2015 ; Vol.25-9: 1476~1484
|Author||Andrey L. Rakitin, Alexandra Y. Ermakova, Nikolai V. Ravin|
|Place of duty||Centre “Bioengineering”, Russian Academy of Sciences, Moscow 117312, Russia|
|Title||Novel Endoxylanases of the Moderately Thermophilic Polysaccharide-Degrading Bacterium Melioribacter roseus|
J. Microbiol. Biotechnol.2015 ;
|Abstract||Three endoxylanase-encoding genes from the moderately themophilic chemoorganotrophic
bacterium Melioribacter roseus were cloned and expressed in Escherichia coli. Genes xyl2091
(Mros_2091) and xyl2495 (Mros_2495) encode GH10 family hydrolases, whereas xyl2090
(Mros_2090) represents the GH30 family. In addition to catalytic domains, Xyl2090 and
Xyl2091 contain carbohydrate-binding modules that could facilitate their binding to xylans
and Por sorting domains associated with the sorting of proteins from the periplasm to the
outer membrane, where they are covalently attached. Recombinant endoxylanase Xyl2495
exhibited a high specific activity of 1,920 U/mg on birchwood xylan at 40oC. It is active at low
temperatures, exhibiting more than 30% of the maximal activity even at 0oC. Endoxylanases
Xyl2090 and Xyl2091 have lower specific activities but higher temperature optima at 80oC and
65oC, respectively. Analysis of xylan hydrolysis products revealed that Xyl2090 generates
xylo-oligosaccharides longer than xylopentaose. Xylose and xylobiose are the major products
of xylan hydrolysis by the recombinant Xyl2091 and Xyl2495. No activity against cellulose was
observed for all enzymes. The presence of three xylanases ensures efficient xylan hydrolysis
by M. roseus. The highly processive “free” endoxylanase Xyl2495 could hydrolyze xylan under
moderate temperatures. Xylan hydrolysis at elevated temperatures could be accomplished by
concerted action of two cell-bound xylanases; Xyl2090 that probably degrades xylans to long
xylo-oligosaccharides, and Xyl2091 hydrolyzing them to xylose and xylobiose. The new
endoxylanases could be useful for saccharification of lignocellulosic biomass in biofuels
production, bleaching of paper pulp, and obtaining low molecular weight xylooligosaccharides.|
|Key_word||Xylan, endoxylanase, thermostability, thermophilic bacterium|
Aachary AA, Prapulla SG. 2011. Xylooligosaccharides (XOs) as an emerging prebiotic: microbial synthesis, utilization, structural characterization, bioactive properties, and applications. Compr. Rev. Food Sci. Food Saf. 10: 2-16.
Bhalla A, Bischoff KM, Uppugundla N, Balan V, Sani RK. 2014. Novel thermostable endo-xylanase cloned and expressed from bacterium Geobacillus sp. WSUCF1. Bioresour. Technol. 165: 314-318.
Biely P. 1985. Microbial xylanolytic systems. Trends Biotechnol. 3: 286-290.
Chen C, Adolphson R, Dean F, Eriksson K, Adamas M, Westpheling J. 1997. Release of lignin from kraft pulp by a hyperthermophilic xylanase from Thermatoga maritima. Enzyme Microb. Technol. 20: 39-45.
Coughlan MP, Hazlewood GP. 1993. Beta-1,4-D-xylan degrading enzyme systems: biochemistry, molecular biology and applications. Biotechnol. Appl. Biochem. 17: 259-289.
Juturu V, Wu JC. 2012. Microbial xylanases: engineering, production and industrial applications. Biotechnol. Adv. 30:1219-1227.
Kadnikov VV, Mardanov AV, Podosokorskaya OA, Gavrilov SN, Kublanov IV, Beletsky AV, et al. 2013. Genomic analysis of Melioribacter roseus, facultatively anaerobic organotrophic bacterium representing a novel deep lineage within Bacteriodetes/Chlorobi group. PLoS One 8: e53047.
Karlsson EN, Hachem MA, Ramchuran S, Costa H, Holst O, Fex Svenningsen Å, Hreggvidsson GO. 2004. The modular xylanase Xyn10A from Rhodothermus marinus is cell-attached, and its C-terminal domain has several putative homologues among cell-attached proteins within the phylum Bacteroidetes. FEMS Microbiol. Lett. 241: 233-242
Leuschner C, Antranikan G. 1995. Heat stable enzymes from extremely thermophilic and hyperthermophilic microorganisms. World J. Microbiol. Biotechnol. 11: 95-114.
Lynd LR, Laser MS, Bransby D, Dale BE, Davison B, Hamilton R, et al. 2008. How biotech can transform biofuels. Nat. Biotechnol. 26: 169-172.
Marchler-Bauer A, Derbyshire MK, Gonzales NR, Lu S, Chitsaz F, Geer LY, et al. 2015. CDD: NCBI’s conserved domain database. Nucleic Acids Res. 43(Database issue):D222-D226.
Miller GL. 1959. Use of dinitrosalicylic acid reagent for determination of reducing sugar. Anal. Chem. 31: 426-428.
Podosokorskaya OA, Kadnikov VV, Gavrilov SN, Mardanov AV, Merkel AY, Karnachuk OV, et al. 2013. Characterization of Melioribacter roseus gen. nov., sp. nov., a novel facultatively anaerobic thermophilic cellulolytic bacterium from the class Ignavibacteria, and a proposal of a novel bacterial phylum Ignavibacteriae. Environ. Microbiol. 15: 1759-1571.
Rastogi G, Bhalla A, Adhikari A, Bischoff KM, Hughes SR, Christopher LP, Sani RK. 2010. Characterization of thermostable cellulases produced by Bacillus and Geobacillus strains. Bioresour. Technol. 101: 8798-8806.
Sakka M, Tachino S, Katsuzaki H, van Dyk JS, P letschke BI, Kimura T, Sakka K. 2012. Characterization of Xyn30A and Axh43A of Bacillus licheniformis SVD1 identified by its genomic analysis. Enzyme Microb. Technol. 51: 193-199.
Shi H, Zhang Y, Li X, Huang Y, Wang L, Wang Y, et al. 2013. A novel highly thermostable xylanase stimulated by Ca2+ from Thermotoga thermarum: cloning, expression and characterization. Biotechnol. Biofuels 6: 26.
Slakeski N, Seers CA, Ng K, Moore C, Cleal SM, Veith PD, et al. 2011. C-terminal domain residues important for secretion and attachment of RgpB in Porphyromonas gingivalis. J. Bacteriol. 193: 132-142.
Vázquez MJ, Alonso JL, Domínguez H, Parajó JC. 2001. Xylooligosaccharides: manufacture and applications. Trends Food Sci. Technol. 11: 387-393.
Verma D, Anand A, Satyanarayana T. 2013. Thermostable and alkalistable endoxylanase of the extremely thermophilic bacterium Geobacillus thermodenitrificans TSAA1: cloning, expression, characteristics and its applicability in generating xylooligosaccharides and fermentable sugars. Appl. Biochem. Biotechnol. 170: 119-130.
Verma D, Satyanarayana T. 2012. Cloning, expression and applicability of thermoalkali-stable xylanase of Geobacillus thermoleovorans in generating xylooligosaccharides from agroresidues. Bioresour. Technol. 107: 333-338.
Wakarchuk WW, Sung, WL, Campbell RL, Cunningham A, Watson DC, Yaguchi M. 1994. Thermostabilization of the Bacillus circulans xylanase by the introduction of disulfide bonds. Protein Eng. 7: 1379-1386.
Winterhalter C, Heinrich P, Candussio A, Wich G, Liebl W. 1995. Identification of a novel cellulose-binding domain within the multidomain 120 kDa xylanase XynA of the hyperthermophilic bacterium Thermotoga maritima. Mol. Microbiol. 15: 431-444.
Wong KK, Tan LU, Saddler JN. 1988. Multiplicity of beta1,4-xylanase in microorganisms: functions and applications. Microbiol. Rev. 52: 305-317.
Zverlov V, Piotukh K, Dakhova O, Velikodvorskaya G, Borriss R. 1996. The multidomain xylanase A of the hyperthermophilic bacterium Thermotoga neapolitana is extremely thermoresistant. Appl. Microbiol. Biotechnol. 45: 245-247.