Abstract: Antibiotic phenazine-1-carboxylic acid (PCA) was primarily separated from fermentation broth by a novel flocculation process. The solubility of PCA was firstly measured to prove rising with pH value. Based on a comparison of 9 types of flocculant, polyaluminum chloride was proved to be the best choice. The sedimentation rate of the flocs increased and PCA recovery rate severely increased after the broth was diluted. The factor of pH value had great effect on PCA recovery and purity. Temperature had obvious effect on filtration and PCA recovery rates, but not on its purity. The results of orthogonal experiments indicated that the best separation conditions were 4 times dilution, pH 8.5 and 30℃, under which PCA content of the product was 69.9%, and PCA recovery rate 91.3%.

Key words: biopesticide, phenazine-1-carboxylic acid, fermentation broth, separation, flocculation

摘要： 通过考察吩嗪-1-羧酸(PCA)在不同pH值下的溶解度，利用PCA碱溶酸沉的性质，采用絮凝法去除发酵液中的大分子蛋白质和菌丝体等杂质，初步分离出代谢产物PCA；研究了絮凝剂用量、发酵液稀释倍数、pH值及温度对过滤速度、终产品PCA含量和回收率的影响. 结果表明，当以聚氯化铝为絮凝剂、发酵液稀释4倍、絮凝pH值为8.5、絮凝温度为30℃时，所得产品中PCA含量达69.9%，产品对发酵液的PCA回收率为91.3%.

关键词: 生物农药, 吩嗪-1-羧酸, 絮凝, 分离, 发酵液