Glycerol as alternative substrate for bioethanol production using free and immobilized Escherichia coli SS1

Increase in the crude oil price and the concern about climatic change has resulted in the rapid increase of biodiesel production. In the production of this biofuel, glycerol will essentially generate as by-product. As a result, the production of glycerol has also increased. Biofuel from glycerol can...

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Main Author:	Adnan, Nur Amelia Azreen
Format:	Thesis
Language:	English
Published:	2014
Subjects:	Escherichia coli Glycerols Biodiesel fuels - Research
Online Access:	http://psasir.upm.edu.my/id/eprint/39629/7/FBSB%202014%2011%20IR.pdf
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spelling	my-upm-ir.396292015-07-31T08:44:39Z Glycerol as alternative substrate for bioethanol production using free and immobilized Escherichia coli SS1 2014-06 Adnan, Nur Amelia Azreen Increase in the crude oil price and the concern about climatic change has resulted in the rapid increase of biodiesel production. In the production of this biofuel, glycerol will essentially generate as by-product. As a result, the production of glycerol has also increased. Biofuel from glycerol can be categorized as second generation of biofuels where it can be used to replace the first generation of biofuel including glucose and vegetable oils as feedstock to reduce the competition between biofuel and food production. Thus the aim of this study is to carry out bioethanol production using glycerol in batch and continuous fermentation by free and immobilized Escherichia coli SS1. Bioethanol production was carried out using both free and immobilized cells in 2 liter bioreactor with 800 mL working volume. Glycerol concentration of 20 g/L, 35 g/L and 45 g/L were used as initial substrate concentration in batch free cells fermentations. Dilution rate of 0.1/h and 0.2/h were used and was selected based on the maximum specific growth rate from batch fermentation. Immobilization of E.coli SS1 was done by using sodium alginate and calcium chloride as crossed link agent. Optimization study was done to determine the stability and rigidity of alginate beads. Parameters involved in this optimization study were sodium alginate concentration, calcium chloride concentration, beads diameter and initial pH of medium. The optimum conditions for cell immobilization were 0.2 M calcium chloride, at pH 7 with 3% concentration of sodium alginate and beads diameter of 3 mm. Results showed that high glycerol concentration did not affect the yield of ethanol with the yield was closed to theoretical yield; 1 mol ethanol per 1 mol glycerol. Dilution rate of 0.1/h was the optimum dilution rate to be used in this fermentation where glycerol consumption and ethanol production was similar to batch fermentation by yielding 1 mol ethanol per mol glycerol. Continuous fermentation of immobilized E. coli SS1 was done by using the optimized beads with the dilution rate of 0.2/h and 20 g/L. The results showed that immobilized cells can last up to 3rd cycle of continuous fermentation. Ethanol production obtained was 6.17 g/L by utilizing approximately 19 g/L glycerol. The yield achieved was 0.65 mol ethanol per mol glycerol. Compare with other studies, the result in this experiment was slightly lower where other managed to obtain about 0.6 to 0.8 mol ethanol per mol glycerol, respectively. Escherichia coli Glycerols Biodiesel fuels - Research 2014-06 Thesis http://psasir.upm.edu.my/id/eprint/39629/ http://psasir.upm.edu.my/id/eprint/39629/7/FBSB%202014%2011%20IR.pdf application/pdf en public masters Universiti Putra Malaysia Escherichia coli Glycerols Biodiesel fuels - Research
institution	Universiti Putra Malaysia
collection	PSAS Institutional Repository
language	English
topic	Escherichia coli Glycerols Biodiesel fuels - Research
spellingShingle	Escherichia coli Glycerols Biodiesel fuels - Research Adnan, Nur Amelia Azreen Glycerol as alternative substrate for bioethanol production using free and immobilized Escherichia coli SS1
description	Increase in the crude oil price and the concern about climatic change has resulted in the rapid increase of biodiesel production. In the production of this biofuel, glycerol will essentially generate as by-product. As a result, the production of glycerol has also increased. Biofuel from glycerol can be categorized as second generation of biofuels where it can be used to replace the first generation of biofuel including glucose and vegetable oils as feedstock to reduce the competition between biofuel and food production. Thus the aim of this study is to carry out bioethanol production using glycerol in batch and continuous fermentation by free and immobilized Escherichia coli SS1. Bioethanol production was carried out using both free and immobilized cells in 2 liter bioreactor with 800 mL working volume. Glycerol concentration of 20 g/L, 35 g/L and 45 g/L were used as initial substrate concentration in batch free cells fermentations. Dilution rate of 0.1/h and 0.2/h were used and was selected based on the maximum specific growth rate from batch fermentation. Immobilization of E.coli SS1 was done by using sodium alginate and calcium chloride as crossed link agent. Optimization study was done to determine the stability and rigidity of alginate beads. Parameters involved in this optimization study were sodium alginate concentration, calcium chloride concentration, beads diameter and initial pH of medium. The optimum conditions for cell immobilization were 0.2 M calcium chloride, at pH 7 with 3% concentration of sodium alginate and beads diameter of 3 mm. Results showed that high glycerol concentration did not affect the yield of ethanol with the yield was closed to theoretical yield; 1 mol ethanol per 1 mol glycerol. Dilution rate of 0.1/h was the optimum dilution rate to be used in this fermentation where glycerol consumption and ethanol production was similar to batch fermentation by yielding 1 mol ethanol per mol glycerol. Continuous fermentation of immobilized E. coli SS1 was done by using the optimized beads with the dilution rate of 0.2/h and 20 g/L. The results showed that immobilized cells can last up to 3rd cycle of continuous fermentation. Ethanol production obtained was 6.17 g/L by utilizing approximately 19 g/L glycerol. The yield achieved was 0.65 mol ethanol per mol glycerol. Compare with other studies, the result in this experiment was slightly lower where other managed to obtain about 0.6 to 0.8 mol ethanol per mol glycerol, respectively.
format	Thesis
qualification_level	Master's degree
author	Adnan, Nur Amelia Azreen
author_facet	Adnan, Nur Amelia Azreen
author_sort	Adnan, Nur Amelia Azreen
title	Glycerol as alternative substrate for bioethanol production using free and immobilized Escherichia coli SS1
title_short	Glycerol as alternative substrate for bioethanol production using free and immobilized Escherichia coli SS1
title_full	Glycerol as alternative substrate for bioethanol production using free and immobilized Escherichia coli SS1
title_fullStr	Glycerol as alternative substrate for bioethanol production using free and immobilized Escherichia coli SS1
title_full_unstemmed	Glycerol as alternative substrate for bioethanol production using free and immobilized Escherichia coli SS1
title_sort	glycerol as alternative substrate for bioethanol production using free and immobilized escherichia coli ss1
granting_institution	Universiti Putra Malaysia
publishDate	2014
url	http://psasir.upm.edu.my/id/eprint/39629/7/FBSB%202014%2011%20IR.pdf
_version_	1747811798313074688

Glycerol as alternative substrate for bioethanol production using free and immobilized Escherichia coli SS1

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