Analysis of polysaccharide hydrolases secreted by Aspergillus flavipes FP-500 on corn cobs and wheat bran as complex carbon sources

Abstract

Aspergillus flavipes FP-500 is a Mexican native strain that has been reported as a good producer of xylanases and pectinases; therefore, it promises a strong impact on biotechnology. To provide an overview of protein secretion by A. flavipes, we carried out a comparative proteome analysis of extracellular proteins in liquid cultures with two heterogeneous agro-industrial residues; corn cob (CC) and wheat bran (WB), as carbon sources. Extracellular proteins obtained from both cultures were identified using MS/MS spectrometry. We identified 134 proteins, which were classified into four groups: glycosyl hydrolases (GH), esterases/proteases, miscellaneous proteins, and unidentified proteins. Around 50% of the total proteins identified were GH such as xylanases, β-xylosidases, β-galactosidases, cellulolytic enzymes like β-glucosidase, endoglucanases, and cellobiohydrolases. From this family, a core of 22 (16%) of the proteins identified were found in both substrates, CC and WB, whereas 30% and 54% were unique for CC and WB, respectively. In the esterases/proteases group, proteases, lipases and esterases like feruloylesterases, and acetyl-xylanesterase were identified. Proteins with diverse functions such as monophosphate dehydrogenase or N-acetylglucosaminidase were present. Here, we present strong evidences indicating that the composition and heterogeneity of the used carbon source determine the specific set of protein secreted by the fungus.

Keywords:

• Aspergillus flavipes
• CAZy
• complex carbon source
• corncobs
• secretome
• wheat bran

Disclosure statement

The authors declare that there is no conflict of interest. G.M.H. passed away.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was carried out with the support by Dirección General de Asuntos del Personal Académico (DGAPA-UNAM), projects [PAPIIT IN219813 and IN225319]. The authors acknowledge also the support of Programa PAIP 5000-9093, from the Faculty of Chemistry of the National University of Mexico. MTA-Z acknowledges the postdoctoral DGAPA-UNAM program for her postdoctoral fellowship.