Isolation and characterization of cell wall and extracellular polysaccharides from cultures of the mycoparasitic strain Tirochoderma koningiopsis

Abstract

The Trichoderma koningiopsis strain showed an extracellular polymers (EPS) synthesis capacity of 1.17 g/L in an optimised Czapek-Dox medium containing sucrose (30 g/L) and yeast extract (7.5 g/L). Three fractions of wall polymers were extracted from the biomass obtained after culture: cold water soluble (WPSZ), hot water soluble (WPSC) and alkali soluble (WPSNaOH), which accounted for 13.3%, 1.8% and 20.2% of the mycelial dry weight, respectively. Structural analyses indicated that the EPS obtained was mannan, and the WPS fractions were glucans containing predominantly [->]4)-Glc-(1[->] linked residues, with branching at [->]3,6)- as well as [->]4,6)-positions. FT-IR and FT-Raman analyses showed that -bonds dominate in the WPSZ and WPSC fractions, whereas {beta}-bonds dominate in the EPS and WPSNaOH fractions. The obtained polymer fractions (PS) showed antioxidant properties in the ABTS, DPPH and FRAP methods and the ability to bind bisphenol A from an aqueous environment. The most important property of the obtained PSs is their ability to reduce germination and inhibit the growth of mycelia of the phytopathogenic Fusarium culmorum strain. The obtained polymers exhibit a number of bioactive properties and can be used in various areas of human life. HighlightsO_LITrichoderma koningiopsis has the ability to synthesise EPS C_LIO_LIEPS are mainly composed of mannose and WPS of glucose C_LIO_LIPS have the ability to chelate BPA and have antioxidant properties C_LIO_LIThe PS obtained has inhibitory properties against F. culmorum. C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=151 SRC="FIGDIR/small/605896v1_ufig1.gif" ALT="Figure 1"> View larger version (46K): org.highwire.dtl.DTLVardef@aaf140org.highwire.dtl.DTLVardef@c4c0e4org.highwire.dtl.DTLVardef@153de0eorg.highwire.dtl.DTLVardef@117a135_HPS_FORMAT_FIGEXP M_FIG C_FIG