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Arbter P, Widderich N, Utesch T, Hong Y, Zeng AP. Control of redox potential in a novel continuous bioelectrochemical system led to remarkable metabolic and energetic responses of Clostridium pasteurianum grown on glycerol. Microb Cell Fact 2022; 21:178. [PMID: 36050762 PMCID: PMC9434860 DOI: 10.1186/s12934-022-01902-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Accepted: 08/11/2022] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Electro-fermentation (EF) is an emerging tool for bioprocess intensification. Benefits are especially expected for bioprocesses in which the cells are enabled to exchange electrons with electrode surfaces directly. It has also been demonstrated that the use of electrical energy in BES can increase bioprocess performance by indirect secondary effects. In this case, the electricity is used to alter process parameters and indirectly activate desired pathways. In many bioprocesses, oxidation-reduction potential (ORP) is a crucial process parameter. While C. pasteurianum fermentation of glycerol has been shown to be significantly influenced electrochemically, the underlying mechanisms are not clear. To this end, we developed a system for the electrochemical control of ORP in continuous culture to quantitatively study the effects of ORP alteration on C. pasteurianum by metabolic flux analysis (MFA), targeted metabolomics, sensitivity and regulation analysis. RESULTS In the ORP range of -462 mV to -250 mV, the developed algorithm enabled a stable anodic electrochemical control of ORP at desired set-points and a fixed dilution rate of 0.1 h-1. An overall increase of 57% in the molar yield for 1,3-propanediol was observed by an ORP increase from -462 to -250 mV. MFA suggests that C. pasteurianum possesses and uses cellular energy generation mechanisms in addition to substrate-level phosphorylation. The sensitivity analysis showed that ORP exerted its strongest impact on the reaction of pyruvate-ferredoxin-oxidoreductase. The regulation analysis revealed that this influence is mainly of a direct nature. Hence, the observed metabolic shifts are primarily caused by direct inhibition of the enzyme upon electrochemical production of oxygen. A similar effect was observed for the enzyme pyruvate-formate-lyase at elevated ORP levels. CONCLUSIONS The results show that electrochemical ORP alteration is a suitable tool to steer the metabolism of C. pasteurianum and increase product yield for 1,3-propanediol in continuous culture. The approach might also be useful for application with further anaerobic or anoxic bioprocesses. However, to maximize the technique's efficiency, it is essential to understand the chemistry behind the ORP change and how the microbial system responds to it by transmitted or direct effects.
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Affiliation(s)
- Philipp Arbter
- Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, Denickestraße 15, 21073, Hamburg, Germany
| | - Niklas Widderich
- Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, Denickestraße 15, 21073, Hamburg, Germany
| | - Tyll Utesch
- Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, Denickestraße 15, 21073, Hamburg, Germany
| | - Yaeseong Hong
- Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, Denickestraße 15, 21073, Hamburg, Germany
| | - An-Ping Zeng
- Center of Synthetic Biology and Integrated Bioengineering, School of Engineering, Westlake University, Hangzhou, 310024, Zhejiang, China.
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Evaluation of microtiter plate as a high-throughput screening platform for beer fermentation. Eur Food Res Technol 2022. [DOI: 10.1007/s00217-022-04009-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractDownscaling the anaerobic fermentation in a microtiter plate (MTP) facilitates high throughput screening (HTS) applications. This study investigates the impacts of MTP configurations (scale, shaking, and cover) on the S. pastorianus beer fermentation compared to that in the shaking flask (SF) and European Brewing Convention (EBC) tube regarding fermentation performances and flavor attributes. The lager strains in MTPs accelerated cells reproduction and vitalization, sugar consumption, and glycerol accumulation. The microscale beer fermentation was closer to the SF but differed greatly from EBC tube fermentation depending on the MTP configurations. The downscaling from 2 mL to 0.2 mL in MTP increased the cell growth rate and vitality but did not change the maximum cell density. The shaking MTP did not promote early growth but sustained significantly higher cell numbers at the later fermentation stage. More than 1.5-folds acetaldehyde and higher alcohols, yet less than half esters, were obtained from the MTP and SF fermentations relative to that in the EBC tube. The air-tight MTP cover, as compared to the gas-permeable cover, not only balanced the above volatile flavors but also maintained integrity to the endogenous carbon dioxide pressure during beer fermentation. Additionally, fermentative activities were reduced by excluding air in either the material or the headspace of MTP. Hence, MTP configurations influenced S. pastorianus beer fermentation. These influences were partly attributed to their impacts on air accessibility. Conscious of the impacts, this study helps interpret the minimized fermentation and sheds light on the development of MTP based HTS platform for anaerobic cultivations.
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Minden S, Aniolek M, Sarkizi Shams Hajian C, Teleki A, Zerrer T, Delvigne F, van Gulik W, Deshmukh A, Noorman H, Takors R. Monitoring Intracellular Metabolite Dynamics in Saccharomyces cerevisiae during Industrially Relevant Famine Stimuli. Metabolites 2022; 12:metabo12030263. [PMID: 35323706 PMCID: PMC8953226 DOI: 10.3390/metabo12030263] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 03/08/2022] [Accepted: 03/16/2022] [Indexed: 11/16/2022] Open
Abstract
Carbon limitation is a common feeding strategy in bioprocesses to enable an efficient microbiological conversion of a substrate to a product. However, industrial settings inherently promote mixing insufficiencies, creating zones of famine conditions. Cells frequently traveling through such regions repeatedly experience substrate shortages and respond individually but often with a deteriorated production performance. A priori knowledge of the expected strain performance would enable targeted strain, process, and bioreactor engineering for minimizing performance loss. Today, computational fluid dynamics (CFD) coupled to data-driven kinetic models are a promising route for the in silico investigation of the impact of the dynamic environment in the large-scale bioreactor on microbial performance. However, profound wet-lab datasets are needed to cover relevant perturbations on realistic time scales. As a pioneering study, we quantified intracellular metabolome dynamics of Saccharomyces cerevisiae following an industrially relevant famine perturbation. Stimulus-response experiments were operated as chemostats with an intermittent feed and high-frequency sampling. Our results reveal that even mild glucose gradients in the range of 100 µmol·L−1 impose significant perturbations in adapted and non-adapted yeast cells, altering energy and redox homeostasis. Apparently, yeast sacrifices catabolic reduction charges for the sake of anabolic persistence under acute carbon starvation conditions. After repeated exposure to famine conditions, adapted cells show 2.7% increased maintenance demands.
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Affiliation(s)
- Steven Minden
- Institute of Biochemical Engineering, University of Stuttgart, 70569 Stuttgart, Germany; (S.M.); (M.A.); (C.S.S.H.); (A.T.); (T.Z.)
| | - Maria Aniolek
- Institute of Biochemical Engineering, University of Stuttgart, 70569 Stuttgart, Germany; (S.M.); (M.A.); (C.S.S.H.); (A.T.); (T.Z.)
| | - Christopher Sarkizi Shams Hajian
- Institute of Biochemical Engineering, University of Stuttgart, 70569 Stuttgart, Germany; (S.M.); (M.A.); (C.S.S.H.); (A.T.); (T.Z.)
| | - Attila Teleki
- Institute of Biochemical Engineering, University of Stuttgart, 70569 Stuttgart, Germany; (S.M.); (M.A.); (C.S.S.H.); (A.T.); (T.Z.)
| | - Tobias Zerrer
- Institute of Biochemical Engineering, University of Stuttgart, 70569 Stuttgart, Germany; (S.M.); (M.A.); (C.S.S.H.); (A.T.); (T.Z.)
| | - Frank Delvigne
- Microbial Processes and Interactions (MiPI), TERRA Research and Teaching Centre, Gembloux Agro Bio Tech, University of Liege, 5030 Gembloux, Belgium;
| | - Walter van Gulik
- Department of Biotechnology, Delft University of Technology, van der Maasweg 6, 2629 HZ Delft, The Netherlands;
| | - Amit Deshmukh
- Royal DSM, 2613 AX Delft, The Netherlands; (A.D.); (H.N.)
| | - Henk Noorman
- Royal DSM, 2613 AX Delft, The Netherlands; (A.D.); (H.N.)
- Department of Biotechnology, Delft University of Technology, 2628 CD Delft, The Netherlands
| | - Ralf Takors
- Institute of Biochemical Engineering, University of Stuttgart, 70569 Stuttgart, Germany; (S.M.); (M.A.); (C.S.S.H.); (A.T.); (T.Z.)
- Correspondence:
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Predicting By-Product Gradients of Baker’s Yeast Production at Industrial Scale: A Practical Simulation Approach. Processes (Basel) 2020. [DOI: 10.3390/pr8121554] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Scaling up bioprocesses is one of the most crucial steps in the commercialization of bioproducts. While it is known that concentration and shear rate gradients occur at larger scales, it is often too risky, if feasible at all, to conduct validation experiments at such scales. Using computational fluid dynamics equipped with mechanistic biochemical engineering knowledge of the process, it is possible to simulate such gradients. In this work, concentration profiles for the by-products of baker’s yeast production are investigated. By applying a mechanistic black-box model, concentration heterogeneities for oxygen, glucose, ethanol, and carbon dioxide are evaluated. The results suggest that, although at low concentrations, ethanol is consumed in more than 90% of the tank volume, which prevents cell starvation, even when glucose is virtually depleted. Moreover, long exposure to high dissolved carbon dioxide levels is predicted. Two biomass concentrations, i.e., 10 and 25 g/L, are considered where, in the former, ethanol production is solely because of overflow metabolism while, in the latter, 10% of the ethanol formation is due to dissolved oxygen limitation. This method facilitates the prediction of the living conditions of the microorganism and its utilization to address the limitations via change of strain or bioreactor design or operation conditions. The outcome can also be of value to design a representative scale-down reactor to facilitate strain studies.
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Importance of consideration of oxidoreduction potential as a critical quality parameter in food industries. Food Res Int 2020; 132:109108. [PMID: 32331669 DOI: 10.1016/j.foodres.2020.109108] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 02/14/2020] [Accepted: 02/16/2020] [Indexed: 12/11/2022]
Abstract
There are many intrinsic and extrinsic factors affecting the nutritional, organoleptic, microbial-enzymatic and physicochemical characteristics of food products. Some of these factors are commonly considered by food processors such as the temperature, water activity, pH, dissolved oxygen and chemical composition, while others are less considered such as the oxidoreduction potential (Eh). This latter factor is an intrinsic electrochemical parameter expressing the tendency of the substance/medium to give or receive electrons. Contrary to what is expected, the important role of Eh is not limited to inorganic chemistry, metallic chemistry, natural water, and wastewater treatment fields but it also covers many domains in biology such as metabolic engineering, enzymatic functions, food safety, and biotechnology. Unfortunately, although the critical roles of Eh in several key reactions occurred in biological media such as food and biotechnological products, its application or controlling is still uncommon or mis-considered by food processors. The lack of specific studies and reviews concerning the Eh and its influences on the quality parameters of products could be a reason for this lack of interest from the side of food processors. Recent studies reported the potential application of this parameter in novel food processing techniques such as reducing atmosphere drying (RAD) of food products and reducing atmosphere packaging (RAP) of fresh food products for preserving the quality attributes and extending the shelf-life of food products. This paper aims to help the technical and operational personnel working in food industry sectors as well as the scientific community to have an updated and a comprehensible review about the Eh parameter permitting its consideration for potential applications in food industries.
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Groeger C, Sabra W, Zeng AP. Simultaneous production of 1,3-propanediol andn-butanol byClostridium pasteurianum: In situ gas stripping and cellular metabolism. Eng Life Sci 2016. [DOI: 10.1002/elsc.201600058] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Affiliation(s)
- Christin Groeger
- Institute of Bioprocess and Biosystems Engineering; Hamburg University of Technology; Hamburg Germany
| | - Wael Sabra
- Institute of Bioprocess and Biosystems Engineering; Hamburg University of Technology; Hamburg Germany
| | - An-Ping Zeng
- Institute of Bioprocess and Biosystems Engineering; Hamburg University of Technology; Hamburg Germany
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Carbó R, Ginovart M, Carta A, Portell X, del Valle LJ. Effect of aerobic and microaerophilic culture in the growth dynamics of Saccharomyces cerevisiae and in training of quiescent and non-quiescent subpopulations. Arch Microbiol 2015. [PMID: 26206245 DOI: 10.1007/s00203-015-1136-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Saccharomyces cerevisiae is industrially the most important yeast, and its growth in different concentrations of oxygen can be used to improve various application processes. The aims of this work were to study in aerobic and microaerophilic growth conditions the cell size and tendency of morphological changes in S. cerevisiae in different stages of growth and to assess the effect of the two growth conditions in the differentiation of quiescent and non-quiescent subpopulations in the stationary phase. Dissolved oxygen levels in the culture medium for aerobic and microaerophilic conditions were 6.6 and 5.2 mg L(-1), respectively. In both growth conditions, similar viable cell populations were obtained, although in aerobic conditions the stationary phase was reached and the quiescent and non-quiescent subpopulations were also differentiated. The microaerophilic growth produced a significant reduction in the specific growth rate and consequently also in glucose and oxygen consumption. The most notable changes in cellular size and morphology occurred with the depletion of glucose and oxygen. The concentration of dissolved oxygen in the culture medium significantly modulated the growth kinetics of S. cerevisiae and their development and differentiation to quiescent cells. This could justify the need to readjust small variations in oxygen levels during yeast cultures in biotechnological processes.
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Affiliation(s)
- Rosa Carbó
- Department of Agri-Food Engineering and Biotechnology, Universitat Politècnica de Catalunya, Campus Baix Llobregrat, Esteve Terradas 8, 08860, Castelldefels, Barcelona, Spain,
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Afzal MI, Boulahya KA, Paris C, Delaunay S, Cailliez-Grimal C. Effect of oxygen on the biosynthesis of flavor compound 3-methylbutanal from leucine catabolism during batch culture in Carnobacterium maltaromaticum LMA 28. J Dairy Sci 2012. [PMID: 23182362 DOI: 10.3168/jds.2012-6088] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In this study, we demonstrated the effect of different dissolved oxygen concentrations (DOC) on cell growth and intracellular biosynthesis of 3-methylbutanal from leucine catabolism in Carnobacterium maltaromaticum LMA 28 during batch culture. The maximum specific growth rate was obtained in culture when DOC was controlled at 50% of air saturation. The specific consumption rates of glucose and specific production rates of lactate were higher at a DOC at 50 or 90% of air saturation. Carnobacterium maltaromaticum LMA 28 produced high quantities of 3-methylbutanal and 3-methylbutanol during culture with DOC maintained at 90%, suggesting that oxygen had a significant effect of the formation of these flavor compounds. This high formation of flavor compounds in an oxygen-rich environment was attributed to the simultaneous activation and stimulation of both α-ketoacid decarboxylase (KADC) and α-ketoacid dehydrogenase (KADH) pathways. Thus, intracellular biosynthesis of 3-methylbutanal can be controlled by modifying the DOC of the culture or food product during fermentation.
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Affiliation(s)
- M I Afzal
- Laboratoire d'ingénierie des biomolécules, Université de Lorraine, 2 avenue de la Forêt de Haye B.P. 172, Vandoeuvre-lès-Nancy F-54505, France
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Liu CG, Xue C, Lin YH, Bai FW. Redox potential control and applications in microaerobic and anaerobic fermentations. Biotechnol Adv 2012. [PMID: 23178703 DOI: 10.1016/j.biotechadv.2012.11.005] [Citation(s) in RCA: 144] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Many fermentation products are produced under microaerobic or anaerobic conditions, in which oxygen is undetectable by dissolved oxygen probe, presenting a challenge for process monitoring and control. Extracellular redox potentials that can be detected conveniently affect intracellular redox homeostasis and metabolism, and consequently control profiles of fermentation products, which provide an alternative for monitoring and control of these fermentation processes. This article reviews updated progress in the impact of redox potentials on gene expression, protein biosynthesis and metabolism as well as redox potential control strategies for more efficient production of fermentation products, taking ethanol fermentation by the yeast Saccharomyces under microaerobic conditions and butanol production by the bacterium Clostridium under anaerobic conditions as examples.
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Affiliation(s)
- Chen-Guang Liu
- School of Life Sciences and Biotechnology, Dalian University of Technology, Dalian 116023, China
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10
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Portell X, Ginovart M, Carbó R, Vives-Rego J. Differences in stationary-phase cells of a commercial Saccharomyces cerevisiae wine yeast grown in aerobic and microaerophilic batch cultures assessed by electric particle analysis, light diffraction and flow cytometry. J Ind Microbiol Biotechnol 2010; 38:141-51. [PMID: 20820858 DOI: 10.1007/s10295-010-0839-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Accepted: 07/26/2010] [Indexed: 11/30/2022]
Abstract
We applied electric particle analysis, light diffraction and flow cytometry to obtain information on the morphological changes during the stationary phase of Saccharomyces cerevisiae. The reported analyses of S. cerevisiae populations were obtained under two different conditions, aerobic and microaerophilic, at 27°C. The samples analysed were taken at between 20 and 50 h from the beginning of culture. To assist in the interpretation of the observed distributions a complexity index was used. The aerobically grown culture reached significantly greater cell density. Under these conditions, the cell density experienced a much lower reduction (3%) compared with the microaerophilic conditions (30%). Under aerobic conditions, the mean cell size determined by both electric particle analysis and light diffraction was lower and remained similar throughout the experiment. Under microaerophilic conditions, the mean cell size determined by electric particle analysis decreased slightly as the culture progressed through the stationary phase. Forward and side scatter distributions revealed two cell subpopulations under both growth conditions. However, in the aerobic growing culture the two subpopulations were more separated and hence easier to distinguish. The distributions obtained with the three experimental techniques were analysed using the complexity index. This analysis suggested that a complexity index is a good descriptor of the changes that take place in a yeast population in the stationary phase, and that it aids in the discussion and understanding of the implications of these distributions obtained by these experimental techniques.
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Affiliation(s)
- X Portell
- Department of Agri-Food Engineering and Biotechnology, Universitat Politècnica de Catalunya, Campus Baix Llobregat, Esteve Terradas 8, 08860, Castelldefels, Barcelona, Spain.
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Current awareness on yeast. Yeast 2006. [DOI: 10.1002/yea.1617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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