Goyari S, Devi S H, Bengyella L, Khan M, Sharma C K, Kalita M C, Talukdar N C
Institute of Bioresources and Sustainable development (IBSD), Imphal, Manipur, India.
Institute of Advanced Study in Science and Technology (IASST), Boragaon, Assam, India.
J Appl Microbiol. 2015 Jul;119(1):88-98. doi: 10.1111/jam.12816. Epub 2015 May 18.
Elucidation of different physico-chemical parameters and the secretory enzymes released by Talaromyces verruculosus SGMNPf3 during cellulosic biomass degradation.
We determined the optimal pH, temperature and time course parameters for the efficient degradation of different natural and commercial cellulosic substrates by T. verruculosus SGMNPf3, previously isolated from a forest soil. The optimal growth of the fungus and production of its cellulases were obtained when the culture condition was maintained at pH 3·3 and temperature 30°C. Activity of the crude cellulases was maximum at 60°C. Activity of cellulase enzymes produced on natural cellulose substrates was higher than that on commercial cellulose substrates. A continuous increase in cellulase activity at different time points indicated no apparent end product inhibition. This might be attributed to the high individual cellulases, notably β-glucosidase (316·1 μmol g(-1) ) production. Zymogram of extracellular crude proteins showed two dominant extracellular protein bands of molecular weight 72·3 and 61·4 kDa, indicating their cellulolytic nature. MALDI-TOF and LC-MS/MS analysis of the 2DE spots also identified several enzymes including β-glucosidase involved in the process of cellulose degradation.
Based on its optimal parameters for cellulolytic activities, we suggest that the fungus is acido-mesophilic. There was apparently no end-product inhibition of the cellulase activity and this is attributed to the ability of the fungus to produce sufficient β-glucosidase. The dominant proteins secreted by the fungus were confirmed to be cellulases.
The high individual cellulase activities, better cellulase production on natural substrates and apparent absence of end-product inhibition are characteristics of T. verruculosus SGMNPf3 for use in harvesting naturally endowed energy in cellulosic biomass.
阐明疣孢青霉SGMNPf3在纤维素生物质降解过程中释放的不同物理化学参数和分泌酶。
我们确定了先前从森林土壤中分离出的疣孢青霉SGMNPf3高效降解不同天然和商业纤维素底物的最佳pH值、温度和时间进程参数。当培养条件维持在pH 3.3和温度30°C时，该真菌实现了最佳生长并产生了纤维素酶。粗纤维素酶的活性在60°C时最高。在天然纤维素底物上产生的纤维素酶活性高于商业纤维素底物上的活性。不同时间点纤维素酶活性持续增加表明没有明显的终产物抑制作用。这可能归因于高个体纤维素酶，尤其是β-葡萄糖苷酶（316.1 μmol g(-1)）的产生。细胞外粗蛋白的酶谱显示出两条主要的细胞外蛋白带，分子量分别为72.3和61.4 kDa，表明它们具有纤维素分解性质。对二维电泳斑点的基质辅助激光解吸电离飞行时间质谱（MALDI-TOF）和液相色谱-串联质谱（LC-MS/MS）分析还鉴定出了几种参与纤维素降解过程的酶，包括β-葡萄糖苷酶。
基于其纤维素分解活性的最佳参数，我们认为该真菌是嗜酸嗜温菌。纤维素酶活性显然没有终产物抑制作用，这归因于该真菌产生足够β-葡萄糖苷酶的能力。已证实该真菌分泌的主要蛋白质是纤维素酶。
高个体纤维素酶活性、在天然底物上更好的纤维素酶产生以及明显不存在终产物抑制作用是疣孢青霉SGMNPf3用于获取纤维素生物质中天然能量的特征。
