Characterization of cellulase producing Bacillus sp. for effective degradation of leaf litter biomass

Abstract

Cellulose degrading Bacillus spp. (AS1, AS2, and AS3) were isolated from cow dung and identified phylogenetically by 16S ribosomal RNA (16S rRNA) sequence analysis. Bacillus sp. AS1 showed 99% homology with Bacillus megaterium whereas, Bacillus sp. AS2 and AS3 were similar to B. subtilis. The activity of extracellular carboxymethyl cellulase in presence of 1% carboxymethyl cellulose at 508C was 0.04 U/mL for Bacillus sp. AS1 and 0.06 U/mL for Bacillus sp. AS2 at pH 7.0, whereas higher activity of 0.08 U/mL was observed for Bacillus sp. AS3 at pH 9.0. Crude cellulase from all the three Bacillus sp. were stable over a wide range of pH (5.0-9.0) and thermally stable up to 608C. Carboxymethyl cellulase, filter paperase, and b-glucosidase activity of Bacillus sp. AS3 was 0.07, 0.02, and 0.04 U/ml, respectively. Degradation of leaf litter biomass treated by Bacillus sp. AS3 showed 47% drop in carbon:nitrogen (C:N) ratio and x-ray diffractograph revealed decline in crystalline structure.

Millet Cobs: A Source of Microbial Enzymes

“…The lignocellulosic structure of millet cobs maybe a factor responsible for the low microbial population present particularly in the undegraded sample [27][28][29]. The presence of bacteria such as B. cereus, B. licheniformis and B. subtilis in the undegraded sample agrees with the findings of Kunchala when sorghum and pearl millet from semiarid tropics were characterized for potential probiotic bacteria [30].…”

“…The presence of Bacillus spp may contribute to the production of cellulase in the degrading millet cobs which were shown by the zone of hydrolysis in their screening for cellulase production. Separate findings of Akhtar and Saowapar agrees with this finding when different species of Bacillus produced cellulose [21,29]. Shilpa and Pethe also isolated different cellulolytic bacteria from the soil in which B. thurigenesis showed the highest zone of hydrolysis when these bacteria were optimized at different condition [59].…”

“…The increased population of A. flavus, A. fumigatus and R. stolonifer in day 4 may be as a result of the reduced lignocellulosic component of the millet cobs [27][28][29]. The increased moisture content of the degraded millet cob as the degradation progressed could be responsible for the reduction in the fungal population [43].…”

Isolation, Identification, and Characterization of a CellulolyticBacillus amyloliquefaciensStrain SS35 from Rhinoceros Dung

“…Also, the habitat of bacteria covers different environmental niches, which favors the existence of versatile strains such as thermophiles [12], psychrophiles, alkaliphiles, and acidophiles. The culturable cellulase producing bacteria have been isolated from the variety of sources such as composting heaps, decaying agricultural wastes, the feces of cow [13] and elephant, gastrointestinal tract of buffalo and horse [14], soil, and extreme environments like hot-springs [15]. Cellulose degrading bacteria play an important role in energy supply for forage animals.…”

Simplification and optimization of media ingredients for enhanced production of CMCase by newly isolatedBacillussubtilisNA15

“…Cellulose degradation is largely an aerobic process, selected primary aerobic cellulolytic bacterial isolates are Bacillus strain C1 , Bacillus sp. AS3 , B. subtilis GN156 , and B. amyloliquefaciens DL‐3 . Therefore, for optimum production and effective utilization of extracellular bacterial cellulase, the medium ingredients have to be optimized, as its production in microorganisms is significantly influenced by medium constituents , temperature, pH, aeration, and other physical parameters .…”