Mukhtar Hamid, Haq Ikramul
Institute of Industrial Biotechnology, GC University, Lahore 54000, Pakistan.
ScientificWorldJournal. 2013 Oct 31;2013:538067. doi: 10.1155/2013/538067. eCollection 2013.
The present study describes the screening of different agroindustrial byproducts for enhanced production of alkaline protease by a wild and EMS induced mutant strain of Bacillus subtilis IH-72(EMS8). During submerged fermentation, different agro-industrial byproducts were tested which include defatted seed meals of rape, guar, sunflower, gluten, cotton, soybean, and gram. In addition to these meals, rice bran, wheat bran, and wheat flour were also evaluated for protease production. Of all the byproducts tested, soybean meal at a concentration of 20 g/L gave maximum production of the enzyme, that is, 5.74 ± 0.26 U/mL from wild and 11.28 ± 0.45 U/mL from mutant strain, during submerged fermentation. Different mesh sizes (coarse, medium, and fine) of the soybean meal were also evaluated, and a finely ground soybean meal (fine mesh) was found to be the best. In addition to the defatted seed meals, their alkali extracts were also tested for the production of alkaline protease by Bacillus subtilis, but these were proved nonsignificant for enhanced production of the enzyme. The production of the enzyme was also studied in solid state fermentation, and different agro-industrial byproducts were also evaluated for enzyme production. Wheat bran partially replaced with guar meal was found as the best substrate for maximum enzyme production under solid state fermentation conditions.
本研究描述了利用枯草芽孢杆菌IH-72（EMS8）的野生型和经甲基磺酸乙酯（EMS）诱变的突变株，筛选不同农业工业副产品以提高碱性蛋白酶产量的过程。在深层发酵过程中，测试了不同的农业工业副产品，包括油菜籽粕、瓜尔豆粕、向日葵粕、面筋、棉籽粕、大豆粕和鹰嘴豆粕。除了这些粕类，还评估了米糠、麦麸和小麦粉用于蛋白酶生产的情况。在所有测试的副产品中，浓度为20 g/L的大豆粕在深层发酵过程中酶产量最高，野生型菌株产生的酶量为5.74±0.26 U/mL，突变株产生的酶量为11.28±0.45 U/mL。还评估了不同目数（粗、中、细）的大豆粕，发现细磨的大豆粕（细目）是最好的。除了脱脂粕类，还测试了它们的碱提取物用于枯草芽孢杆菌生产碱性蛋白酶的情况，但结果表明这些提取物对提高酶产量没有显著作用。还研究了固态发酵中该酶的生产情况，并评估了不同农业工业副产品用于酶生产的情况。发现在固态发酵条件下，用瓜尔豆粕部分替代的麦麸是产生最大酶量的最佳底物。
