Xylanase from Marine Filamentous Fungus<i> Pestalotiopsis</i> sp. AN-7 Was Activated with Diluted Salt Solution Like Brackish Water

Abstract

The genus Pestalotiopsis are endophytic fungi that have recently been identified as cellulolytic system producers. We herein cloned a gene coding for a xylanase belonging to glycoside hydrolase (GH) family 10 (PesXyn10A) from Pestalotiopsis sp. AN-7, which was isolated from the soil of a mangrove forest. This protein was heterologously expressed by Pichia pastoris as a host, and its enzymatic properties were characterized. PesXyn10A was produced as a glycosylated protein and coincident to theoretical molecular mass (35.3 kDa) after deglycosylation by peptide-N-glycosidase F. Purified recombinant PesXyn10A exhibited maximal activity at pH 6.0 and 50 °C, and activity was maintained at 90 % at pH 5.0 and temperatures lower than 30 °C for 24 h. The substrate specificity of PesXyn10A was limited and it hydrolyzed glucuronoxylan and arabinoxylan, but not β-glucan. The final hydrolysis products from birchwood xylan were xylose, xylobiose, and 1,2 3-α-D-(4-O-methyl-glucuronyl)-1,4-β-Dxylotriose. The addition of metallic salts (NaCl, KCl, MgCl 2 , and CaCl 2) activated PesXyn10A for xylan degradation, and maximal activation by these divalent cations was approximately 160 % at a concentration of 5 mM. The thermostability of PesXyn10A significantly increased in the presence of 50 mM NaCl or 5 mM MgCl 2. The present results suggest that the presence of metallic salts at a low concentration, similar to brackish water, exerts positive effects on the enzyme activity and thermal stability of PesXyn10A.

Fungi with history: Unveiling the mycobiota of historic documents of Costa Rica

“…Because of the various ecological relationships this genus has with plants, it has attracted attention for its cellulolytic abilities, with over 400 possible enzymes found through the study of a Pestalotiopsis isolated from a mangrove [ 63 ]. So far, there are some cellulolytic enzymes known from this genus that have been studied, such as the xylanase [ 64 ] or the cellulases [ 65 ]. Another single isolate obtained from the Political Constitution was Periconia CP1-A1C, which belongs to the dark septate fungi Pleosporales, with some isolates reported with thermostable β-Glucosidases suitable for biotechnological processes [ 66 ].…”

Fungi with history: Unveiling the mycobiota of historic documents of Costa Rica

“…Pestalotiopsis isolated from a mangrove (Arfi et al 2013). So far, there are some cellulolytic enzymes known from this genus that have been studied, such as the xylanase (Koh et al 2021) or the cellulases (Goukanapalle et al 2020). Another single isolate obtained from the Political Constitution was Periconia CP1-A1C, which belongs to the dark septate fungi Pleosporales, with some isolates reported with thermostable b-Glucosidases suitable for biotechnological processes (Harnpicharnchai et al 2009) (Borgi and Gargouri 2016).…”

“…2013). So far, there are some cellulolytic enzymes known from this genus that have been studied, such as the xylanase (Koh et al . 2021) or the cellulases (Goukanapalle et al .…”

Pestalotiopsis Diversity: Species, Dispositions, Secondary Metabolites, and Bioactivities

“…(33), derivatives (34,35,37,38) of the compound 33, and 6-pentyl-4-methoxypyran-2-one (36) [99]. None of these compounds (33)(34)(35)(36)(37)(38) showed antibiotic activities against B. subtilis and Geotrichum candidum when tested up to 100 μg per diskette [99].…”

“…P. guepinii produced phytotoxic α-pyrones, including 6-(1-hydroxypentyl)-4-methoxypyran-2-one (33), derivatives (34,35,37,38) of the compound 33, and 6-pentyl-4-methoxypyran-2-one (36) [99]. None of these compounds (33)(34)(35)(36)(37)(38) showed antibiotic activities against B. subtilis and Geotrichum candidum when tested up to 100 µg per diskette [99]. (56), and (R)-3-hydroxy-1-[(S)-4-hydroxy-1,3dihydroisobenzo-furan-1-yl]butan-2-one (57) were isolated and identified in the marine spongederived P. heterocornis [29].…”