Comparative Studies on Ethanol Production Efficiency using Zymomonas mobilis, Erwinia carotovora and Saccharomyces cerevisae

摘要

Ethyl alcohol used to be produced from cane sugar waste. The old process requires 4 kg of cane sugar waste worth to produce a liter of ethyl alcohol. Production of ethyl alcohol from sugary materials is one of the oldest known microbiological processes. Alcohol is an important solvent and raw material used in a variety of chemical industries. Although today industrial alcohol is also produced synthetically from ethylene, production of alcohol by fermentation of cheap sugary materials such as molasses by yeast is still an important industry. In this project work, a detailed study was carried out about "Ethanol production efficiency from molasses using yeast and two different species of bacteria". The bacterial species are Zymomonas mobilis and Erwinia species. The main aim of the project work is to compare the efficiency and give the detailed study of the results. The raw materiel generally used is either crude cane molasses or best molasses which contain about 50 per cent fermentable sugars. For ethyl alcohol production, selected strains of Saccharomyces cerevisiae are employed since all the strains are not equally efficient. The alcohol tolerance and sugar tolerance are important criteria used in the selection of yeast strains. Strains tolerant to high sugar and alcohol concentration are desired. Ethanol production from molasses using Saccharomyces cerevisiae was studied. The yield and efficiency of the ethanol were determined. Similar work is carried out using Zymomonas mobilis and Erwinia species.