Karmakar M
Microbiology Research Laboratory, Department of Zoology, Molecular Biology & Genetics, Presidency University, Kolkata 1700 073, India.
Prikl Biokhim Mikrobiol. 2013 Jul-Aug;49(4):391-5. doi: 10.7868/s0555109913040077.
The induction of endoglucanase of Rhizopus oryzae PR7 MTCC 9642 has been observed in cultivation medium using a batch-fermentation technique. The effect of various experimental parameters such as use various carbon sources as inducers, concentration of inducer and effect of different additives were investigated. Salicin at concentrations from 0.25 to 0.75% (w/v) was found to bring about a remarkable increase in endoglucanase synthesis when used as a sole carbon source and thought to act as a gratuitous inducer of the enzyme. Endoglucanase activity increased within 24 h after the addition of salicin, reached maximum after 48 h and maintained high level even after 120 h of fungal growth. Repression of enzyme synthesis by glucose could partially be restored by addition of salicin at an early phase of growth. The carboxymethyl cellulose induced enzyme was inhibited by cyclohexamide and ethidium bromide and partially recovered by the salicin which indicated that salicin might act at the transcriptional but not translational level.
利用分批发酵技术在培养基中观察到米根霉PR7 MTCC 9642内切葡聚糖酶的诱导情况。研究了各种实验参数的影响，如使用各种碳源作为诱导剂、诱导剂浓度以及不同添加剂的作用。当水杨苷作为唯一碳源，浓度为0.25%至0.75%（w/v）时，发现其能显著提高内切葡聚糖酶的合成，被认为是该酶的一种安慰诱导剂。添加水杨苷后24小时内内切葡聚糖酶活性增加，48小时后达到最大值，即使在真菌生长120小时后仍保持高水平。在生长早期添加水杨苷可部分恢复葡萄糖对酶合成的抑制作用。羧甲基纤维素诱导的酶受到环己酰亚胺和溴化乙锭的抑制，并被水杨苷部分恢复，这表明水杨苷可能作用于转录水平而非翻译水平。
