%0 Journal Article
%T Isolation, Identification, and Characterization of a Cellulolytic Bacillus amyloliquefaciens Strain SS35 from Rhinoceros Dung
%A Shuchi Singh
%A Vijayanand S. Moholkar
%A Arun Goyal
%J ISRN Microbiology
%D 2013
%R 10.1155/2013/728134
%X Cellulose hydrolyzing bacteria were isolated from rhinoceros dung and tested for clear zone formation around the colonies on the agar plates containing the medium amended with carboxymethylcellulose as a sole carbon source. Isolates were further screened on the basis of carboxymethylcellulase production in liquid medium. Out of 36 isolates, isolate no. 35 exhibited maximum enzyme activity of 0.079£¿U/mL and was selected for further identification by using conventional biochemical tests and phylogenetic analyses. This was a Gram-positive, spore forming bacterium with rod-shaped cells. The isolate was identified as Bacillus amyloliquefaciens SS35 based on nucleotide homology and phylogenetic analysis using 16S rDNA and gyrase A gene sequences. 1. Introduction Cellulose, a structural carbohydrate of the plant cell wall, is an abundant and ubiquitous polymer. The use of cellulose for the second generation biofuel production involves the hydrolysis of cellulosic biomass, that is, saccharification, to form simple sugar monomers for the fermentation into bioethanol [1¨C3]. Cellulases are the group of enzymes involved in the conversion of cellulosic substrates to fermentable sugars. Main members of this group include endoglucanase (EC 3.2.1.4), exoglucanase or cellobiohydrolase (EC 3.2.1.91), and -glucosidase (EC 3.2.1.21) [4]. The endoglucanase hydrolyzes -1,4 bonds in cellulose molecule, whereas exoglucanase cleaves the ends to release cellobiose, and -glucosidase converts cellobiose to glucose [5]. Several cellulase producing fungi such as Aspergillus, Rhizopus, and Trichoderma species [6, 7] and bacteria such as Bacillus, Clostridium, Cellulomonas, Thermomonospora, Ruminococcus, Bacteroides, Erwinia, and Acetivibrio species [8¨C10] have been identified. However, the isolation and characterization of novel cellulose hydrolyzing enzymes from bacteria are still a highly active research area, because bacteria have a higher growth rate than fungi, leading to greater production of enzymes [11]. 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. Wahyudi et al.
%U http://www.hindawi.com/journals/isrn.microbiology/2013/728134/