Characterization of an Alkaline Thermostable Pectin Lyase from Newly Isolated Aspergillus niger _WHAK1 and Its Application on Fruit Juice Clarification

详细信息    查看全文

• 作者：K. Poturcu ; I. Ozmen ; H. H. Biyik
• 关键词：Aspergillus niger ; Chromatography ; Fruit juice clarification ; Metal ions ; Optimization ; Pectin lyase ; Pectin lyase purification ; SDS ; PAGE ; Submerged culture fermentation ; Viscosity of fruit juices
• 刊名：Arabian Journal for Science and Engineering
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：42
• 期：1
• 页码：19-29
• 全文大小：
• 刊物类别：Engineering
• 刊物主题：Engineering, general; Science, Humanities and Social Sciences, multidisciplinary;
• 出版者：Springer Berlin Heidelberg
• ISSN：2191-4281
• 卷排序：42

文摘

Pectin lyase degrades pectic substances that are complex polysaccharides of middle lamella and primary cell walls of plants. In this study, alkaline thermostable pectin lyase from Aspergillus niger strain_WHAK1 was produced on wheat bran and citrus pectin in submerged culture. Pectin lyase was purified by ammonium sulfate fractionation, gel filtration and ion-exchange chromatography, and 76.5 purification fold was obtained. Optimum pH and temperature values of pectin lyase were 8.0 and 40°C at 60min, respectively. The enzyme was stable for 17 months at 4°C. K_m and V_max values were found to be 5.2mg/mL and 0.2(mmol/min)−1 mL, respectively. Molecular weight of pectin lyase was nearly 23.3 kDa. Effects on PL activity of metal ions (NaCl, KCl, CaCl₂, MgCl₂, CoCl₂, CuCl₂.H₂O, FeCl₃.6H₂O, ZnSO₄.7H₂O, (NH₄)₂SO₄, MnSO₄), amino acids (l-tryptophan, l-cysteine hydrochloride monohydrate, l-arginine monohyd rate), ascorbic acid, citric acid monohydrate, EDTA and resorcinol were studied. The presence of FeCl₃, CaCl₂ and ascorbic acid significantly enhanced relative pectin lyase activity (%). The purified pectin lyase induced viscosity reduction in fruit juice samples, and it was effective for clarification of fruit juices. Pectin lyase showed substrate preference against fruit juice samples.