Function of a Low Molecular Weight Peptide from Trichoderma pseudokoningii S38 During Cellulose Biodegradation

Abstract

The biochemical mechanism for cellulose decomposition by a low molecular weight peptide, named short fiber generating factor (SFGF), derived from the culture supernatant of a cellulolytic fungus Trichoderma pseudokoningii S-38, was determined. Sufficient information obtained by biochemical and biophysical studies and combined with observation with a scanning electron microscope provided further evidence for the earlier studies that the SFGF had a high capacity for chelating and reducing ferric ions, and could produce free radical by reduction of Fe(3+) to Fe(2+) in the presence of oxygen molecule. These studies suggested that the effect of SFGF on cellulose is directly related to an oxidative reaction and is different from the hydrolysis of cellulose by cellulases. The alcoholic hydroxyl groups in cellulose can be oxidized by SFGF, which leads to destruction of the hydrogen bond network in cellulose and cleavage of glycosidic linkages. Both effects led to the de-polymerization of cellulose and the formation of short fibers, and increase of reducing groups in residual cellulose, then the cellulose substrates became more susceptible for hydrolysis by cellulases.

Biodegradation of Natural Textile Materials in Soil

“…ey surmised that these bands are characteristic for amide group and they appearance a er degradation suggesting that the proteins are bound to the residuals bres. Furthermore investigations [10,11,16,18,20,21] conrmed presence of the bands at 1640 and 1548 cm -1 belonging to the Amide I and II and are result of protein produced by microbial growth. According to reference [22] the spectra of cellulose show decrease of bands particularly at 1372 cm -1 , 1336 cm -1 , 1313 cm -1 , 1280 cm -1 ,1160 cm -1 and 1105 cm -1 when moving from high crystalline to amorphous cellulose, which indicates apart from chemical changes mentioned above that the samples are degraded.…”

N-Glycoform Diversity of Cellobiohydrolase I from Penicillium decumbens and Synergism of Nonhydrolytic Glycoform in Cellulose Degradation

“…More than 60 years ago, Reese et al (28) first proposed that the C1 factor destroying the crystalline of cellulose is beneficial for the hydrolysis of cellulose by cellulase. In the course of exploring the mechanism of cellulose degradation, many studies discovered several materials with a similar function to C1, including swollenin from T. reesei (29), CDH from Phanerichaete chrysoporiu (30), HO ⅐ from T. reesei (31), and the short fiber-generating factor from T. pseudokoningi (32). However, the above materials are subject to much debate because of their unapparent synergism with commercial cellulases.…”

Toward an aggregated understanding of enzymatic hydrolysis of cellulose: Noncomplexed cellulase systems

“…Increased cellulose accessibility during enzymatic hydrolysis has been attributed to many factors. These include H 2 O 2 production in the presence of Fe ion (Koenigs, 1975), or the shortfiber-forming factor in filtrates of T. koningii (Halliwell and Riaz, 1970), or T. reesei CBH1 (Chanzy et al, 1983;Lee et al, 2000) or its catalytic domain (Lee et al, 1996) or the CBH2 catalytic domain (Woodward et al, 1992), T. reesei endoglucanase -exoglucanase complex (Sprey and Bochem, 1993), Humicola insolens CBH2 (Boisset et al, 2000), Thermomonospora fusca cellulases E3 and E5 (Walker et al, 1990, some noncatalytic domains of cellulase such as the CBM of C. fimi endoglucanase A (Din et al, 1991(Din et al, , 1994, a short fiber-generating polypeptide from T. pseudokoningii (Wang et al, 2003), a T. reesei fibril-forming protein (MW = 11.4 kD) (Banka et al, 1998), and a novel T. reesei protein called swollenin (MW = 49 kD) (Saloheimo et al, 2002).…”