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Rice straw is a major agricultural waste that can be used as an alternative substrate to expensive raw materials for endoglucanases (CMCase) production by microorganisms. This study aimed to search for a microorganism having the potential to produce endoglucanase from rice straw. From compost samples, 40 bacterial colonies were isolated on carboxymethylcellulose (CMC) agar. Among them, 16 isolates showed a hydrolysis zone on a CMC agar plate with hydrolysis (HC) values ranging from 1.15±0.02 to 4.40±0.52. Based on hydrolysis zone diameter and HC value, isolates CP1, CP2 and CP3 were further examined for their CMCase production in CMC broth. According to CMCase production and stability, isolate CP1 was selected for further study. The optimal pH and temperature for CMCase production of isolate CP1 were 5 and 45 °C, respectively. When using pre-treated rice straw as a substrate for semi-solid-state fermentation, the highest CMCase activity of 0.142 ± 0.008 U/mL was obtained in a medium containing pre-treated rice straw of 60 g/L. The sequence alignment analysis and phylogenetic analysis suggested that the isolate CP1 was likely to be Streptomyces thermocoprophilus. The microorganism obtained from this study may be not only industrially important but also beneficial to the environment.

The cellulase and xylanase productions from the pretreated empty fruit bunch as the low-cost substrate in a submerged fermentation were investigated. The objectives of this study were selected the local strain that produced high cellulase and xylanase and enhanced the enzymes production by the selected strain. Ten Streptomyces strains were cultivated in the complex medium [(g/l); CaCl2·2H2O 0.1, MgSO4·7H2O 0.1, KH2PO4 0.5, K2HPO4 1.0, NaCl 0.2, NH4NO3 1.0, yeast extract 5.0 and Tween 80 0.5 with alkaline peroxide pretreated empty fruit bunch (APEFB) 20 in distilled water, pH 7.0] in an incubator shaker at 150 rpm and 45 °C for 120 h. The strain TC13W gave the highest cellulase and xylanase activities (280 and 878 U/g APEFB, respectively). This strain was identified by 16S rDNA method as Streptomyces thermocoprophilus (96% similarity). Cellulase and xylanase productions by S. thermocoprophilus TC13W in the optimized medium with 1% (w/v) APEFB and 0.5% (w/v) yeast extract, pH 6.5 at 150 rpm and 40 °C for 120 h gave the maximum cellulase and xylanase activities of 925 and 1796 U/g APEFB, respectively. The increasing of cellulase and xylanase activities in the optimized medium was 3.30 and 2.04 folds, respectively in comparison to the original medium. These in-house enzymes could be used as the promising candidate enzyme for produce various value-added products via an enzymatic hydrolysis of the lignocellulosic waste.

The modified medium composed of the alkaline-pretreated oil palm empty fruit bunch (APEFB) and tuna condensate powder was used for cellulase and xylanase productions by Streptomyces thermocoprophilus strain TC13W. The APEFB contained 74.46% (w/w) cellulose, 15.72% (w/w) hemicellulose, and 6.40% (w/w) lignin. The tuna condensate powder contained 55.49% (w/w) protein and 11.05% (w/w) salt. In the modified medium with only 6.75 g/l tuna condensate powder, 10 g/l APEFB, and 0.5 g/l Tween 80, S. thermocoprophilus strain TC13W produced cellulase 4.9 U/ml and xylanase 9.0 U/ml. The enzyme productions in the modified medium were lower than cellulase (6.0 U/ml) and xylanase (12.0 U/ml) productions in the complex medium (CaCl2 0.1, MgSO4·7H2O 0.1, KH2PO4 0.5, K2HPO4 1.0, NaCl 0.2, yeast extract 5.0, NH4NO3 1.0, Tween 80 0.5). When tuna condensate powder in the modified medium was reduced to 5.0 g/l and Tween 80 was increased to 1.5 g/l, S. thermocoprophilus strain TC13W produced cellulase and xylanase activities of 9.1 and 12.1 U/ml, respectively. This study shows that the cost of enzyme production could be reduced by using pretreated EFB and tuna condensate as a carbon and a nitrogen source, respectively.

Description of Streptomyces thermocoprophilus BS 22 Cells are Gram­staining­positive, non­flagellated, nonpigmented and branched mycelium-forming. Colonies are lenticular, raised, entire and white-colored after 2 days on R2A at 30°C. Positive for nitrate reduction, arginine dihydrolase, urease, esculin hydrolysis, gelatinase, β­galactosidase in API 20NE but negative for indole production and glucose fermentation. D-Glucose, L-arabinose, D-mannitol, D-mannose, N-acetyl-glucosamine, D-maltose, gluconate, adipate, malate, citrate and phenylacetate are utilized. Does not utilize caprate. Strain BS22 (= NIBRBA0000114835) has been isolated from spent mushroom compos, Yesan, Korea., Published as part of Ko, Kwan Su, Cha, Chang-Jun, Im, Wan-Taek, Kim, Seung-Bum, Seong, Chi-Nam, Bae, Jin-Woo, Jahng, Kwangyeop, Cho, Jang-Cheon, Joh, Ki-seong & Lee, Soon Dong, 2017, A report of 34 unrecorded bacterial species in Korea, belonging to the Actinobacteria, pp. 1-14 in Journal of Species Research 6 (1) on page 12, DOI: 10.12651/JSR.2017.6.1.001, http://zenodo.org/record/8120377

The taxonomic position of a thermophilic actinomycete strain isolated from poultry faeces was examined using a polyphasic approach. The isolate, designated B19T, was assigned to the genus Streptomyces on the basis of chemotaxonomic and morphological criteria. An almost complete 16S rRNA gene (rDNA) sequence obtained for the test strain was compared with those of representative streptomycetes, notably thermophilic streptomycetes. 16S rDNA sequence data not only supported the assignment of the strain to the genus Streptomyces but also showed that the isolate formed a distinct phyletic line within the evolutionary branch composed of Streptomyces thermodiastaticus and related species. The strain was distinguished from related validly described Streptomyces species by a number of phenotypic properties. It is, therefore, proposed that strain B19T be classified in the genus Streptomyces as Streptomyces thermocoprophilus sp. nov.