1株冷泉芽孢细菌发酵液絮凝除菌工艺的优化

Flocculation Process Optimization of Fermentation Broth of a Paenibacillus algorifonticola Strain

为从微生物中寻求新的抗菌活性物质，采用单因素试验方法，研究 pH 值、壳聚糖用量和海藻酸钠用量对冷泉芽孢细菌（Paenibacillus algorifonticola）发酵液絮凝除菌效果的影响，并进一步考察了加酸方式和发酵液中碳酸钙含量对絮凝效果的影响。结果表明：初步优化工艺为最适絮凝 pH 6．0，壳聚糖用量0．75 mL和海藻酸钠1．25 mL；经进一步优化，培养基中碳酸钙可以作为絮凝过程中pH缓冲剂而使其缓慢变化，从而达到最优值（pH 5～6），其工艺为先在发酵液中加入壳聚糖和海藻酸钠，使其在发酵液中的浓度分别达0．375 g/L和0．625 g/L，然后加入1 mol/L的盐酸100μL，絮凝率达95％以上。

In order to screen new antibacterial substances,the effects of pH,chitosan dosage and sodium alginate dosage,acid adding type and calcium carbonate on flocculation of P.algorifonticola fermentation broth were investigated.The results showed that the optimum process conditions included pH 5.0～6.0,chitosan 0.75 mL and sodium alginate 1.25 mL.Calcium carbonate in medium could be used as pH buffer to reach the optimum pH value.Suitable flocculation process was：chitosan and sodium alginate were added into fermentation broth at concentration of 0.375 g/L and 0.625 g/L;then 100 microliters of 1 mol/L hydrochloric acid were added.Flocculation rate could reach 9 5% or more.