Effects of Fermentation Conditions on the Production of Thermostable Lipase by Recombinant E. Coli

A recombinant Escherichia coli BL21 (DE3) plysS (pGEX / T1S) strain harbouring thermostable lipase (E.C.3.1.1.3) gene from Geobacillus sp. was used through out this study. Lipase production was investigated using 2 L fermenter with 1.5 L working volume. Initial fermenter operation resulted in 11....

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Main Author:	Ismail, Fadzlirahimi
Format:	Thesis
Language:	English English
Published:	2006
Subjects:	Fermentation Escherichia coli Lipase
Online Access:	http://psasir.upm.edu.my/id/eprint/9814/1/FBSB_2006_41_A.pdf
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spelling	my-upm-ir.98142013-05-27T07:43:48Z Effects of Fermentation Conditions on the Production of Thermostable Lipase by Recombinant E. Coli 2006-03 Ismail, Fadzlirahimi A recombinant Escherichia coli BL21 (DE3) plysS (pGEX / T1S) strain harbouring thermostable lipase (E.C.3.1.1.3) gene from Geobacillus sp. was used through out this study. Lipase production was investigated using 2 L fermenter with 1.5 L working volume. Initial fermenter operation resulted in 11.07 U/mL activity with 24 h inoculum, temperature of 30°C, 250 rpm impeller speed and without pH and dissolve oxygen tension (DOT) control strategy. Optimisation of fermentation operation conditions such as inoculum age, temperature, impeller speed, airflow rate, pH and dissolve oxygen tension (DOT) control strategy throughout the fermentation were carried out and compared. A substantial high activity of lipase was detected during fermentation with 10 h inoculum. Lipase production was 41.18 U/mL activity which was comparable to previous optimised shake bottle and was 3.7 times higher than with 24 h inoculum. Increasing the cultivation temperature to 37°C, resulted in an increased of lipase production to 89.82 U/mL activity with highest cell mass attained of 6.63 g/L. However, no significant difference (41.18 and 46.71 U/mL activity) in lipase production was observed at temperature 30°C and 40°C, respectively. Lipase production increased with an increasing airflow rate, with highest production of 89.82 U/mL activity observed at 1.5 L/min (1 vvm). In contrast, lipase production decreased to 47.30 U/mL activity with higher airflow rate, which was 2 times lower than those obtained at low airflow rates. Further experiment on impeller speed showed only slight increased in lipase production. When impeller speed increased from 250 to 350 rpm, only slight increase of lipase production observed, from 89.82 U/mL to 93.03 U/mL activity. Higher and lower impeller speed showed no improvement in lipase production. Production time was reduced from 8 h to 5 h. Maximum cell mass decreased with increasing controlled pH and no improvement in overall productivity observed. At all dissolve oxygen control (DOT) strategy studied, no improvement in lipase production was observed. Highest production was observed in fermentation when DOT was controlled at 80% saturation which gave productivity of 4.85 U/mL.h. Fermentation Escherichia coli Lipase 2006-03 Thesis http://psasir.upm.edu.my/id/eprint/9814/ http://psasir.upm.edu.my/id/eprint/9814/1/FBSB_2006_41_A.pdf application/pdf en public masters Universiti Putra Malaysia Fermentation Escherichia coli Lipase Faculty Biotechnology and Biomolecular Sciences English
institution	Universiti Putra Malaysia
collection	PSAS Institutional Repository
language	English English
topic	Fermentation Escherichia coli Lipase
spellingShingle	Fermentation Escherichia coli Lipase Ismail, Fadzlirahimi Effects of Fermentation Conditions on the Production of Thermostable Lipase by Recombinant E. Coli
description	A recombinant Escherichia coli BL21 (DE3) plysS (pGEX / T1S) strain harbouring thermostable lipase (E.C.3.1.1.3) gene from Geobacillus sp. was used through out this study. Lipase production was investigated using 2 L fermenter with 1.5 L working volume. Initial fermenter operation resulted in 11.07 U/mL activity with 24 h inoculum, temperature of 30°C, 250 rpm impeller speed and without pH and dissolve oxygen tension (DOT) control strategy. Optimisation of fermentation operation conditions such as inoculum age, temperature, impeller speed, airflow rate, pH and dissolve oxygen tension (DOT) control strategy throughout the fermentation were carried out and compared. A substantial high activity of lipase was detected during fermentation with 10 h inoculum. Lipase production was 41.18 U/mL activity which was comparable to previous optimised shake bottle and was 3.7 times higher than with 24 h inoculum. Increasing the cultivation temperature to 37°C, resulted in an increased of lipase production to 89.82 U/mL activity with highest cell mass attained of 6.63 g/L. However, no significant difference (41.18 and 46.71 U/mL activity) in lipase production was observed at temperature 30°C and 40°C, respectively. Lipase production increased with an increasing airflow rate, with highest production of 89.82 U/mL activity observed at 1.5 L/min (1 vvm). In contrast, lipase production decreased to 47.30 U/mL activity with higher airflow rate, which was 2 times lower than those obtained at low airflow rates. Further experiment on impeller speed showed only slight increased in lipase production. When impeller speed increased from 250 to 350 rpm, only slight increase of lipase production observed, from 89.82 U/mL to 93.03 U/mL activity. Higher and lower impeller speed showed no improvement in lipase production. Production time was reduced from 8 h to 5 h. Maximum cell mass decreased with increasing controlled pH and no improvement in overall productivity observed. At all dissolve oxygen control (DOT) strategy studied, no improvement in lipase production was observed. Highest production was observed in fermentation when DOT was controlled at 80% saturation which gave productivity of 4.85 U/mL.h.
format	Thesis
qualification_level	Master's degree
author	Ismail, Fadzlirahimi
author_facet	Ismail, Fadzlirahimi
author_sort	Ismail, Fadzlirahimi
title	Effects of Fermentation Conditions on the Production of Thermostable Lipase by Recombinant E. Coli
title_short	Effects of Fermentation Conditions on the Production of Thermostable Lipase by Recombinant E. Coli
title_full	Effects of Fermentation Conditions on the Production of Thermostable Lipase by Recombinant E. Coli
title_fullStr	Effects of Fermentation Conditions on the Production of Thermostable Lipase by Recombinant E. Coli
title_full_unstemmed	Effects of Fermentation Conditions on the Production of Thermostable Lipase by Recombinant E. Coli
title_sort	effects of fermentation conditions on the production of thermostable lipase by recombinant e. coli
granting_institution	Universiti Putra Malaysia
granting_department	Faculty Biotechnology and Biomolecular Sciences
publishDate	2006
url	http://psasir.upm.edu.my/id/eprint/9814/1/FBSB_2006_41_A.pdf
_version_	1747811001579864064

Effects of Fermentation Conditions on the Production of Thermostable Lipase by Recombinant E. Coli

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