Production and properties of the cellulase-free xylanase from Thermomyces lanuginosus IOC-4145

Abstract

In recent years, xylanases have expanded their use in many processing industries, such as pulp and paper, food and textile. Thermomyces lanuginosus IOC-4145 was able to produce a very high level of cellulase-free xylanase in shaken cultures using corncob as substrate (500 U/mL). An optimization of the medium composition in submerged fermentation was carried out aiming at a low cost medium composition for enzyme production. Statistical experiment design was employed for this purpose, pointing out corncob as the most important parameter, which affects enzyme production. Additionally, the influence of several chemicals on xylanase activity was investigated in the crude extract. A slight stimulation of the enzyme (5-15%) was achieved with NaCl and urea, both at 3 and 5 mM of concentration. On the other hand, dithiothreitol and β-mercaptoethanol at a molarity of 5mM have caused a strong stimulation of the enzyme (40-53%). The crude xylanase displayed appreciable thermostability, retaining almost 50% of activity during 24 hours of incubation at 50ºC; about 50% of activity was present at 60ºC even after 4 hours of incubation. The enzyme also exhibited good storage stability at-20ºC without any stabilizing agent.

Purification and characterisation of a xylanase from Thermomyces lanuginosus and its functional expression by Pichia pastoris

“…To this end, enhanced activity displayed by the xylanase from T. lanuginosus 195 may also be attributed to the increased solubility of oat spelt xylan. A similar preference to oat spelt xylan was also documented by Damaso et al [35] for a xylanase produced by T. lanuginosus.…”

Selection of cellulolytic fungi isolated from diverse substrates

“…1) in the present study showed a value 3 times greater (15 U/mL) for the endophytic strain of Aspergillus (strain 15). Damaso et al (2002) obtained a xylanase activity of 500 U/mL with Thermomyces lanuginosus IOC-4145 on corn cobs by semi-solid fermentation after 96 h of production. Xylanase presented 167 and 178 U/mL for the best strains (2, 4 and 11) (Fig.…”

“…4). However, the aim of this study was the selection of microorganisms and production time (48 h), in other words, in half the time used by Damaso et al (2002). Taragano et al (1997) studied an A. niger strain using wheat bran as substrate and the maximum polygalacturonase (PG) activity obtained was 30 U/mL.…”

Kinetics of high-Level of ß-glucosidase production by a 2-deoxyglucose-resistant mutant of Humicola lanuginosa in submerged fermentation

“…Cost of substrate plays a major role in the economics of enzyme production (15). Hence approach to use cheaper lignocellulosic (corncobs) rather than opting for expensive cellobiose will decrease cost of BGL production.…”

“…This work examines the potential of a DG resistant mutant of H. lanuginosa for production of BGL and evaluates the key role of substrate, nitrogen source, pH of the medium and temperature in the life of a thermophilic mould during growth and to maximize the production of BGL as reported in other mutant organisms (12,15,21).…”