Abstract
The present process is a single step preparation of ethanol from corn meal using powdered dry stems of the Tinospora cordifolia. as source of saccharifying enzymes and Saccharomyces cerevisiae as ethanol producer, both working simultaneously in the same vessel. In the present day, new technology needs to be developed urgently to use alternative energy resources that are renewable and environmentally friendly. Ethanol has higher octane number, low cetane number and higher heat of vaporization than petrol and can be blended with the same. Three types of bioethanol feedstock are available today viz i) sucrose-based feedstock e.g. molasses, sugar beet, sweet sorghum and sugar cane, ii) starch-based feedstock e.g. wheat, corn, rice, potato, and barley and iii) lignocellulosic biomass.Bioethanol production from cereal starch like corn is more economic than from glucose. The present technology to produce fermentable sugar from cereal starch includes thermostable a-amylase or starch liquefying enzyme which catalyzes hydrolysis of internal α-1, 4 glycosidic linkages of starch into dextrin. Next glucoamylase catalyses hydrolysis α-1, 4 and a -1, 6 glycosidic bonds of dextrins into glucose as final product. Commercially it is known as "Two enzyme cold process". Presently saccharification steps and fermentation steps are carried out in separate vessels under different conditions. The ideal situation for the production of bioethanol from starch may be simultaneous single step saccharification of starch into glucose by a single enzyme composition and fermentation of the glucose into ethanol under the same reaction conditions. In 2002, Sengupta et al. first reported huge extracellular a-amylase by Tinospora cordifolia . The amylase is a thiol protein which hydrolyses both amylose and amylopectin with the production of disaccharide as major end product. A number of disaccharidases like maltase, isomaltase, sucrase lactase etc were found to be present in the crude enzyme preparation. Accordingly, the present invention provides a process (three example described) for the production of ethanol from corn meal which includes gelatinization of corn meal at 100°C in an aqueous medium at a pH of 4.5 to 7.0, mixing with 0.5 to 1.5 % (w/w) dry Tinospora cordifolia stem powder, incubating the mixture at temperature 45-50°C for 48 hours followed by adding 5-10% (v/v) 48 hours grown Saecharomyces cerevisiae. in a suitable medium containing glucose, ammonium sulphate, sodium hydrogen phosphate and yeast extract, further incubating at 30-37°C for 48 hours, separating the liquid by a known process of filtration and collecting the filtrate as a solution ethanol. Major advantages (12) of the single step process using unique biocatalyst process over conventional two stage process for bioethanol production have been indicated. Patent includes ten claims for the process as described.
