Ge Jingping, Du Renpeng, Zhao Dan, Song Gang, Jin Man, Ping Wenxiang
Key Laboratory of Microbiology, College of Life Science, Heilongjiang University, Harbin, 150080 People's Republic of China.
School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People's Republic of China.
Springerplus. 2016 Oct 21;5(1):1824. doi: 10.1186/s40064-016-3496-3. eCollection 2016.
The microbial -mannanases have been increasingly exploited for bioconversion of biomass materials and various potential industrial applications, such as bleaching of softwood pulps, scouring and desizing, food and feed additive, and oil and textile industries. In this paper, a -mannanase was characterization from the bacteria, HDYM-04, which was a high -mannanase-producing strain (576.16 ± 2.12 U/mL at 48 h during fermentation).
The michaelis constant ( ) and maximum velocity ( ) of -mannanase were determined. The effect of organic solvents, inhibitors, detergents, chelating agents, oxidizing agents and reducing agents on the stability of enzyme were determined. The degradation of twenty-two structurally different dyes by the purified -mannanase produced by HDYM-04 was determined by full spectrum scan among 200-1000 nm at 0 min and 10 min, respectively.
-Mannanase produced by HDYM-04 was highly specific towards glucomannan, where as exhibited low activity towards guar gum. Michaelis constant ( ) and maximum velocity ( ) of glucomannan substrate were 2.69 mg/ml and 251.41 U/mg, respectively. The activity of different organic solvents showed significantly difference ( < 0.05). It retained > 80 % activity in dimethyl sulfoxide, acetone, chloroform, benzene, hexane. In the presence of solvents, citric acid, ethylene diamine teraacetic acid and potassium iodide, it retained > 80 % residual activity. Twenty-two structurally different dyes could be effectively decolourised by -mannanase within 12 h, in which methyl orange (99.89 ± 2.87 %), aniline blue (90.23 ± 2.87 %) and alizalin (83.63 ± 2.89 %) had high decolorization rate.
The obtained results displayed that the -mannanase produced by HDYM-04 showed high stability under different chemical reagents and was found to be capable of decolorizing synthetic dyes with different structures. So, the reported biochemical properties of the purified -mannanase and its rapid decolorizations of dyes suggested that it might be suitable for industrial wastewater bioremediation.
微生物β-甘露聚糖酶已越来越多地用于生物质材料的生物转化及各种潜在的工业应用，如软木纸浆漂白、精练和退浆、食品和饲料添加剂以及石油和纺织工业。本文对从高产β-甘露聚糖酶菌株HDYM-04中获得的β-甘露聚糖酶进行了表征（发酵48小时时酶产量为576.16±2.12 U/mL）。
测定了β-甘露聚糖酶的米氏常数（Km）和最大反应速度（Vmax）。测定了有机溶剂、抑制剂、去污剂、螯合剂、氧化剂和还原剂对该酶稳定性的影响。通过在200 - 1000 nm波长范围内分别于0分钟和10分钟进行全光谱扫描，测定了HDYM-04产生的纯化β-甘露聚糖酶对22种结构不同的染料的降解情况。
HDYM-04产生的β-甘露聚糖酶对葡甘露聚糖具有高度特异性，而对瓜尔豆胶活性较低。葡甘露聚糖底物的米氏常数（Km）和最大反应速度（Vmax）分别为2.69 mg/ml和251.41 U/mg。不同有机溶剂对酶活性的影响差异显著（P < 0.05）。在二甲基亚砜、丙酮、氯仿、苯、己烷中该酶保留>80%的活性。在柠檬酸、乙二胺四乙酸和碘化钾存在下，该酶保留>80%的残余活性。22种结构不同的染料在12小时内可被β-甘露聚糖酶有效脱色，其中甲基橙（99.89±2.87%）、苯胺蓝（90.23±2.87%）和茜素（83.63±2.89%）脱色率较高。
所得结果表明，HDYM-04产生的β-甘露聚糖酶在不同化学试剂作用下表现出高稳定性，且能够使不同结构的合成染料脱色。因此，所报道的纯化β-甘露聚糖酶的生化特性及其对染料的快速脱色表明它可能适用于工业废水的生物修复。
