Bajpai B, Banerjee T, Patil S
School of Life Sciences, Devi Ahilya University, Vigyan Bhawan, Indore, India.
Indian J Exp Biol. 1999 Jan;37(1):94-7.
Hydrolysis of gallotannin to gallic acid by immobilized mycelia of Aspergillus niger MTCC 282, Aspergillus fischerii MTCC 150, Fusarium solani MTCC 350 and Trichoderma viride MTCC 167 in a packed bed bioreactor was studied. Fungal mycelia preinduced with 5 g L-1 gallotannin were immobilized in calcium alginate gel (1.5%) and the resultant beads were packed in a column to a bed volume of 175 mm3. Gallotannin dissolved in distilled water was passed through the column and the eluate was recycled after adjusting pH to 6 with ammonium hydroxide (10%). Maximum hydrolysis of gallotannin was recorded by immobilized mycelia of F. solani and T. viride at 35 degrees and 45 degrees C after 175 and 60 min of residency period respectively. Optimum substrate concentration required for maximum hydrolysis was 10 g L-1 at pH 5 for both the fungi. Immobilized mycelia of A. niger and A. fischerii revealed maximum operational stability. Loss of activity after eighth run was in the order of-A. niger (no loss), A. fischerii (7.5%), F. solani (18%) and T. viride (18%). Stability in terms of retention of enzyme activity after 150 days of storage at 4 degrees C was A. niger (58%), A. fischerii (26.8%), F. solani (83%) and T. viride (85.1%).
研究了在填充床生物反应器中，黑曲霉MTCC 282、费氏曲霉MTCC 150、茄病镰刀菌MTCC 350和绿色木霉MTCC 167的固定化菌丝体将没食子单宁水解为没食子酸的过程。用5 g L-1没食子单宁预诱导的真菌菌丝体固定在1.5%的海藻酸钙凝胶中，将所得珠子填充到柱中，床体积为175 mm3。将溶解在蒸馏水中的没食子单宁通过柱子，并用氢氧化铵（10%）将洗脱液的pH值调至6后进行循环。茄病镰刀菌和绿色木霉的固定化菌丝体分别在35℃和45℃下，经过175分钟和60分钟的停留时间后，记录到没食子单宁的最大水解率。两种真菌在pH 5时，最大水解所需的最佳底物浓度均为10 g L-1。黑曲霉和费氏曲霉的固定化菌丝体显示出最大的操作稳定性。第八次运行后活性损失的顺序为：黑曲霉（无损失）、费氏曲霉（7.5%）、茄病镰刀菌（18%）和绿色木霉（18%）。在4℃储存150天后，以酶活性保留率衡量的稳定性为：黑曲霉（58%）、费氏曲霉（26.8%）、茄病镰刀菌（83%）和绿色木霉（85.1%）。
