Bioreactor operation parameters as tools for metabolic regulations in fermentation processes: influence of pH conditions

Date

2003-02-01

Author

Çalık, Pınar
Calik, G
Ozdamar, TH

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

230
views

0
downloads

The influence of controlled- and uncontrolled-pH conditions together with the initial pH on the product and by-product distributions and oxygen transfer characteristics, whereupon the process rate limitations in relation to the intracellular reaction rates were investigated in serine alkaline protease (SAP) fermentation process by recombinant Bacillus licheniformis carrying pHV1431::subC on a defined medium with the sole carbon source glucose in the pH range of 6.80-7.25 in batch bioreactors. Although the same amount of cell was produced at all the conditions in each type of operation, with the increase of initial pH the cell formation rates increased; moreover, uncontrolled-pH operation was favourable for the cell formation. The SAP synthesis rates and concentrations were higher at uncontrolled-pH operations. Among the fermentations, pH(0) = 7.10 uncontrolled-pH operation produced maximum SAP activity that was ca. 900 U cm(-3) at t = 21 h. According to the biomass and SAP production profiles, bioprocess was divided into two periods; Period I (0 < t less than or equal to 10 h) covers the cell growth phase and Period II (10 < t less than or equal to 24 h) covers the SAP production phase. In Period I in both operations, while the oxygen uptake rate (OUR) increased with the increase in initial pH the oxygen transfer rate (OTR) decreased. In Period II, among uncontrolled-pH operations OUR was the lowest at pH = 7.10 while OTR decreased with the increase in initial pH. At the oxygen transfer condition applied, the bioprocess is biochemical reaction limited at all the conditions; nevertheless, with the decrease in initial pH, Damkohler number that is the oxygen transfer limitation decreases. Further, the perturbation effects of initial pH and the operation conditions on the intracellular reaction rates were calculated for Periods I and II by using the experimental data obtained and, the diversions in the pathways and certain metabolic reactions and potential strategies for improving SAP production are also discussed.

Subject Keywords

Industrial and Manufacturing Engineering, Applied Mathematics, General Chemistry, General Chemical Engineering

URI

https://hdl.handle.net/11511/35684

Journal

CHEMICAL ENGINEERING SCIENCE

DOI

https://doi.org/10.1016/s0009-2509(02)00605-x

Collections

Department of Chemical Engineering, Article

Suggestions

OpenMETU
Core

Bioreaction network flux analysis for human protein producing Bacillus subtilis based on genome-scale model ÖZDAMAR, HASAN TUNÇER; Senturk, Birguel; YILMAZ, OĞUZ; KOCABAŞ, PINAR; Calik, Guezide; Çalık, Pınar (Elsevier BV, 2010-01-01) To interpret the effect of human protein gene, e.g., human growth hormone gene hGH, on the intracellular bioreaction network of Bacillus subtilis, the intracellular reaction fluxes were calculated by solving the mass-balance-based genome-scale mathematical model, at pseudo-steady state by using bioreactor data. The bioreaction network consists of 1340 reactions including 990 metabolites. Reaction fluxes in B. subtilis carrying pMK4::pre(subC)::hGH (rBsHGH) and B. subtilis carrying merely pMK4 (rBsP) were ca...
Bioreaction network flux analysis for industrial microorganisms: A review Çalık, Pınar (Walter de Gruyter GmbH, 2002-01-01) This review focuses on the analysis of the bioreaction networks of the microorgansims used in fermentation processes, by metabolic flux analysis that is the novel tool of biochemical reaction engineering, required for the quantitative analysis of cell metabolism which is under the control of the cell physiology. Metabolic flux analysis (MFA) is based on calculation of intracellular reaction network rates through various reaction pathways either theoretical or by using elaborate experimental data on uptake, ...
Metabolic engineering of aromatic group amino acid pathway in Bacillus subtilis for L-phenylalanine production Ozcelik, IS; Çalık, Pınar; Calik, G; Ozdamar, TH (Elsevier BV, 2004-11-01) Metabolic control sites in the aromatic group amino acid pathway (AAAP) of Bacillus subtilis for L-Phenylalanine (Phe) overproduction were determined; and aiming pathway flux amplification, by cloning the flux controlling gene aroH to a multi-copy plasmid, the impact of single gene cloning on pathway flux distributions were investigated. The branch-point metabolites E4P and PEP+E4P supplied in vitro, enhanced Phe production and well defined perturbations were achieved on the AAAP reactions. The intracellula...
PH influences intracellular reaction network of beta-lactamase producing Bacillus licheniformis Çalık, Pınar (Elsevier BV, 2007-09-01) Effects of pH on metabolic flux distributions in P-lactamase producing Bacillus licheniformis were investigated using metabolic flux analysis, at pH(C) = 6.5, 7.0 and 7.5 controlled-pH conditions. The bioprocess was divided into three periods: Period I (0 < t < 6 h) is the growth phase where beta-lactamase synthesis starts; Period II (6 < t < 8 h) is the transition phase; Period III (8 < t < 12 h) is the stationary phase for the cell-growth where beta-lactamase synthesis increases. The central pathways were...
Effect of Midsynthesis Addition of Silica to the Synthesis Medium on the Properties of MFI-Type Zeolite Membranes Soydas, Belma; Kalıpçılar, Halil; Culfaz, Ali (American Chemical Society (ACS), 2010-06-02) Thin zeolite membranes of MFI type were prepared on alpha-Al2O3 supports by midsynthesis addition of silica in a recirculating flow system at 95 degrees C The synthesis was started with the batch composition of 80SiO(2): 30TPAOH:1500H(2)O which was changed to 80SiO(2)center dot 9TPAOH:1500H(2)O by addition of silica Mkt 24, 48, or 72 h Compared to synthesis at constant composition. it is possible to affect the rates of nucleation and crystal growth to obtain membranes with better quality by changing the ove...

Citation Formats

P. Çalık, G. Calik, and T. Ozdamar, “Bioreactor operation parameters as tools for metabolic regulations in fermentation processes: influence of pH conditions,” CHEMICAL ENGINEERING SCIENCE, pp. 759–766, 2003, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/35684.