Purification and biochemical characterization of a novel thermostable endo-polygalacturonase from Aspergillus niger strain HO32 and its suitability for clarification of orange juice
{"title":"Purification and biochemical characterization of a novel thermostable endo-polygalacturonase from Aspergillus niger strain HO32 and its suitability for clarification of orange juice","authors":"Nour Eddine Bentouhami , Abdeslam Asehraou , Sondes Mechri , Ismail Hasnaoui , Sara Moumnassi , Meryem Idrissi Yahyaoui , Fatima Brahmi , Mohamed Taibi , Reda Bellaouchi , Abdelkarim Abousalham , Loubna Firdaous , Ennouamane Saalaoui , Bassem Jaouadi","doi":"10.1016/j.procbio.2024.06.013","DOIUrl":null,"url":null,"abstract":"<div><p>A novel <em>endo</em>-polygalacturonase (PGC-AN64) from <em>Aspergillus niger</em> HO32 was produced (88.22 U/mL) on orange peel by-product (OPP), purified, biochemically characterized, and its utility in clarification of orange juice was elucidated. The enzyme was purified by ammonium sulfate fractionation (80 %) and gel filtration chromatography on Sephacryl® S-200 HR column. Its pH and temperature optima were 6.5 and 70 °C, respectively, and was stable over a pH range of 5–7 and temperature 60–80 °C. The 26-residue NH<sub>2</sub>-terminal sequence of PGC-AN64 showed high homology with those of <em>Aspergillus</em> pectinases. Metal ions (Na<sup>+</sup>, Ca<sup>2+</sup>, Mg<sup>2+</sup>, Mn<sup>2+</sup>, and Zn<sup>2+</sup>) positively affect PGC-AN64 activity, while Ba<sup>2+</sup>, Cd<sup>2+</sup>, and Cr<sup>3+</sup> negatively affect its original activity. Interestingly, PGC-AN64 exhibited a considerable substrate specificity and catalytic efficiency compared to the commercial enzymes PECLYVE V (P1) and PECLYVE CP (P2). More interestingly and compared to P1 and P2, PGC-AN64 showed that the clarification process had a significant effect on the transmittance percentages with 84.68 ± 2.08, 88.05 ± 1.79, and 93.13 ± 3.58 % for PGC-AN64, P1, and P2, respectively. Furthermore, color parameters after the clarification process increase in the L* and b* values, and led to a decrease in the a* value. The obtained results suggest that PGC-AN64 revealed its potential in orange juice clarification.</p></div>","PeriodicalId":20811,"journal":{"name":"Process Biochemistry","volume":null,"pages":null},"PeriodicalIF":3.7000,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Process Biochemistry","FirstCategoryId":"99","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1359511324001995","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
A novel endo-polygalacturonase (PGC-AN64) from Aspergillus niger HO32 was produced (88.22 U/mL) on orange peel by-product (OPP), purified, biochemically characterized, and its utility in clarification of orange juice was elucidated. The enzyme was purified by ammonium sulfate fractionation (80 %) and gel filtration chromatography on Sephacryl® S-200 HR column. Its pH and temperature optima were 6.5 and 70 °C, respectively, and was stable over a pH range of 5–7 and temperature 60–80 °C. The 26-residue NH2-terminal sequence of PGC-AN64 showed high homology with those of Aspergillus pectinases. Metal ions (Na+, Ca2+, Mg2+, Mn2+, and Zn2+) positively affect PGC-AN64 activity, while Ba2+, Cd2+, and Cr3+ negatively affect its original activity. Interestingly, PGC-AN64 exhibited a considerable substrate specificity and catalytic efficiency compared to the commercial enzymes PECLYVE V (P1) and PECLYVE CP (P2). More interestingly and compared to P1 and P2, PGC-AN64 showed that the clarification process had a significant effect on the transmittance percentages with 84.68 ± 2.08, 88.05 ± 1.79, and 93.13 ± 3.58 % for PGC-AN64, P1, and P2, respectively. Furthermore, color parameters after the clarification process increase in the L* and b* values, and led to a decrease in the a* value. The obtained results suggest that PGC-AN64 revealed its potential in orange juice clarification.
期刊介绍:
Process Biochemistry is an application-orientated research journal devoted to reporting advances with originality and novelty, in the science and technology of the processes involving bioactive molecules and living organisms. These processes concern the production of useful metabolites or materials, or the removal of toxic compounds using tools and methods of current biology and engineering. Its main areas of interest include novel bioprocesses and enabling technologies (such as nanobiotechnology, tissue engineering, directed evolution, metabolic engineering, systems biology, and synthetic biology) applicable in food (nutraceutical), healthcare (medical, pharmaceutical, cosmetic), energy (biofuels), environmental, and biorefinery industries and their underlying biological and engineering principles.