Efficient Over-expression and Application of High-performance Pectin Lyase by Screening Aspergillus niger Pectin Lyase Gene Family

Comparative Characterization of Aspergillus Pectin Lyases by Discriminative Substrate Degradation Profiling

“…Finally, the consistently low activities of all pectin lyases on polygalacturonic acid (Table 3) confirm the requirement for methoxylation to achieve pectin lyase activity. The same trend was recently reported for PelA from A. niger CBS 513.88, which had highest activity on citrus pectin (DM ≥ 85%), a relative activity of 59% compared to citrus pectin on a sample of apple pectin with a DM of 50-75%, and almost no activity on polygalacturonic acid (He et al, 2018). Among the six pectin lyases, AlPelB had the highest initial rate on both apple pectin and citrus pectin, whereas AaPelA had highest activity on sugar beet pectin ( Table 3).…”

“…The multigenecity of pectinolytic enzymes from Aspergilli has been the subject of several studies over the last three decades ( Harmsen et al, 1990 ; Kusters-van Someren et al, 1992 ; de Vries et al, 2002 ; Martens-Uzunova and Schaap, 2009 ; Benoit et al, 2012 ; Kowalczyk et al, 2017 ; He et al, 2018 ). Differences in pH optima ( Supplementary Table S1 ) and expression inducers may partially explain the large gene families observed for several different classes of pectinolytic enzymes ( Martens-Uzunova and Schaap, 2009 ; Andersen et al, 2012 ), but there is a need for rigorous biochemical characterization of the gene products including specificity toward pectins of different origin and in particular determination of product profiles in order to fully understand this multigenecity.…”

“…As expected, Aa PelA clusters with At PelA and PelA ( Figure 2 , Table 1 , and Supplementary Figure S2 ). The decision to include Aa PelA and no other A. aculeatus PL1_4 enzymes in the study reflects the fact that PelA is the most studied enzyme of the five, possibly due to its high activity and expression levels ( He et al, 2018 ).…”

“…The genomes of the A. tubingensis and A. luchuensis strains from which pectin lyases were sourced in the current work also contain pelE genes (UniProt entries A0A100I604 and G7XZW9, respectively), but no reports on PelE expression or activity of the pectin lyases from these strains exist. In a recent study, all five pectin lyase genes of A. niger CBS 513.88 -pelA, pelB, pelC, pelD, and pelF -were cloned and overexpressed in A. niger SH-2 (He et al, 2018). Of these, the pelA-recombinant strain exhibited the highest pectin lyase activity on apple pectin (DM 50-75%), and thus only PelA was selected for characterization.…”

“…are scarce ( Supplementary Table S1). Recently, the optima for PelA from A. niger CBS 513.88 were determined separately on citrus pectin (DM ≥ 85%) to pH 4.5 and 50 • C (He et al, 2018). Previously, PelA from A. niger (identified as PLII in the commercial Ultrazym preparation) was found to have a slightly substrate concentration-dependent optimum around pH 5.5-6.5 when determined at 25 • C on apple pectin with a DM of 94% (van Houdenhoven, 1975;Kester and Visser, 1994).…”