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【目的】明确极端嗜热厌氧木质纤维素降解菌解糖热解纤维素菌F32代谢特征,并分析其产酶特性。【方法】使用细胞计数法绘制菌株的生长曲线,使用离子色谱及气相色谱进行产物和残糖量分析,以DNS法及对硝基苯酚法检测菌株胞外蛋白的酶活性。【结果】解糖热解纤维素菌F32在以葡萄糖、微晶纤维素和未经预处理小麦秸秆为碳源时生长状况优于解糖热解纤维素菌DSM 8903。在以葡萄糖为碳源进行培养时,与菌株DSM 8903相比,菌株F32具有产乳酸较多,而产氢气较少的特点。在以微晶纤维素和未经预处理小麦秸秆为碳源进行培养时,与菌株DSM 8903相比,菌株F32胞外蛋白具有较高的内切纤维素酶活性和木聚糖酶活性。【结论】解糖热解纤维素菌F32表现出较强的木质纤维素降解能力,其与DSM 8903的产物组成及胞外蛋白的酶活性具有明显差异。
【Objective】 The purpose of this study was to determine the metabolic characteristics of cellulase-degrading cellulase F32 from extreme thermophilic anaerobic lignocellulosic degrading bacteria and to analyze its enzyme-producing characteristics. 【Method】 The growth curves of the strains were drawn by cell counting method. The products and residual sugar contents were analyzed by ion chromatography and gas chromatography. The enzyme activity of extracellular proteins was tested by DNS and p-nitrophenol method. 【Result】 The results showed that the growth of glucose-decomposing cellulolytic bacterium F32 was better than that of DSM 8903 with glucose, microcrystalline cellulose and non-pretreated wheat straw as carbon sources. When cultured with glucose as a carbon source, strain F32 has the advantage of producing more lactic acid and less hydrogen when compared to strain DSM 8903. Compared with strain DSM 8903, strain F32 extracellular protein had higher endo-cellulase activity and xylanase activity when cultured with microcrystalline cellulose and wheat straw without carbon pre-treatment. 【Conclusion】 Lysosmic-hydrolyzed Cellulose F32 showed strong ability of degrading lignocellulose, which was significantly different from the product composition of DSM 8903 and the activity of extracellular protein.