Screening of novel fungal Carbohydrate Esterase family 1 enzymes identifies three novel dual feruloyl/acetyl xylan esterases

Abstract

Feruloyl esterases (FAEs) and acetyl xylan esterases (AXEs) are important enzymes for plant biomass degradation and are both present in Carbohydrate Esterase family 1 (CE1) of the Carbohydrate‐Active enZymes database. In this study, ten novel fungal CE1 enzymes from different subfamilies were heterologously produced and screened for their activity towards model and complex plant biomass substrates. CE1_1 enzymes possess AXE activity, while CE1_5 enzymes showed FAE activity. Two enzymes from CE1_2 and one from CE1_5 possess dual feruloyl/acetyl xylan esterase (FXE) activity, showing expansion of substrate specificity. The new FXEs from CE1 can efficiently release both feruloyl and acetyl residues from feruloylated xylan, making them particularly interesting novel components of industrial enzyme cocktails for plant biomass degradation.

Structure-Based Characterization and Improvement of an Enzymatic Activity of Acremonium alcalophilum Feruloyl Esterase

“…The optimum pH (7.5) and temperature (40 °C) of AaFaeD-CD turned out to be similar to those of other cellulolytic enzymes from A. alcalophilum 32 and those of other FAEs in SF5. 9,12,29,31 Here, we have revealed that AaFaeD-CD exerts its enzymatic activity at the highest level at pHs around 7.0−8.5 and temperatures around 40−45 °C.…”

“… In the ESTHER database, Aa FaeD belongs to the FaeC family . Amino acid sequence alignment for the members of SF5 showed moderate sequence identity of approximately 40–55% between Aa FaeD and 10 previously studied FAEs of ascomycetes species, e.g., Neurospora crassa , Aspergillus niger , Aspergillus sydowii , Aspergillus nidulans , Chrysosporium lucknowense , Chaetomium globulosum , Chaetomium thermophilum , and Corynascus sepedonium (Table S1).…”

“…Studying the members of SF5 is important because they have the ability to catalyze the hydrolysis of a wide range of natural substrates, releasing various chemicals such as acetic acid, hydroxycinnamic acid, and diferulate. − Moreover, certain SF5 members were shown to exhibit transesterification activity toward feruloyl derivatives, which is attractive for chemical synthesis. , Understanding the molecular mechanism by which SF5 members catalyze these reactions is crucial when it comes to applying these enzymes in industrial processes. However, despite structural and structure–function relationship studies of members of SF1, SF2 (Esterase_phb), and SF3 (Antigen85c), no such studies have been conducted on the members of SF5 (FaeC family in the ESTHER database).…”

A metagenomic survey of the fecal microbiome of the African savanna elephant (Loxodonta africana)

“…African elephant; however they did not observe Acidaminococcales. Members of Phascolarctobacterium have been found in the fecal microbiomes of rats and humans and have been positively correlated with an increase in α-linolenic acid in humans (Li et al, 2022) and with being differentially less abundant in rats fed with docosahexaenoic acid (Hosomi et al, 2021). Interestingly, when the rats were fed eicosapentaenoic acid instead of docosahexaenoic acid, the relative abundance of Phascolarctobacterium increased, while the relative abundance of Clostridium (found as one of the main orders in the Budd et al study) decreased.…”

The ESTHER database on alpha/beta hydrolase fold proteins - An overview of recent developments

“…These classes are now respectively included into the following ESTHER families: Type-A in Lipase_3, Type-B in Esterase_phb (PHB depolymerase), Type-C in Tannase, Type-D in FaeC, Type-E in A85-Feruloyl-Esterase, Type-F in BD-FAE. A new distribution of feruloyl esterases based on descriptor-based classification and structural analysis resulted in 13 families [64,65], which are now distributed in ESTHER as SF1,2,3,4,9,10,11 in Tannase, SF5 in FaeC, SF6 Esterase_Phb (CE-1 in the subdivision of CaZy [66]), SF7 Lipase_3, SF8 A85_Feruoyl-esterase, SF12,13 in Fungal_Carb_Lip.…”