Centre for Advanced Studies in Botany, University of Madras-Guindy Campus, Chennai, India.
J Microbiol Biotechnol. 2011 Jun;21(6):627-36.
A commercially important alkaline protease, produced by Bacillus sp. RRM1 isolated from the red seaweed Kappaphycus alvarezii (Doty) Doty ex Silva, was first recognized and characterized in the present study. Identification of the isolated bacterium was done using both biochemical characterization as well as 16S rRNA gene sequencing. The bacterial strain, Bacillus sp. RRM1, produced a high level of protease using easily available, inexpensive agricultural residues solid-state fermentation (SSF). Among them, wheat bran was found to be the best substrate. Influences of process parameters such as moistening agents, moisture level, temperature, inoculum concentration, and co-carbon and co-nitrogen sources on the fermentation were also evaluated. Under optimized conditions, maximum protease production (i.e., 2081 U/g) was obtained from wheat bran, which is about 2-fold greater than the initial conditions. The protease enzyme was stable over a temperature range of 30-60 degrees C and pH 6-12, with maximum activity at 50 degrees C and pH 9.0. Whereas the metal ions Na+, Ca2+, and K+ enhanced the activity of the enzyme, others such as Hg2+, Cu2+, Fe2+, Co2+, and Zn2+ had rendered negative effects. The activity of the enzyme was inhibited by EDTA and enhanced by Cu2+ ions, thus indicating the nature of the enzyme as a metalloprotease. The enzyme showed extreme stability and activity even in the presence of detergents, surfactants, and organic solvents. Moreover, the present findings opened new vistas in the utilization of wheat bran, a cheap, abundantly available, and effective waste as a substrate for SSF.
从红海藻 Kappaphycus alvarezii（Doty）Doty ex Silva 中分离出的芽孢杆菌 RRM1 产生的一种具有商业重要性的碱性蛋白酶，在本研究中首次被识别和表征。通过生化特征和 16S rRNA 基因测序对分离出的细菌进行鉴定。该细菌菌株 Bacillus sp. RRM1 使用易于获得、廉价的农业残留物固态发酵（SSF）生产高水平的蛋白酶。其中，发现麦麸是最好的底物。还评估了过程参数（如润湿剂、水分水平、温度、接种浓度以及共碳和共氮源）对发酵的影响。在优化条件下，从麦麸中获得最大蛋白酶产量（即 2081 U/g），比初始条件高约 2 倍。该蛋白酶在 30-60°C 的温度范围内和 pH6-12 的范围内稳定，最大活性在 50°C 和 pH9.0 时达到。而金属离子 Na+、Ca2+和 K+增强了酶的活性，而 Hg2+、Cu2+、Fe2+、Co2+和 Zn2+等其他金属离子则产生了负效应。该酶的活性被 EDTA 抑制，被 Cu2+离子增强，这表明该酶的性质为金属蛋白酶。该酶即使在存在洗涤剂、表面活性剂和有机溶剂的情况下，也表现出极高的稳定性和活性。此外，本研究结果为利用麦麸作为 SSF 的廉价、丰富和有效的底物开辟了新的前景。
