PLoS ONE (Jan 2020)

Isolation and characterization of thermophilic cellulose and hemicellulose degrading bacterium, Thermoanaerobacterium sp. R63 from tropical dry deciduous forest soil.

  • Phurt Harnvoravongchai,
  • Ratiyakorn Singwisut,
  • Puey Ounjai,
  • Amornrat Aroonnual,
  • Pahol Kosiyachinda,
  • Tavan Janvilisri,
  • Surang Chankhamhaengdecha

DOI
https://doi.org/10.1371/journal.pone.0236518
Journal volume & issue
Vol. 15, no. 7
p. e0236518

Abstract

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Thermophilic microorganisms and their enzymes have been utilized in various industrial applications. In this work, we isolated and characterized thermophilic anaerobic bacteria with the cellulose and hemicellulose degrading activities from a tropical dry deciduous forest in northern Thailand. Out of 502 isolated thermophilic anaerobic soil bacteria, 6 isolates, identified as Thermoanaerobacterium sp., displayed an ability to utilize a wide range of oligosaccharides and lignocellulosic substrates. The isolates exhibited significant cellulase and xylanase activities at high temperature (65°C). Among all isolates, Thermoanaerobacterium sp. strain R63 exhibited remarkable hydrolytic properties with the highest cellulase and xylanase activities at 1.15 U/mg and 6.17 U/mg, respectively. Extracellular extract of Thermoanaerobacterium sp. strain R63 was thermostable with an optimal temperature at 65°C and could exhibit enzymatic activities on pH range 5.0-9.0. Our findings suggest promising applications of these thermoanaerobic bacteria and their potent enzymes for industrial purposes.