绿色木霉对小球藻细胞壁的酶解作用

Effect of Trichoderma viride on resolving cell wall of Chlorella

摘要:

【目的】探讨绿色木霉分泌液能否分解小球藻细胞壁。【方法】用海藻酸钠和氯化钙固定绿色木霉，将游离绿色木霉和固定化绿色木霉分别培养一段时间，离心培养液，用分光光度计法检测上清液中纤维素酶活性。在上清液中加入浓缩的小球藻悬浮液，用显微镜计数细胞壁破碎的小球藻。【结果】绿色木霉能同时分泌内切葡聚糖酶、外切葡聚糖酶及β-1,4葡萄糖苷酶3种纤维素酶，其中外切葡聚糖酶活性最高。固定化绿色木霉反复使用5次后，分泌的纤维素酶活性能保持到初次的67.4%。市售纤维素酶、游离绿色木霉、固定化绿色木霉初次及第5次分解小球藻细胞壁的效率分别为47.3%、86.5%、81.5%、52.1%。【结论】市售纤维素酶、游离绿色木霉、固定化绿色木霉都能分解小球藻细胞壁，其中固定化绿色木霉因可重复使用，具有潜在的应用前景。

Abstract:

[Objective] We studied the effect of Trichoderma viride on resolving Chlorella cell wall. [Methods] The cell wall of Chlorella was resolved by the secretion from free T. viride or immobilized T. viride in sodium alginate and calcium chloride. The activity of cellulases secreted by free T. viride or immobilized T. viride was determined by spectrophotometry. [Results] Cell wall of Chlorella was resolved by 86.5% by the secretion of free T. viride, 34.3% higher than that by cellulases R-10 containing only β-glucosidase. Compared to cellulases R-10, T. viride secretion contained three cellulases, namely, endo-glucanase, exo-glucanase and β-glucosidase. This was probably the reason why T. viride secretion had higher rate of resolving cell wall. Immobilized T. viride could be used repeatedly at least 5 times. The rate of resolving Chlorella cell wall by immobilized T. viride in the first time and the fifth time was 81.5% and 52.1% respectively. [Conclusion] Cell wall of Chlorella can be resolved by the secretion both from free T. viride and immobilized T. viride.