Bioethanol production by Zymomonas mobilis using passion fruit residues

Abstract

In 1973 the oil crisis inspired the search for renewable energy sources that could replace the current petrochemical products. Agricultural wastes are the biggest part of the biomass residues production and are important energy sources for both domestic consumptions and for the industry, being used as a feedstock for biofuel production. In general, agricultural crops produce a number of wastes much larger than the portion used for food or industrial use. Passion fruit is a fruit grown in regions of subtropical and tropical weather, producing for 8 months of the year, and Brazil is the largest producer (about 664 000 tonnes per year) with emphasis on the Northeast, which represents 74% of production. Juice industries of certain fruits, such as passion fruit, grown in almost all Brazilian territory, generate large amounts of waste (peels and seeds) from the crush of tons of fruit to obtain the juice. Thus, there is a great amount of passion fruit waste that could be processed in ethanol. Studies have been carried out using bacteria instead of yeasts to reduce the fermentation time. Alcohol bacteria of Zymomonas mobilis species present technological attributes that enhance their use in alcoholic fermentation, they produce 1.9 mol of ethanol per mole of glucose at a speed about three to four times greater than Saccharomyces cerevisiae. This study aims to assess the effect of hydrolysis of passion fruit wastes for the production of ethanol by Zymomonas mobilis CCT 4494. It will be considered the effects of variation of the substrate, the sucrose content added to the fermentation media, time and temperature.(AU)