Bou-Mitri Christelle, Kermasha Selim
Faculty of Nursing and Health Sciences, Notre Dame University Zouk Mosbeh, P.O.Box: 72, Zouk Mikael, Lebanon.
Department of Food Science and Agricultural Chemistry, McGill University, 21,111 Lakeshore, Ste-Anne de Bellevue, QC, H9X 3V9, Canada.
AMB Express. 2018 Sep 27;8(1):152. doi: 10.1186/s13568-018-0683-3.
The development of stable lyophilized laccase, obtained from Coriolus hirsutus, using a wide range of temperature treatments and storage conditions, was investigated. Using selected lyoprotectants, including, dextran 6 kDa, sucrose and a mixture of sodium benzoate, potassium sorbate and sorbitol (BKSS) (1.5:1.0:98.5; w/w/w) resulted by 2.4, 1.4 and 1.8-fold increase in laccase activity after lyophilization as compared to the fresh enzyme, respectively, whereas the addition of mannitol preserved 98.2% of its activity. Using 2.5% (w/v) dextran (15-25 kDa) or mannitol appeared to be the most appropriate lyoprotectants for the laccase activity. The laccase stability of the lyophilized enzymatic extract was greatly enhanced with the presence of mannitol, with 96.2, 38.9 and 24.7% of residual activity after 4 weeks of storage at - 80, 4 and 25 °C, respectively. The inactivation constant (k) value and the amount required to decrease 50% of the laccase activity (C) showed that Carbowax polyethylene glycol (PEG)-8000 was the most appropriate additive for laccase activity, followed by glycerol and CuSO. When the enzymatic extract was incubated at 50 °C in the presence of either CuSO, PEG-8000 or glycerol, the time required to decrease 50% of the laccase initial activity (t), were 52.9, 54.6, 50.2 h, respectively, as compared to that of the control trial of 38.9 h.
研究了从糙皮侧耳中获得的稳定冻干漆酶在广泛的温度处理和储存条件下的情况。使用选定的冻干保护剂，包括6 kDa葡聚糖、蔗糖以及苯甲酸钠、山梨酸钾和山梨醇的混合物（BKSS）（1.5:1.0:98.5；w/w/w），冻干后漆酶活性分别比新鲜酶提高了2.4倍、1.4倍和1.8倍，而添加甘露醇可保留其98.2%的活性。使用2.5%（w/v）的葡聚糖（15 - 25 kDa）或甘露醇似乎是漆酶活性最合适的冻干保护剂。在甘露醇存在的情况下，冻干酶提取物的漆酶稳定性大大提高，在-80、4和25℃储存4周后，残留活性分别为96.2%、38.9%和24.7%。失活常数（k）值和使漆酶活性降低50%所需的量（C）表明，聚乙二醇（PEG）-8000是漆酶活性最合适的添加剂，其次是甘油和硫酸铜。当酶提取物在硫酸铜、PEG - 8000或甘油存在下于50℃孵育时，使漆酶初始活性降低50%所需的时间（t）分别为52.9、54.6、50.2小时，而对照试验为38.9小时。
