Improvement of cyclodextrin glycosyltransferase biosynthesis by recombinant Lactococcus lactis NZ:NSP:CGT

Cyclodextrin glycosyltransferase (CGTase) is a distinctive enzyme that has the capability of producing cyclodextrin (CD) from starch. The CD as the product of CGTase has numerous applications in various industries such as foods, cosmetics and toiletries, textiles and agrochemistry. Therefore, CGTase...

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Main Author:	Amiri, Azin
Format:	Thesis
Language:	English
Published:	2014
Subjects:	Cyclodextrins Glycosyltransferases Lactococcus lactis
Online Access:	http://psasir.upm.edu.my/id/eprint/51984/1/FBSB%202014%2013RR.pdf
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spelling	my-upm-ir.519842017-05-16T08:32:20Z Improvement of cyclodextrin glycosyltransferase biosynthesis by recombinant Lactococcus lactis NZ:NSP:CGT 2014-03 Amiri, Azin Cyclodextrin glycosyltransferase (CGTase) is a distinctive enzyme that has the capability of producing cyclodextrin (CD) from starch. The CD as the product of CGTase has numerous applications in various industries such as foods, cosmetics and toiletries, textiles and agrochemistry. Therefore, CGTase is considered as an industrially important enzyme and its production improvement is very crucial. So,essential efforts to increase its activity are desirable. CGTase production has never been investigated in Generally Regarded as Safe (GRAS) organism, Lactococcus lactis despite its advantages. The CGTase biosynthesis by recombinant Lactococcuslac tis NZ:NSP:CGT using different carbon sources ((corn starch), potato (dextrin from starch), tapioca starch and several soluble potato starches) and nitrogen sources (yeast extract, meat extract, peptone from meat, peptone from soymeal and peptone from casein) was carried out in batch cultivation using 250 mL shake-flask. Statistical optimization was performed using artificial neural network technique in order to optimize the culture condition (temperature) and medium compositions (carbon and nitrogen sources concentrations) to achieve maximum CGTase production. The experimental data from the aforementioned fermentation experiments were analyzed in order to obtain the kinetic parameter values and establish the basis of a kinetic model. The optimum parameters obtained were used to run batch fermentation in a 2L stirred tank bioreactor. The best carbon source leading to maximum CGTase biosynthesis was determined as Nacalai Tesque GR soluble potato starch. The maximum CGTase activity and productivity obtained by this carbon source were 7.99 U/mL and 1 U/mL.h, respectively. Yeast extract (Merck) was selected as the best nitrogen source due to its highest CGTase activity (9.88 U/mL) and productivity (0.99 U/mL.h) obtained. In screening stage of CGTase fermentation, carbon source concentration, nitrogen source concentration and temperature were recognized as three significant fermentation parameters. The optimum values for these parameters were determined through statistical optimization as 20°C for temperature and 3.82 and 5.67% (w/v) of soluble starch and yeast extract concentrations, respectively. The maximum CGTase activity obtained using the optimum values was 22.09 U/mL, which was closed to the predicted value (24.17 U/mL). The models used in this study were based on unstructured model equations including logistic and Luedeking-Piret, which were suitable to explain the growth, substrate consumption and CGTase production by L. lactis NZ:NSP:CGT in batch cultivation. According to the results, CGTase production is a growth-associated process. Production of CGTase in 2L stirred tank bioreactor (15.36 U/mL) was lower than shake-flask, which shows the essential optimization studies in bioreactor scale. Cyclodextrins Glycosyltransferases Lactococcus lactis 2014-03 Thesis http://psasir.upm.edu.my/id/eprint/51984/ http://psasir.upm.edu.my/id/eprint/51984/1/FBSB%202014%2013RR.pdf application/pdf en public masters Universiti Putra Malaysia Cyclodextrins Glycosyltransferases Lactococcus lactis
institution	Universiti Putra Malaysia
collection	PSAS Institutional Repository
language	English
topic	Cyclodextrins Glycosyltransferases Lactococcus lactis
spellingShingle	Cyclodextrins Glycosyltransferases Lactococcus lactis Amiri, Azin Improvement of cyclodextrin glycosyltransferase biosynthesis by recombinant Lactococcus lactis NZ:NSP:CGT
description	Cyclodextrin glycosyltransferase (CGTase) is a distinctive enzyme that has the capability of producing cyclodextrin (CD) from starch. The CD as the product of CGTase has numerous applications in various industries such as foods, cosmetics and toiletries, textiles and agrochemistry. Therefore, CGTase is considered as an industrially important enzyme and its production improvement is very crucial. So,essential efforts to increase its activity are desirable. CGTase production has never been investigated in Generally Regarded as Safe (GRAS) organism, Lactococcus lactis despite its advantages. The CGTase biosynthesis by recombinant Lactococcuslac tis NZ:NSP:CGT using different carbon sources ((corn starch), potato (dextrin from starch), tapioca starch and several soluble potato starches) and nitrogen sources (yeast extract, meat extract, peptone from meat, peptone from soymeal and peptone from casein) was carried out in batch cultivation using 250 mL shake-flask. Statistical optimization was performed using artificial neural network technique in order to optimize the culture condition (temperature) and medium compositions (carbon and nitrogen sources concentrations) to achieve maximum CGTase production. The experimental data from the aforementioned fermentation experiments were analyzed in order to obtain the kinetic parameter values and establish the basis of a kinetic model. The optimum parameters obtained were used to run batch fermentation in a 2L stirred tank bioreactor. The best carbon source leading to maximum CGTase biosynthesis was determined as Nacalai Tesque GR soluble potato starch. The maximum CGTase activity and productivity obtained by this carbon source were 7.99 U/mL and 1 U/mL.h, respectively. Yeast extract (Merck) was selected as the best nitrogen source due to its highest CGTase activity (9.88 U/mL) and productivity (0.99 U/mL.h) obtained. In screening stage of CGTase fermentation, carbon source concentration, nitrogen source concentration and temperature were recognized as three significant fermentation parameters. The optimum values for these parameters were determined through statistical optimization as 20°C for temperature and 3.82 and 5.67% (w/v) of soluble starch and yeast extract concentrations, respectively. The maximum CGTase activity obtained using the optimum values was 22.09 U/mL, which was closed to the predicted value (24.17 U/mL). The models used in this study were based on unstructured model equations including logistic and Luedeking-Piret, which were suitable to explain the growth, substrate consumption and CGTase production by L. lactis NZ:NSP:CGT in batch cultivation. According to the results, CGTase production is a growth-associated process. Production of CGTase in 2L stirred tank bioreactor (15.36 U/mL) was lower than shake-flask, which shows the essential optimization studies in bioreactor scale.
format	Thesis
qualification_level	Master's degree
author	Amiri, Azin
author_facet	Amiri, Azin
author_sort	Amiri, Azin
title	Improvement of cyclodextrin glycosyltransferase biosynthesis by recombinant Lactococcus lactis NZ:NSP:CGT
title_short	Improvement of cyclodextrin glycosyltransferase biosynthesis by recombinant Lactococcus lactis NZ:NSP:CGT
title_full	Improvement of cyclodextrin glycosyltransferase biosynthesis by recombinant Lactococcus lactis NZ:NSP:CGT
title_fullStr	Improvement of cyclodextrin glycosyltransferase biosynthesis by recombinant Lactococcus lactis NZ:NSP:CGT
title_full_unstemmed	Improvement of cyclodextrin glycosyltransferase biosynthesis by recombinant Lactococcus lactis NZ:NSP:CGT
title_sort	improvement of cyclodextrin glycosyltransferase biosynthesis by recombinant lactococcus lactis nz:nsp:cgt
granting_institution	Universiti Putra Malaysia
publishDate	2014
url	http://psasir.upm.edu.my/id/eprint/51984/1/FBSB%202014%2013RR.pdf
_version_	1747812077974585344

Improvement of cyclodextrin glycosyltransferase biosynthesis by recombinant Lactococcus lactis NZ:NSP:CGT

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