Suberin of Potato (Solanum tuberosum Var. Nikola): Comparison of the Effect of Cutinase CcCut1 with Chemical Depolymerization

Abstract

Chemical and enzymatic depolymerizations of suberin isolated from potato peel (Solanum tuberosum var. Nikola) were performed under various conditions. Enzymatic hydrolysis with cutinase CcCut1 and chemical methanolysis with NaOMe of suberin yielded monomeric fragments, which were identified as TMS derivatives with GC-MS and GC-FID. The solid, hydrolysis-resistant residues were analyzed with solid state 13 C CPMAS NMR, FT-IR, and microscopic methods. Methanolysis released more CHCl 3 -soluble material than the cutinase treatment when determined gravimetrically. Interestingly, cutinase-catalyzed hydrolysis produced higher proportions of aliphatic monomers than hydrolysis with the NaOMe procedure when analyzed by GC in the form of TMS derivatives. Monomers released by the two methods were mainly R,ω-dioic acids and ω-hydroxy acids, but the ratios of the detected monomers were different, at 40.0 and 32.7% for methanolysis and 64.6 and 8.2% for cutinase, respectively. Thus, cutinase CcCut1 showed higher activity toward ester bonds of R,ω-dioic acids than toward the bonds of ω-hydroxy acids. The most abundant monomeric compounds were octadec-9-ene-1,18-dioic acid and 18-hydroxyoctadec-9-enoic acid, which accounted for ca. 37 and 28% of all monomers, respectively. The results of the analyses of the chemical and enzymatic hydrolysis products were supported by the spectroscopic analyses with FT-IR and CPMAS 13 C NMR together with the analysis of the microstructures of the hydrolysis residues by light and confocal microscopy.

Differences in suberin content and composition between two varieties of potatoes (Solanum tuberosum) and effect of post-harvest storage to the composition

“…When using cholesterol as internal standard, w50e60 w-% of the CHCl 3 -soluble methanolysis product was detected with GC [no difference (p > 0.05) within or between varieties]. This is in accordance with previously published results (Graça & Pereira, 2000;Järvinen et al, 2009). Thus the proportions of monomers could be reliably compared.…”

“…The aliphatic domain of the native potato suberin consists of a three-dimensional network of esterified and usually substituted long chain a,u-dicarboxylic acids, u-hydroxy acids, fatty acids and alcohols, in addition to hydroxycinnamic acid derivatives and glycerol (Graça & Pereira, 2000;Järvinen et al, 2009;Kolattukudy & Agrawal, 1974;Schreiber et al, 2005). The polyaromatic domain is composed of p-hydroxycinnamic acids and guaiacyl-monolignols, as most recently studied with 31 P-NMR after solubilization in ionic liquids (Mattinen et al, 2009).…”

Which properties of cutinases are important for applications?

“…Cutin preparations contain the non-hydrolysable component cutan, and suberins consist of polyphenolics in addition to polyesters. For instance, a degree of hydrolysis of 27 % (w/w) of potato suberin was obtained by methanolysis, whereas hydrolysis with the cutinase from Coprinopsis cinerea as the catalyst yielded 15 % of hydrolysis (Järvinen et al 2009). This suggests that although chemical depolymerisation was in this case more efficient, with both methods a considerable unhydrolysed residue remains.…”

ANCUT2, an Extracellular Cutinase from Aspergillus nidulans Induced by Olive Oil

“…The organic phase was extracted with chloroform and filtrated by suction filtration on a Büchner funnel through a 0.45-μm nylon membrane (Whatman) [17]. The solvent was removed by suction and the samples were analyzed by infrared spectroscopy as described above.…”