化感链霉菌6803菌株液体发酵工艺优化的研究

土壤微生物链霉菌6803菌株被证明对高等植物具有化感作用。采用单因子实验方法，研究液体发酵碳源、氮源、无机盐、发酵温度、发酵液初始pH值、摇床转速、发酵时间等对链霉菌6803菌株菌丝体产量及发酵液化感作用的影响，用均匀试验设计法优化了发酵工艺条件。结果表明：链霉菌6803菌株生长和产生化感作用的最佳发酵条件为：p（淀粉）=26．67g·L-1，p（蔗糖）=25．15g·L-1，p（NH4C1）=0．30g．L-1，黄豆饼粉浸液8．88％，所（NI-h）H2P04]=O．18g·L-1，p（FeS04．7H20）=O．002g·L-1，p（NaCl）=0．75g·L-1，pH值7．6，装量系数O．16，接种量3％，温度36℃，转速200r·min-1，发酵144h。本研究为利用微生物次生代谢产物作为天然除草剂奠定了基础。

Study on optimization of fermentation of Streptomyces sp. 6803 with allelopathic effects

It has been demonstrated that Streptomyces sp. 6803 has allelopathic effects on higher plants. The single factor test was used to determine the optimal carbon source, nitrogen source, inorganic salts, temperature, initial medium pH, shaker rotation veloci- ty, culture duration for mycelium growth and allelopathic effects on the seedling growth of bamyardgrass （Echinochloa crusgalli） and rape （Brassica campestris）. Uniform design was used to optimize fermentation media and conditions for Streptomyces sp. 6803. The result showed that the optimal fermentation conditions ofStreptomyces sp. 6803 were soluble starch 26.67 g＇L1, sucrose 25.15 g.L-1, beancake powder extract 8.88%, ammonium chloride 0.30 g.L-1, ammonium phosphate monobasic 0.18 g.L-t, ferrous sulfate, 0.002 g.L-1, sodium chloride 0.75 g.L-1, pH 7.6, loading coefficient 0.16, pitching rate 3%, temperature 36℃, rotational speed 200 r.min-l and fermented duration 144 h. This study provides the basic information on using secondary metabolites of microorganisms as natural herbicide.