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An acidic pectin lyase from Aspergillus niger with favourable efficiency in fruit juice clarification
Author(s) -
Xu S.X.,
Qin X.,
Liu B.,
Zhang D.Q.,
Zhang W.,
Wu K.,
Zhang Y.H.
Publication year - 2015
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1111/lam.12357
Subject(s) - pectin lyase , aspergillus niger , chemistry , pectin , pectinase , food science , pichia pastoris , chromatography , ultrafiltration (renal) , esterase , fruit juice , biochemistry , enzyme , recombinant dna , gene
The pectin lyase gene pnl‐zj5a from Aspergillus niger ZJ5 was identified and expressed in Pichia pastoris . PNL‐ZJ5A was purified by ultrafiltration, anion exchange and gel chromatography. The K m and V max values determined using citrus pectin were 0·66 mg ml −1 and 32·6 μ mol min −1 mg −1 , respectively. PNL‐ZJ5A exhibited optimal activity at 43°C and retained activity over 25–50°C. PNL‐ZJ5A was optimally active at pH 5 and effective in apple juice clarification. Compared with controls, PNL‐ZJ5A increased the fruit juice yield significantly. Furthermore, PNL‐ZJ5A reduced the viscosity of apple juice by 38·8% and increased its transmittance by 86·3%. PNL‐ZJ5A combined with a commercial pectin esterase resulted in higher juice volume. Significance and Impact of the Study In this study, pectin lyase gene pnl‐zj5a from Aspergillus niger ZJ5 was expressed successfully in Pichia pastoris . The purified enzyme PNL‐ZJ5A exhibited optimal activity at 43°C and pH 5. In addition, the acidic pectin lyase PNL‐ZJ5A can effectively decreased the viscosity and improved the yield of apple juice and light transmittance. These favourable enzymatic properties of PNL‐ZJ5A show potential application in food industry, especially in juice‐processing applications and the extraction of plant tissue.