes of B1619 at 24,48 and 72 h by scanning electron microscopy.