Isolation and characterization of a cellulolytic Geobacillus thermoleovorans T4 strain from sugar refinery wastewater

Abstract

A novel, cellulolytic, bacterial thermophilic strain, T4, was isolated from sugar refinery wastewater in southern Taiwan. This isolate, a Gram-negative, motile, aerobically growing sporulating rod, can secrete thermostable endocellulase (endo-1,4-beta-D-glucanase, EC 3.2.1.4) and hydrolyze carboxymethylcellulose (CMC), phosphoric acid-swollen cellulose, Avicel, filter paper, and salicin. When strain T4 was grown in CMC medium, the cellulolytic enzyme activity in culture supernatants was stable up to 70 degrees C. More than 10% of the original activity was still detectable after heating to 100 degrees C with a pH 7.0 for 1 h. Based on 16S rDNA sequence analysis, DNA base composition, phenotypic and physiological characteristics, as well as DNA-DNA hybridization, strain T4 was classified as Geobacillus thermoleovorans T4 (DSM 14791 = CCRC 17200). We also demonstrated that the type species G. stearothermophilus (DSM 22 = ATCC 12980) could hydrolyze amorphous and crystalline (filter paper) celluloses at a rate of 13 and 14%, respectively, in comparison with strain T4.

Phylogenetic Diversity and Characterization of Novel and Efficient Cellulase Producing Bacterial Isolates from Various Extreme Environments

“…Thermophilic cellulases with high thermal stability have been isolated from few bacilli and related genera. 7,29) Kinetic characterization of CMCases The K m and V max values for the two isolates were calculated by Lineweaver-Burk plots. In case of IARI-M-75, the K m and V max values for CMC were 3.11 mg/ mL and 0.056 U/mg, respectively, while for IARI-AN-27 they were 1.08 mg/mL and 0.635 U/mg respectively.…”

“…Niches with high organic matter content such as compost, forest and marshes are the best niches for the isolation of cellulase producers, but extreme environments can also be exploited for cellulases with specific properties. Microorgansims from different extreme environments have been explored for production of cellulases, [3][4][5][6][7] but there is a paucity of information regarding the cellulase producing abilities of these microbial resources.…”

Isolation of a Thermostable Alkaline Cellulase-producing Bacterium Strain from a Garbage Dump

“…Notably, both the endoglucanase and cellubiohydrolase could effectively hydrolyze their substrates in the temperature range from 20 to 90°C. In contrast, most previously reported bacteria did not functionally work under the wide range of temperature and pH (Sleat et al, 1984;Tai et al, 2004;Taya et al, 1988;Trivedi et al, 2011).…”

“…Up to date, cellulolytic enzymeproducing bacteria have been isolated from soil (Hakamada et al, 1997), and marine sediments (Annamalai et al, 2012). But most previously reported bacteria did not functionally work under the wide range of temperature and pH (Sleat et al, 1984;Taya et al, 1988;Trivedi et al, 2011;Tai et al, 2004). This seriously limited their wide application in industrial fermentation.…”

“…2d). Compared with those from Bacillus, Geobacillus, and Trichoderma (Annamalai et al, 2012;Bhikhabhai et al, 1984;Hakamada et al, 1997;Tai et al, 2004), the cellulolytic enzymes are more stable against high temperature.…”