新種Piromyces sp.瘤胃厭氧真菌之生化性質分析及稻稈降解應用研究

Novel Rumen Anaerobic Fungus Piromyces sp.: Biochemical Characterization and Rice Straw Degradation Studies

蔡承佳(Zheng-Chia Tsai) ； 陳勁中(Chin-Chung Chen) ； 陳寶東(Bao-Dong Chen) ； 許惠茹(Huei-Ju Hsu)

《石油季刊》 52卷1期 (2016/03) Pp. 123-138

摘要

瘤胃厭氧真菌能夠分泌木質纖維分解酵素，在木質纖維素的降解中扮演重要角色，因此可應用於開發新式工業用酵素。本研究成功地自水牛中分離出瘤胃真菌CPCW10，經形態與核醣體基因鑑定結果推測與 Piromyces 屬菌株親緣關係最接近，尤其該菌株的假根在成熟後會出現類似珠狀的形態，這個形態特徵在其他Piromyces 屬的菌株中仍未被發表， 有可能屬於新種菌株。以CPCW10 菌株探討木質纖維分解酵素生產時，發現以稻稈或結晶型纖維素作為碳源下，對於酵素群之誘導生產均優於羧甲基纖維素(CMC)，也發現稻稈較易誘導聚木聚酶(Xylanase)酵素表現。聚木糖酶最佳反應活性落在pH 4～5 與50℃左右、內切型纖維分解酵素(CMCase)最佳反應活性則落在 pH 5 與40～50℃之間。以稻稈培養CPCW10 經過5 天後，發現35% 稻稈木質纖維素降解完成。

關鍵字

厭氧真菌 ； 纖維素分解酵素 ； 稻稈

並列摘要

Rumen anaerobic fungi are known to secrete lignocellulolytic enzymes which play an important role in lignocellulose degradation. So that can be applied to the development of novel industrial enzymes. In this study, we have successfully isolated the fungus CPCW10 from water buffalo rumen Results from morphological and ribosomal gene analysis indicated that it belonged most likely to Piromyces sp. The beaded morphology of mature CPCW10 rhizoids has not yet been documented in other Piromyces sp., implying that it may be a novel strain. Subsequent investigation on CPCW10 to produce lignocellulolytic enzymes showed that using rice straw or avicel as a carbon source yielded better results than using carboxymethyl cellulose (CMC), and xylanase production was also induced easier than others by using rice straw as a carbon source. The optimal conditions for the highest xylanase activity were pH 4 to 5 and at 50 °C. The optimal conditions for the highest endoglucanase activity were pH 5 and 40 to 50 °C. After five days of cultivation, CPCW10 was able to degrade up to 35% of lignocellulose in the rice straw.

並列關鍵字

Rumen Fungi ； Lignocellulolytic Enzymes ； Rice Straw