固定化黑曲霉发酵玉米糖液生产柠檬酸的研究

STUDIES ON CITRIC ACID PRODUCTION FROM CORN SACCHARIFYING LIQUID BY IMMOBILIZED ASPERGILLUS NIGER

利用PVA复合凝胶包埋黑曲霉的孢子及菌丝体。固定后的细胞经过一系列预培养 ,用于发酵玉米生产柠檬酸。试验确定的固定化细胞摇瓶发酵生产柠檬酸最适条件为 :玉米糖液浓度 1 0Bx,培养温度 35℃ ,摇瓶转速 2 5 0r/min。经此条件发酵 64h ,柠檬酸产率最高达到 96g/L ,通常稳定在 90g/L左右。同时对柠檬酸连续批次发酵生产进行了初步研究 ,固定化黑曲霉可连续使用 8批次以上 ,其柠檬酸产量稳定在 86～ 92g/L之间 ,这为柠檬酸连续发酵提供了有利的保证 。

The immobilized cells of Aspergillus niger with complex PVA were used to produce citric acid by fermentating corn saccharifying liquid.The suitable conditions for fermentation in shaking flask were determined as follows:corn saccharifying liquid concentration 10Bx,temperature 35℃ and rotatory speed of shaking flask 250r/min.The citric acid yield reached 96g/L maximally and usually was 90g/L after 64h fermentation under the suitable conditions.The continuous fermentation of immobilized cell was studied primarily.The experimental result showed that immobilized Aspergillus niger can be used continuous for more than eight times and citric acid yield was 86～92g/L.