%0 Journal Article
%T Evaluation of Packed-Bed Reactor and Continuous Stirred Tank Reactor for the Production of Colchicine Derivatives
%A Kashyap Kumar Dubey
%A Dhirendra Kumar
%A Punit Kumar
%A Shafiul Haque
%A Arshad Jawed
%J ISRN Chemical Engineering
%D 2013
%R 10.1155/2013/865618
%X Bioconversion of colchicine into its pharmacologically active derivative 3-demethylated colchicine (3-DMC) mediated by P450BM3 enzyme is an economic and promising strategy for the production of this inexpensive and potent anticancer drug. Continuous stirred tank reactor (CSTR) and packed-bed reactor (PBR) of 3£¿L and 2£¿L total volumes were compared for the production of 3-demethylated colchicine (3-DMC) a colchicine derivative using Bacillus megaterium MTCC*420 under aerobic conditions. Statistical optimization technique was utilized with the most significant variables, that is, dissolved oxygen (DO), colchicine concentration, and process time for optimization. The validation of the model was performed by experiments on the predicted values in an individual run, and the optimum parameters were DO (~50%), colchicine concentration (7.5£¿g/L), and process time (39£¿h) resulted in a maximum bioconversion of 3-DMC 3.36£¿g/L. The PBR reactor achieved much higher productivity (6.58£¿g/L/h) as reported by earlier researchers. This is the first report on the use of PBR for bioconversion of colchicine. 1. Introduction Bioreactor design is of crucial importance in the development of bioprocesses. Once a microorganism is selected and the culture and/or production conditions are optimized at laboratory scale, the next issue is proceeding to larger scale so that bulk quantities of the desired product can be produced optimally in a cost-effective manner. The selection of a proper reactor type is critical to such processes and plays a major role in large-scale production. The bioreactors widely used in today¡¯s fermentation industry are mainly those developed in the past decades purely for chemical reactions [1, 2]. Among others, Stirred Tank Reactors (STRs) and Packed-Bed Reactors (PBRs) find the widest application. The application of these reactors for biological processes has been intensively studied with aerobic cultures [3¨C5]. Colchicine is a well-documented pseudo alkaloid obtained from Colchicum autumnale L. and Gloriosa superba, widely used in therapy for the treatment of gout pain persisting for a very long time [6, 7]. It is too toxic to be of value as an antitumor drug, in its native form. Derivatives of colchicine, that is, 3-demethylcolchicine, colchicoside, and thiocolchicoside with improved therapeutic properties for anti-inflammatory and anti-tumor drugs, have good commercial demand as these compounds are known to have clinical significance for the treatment of certain forms of leukemia and solid tumors [8, 9]. Colchicine and a number of its prepared
%U http://www.hindawi.com/journals/isrn.chemical.engineering/2013/865618/