title: A novel thermoalkaliphilic xylanase from Gordonia sp. is salt, solvent and surfactant tolerant.
abstract: Two aerobic bacterial consortia namely Con T and Con R were developed by enrichment technique from termite gut and cow dung respectively, using xylan as a sole carbon source. Molecular characterization of Con R based on 16S rRNA sequence analysis showed the presence of Pannonibacter sp. R-3 and Pseudoxanthomas sp. R-5. On the other hand, Con T showed the presence of Pseudoxanthomas sp. T-5, Cellulosimicrobium sp. T-21, and Gordonia sp. T-30. Being the maximum xylanase producer among the five isolates and being a novel xylanase producing bacterial genus, Gordonia sp. T-30 was selected. Xylanase produced by Gordonia sp. T-30 showed optimum activity at 60 °C and pH 9. Xylanase was 95% stable for 120 min at pH 9.0 and 98% stable at 60 °C for 90 min. Xylanase activity was stimulated in the presence of organic solvents such as petroleum ether, acetone, diethyl ether, n-hexane, and benzene. Detergent like cetyltrimethylammonium bromide and presence of NaCl also accelerated the xylanase function. Comparative evaluation was studied between sterilized and non-sterilized solid fermentation to produce xylanase by Gordonia sp. T-30 using various agricultural residues as growth substrate in cost effective manner. Industrially important features endowed by this xylanase make it a very promising candidate for food, feed, and fuel industry.
authors.affiliation: Department of Biotechnology, National Institute of Medical Sciences (NIMS) University, Jaipur, India.
authors.forename: Radhika
authors.initials: R
authors.lastname: Kashyap
authors.lastname: Monika
authors.forename: Enketeswara
authors.initials: E
authors.lastname: Subudhi
mesh_terms: D000818:Animals; D002417:Cattle / Q000382:microbiology; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry*; D004795:Enzyme Stability; D005243:Feces / Q000382:microbiology; D005285:Fermentation; D020459:Genes, rRNA; D033601:Gordonia Bacterium / Q000201:enzymology* / Q000302:isolation & purification; D007422:Intestines / Q000382:microbiology; D020049:Isoptera / Q000382:microbiology; D059013:Microbial Consortia; D012965:Sodium Chloride / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D012997:Solvents; D013501:Surface-Active Agents; D012965:Sodium Chloride; D043364:Endo-1,4-beta Xylanases
keywords: Aerobic consortia; Gordonia sp. T-30; Non-sterilized solid state fermentation; Termite gut; Xylanase