Kinetic study of recombinant beta-mannanase production from Escherichia coli KMAN-3 in a bioreactor using auto-induction system

Name: Kanok-On Khongcharoen

LCSH: Kasetsart University -- Theses. M.S. (Biotechnology) 2020

Classification :.LCCS: QP609.G45

LCSH: Kasetsart University. -- Department of Biotechnology -- Theses

LCSH: Glycosidases

LCSH: Bioreactors

LCSH: Escherichia coli

LCSH: Genetic recombination

Abstract: Beta-mannanase is an enzyme that is classified in the glycoside hydrolase group. It can randomly hydrolyze mannan and heteromannan molecules. β-mannanase is widely used in many industries such as pulp and paper, instant coffee, and for dietary prebiotic mannooligosaccharides (MOS). To satisfy industrial demand, recombinant β-mannanase was developed by E. coli KMAN-3 in a bioreactor. The effect of glucose, an alternative inducer, and inducer concentration using the auto-induction system was studied at the flask scale. Experiments were carried out in a 2-L bioreactor. Results of the flask scale experiments showed that the growth of E. coli KMAN-3 depended on the presence of glucose in the medium. Galactose provided the high β-mannanase activity of 83,310±499.38 U/L that was significantly lower than isopropyl β-D-1- thiogalactopyranoside (IPTG) induction but significantly higher than lactose autoinduction. Galactose was selected to study the effect of inducer concentration on βmannanase production. The maximum β-mannanase activity was 138,004±7,886.68 U/L at 36 h derived from 1 g/L galactose. In the bioreactor experiment, maximum β-mannanase production was derived from 1.0 g/L with maximum enzyme activity at 1,049,510.12±446,028.45 U/L. At optimal glucose concentration, the kinetic parameters of the bioreactor experiment consisted of specific growth rate, specific substrate utilization rate, specific product formation rate, and product yield coefficients as 0.643 h-1 , 0.869 h-1 , 0.796 h-1 , and 1.237 g/g, respectively. Simulation models were constructed by MATLAB R2019a version 9.6.0.1174912. Estimated maximum specific growth rate, a saturation constant for growth, maximum specific product formation rate (qp), and saturation constant for production (KSP) were 0.9987 h-1 , 0.253 g/L, 0.835 h-1 , and 0.062 g/L, respectively. The substrate inhibition constant for β-mannanase production (KIP) was 5.7 g/L. Simulation models agreed with the experimental data, indicating their applicability for use in the simulation of the fermentation process.

Kasetsart University. Office of the University Library

Address: Bangkok

Email: tdckulib@ku.ac.th

Name: Kittipong Rattanaporn

Role: Thesis Advisor

Name: Tanat Uan-On

Role: Thesis CO-Advisor

Created: 2020

Modified: 2025-07-09

Issued: 2025-07-09

วิทยานิพนธ์/Thesis

application/pdf

URL: https://www.lib.ku.ac.th/KUthesis/2563/kanok-on-kho-all.pdf

CallNumber: QP609.G45 .K36

eng

DegreeName: Master of Science

Level: Master's Degree

Descipline: Biotechnology

Grantor: Kasetsart University

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