To evaluate the production of a cold-active CMCase (endoglucanase) by Bacillus mycoides AR20-61 isolated from Alpine forest soil and to characterize the crude enzyme. After studying the effect of cultivation parameters (medium composition, temperature, NaCl concentration, pH) on bacterial growth and enzyme production, the crude enzyme was characterized with regard to the effect of pH, temperature, and inhibitors on enzyme activity and stability. Optimum growth and enzyme production occurred at 20–25 °C, pH 7, and 1–1.5% (w/v) CMC. Despite high biomass production over the whole growth temperature range (10–35 °C), enzyme production was low at 10 and 35 °C. CMC concentration had a minor effect on growth, independent of the growth temperature, but a significant effect on CMCase production at temperatures ≥ 20 °C. The crude enzyme was active over a broad temperature range (0–60 °C); the apparent optimum temperature for activity was at 40–50 °C. The cultivation temperature influenced the effect of temperature on enzyme activity and stability. A significantly higher thermosensitivity of the enzyme produced at a cultivation temperature of 10 °C compared to that produced at 25 °C was noted at 50 and 65 °C. The enzyme was highly active over a pH range of 4–6 and showed optimum activity at pH 5. No activity was lost after 60 min of incubation at 30 °C and pH 4–9. The CMCase was resistant against a number of monovalent and divalent metal ions, metal-chelating agents, and phenol. The CMCase produced by the studied strain is characterized by high activities in the low temperature range (down to 0 °C) and acidic pH range, high stability over a broad pH range, and high resistance against a number of effectors. Our results also demonstrate the different, independent roles of temperature in bacterial growth, enzyme production, nutrient requirements during enzyme production, and enzyme characteristics regarding thermosensitivity, which has not yet been described for cellulases.

中文翻译：

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从高山森林站点分离的芽孢杆菌AR20-61的粗冷活性纤维素酶（CMCase）的生产和部分表征

评估从高山森林土壤中分离的Mycoides AR20-61芽孢杆菌产生的冷活性CMCase（内切葡聚糖酶）并鉴定其粗酶。在研究了培养参数（培养基组成，温度，NaCl浓度，pH）对细菌生长和酶产生的影响后，针对pH，温度和抑制剂对酶活性和稳定性的影响，对粗酶进行了表征。在20–25°C，pH 7和1–1.5％（w / v）CMC时，最佳的生长和酶的产生发生了。尽管在整个生长温度范围（10–35°C）中都有较高的生物量产生，但是在10和35°C时酶的产生量较低。CMC浓度对生长的影响不大，与生长温度无关，但在≥20°C的温度下，对CMCase产生的影响显着。粗酶在很宽的温度范围（0–60°C）内有活性；活性的最佳最佳温度为40–50°C。培养温度影响温度对酶活性和稳定性的影响。在50和65°C下，与在25°C下产生的酶相比，在10°C的培养温度下产生的酶的热敏性明显更高。该酶在4-6的pH范围内具有很高的活性，在5 pH值下显示最佳活性。在30°C和pH 4-9的条件下孵育60分钟后，该酶没有损失。CMCase对许多一价和二价金属离子，金属螯合剂和苯酚具有抗性。由研究菌株产生的CMCase的特点是在低温范围（低至0°C）和酸性pH范围内具有高活性，在宽pH范围内具有高稳定性，对多种效应子具有高抵抗力。我们的结果还证明了温度在细菌生长，酶产生，酶产生过程中的营养需求以及关于热敏性的酶特性方面的不同，独立的作用，纤维素酶尚未对此进行描述。