Title
Isolation of thermotolerant Bacillus subtilis DCH4 from Chancos hot spring (Carhuaz, Peru) with potential to degrade lignocellulosic agriculture wastes
Other title
Aislamiento de Bacillus subtilis DCH4 termotolerante de la fuente termal Chancos (Carhuaz, Perú) con potencial para degradar residuos lignocelulósicos agrícolas.
Date Issued
08 March 2020
Access level
open access
Resource Type
journal article
Author(s)
Publisher(s)
Facultad de Ciencias Biologicas, Universidad Nacional Mayor de San Marcos
Abstract
It was isolated bacteria strains from three different types of samples: fresh water, in situ baits and ex situ enrichment. Serial dilutions were prepared and culture was carried at 50 °C using a Basal-Saline medium. Isolated strains were screened for endoglucanase and xylanase activities with qualitative (Congo Red) and quantitative (DNS) methods. Molecular 16S rDNA sequencing analysis was performed for taxonomic identification. It was isolated 31 strains of which 14 showed hydrolytic activities and belonged to Bacillus subtilis and Bacillus licheniformis species. Moreover, the strain B. subtilis DCH4 showed the highest endoglucanase activity at 45°C and pH 5, and xylanase activity at 55°C and pH 6. Then, DCH4 was cultivated by submerged fermentation with two different media supplemented with sugar cane bagasse, wheat straw, or quinoa stalk to evaluate its saccharification capability. Likewise, it was screening its xylanase and cellulase genes employing specific primers; the amplicons obtained were sequenced, and analyzed. It was found that, enzymatic extracts of DCH4 prepared with cane bagasse or quinoa stalk media achieved the highest endoglucanase and xylanase activities. According to molecular analysis of genes involved in the hydrolytic process, the endoglucanase and xylanase activities exhibited by DCH4 could be attributed to a bifunctional cellulase conformed by endo-beta-1,4-glucanase (GH5) joined to cellulose binding domain 3 (CBM3), and an endo-1,4-beta-xylanase (GH11), respectively. Further transcriptomic experiments would be considered to accomplish optimization strategies for biofuel production from lignocellulosic biomass.
Start page
67
End page
78
Volume
27
Issue
1
Language
English
OCDE Knowledge area
Biología celular, Microbiología
Subjects
Scopus EID
2-s2.0-85085660247
Source
Revista Peruana de Biologia
ISSN of the container
15610837
Sponsor(s)
Sirisena DM, Manamendra TP. 1995. Isolation and character-ization of cellulolytic bacteria from decomposing rice straw. Journal of the National Science Foundation of Sri Lanka 23: 25–30.
Sources of information:
Directorio de Producción Científica
Scopus