Production and partial characterisation of xylanase from Streptomyces sp. strain AMT-3 isolated from Brazilian cerrado soil

Xylanase production by a thermo-tolerant Bacillus species under solid-state and submerged fermentation

“…The maximum enzyme activity and biomass however could be obtained after 72 h, suggesting that corn cob supported lesser and slower growth and enzyme synthesis compared to wheat bran. Similar reduction in xylanase activity has been reported on corn cob (9.11 U/ml) compared to wheat bran (28.4 U/ml) in Streptomyces (Nascimento et al, 2002) and fungal (Qinnghe et al, 2004) sp.…”

“…Xylanase stimulation by xylose has been reported in bacteria and fungi (Bataillon et al, 1998;Leathers et al, 1986) and is generally considered as an inducer of the enzyme. Supplementation of wheat bran with a mineral salt solution has also been employed for a Streptomyces sp which produced 28.4U/ml xylanase in submerged condition in 10 days (Nascimento et al, 2002). …”

“…As corn cob is a rich source of both xylan (28%) and xylose (23%), it is potentially an ideal substrate for xylanase production, but reports on utilization of corn cob are limited. This is perhaps due to lower yields observed on corn cob compared to other substrates by some workers (Qinnghe et al, 2004;Nascimento et al, 2002). Hence, further studies on various aspects of corn cob utilization for improved xylanase yields may prove to be beneficial.…”

“…It has been established that solid-state fermentation (SSF) has several advantages over submerged fermentation (SmF), due to smaller volume of solvent required for product recovery, resulting in higher productivity per unit volume, lower contamination and foaming problems and better exploitation of various agro-residues as substrates (Nigam and Singh, 1994;Grajek, 1987;Archana and Satyanarayan, 1997;Kewalrami et al, 1988). Hence, xylanase production using xylan rich agroresidues such as wheat bran, eucalyptus kraft pulp, wheat straw, rice bran, rice straw, sugarcane bagasse and corn cob has been attempted by several workers using fungi (Qinnghe et al, 2004;Bakir et al, 2001;Anthony et al, 2003;Singh et al, 2000), bacteria (Archana and Satyanarayan, 1997;Bataillon et al, 1998;Virupakshi et al, 2005), actinomycetes (Kohli et al, 2001;Beg et al, 2002;Nascimento et al, 2002) and yeasts (Liu et al, 1999). As corn cob is a rich source of both xylan (28%) and xylose (23%), it is potentially an ideal substrate for xylanase production, but reports on utilization of corn cob are limited.…”

“…The aim of this work was therefore to evaluate and compare the induction and repression effects of xylose on xylanase synthesis using corn cob and wheat bran as sole C sources, supplemented with either mineral salt solution (MSS) or a mixture of yeast extract and peptone (YEP) under SSF and SmF. These studies were performed with a thermophilic xylanolytic bacterial species producing thermo-stable xylanase (optimum temp 55°C), as thermo-stable xylanases are more relevant for industrial application (Kohli et al, 2001;Nascimento et al, 2002), and also as xylanase production by thermophilic bacteria under SSF using corn cob has not been reported.…”