Namnuch Nattida, Thammasittirong Anon, Thammasittirong Sutticha Na-Ranong
Department of Microbiology, Faculty of Liberal Arts and Science, Kasetsart University, Nakhon Pathom, Thailand.
Microbial Biotechnology Unit, Faculty of Liberal Arts and Science, Kasetsart University, Nakhon Pathom, Thailand.
Mycology. 2020 Aug 18;12(2):119-127. doi: 10.1080/21501203.2020.1806938.
Lignocellulosic wastes, rice straw, sugarcane bagasse, rice bran and sawdust, and pure commercial carboxymethyl cellulose (CMC) and xylan were used as substrates to cultivate cellulolytic fungus, KUB2, in submerged fermentation at 30°C. Of all the substrates, sugarcane bagasse was a good source for the production of cellulolytic and also hemicellulolytic enzymes. The maximum activities of endoglucanase (CMCase), total cellulase (FPase) and xylanase using sugarcane bagasse as substrate were 8%, 75% and 165%, respectively, higher than those of the commercial substrates. The time course determination of enzyme production revealed that the highest CMCase (1.27 U/ml), FPase (0.72 U/ml) and xylanase (376.81 U/ml) activities were observed at 14 days of fermentation. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) analyses confirmed the efficient structural alteration of sugarcane bagasse caused by enzymatic actions during KUB2 cultivation. Based on the results of the hydrolytic enzyme activities, FTIR and SEM, KUB2 is suggested as an efficient hydrolytic enzymes producer and an effective lignocellulose degrader, while sugarcane bagasse can be applied as a low-cost carbon source for the economical production of lignocellulose hydrolytic enzymes by KUB2.
木质纤维素废料、稻草、甘蔗渣、米糠和锯末,以及纯商业羧甲基纤维素(CMC)和木聚糖被用作底物,在30℃下进行深层发酵培养纤维素分解真菌KUB2。在所有底物中,甘蔗渣是生产纤维素分解酶和半纤维素分解酶的良好来源。以甘蔗渣为底物时,内切葡聚糖酶(CMCase)、总纤维素酶(FPase)和木聚糖酶的最大活性分别比商业底物高8%、75%和165%。酶产生的时间进程测定表明,在发酵14天时观察到最高的CMCase(1.27 U/ml)、FPase(0.72 U/ml)和木聚糖酶(376.81 U/ml)活性。傅里叶变换红外(FTIR)光谱和扫描电子显微镜(SEM)分析证实了在KUB2培养过程中酶促作用导致甘蔗渣的有效结构改变。基于水解酶活性、FTIR和SEM的结果,建议KUB2作为一种高效的水解酶生产者和有效的木质纤维素降解剂,而甘蔗渣可作为低成本碳源用于KUB2经济生产木质纤维素水解酶。