Journal of Pure and Applied MicrobiologyVol. 6 No. 1

The Ascorbic Acid Production in Root, Root Nodule and in Culture by Rhizobium sp. Isolated from the Legume Cajanus cajan (L.) Millspaugh

Pallab Ghosh¹, Sisir Ghosh¹, Pradipta Saha², Shanmugn Mayilraj³ and Tushar Kanti Maiti¹*

¹Microbiology Laboratory, Department of Botany, The University of Burdwan, Golapbag, Rajbati, Burdwan - 713 104, India, ²Department of Microbiology, The University of Burdwan, Golapbag, Rajbati, Burdwan- 713 104, India. ³Microbial Type Culture Collections and Gene Bank, Institute of Microbial Technology Sector 39-A, Chandigarh -160 036, India.

Received on 15 June 2011 and accepted on 05 September 2011

 

ABSTRACT

The root nodules of Cajanus cajan (L.) Millspaugh, a leguminous medicinal plant, was determined to contained high amount of ascorbic acid (AsA). A Glucose pool present in the root nodule might serve as precursor for AsA production. A symbiont was isolated from root nodules of the plant and was identified as a Rhizobium sp. based on biochemical and 16S rDNA based molecular phylogenetic approach. The symbiont produced large amount of AsA (640 µg/ml) from glucose supplemented basal medium. The production of AsA by the symbiont was increased to a greater extent than over control when the glucose (1.0 %) supplemented mineral medium was enriched with biotin (20 µg/100ml), thiamine hydrochloride (20 µg/100ml) and L-glutamic acid (0.2%). Our result supported the modern concept that AsA was also synthesized in root nodules of legume and refute the earlier concept that root nodules can not synthesize AsA.

Keywords : Cajanus cajan, Rhizobium sp., Ascorbic acid (AsA), Root nodules.