摘要
以麦草纤维素酶解液为原料 ,用黑曲霉发酵制备柠檬酸 ,研究了培养基组成、恒温发酵和周期变温发酵对柠檬酸发酵的影响 ,结果表明 ,适宜的培养基组成为NH4 NO3 0 .3% ,KH2 PO4 0 .1% ,Mg2 + 30 0× 10 -6,Fe2 + 10×10 -6,此时 ,柠檬酸产量为 10 .5 2 g/L ,糖转化率为 6 0 .80 %。研究还表明 ,添加低级醇如甲醇和乙醇有利于产酸 ,但添加甲醇的效果要好于添加乙醇的效果 ,适宜的甲醇量为 2 %。在恒温发酵过程中 ,0～ 8h为孢子萌发期 ,产酸较慢 ;8～ 2 4h为对数生长期 ,产酸增加 ;2 4h之后为菌体生长恒定期 ,但产酸继续增加 ;10 4h之后产酸降低。在周期变温发酵过程中 ,0～ 8h产酸较慢 ,8h之后产酸增加。通过对二者的比较可知 ,在 0～ 16h ,周期变温发酵的产酸量要高于恒温发酵的产酸量 ,但在 16h之后 。
Citric acid production with cellulase hydrolyte of wheat stalk by Aspergillus niger , the effects of media component, fermentation at constant temperature, and at periodic variable temperature on citric acid were studied. The results showed that suitable component of the media were 0.3% of NH\-4NO\-3, 0.1% of KH\-2PO\-4, 300×10\+\{-6\} of Mg\+\{2+\}, 10×10\+\{-6\} of Fe\+\{2+\}. The yield of citric acid was 10.52g/L, and the conversion of sugar was 60.80%. At the same time, adding appropriate methanol and ethanol was beneficial to citric acid production. Also, the yield of citric acid by adding methanol was higher than by adding ethanol (added by 2% of the media). Acid production and mycelial growing stage during the fermentation were also observed and recorded.\;
出处
《微生物学杂志》
CAS
CSCD
2001年第3期5-8,共4页
Journal of Microbiology
关键词
纤维素酶解液
黑曲霉素
发酵
柠檬酸
cellulase hydrolyte, Aspergillus niger , fermentation, citric acid.
