南极真菌 Lecanicillium muscarium CCFEE 5003 在台式生物反应器中利用虾废料高产耐寒几丁质酶：生物过程优化和两种主要酶的特性。

High production of cold-tolerant chitinases on shrimp wastes in bench-top bioreactor by the Antarctic fungus Lecanicillium muscarium CCFEE 5003: bioprocess optimization and characterization of two main enzymes.

机构信息

Dipartimento di Scienze Ecologiche e Biologiche, Agroalimentari e Forestali, Largo Università snc, University of Tuscia, I-01100 Viterbo, Italy.

出版信息

Enzyme Microb Technol. 2013 Oct 10;53(5):331-8. doi: 10.1016/j.enzmictec.2013.07.005. Epub 2013 Jul 20.

DOI:10.1016/j.enzmictec.2013.07.005

PMID:24034432

Abstract

The Antarctic fungus Lecanicillium muscarium CCFEE-5003 was preliminary cultivated in shaken flasks to check its chitinase production on rough shrimp and crab wastes. Production on shrimp shells was much higher than that on crab shells (104.6±9.3 and 48.6±3.1U/L, respectively). For possible industrial applications, bioprocess optimization was studied on shrimp shells in bioreactor using RSM to state best conditions of pH and substrate concentration. Optimization improved the production by 137% (243.6±17.3). Two chitinolytic enzymes (CHI1 and CHI2) were purified and characterized. CHI1 (MW ca. 61kDa) showed optima at pH 5.5 and 45°C while CHI2 (MW ca. 25kDa) optima were at pH 4.5 and 40°C. Both enzymes maintained high activity levels at 5°C and were inhibited by Fe(++), Hg(++) and Cu(++). CHI2 was strongly allosamidin-sensitive. Both proteins were N-acetyl-hexosaminidases (E.C. 3.2.1.52) but showed different roles in chitin hydrolysis: CHI1 could be defined as "chitobiase" while CHI2 revealed a main "eso-chitinase" activity.

摘要

南极真菌 Lecanicillium muscarium CCFEE-5003 最初在摇瓶中培养，以检查其在粗虾蟹废物上产生的几丁质酶。虾壳上的产量明显高于蟹壳（分别为 104.6±9.3 和 48.6±3.1U/L）。为了可能的工业应用，使用 RSM 在生物反应器中对虾壳进行生物过程优化，以确定最佳 pH 和底物浓度条件。优化使产量提高了 137%（243.6±17.3）。两种几丁质酶（CHI1 和 CHI2）被纯化和表征。CHI1（MW 约 61kDa）在 pH 5.5 和 45°C 时表现出最佳活性，而 CHI2（MW 约 25kDa）在 pH 4.5 和 40°C 时表现出最佳活性。两种酶在 5°C 时均保持高活性水平，并被 Fe(++), Hg(++) 和 Cu(++）抑制。CHI2 对 allo 他定高度敏感。两种蛋白质都是 N-乙酰己糖胺酶（E.C. 3.2.1.52），但在几丁质水解中表现出不同的作用：CHI1 可以定义为“壳二糖酶”，而 CHI2 显示出主要的“外切壳多糖酶”活性。