- January 18, 2018
- Posted by: RSIS
- Categories: Applied Science, Botany and Microbiology
International Journal of Research and Scientific Innovation (IJRSI) | Volume V, Issue I, January 2018 | ISSN 2321–2705
Raja Hima Bindhu Madasu1, Vijayalakshmi Muvva1 and Lakshmi Hima Bindu Madasu2
1Department of Botany and Microbiology, Acharya Nagarjuna University, Guntur – 522510, A. P., India
2Department of Microbiology, Govt. Degree college for Women, Guntur-522002, A. P., India
Abstract:-Eight predominant actinomycetes strains isolated from the marine soil samples collected from Nizampatnam coast of Andhra Pradesh demonstrated high chitinase activity on Colloidal chitin agar medium with average clearing zone of 20mm. A study was undertaken to screen these isolates for the production of chitinase. One of the strain produced higher amount of chitinase enzyme relative to the other strains thus the strain was identified based on 16s rDNA sequencing and designated as Rhodococcus sp. SVL. It grew maximally in shake flask and produced significant amount of chitinase at 35°C, pH 7.0. It has also shown a pronounced inhibitory activity against phytopathogenic fungi such as Botrytis cinerea, Fusarium oxysporum and F. solani. This is the first report of chitinase production from Rhodococcus sp.
Key words: Chitinase, Rhodococcus sp. SVL, colloidal chitin agar, optimization, Phytopathogenic fungi.
I. INTRODUCTION
Chitin is a polymer of unbranched chains of β-1, 4-linked 2-acetamido-2-deoxy-Dglucose (GlcNAc; N-acetylglucosamine; NAG) and is the structural component of fungi as well as the shell or cuticles of arthropods. Chitinases (EC 3.2.1.14) are produced by many organisms, such as bacteria, higher plants and animals, and play important physiological and ecological roles (Gooday, 1990). Actinomycetes are an important group of microorganisms, not only as degraders of organic matter in the natural environment, but also as producers of antibiotics and other useful compounds of commercial interest (Bentley et al. 2002; Basilio et al. 2003; Saugar et al. 2002;).
In addition, actinomycetes are important for the production of enzymes, such as chitinase (Streptomyces viridificans), cellulases (Thermonospora spp.), proteases (Nocardia spp.), xylanases (Microbispora spp.), ligninases (Nocardia autotrophica), amylases (Thermomonospora curvata) and sugar isomerases (Actinoplanes missouriensis) (Solans and Vobis, 2003). Actinomycetes are a very sturdy group of microorganisms found in a myriad of environments including some extreme ones and are known to be major producers of chitinases. Chitooligosaccharides and their N-acetylated analogues are useful for applications not only due to their specific biological activities such as antimicrobial activity, antitumor activity and immuno-enhancing effects (Gohel et al. 2006) but also for their potential in drug delivery (Kadowaki et al. 1997), wound healing, dietary fiber and in wastewater treatments (Dixon, 1995; Flach et al. 1992). Some chitooligosaccharides such as (GlcNAc6) and GlcNAc7 have been reported to possess antitumor activity (Liang et al. 2007; Suzuki et al. 1986). Chitinase-producing organisms could be used directly as potential biocontrol agents or indirectly using their purified protein (Gomes et al. 2001; Gunaratna et al. 1994; Ueno et al. 1990) or through gene manipulation (Gupta et al. 1995; Singh et al. 1999).
The aim of this study was to screen the marine actinomycete isolates for their capacity to produce chitinase enzyme on Colloidal chitin agar (CCA) (Gupta et al. 1995). Among the several strains isolated, productivity studies were carried out with one potential isolate with a view to explore its commercial potential and also its prospective applications in various fields like biocontrol.
