Bibliographic citations
Tamariz, C., (2014). Diversidad de bacterias termotolerantes celulolíticas y xilanolíticas aisladas de fuentes termales del Callejón de Huaylas [Tesis, Universidad Nacional Mayor de San Marcos]. https://hdl.handle.net/20.500.12672/3777
Tamariz, C., Diversidad de bacterias termotolerantes celulolíticas y xilanolíticas aisladas de fuentes termales del Callejón de Huaylas [Tesis]. PE: Universidad Nacional Mayor de San Marcos; 2014. https://hdl.handle.net/20.500.12672/3777
@phdthesis{renati/1220289,
title = "Diversidad de bacterias termotolerantes celulolíticas y xilanolíticas aisladas de fuentes termales del Callejón de Huaylas",
author = "Tamariz Angeles, Carmen",
publisher = "Universidad Nacional Mayor de San Marcos",
year = "2014"
}
The high demand of energy has increased interest in the use of lignocellulosic biomass to produce biofuel, wherein thermophilic and thermostable hydrolytic enzymes play an important rol. In this context, the aim of this investigation was to isolate and select thermotolerant cellulolytic and xylanolytic bacteria from Chancos, Olleros and Huancarhuaz hot springs located in the Callejon de Huaylas, Ancash - Peru. Isolation of bacteria was performent using fresh samples, ex situ enrichment and in situ baiting, in basal salt medium at 50°C and pH 6,5. The selection was performed by staining Congo Red on culture plates supplemented carboxymethyl cellulose (CMC) or xylan. For taxonomic identification 16S rDNA gen was used. Endoglucanase, total cellulase and xylanase activities were quantified in selected strains. Some crude enzyme extracts that shown the best results were tested to determinated optimum temperature, optimum pH, and thermal stability. It was isolated 62 bacterial strains and 29 showed hydrolysis halo on CMC and xylan plates. The 16S rDNA gene analysis determined that the selected strains correspond to Bacillus licheniformis, B. subtilis and Cohnella laeviribosi. The highest cellulase and xylanase activities were obtained to B. subtilis DCH4, B. subtilis DO6, B. licheniformis EPO2 and C. laevibosi EHB4. Subsequent assays in these strains showed endoglucanase activity optimum betwee n 45-60°C and 5-6 of pH. The xylanase activity optimum was obtained at 55-65°C and pH 6-7. Fifty percent of the endoglucanase activity of C. laevibosi EHB4 after incubation at 80 ° C for 1 hour is maintained, a similar result was obtained in the xylanase activity of B. licheniformis EPO2. It was been demostrated the presence of cellulolytic and xylanolytic thermotolerant bacteria in Chancos, Olleros and Huancarhuaz hot springs. C. laevibosi EHB4 and B. licheniformis EPO2 may contribute to the development of lignocellulosic biomass bioconversion process. Keywords: Thermotoleran, hot spring, cellulases, xylanases, Bacillus, Cohnella.
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