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Schütte L, Hanisch PG, Scheler N, Haböck KC, Huber R, Ersoy F, Berger RG. Squalene production under oxygen limitation by Schizochytrium sp. S31 in different cultivation systems. Appl Microbiol Biotechnol 2024; 108:201. [PMID: 38349390 PMCID: PMC10864429 DOI: 10.1007/s00253-024-13051-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 01/26/2024] [Accepted: 02/02/2024] [Indexed: 02/15/2024]
Abstract
The triterpene squalene is widely used in the food, cosmetics and pharmaceutical industries due to its antioxidant, antistatic and anti-carcinogenic properties. It is usually obtained from the liver of deep sea sharks, which are facing extinction. Alternative production organisms are marine protists from the family Thraustochytriaceae, which produce and store large quantities of various lipids. Squalene accumulation in thraustochytrids is complex, as it is an intermediate in sterol biosynthesis. Its conversion to squalene 2,3-epoxide is the first step in sterol synthesis and is heavily oxygen dependent. Hence, the oxygen supply during cultivation was investigated in our study. In shake flask cultivations, a reduced oxygen supply led to increased squalene and decreased sterol contents and yields. Oxygen-limited conditions were applied to bioreactor scale, where squalene accumulation and growth of Schizochytrium sp. S31 was determined in batch, fed-batch and continuous cultivation. The highest dry matter (32.03 g/L) was obtained during fed-batch cultivation, whereas batch cultivation yielded the highest biomass productivity (0.2 g/L*h-1). Squalene accumulation benefited from keeping the microorganisms in the growth phase. Therefore, the highest squalene content of 39.67 ± 1.34 mg/g was achieved by continuous cultivation (D = 0.025 h-1) and the highest squalene yield of 1131 mg/L during fed-batch cultivation. Volumetric and specific squalene productivity both reached maxima in the continuous cultivation at D = 0.025 h-1 (6.94 ± 0.27 mg/L*h-1 and 1.00 ± 0.03 mg/g*h-1, respectively). Thus, the choice of a suitable cultivation method under oxygen-limiting conditions depends heavily on the process requirements. KEY POINTS: • Measurements of respiratory activity and backscatter light of thraustochytrids • Oxygen limitation increased squalene accumulation in Schizochytrium sp. S31 • Comparison of different cultivation methods under oxygen-limiting conditions.
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Affiliation(s)
- Lina Schütte
- Institute of Food Chemistry, Gottfried Wilhelm Leibniz University Hannover, Hannover, Germany.
| | - Patrick G Hanisch
- Department of Engineering and Management, Munich University of Applied Sciences HM, Munich, Germany
| | - Nina Scheler
- Institute of Food Chemistry, Gottfried Wilhelm Leibniz University Hannover, Hannover, Germany
| | - Katharina C Haböck
- Institute of Food Chemistry, Gottfried Wilhelm Leibniz University Hannover, Hannover, Germany
| | - Robert Huber
- Department of Engineering and Management, Munich University of Applied Sciences HM, Munich, Germany
| | - Franziska Ersoy
- Institute of Food Chemistry, Gottfried Wilhelm Leibniz University Hannover, Hannover, Germany
| | - Ralf G Berger
- Institute of Food Chemistry, Gottfried Wilhelm Leibniz University Hannover, Hannover, Germany
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Stoklosa RJ, García-Negrón V, Latona RJ, Toht M. Limiting acetoin generation during 2,3-butanediol fermentation with Paenibacillus polymyxa using lignocellulosic hydrolysates. BIORESOURCE TECHNOLOGY 2024; 393:130053. [PMID: 37993069 DOI: 10.1016/j.biortech.2023.130053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 11/03/2023] [Accepted: 11/16/2023] [Indexed: 11/24/2023]
Abstract
Recent decarbonization efforts have led to interests in producing more bio-based chemicals. One attractive compound produced biochemically is the platform chemical known as 2,3-butanediol (2,3-BDO). In this work a mild alkaline pretreatment using sodium carbonate was performed on corn stover (CS) and switchgrass (SG) to generate hydrolysates for fermentation with the 2,3-BDO producer bacteria strain Paenibacillius polymyxa. Enzymatic hydrolysis performed on the pretreated CS and SG produced theoretical sugar yields of 80 % and 95 % for glucose and xylose, respectively. Fermentations with P. polymxya conducted in anaerobic bottles produced 2,3-BDO reaching concentrations ranging from 14 to 18 g/L with negligible conversion into acetoin. Bioreactor fermentations using the hydrolysate media generated up to 43 g/L and 34 g/L of 2,3-BDO from pretreated CS and SG, respectively, within 24 h of fermentation. However, 2,3-BDO product output was reduced by 40-50 % over the remainder of the fermentation due to conversion into acetoin caused by glucose depletion.
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Affiliation(s)
- Ryan J Stoklosa
- Sustainable Biofuels and Co-Products Research Unit, Eastern Regional Research Center, USDA-ARS, Wyndmoor, PA, United States.
| | - Valerie García-Negrón
- Sustainable Biofuels and Co-Products Research Unit, Eastern Regional Research Center, USDA-ARS, Wyndmoor, PA, United States
| | - Renee J Latona
- Sustainable Biofuels and Co-Products Research Unit, Eastern Regional Research Center, USDA-ARS, Wyndmoor, PA, United States
| | - Matthew Toht
- Sustainable Biofuels and Co-Products Research Unit, Eastern Regional Research Center, USDA-ARS, Wyndmoor, PA, United States
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3
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Miebach K, Finger M, Scherer AMK, Maaß CA, Büchs J. Hydrogen online monitoring based on thermal conductivity for anaerobic microorganisms. Biotechnol Bioeng 2023; 120:2199-2213. [PMID: 37462090 DOI: 10.1002/bit.28502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 07/06/2023] [Accepted: 07/10/2023] [Indexed: 07/30/2023]
Abstract
H2 -producing microorganisms are a promising source of sustainable biohydrogen. However, most H2 -producing microorganisms are anaerobes, which are difficult to cultivate and characterize. While several methods for measuring H2 exist, common H2 sensors often require oxygen, making them unsuitable for anaerobic processes. Other sensors can often not be operated at high gas humidity. Thus, we applied thermal conductivity (TC) sensors and developed a parallelized, online H2 monitoring for time-efficient characterization of H2 production by anaerobes. Since TC sensors are nonspecific for H2 , the cross-sensitivity of the sensors was evaluated regarding temperature, gas humidity, and CO2 concentrations. The systems' measurement range was validated with two anaerobes: a high H2 -producer (Clostridium pasteurianum) and a low H2 -producer (Phocaeicola vulgatus). Online monitoring of H2 production in shake flask cultivations was demonstrated, and H2 transfer rates were derived. Combined with online CO2 and pressure measurements, molar gas balances of the cultivations were closed, and an anaerobic respiration quotient was calculated. Thus, insight into the effect of medium components and inhibitory cultivation conditions on H2 production with the model anaerobes was gained. The presented online H2 monitoring method can accelerate the characterization of anaerobes for biohydrogen production and reveal metabolic changes without expensive equipment and offline analysis.
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Affiliation(s)
- Katharina Miebach
- Chair of Biochemical Engineering (AVT.BioVT), RWTH Aachen University, Aachen, Germany
| | - Maurice Finger
- Chair of Biochemical Engineering (AVT.BioVT), RWTH Aachen University, Aachen, Germany
| | | | | | - Jochen Büchs
- Chair of Biochemical Engineering (AVT.BioVT), RWTH Aachen University, Aachen, Germany
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Mutyala S, Li S, Khandelwal H, Kong DS, Kim JR. Citrate Synthase Overexpression of Pseudomonas putida Increases Succinate Production from Acetate in Microaerobic Cultivation. ACS OMEGA 2023; 8:26231-26242. [PMID: 37521642 PMCID: PMC10373214 DOI: 10.1021/acsomega.3c02520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 06/28/2023] [Indexed: 08/01/2023]
Abstract
Acetate is an end-product of anaerobic biodegradation and one of the major metabolites of microbial fermentation and lingo-cellulosic hydrolysate. Recently, acetate has been highlighted as a feedstock to produce value-added chemicals. This study examined acetate conversion to succinate by citrate synthase (gltA)-overexpressed Pseudomonas putida under microaerobic conditions. The acetate metabolism is initiated with the gltA enzyme, which converts acetyl-CoA to citrate. gltA-overexpressing P. putida (gltA-KT) showed an ∼50% improvement in succinate production compared to the wild type. Under the optimal pH of 7.5, the accumulation of succinate (4.73 ± 0.6 mM in 36 h) was ∼400% higher than that of the wild type. Overall, gltA overexpression alone resulted in 9.5% of the maximum theoretical yield in a minimal medium with acetate as the sole carbon source. This result shows that citrate synthase is important in acetate conversion to succinate by P. putida under microaerobic conditions.
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Saur KM, Kiefel R, Niehoff PJ, Hofstede J, Ernst P, Brockkötter J, Gätgens J, Viell J, Noack S, Wierckx N, Büchs J, Jupke A. Holistic Approach to Process Design and Scale-Up for Itaconic Acid Production from Crude Substrates. Bioengineering (Basel) 2023; 10:723. [PMID: 37370654 DOI: 10.3390/bioengineering10060723] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 06/01/2023] [Accepted: 06/02/2023] [Indexed: 06/29/2023] Open
Abstract
Bio-based bulk chemicals such as carboxylic acids continue to struggle to compete with their fossil counterparts on an economic basis. One possibility to improve the economic feasibility is the use of crude substrates in biorefineries. However, impurities in these substrates pose challenges in fermentation and purification, requiring interdisciplinary research. This work demonstrates a holistic approach to biorefinery process development, using itaconic acid production on thick juice based on sugar beets with Ustilago sp. as an example. A conceptual process design with data from artificially prepared solutions and literature data from fermentation on glucose guides the simultaneous development of the upstream and downstream processes up to a 100 L scale. Techno-economic analysis reveals substrate consumption as the main constituent of production costs and therefore, the product yield is the driver of process economics. Aligning pH-adjusting agents in the fermentation and the downstream process is a central lever for product recovery. Experiments show that fermentation can be transferred from glucose to thick juice by changing the feeding profile. In downstream processing, an additional decolorization step is necessary to remove impurities accompanying the crude substrate. Moreover, we observe an increased use of pH-adjusting agents compared to process simulations.
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Affiliation(s)
- Katharina Maria Saur
- Fluid Process Engineering (AVT.FVT), RWTH Aachen University, 52074 Aachen, Germany
| | - Robert Kiefel
- Fluid Process Engineering (AVT.FVT), RWTH Aachen University, 52074 Aachen, Germany
| | - Paul-Joachim Niehoff
- Biochemical Engineering (AVT.BioVT), RWTH Aachen University, 52074 Aachen, Germany
| | - Jordy Hofstede
- Process Systems Engineering (AVT.SVT), RWTH Aachen University, 52074 Aachen, Germany
| | - Philipp Ernst
- Forschungszentrum Jülich, Institute of Bio- and Geosciences IBG-1, 52428 Jülich, Germany
| | - Johannes Brockkötter
- Fluid Process Engineering (AVT.FVT), RWTH Aachen University, 52074 Aachen, Germany
| | - Jochem Gätgens
- Forschungszentrum Jülich, Institute of Bio- and Geosciences IBG-1, 52428 Jülich, Germany
| | - Jörn Viell
- Process Systems Engineering (AVT.SVT), RWTH Aachen University, 52074 Aachen, Germany
| | - Stephan Noack
- Forschungszentrum Jülich, Institute of Bio- and Geosciences IBG-1, 52428 Jülich, Germany
| | - Nick Wierckx
- Forschungszentrum Jülich, Institute of Bio- and Geosciences IBG-1, 52428 Jülich, Germany
| | - Jochen Büchs
- Biochemical Engineering (AVT.BioVT), RWTH Aachen University, 52074 Aachen, Germany
| | - Andreas Jupke
- Fluid Process Engineering (AVT.FVT), RWTH Aachen University, 52074 Aachen, Germany
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Ihling N, Munkler LP, Paul R, Berg C, Reichenbächer B, Kadisch M, Lang D, Büchs J. Non-invasive and time-resolved measurement of the respiration activity of Chinese hamster ovary cells enables prediction of key culture parameters in shake flasks. Biotechnol J 2022; 17:e2100677. [PMID: 35377965 DOI: 10.1002/biot.202100677] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 03/27/2022] [Accepted: 04/01/2022] [Indexed: 11/09/2022]
Abstract
BACKGROUND Shake flasks are frequently used for mammalian cell suspension cultures. For process development and routine culture monitoring, information on culture behaviour is needed early on. MAIN METHODS AND MAJOR RESULTS Here, cell-specific oxygen uptake rates (qO2 ) of two CHO cell lines were determined from shake flask experiments by simultaneous measurement of oxygen transfer rates (OTR) and viable cell concentrations (VCC). For cell line one, qO2 decreased from 2.38∙10-10 mmol cell-1 h-1 to 1.02∙10-10 mmol cell-1 h-1 during batch growth. For cell line two, qO2 was constant (1.90∙10-10 mmol h-1 ). Determined qO2 values were used to calculate the VCC from OTR data. Cumulated oxygen consumption and glucose consumption were correlated for both cell lines and enabled calculation of glucose concentrations from OTR data. IgG producing cell line one had an oxygen demand of ∼15 mmoloxygen gglucose -1 , cell line two consumed ∼5 mmoloxygen gglucose -1 . The established correlations for determination of VCC and glucose were successfully transferred to subsequent cultivations for both cell lines. Combined measurement of the OTR and the carbon dioxide transfer rate enabled quantitative determination of the lactate concentration (production and consumption) without sampling. CONCLUSIONS AND IMPLICATIONS Taken together, non-invasive measurement of the respiration activity enabled time-resolved determination of key culture parameters for increased process understanding in shake flasks. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Nina Ihling
- AVT - Biochemical Engineering, RWTH Aachen University, Forckenbeckstr. 51, Aachen, D-52074, Germany
| | - Lara Pauline Munkler
- AVT - Biochemical Engineering, RWTH Aachen University, Forckenbeckstr. 51, Aachen, D-52074, Germany
| | - Richard Paul
- AVT - Biochemical Engineering, RWTH Aachen University, Forckenbeckstr. 51, Aachen, D-52074, Germany
| | - Christoph Berg
- AVT - Biochemical Engineering, RWTH Aachen University, Forckenbeckstr. 51, Aachen, D-52074, Germany
| | | | - Marvin Kadisch
- Rentschler Biopharma SE, Erwin-Rentschler-Str. 21, Laupheim, 88471, Germany
| | - Dietmar Lang
- Rentschler Biopharma SE, Erwin-Rentschler-Str. 21, Laupheim, 88471, Germany
| | - Jochen Büchs
- AVT - Biochemical Engineering, RWTH Aachen University, Forckenbeckstr. 51, Aachen, D-52074, Germany
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Novel Propagation Strategy of Saccharomyces cerevisiae for Enhanced Xylose Metabolism during Fermentation on Softwood Hydrolysate. FERMENTATION 2021. [DOI: 10.3390/fermentation7040288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
An economically viable production of second-generation bioethanol by recombinant xylose-fermenting Saccharomyces cerevisiae requires higher xylose fermentation rates and improved glucose–xylose co-consumption. Moreover, xylose-fermenting S. cerevisiae recognises xylose as a non-fermentable rather than a fermentable carbon source, which might partly explain why xylose is not fermented into ethanol as efficiently as glucose. This study proposes propagating S. cerevisiae on non-fermentable carbon sources to enhance xylose metabolism during fermentation. When compared to yeast grown on sucrose, cells propagated on a mix of ethanol and glycerol in shake flasks showed up to 50% higher xylose utilisation rate (in a defined xylose medium) and a double maximum fermentation rate, together with an improved C5/C6 co-consumption (on an industrial softwood hydrolysate). Based on these results, an automated propagation protocol was developed, using a fed-batch approach and the respiratory quotient to guide the ethanol and glycerol-containing feed. This successfully produced 71.29 ± 0.91 g/L yeast with an average productivity of 1.03 ± 0.05 g/L/h. These empirical findings provide the basis for the design of a simple, yet effective yeast production strategy to be used in the second-generation bioethanol industry for increased fermentation efficiency.
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Ankenbauer A, Nitschel R, Teleki A, Müller T, Favilli L, Blombach B, Takors R. Micro-aerobic production of isobutanol with engineered Pseudomonas putida. Eng Life Sci 2021; 21:475-488. [PMID: 34257629 PMCID: PMC8258000 DOI: 10.1002/elsc.202000116] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/14/2021] [Accepted: 02/16/2021] [Indexed: 11/29/2022] Open
Abstract
Pseudomonas putida KT2440 is emerging as a promising microbial host for biotechnological industry due to its broad range of substrate affinity and resilience to physicochemical stresses. Its natural tolerance towards aromatics and solvents qualifies this versatile microbe as promising candidate to produce next generation biofuels such as isobutanol. In this study, we scaled-up the production of isobutanol with P. putida from shake flask to fed-batch cultivation in a 30 L bioreactor. The design of a two-stage bioprocess with separated growth and production resulted in 3.35 gisobutanol L-1. Flux analysis revealed that the NADPH expensive formation of isobutanol exceeded the cellular catabolic supply of NADPH finally causing growth retardation. Concomitantly, the cell counteracted to the redox imbalance by increased formation of 2-ketogluconic thereby providing electrons for the respiratory ATP generation. Thus, P. putida partially uncoupled ATP formation from the availability of NADH. The quantitative analysis of intracellular pyridine nucleotides NAD(P)+ and NAD(P)H revealed elevated catabolic and anabolic reducing power during aerobic production of isobutanol. Additionally, the installation of micro-aerobic conditions during production doubled the integral glucose-to-isobutanol conversion yield to 60 mgisobutanol gglucose -1 while preventing undesired carbon loss as 2-ketogluconic acid.
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Affiliation(s)
- Andreas Ankenbauer
- Institute of Biochemical EngineeringUniversity of StuttgartStuttgartGermany
| | - Robert Nitschel
- Institute of Biochemical EngineeringUniversity of StuttgartStuttgartGermany
| | - Attila Teleki
- Institute of Biochemical EngineeringUniversity of StuttgartStuttgartGermany
| | - Tobias Müller
- Institute of Biochemical EngineeringUniversity of StuttgartStuttgartGermany
| | - Lorenzo Favilli
- Institute of Biochemical EngineeringUniversity of StuttgartStuttgartGermany
| | - Bastian Blombach
- Microbial BiotechnologyCampus Straubing for Biotechnology and SustainabilityTechnical University of MunichStraubingGermany
| | - Ralf Takors
- Institute of Biochemical EngineeringUniversity of StuttgartStuttgartGermany
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Mann M, Hüser A, Schick B, Dinger R, Miebach K, Büchs J. Online monitoring of gas transfer rates during CO and CO/H 2 gas fermentation in quasi-continuously ventilated shake flasks. Biotechnol Bioeng 2021; 118:2092-2104. [PMID: 33620084 DOI: 10.1002/bit.27722] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 02/18/2021] [Indexed: 12/24/2022]
Abstract
Syngas fermentation is a potential player for future emission reduction. The first demonstration and commercial plants have been successfully established. However, due to its novelty, development of syngas fermentation processes is still in its infancy, and the need to systematically unravel and understand further phenomena, such as substrate toxicity as well as gas transfer and uptake rates, still persists. This study describes a new online monitoring device based on the respiration activity monitoring system for cultivation of syngas fermenting microorganisms with gaseous substrates. The new device is designed to online monitor the carbon dioxide transfer rate (CO2 TR) and the gross gas transfer rate during cultivation. Online measured data are used for the calculation of the carbon monoxide transfer rate (COTR) and hydrogen transfer rate (H2 TR). In cultivation on pure CO and CO + H2 , CO was continuously limiting, whereas hydrogen, when present, was sufficiently available. The maximum COTR measured was approximately 5 mmol/L/h for pure CO cultivation, and approximately 6 mmol/L/h for cultivation with additional H2 in the gas supply. Additionally, calculation of the ratio of evolved carbon dioxide to consumed monoxide, similar to the respiratory quotient for aerobic fermentation, allows the prediction of whether acetate or ethanol is predominantly produced. Clostridium ljungdahlii, a model acetogen for syngas fermentation, was cultivated using only CO, and CO in combination with H2 . Online monitoring of the mentioned parameters revealed a metabolic shift in fermentation with sole CO, depending on COTR. The device presented herein allows fast process development, because crucial parameters for scale-up can be measured online in small-scale gas fermentation.
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Affiliation(s)
- Marcel Mann
- RWTH Aachen University, AVT-Biochemical Engineering, Aachen, Germany
| | - Aline Hüser
- RWTH Aachen University, AVT-Biochemical Engineering, Aachen, Germany
| | - Benjamin Schick
- RWTH Aachen University, AVT-Biochemical Engineering, Aachen, Germany
| | - Robert Dinger
- RWTH Aachen University, AVT-Biochemical Engineering, Aachen, Germany
| | - Katharina Miebach
- RWTH Aachen University, AVT-Biochemical Engineering, Aachen, Germany
| | - Jochen Büchs
- RWTH Aachen University, AVT-Biochemical Engineering, Aachen, Germany
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Model-assisted DoE software: optimization of growth and biocatalysis in Saccharomyces cerevisiae bioprocesses. Bioprocess Biosyst Eng 2021; 44:683-700. [PMID: 33471162 PMCID: PMC7997827 DOI: 10.1007/s00449-020-02478-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Accepted: 11/05/2020] [Indexed: 10/26/2022]
Abstract
Bioprocess development and optimization are still cost- and time-intensive due to the enormous number of experiments involved. In this study, the recently introduced model-assisted Design of Experiments (mDoE) concept (Möller et al. in Bioproc Biosyst Eng 42(5):867, https://doi.org/10.1007/s00449-019-02089-7 , 2019) was extended and implemented into a software ("mDoE-toolbox") to significantly reduce the number of required cultivations. The application of the toolbox is exemplary shown in two case studies with Saccharomyces cerevisiae. In the first case study, a fed-batch process was optimized with respect to the pH value and linearly rising feeding rates of glucose and nitrogen source. Using the mDoE-toolbox, the biomass concentration was increased by 30% compared to previously performed experiments. The second case study was the whole-cell biocatalysis of ethyl acetoacetate (EAA) to (S)-ethyl-3-hydroxybutyrate (E3HB), for which the feeding rates of glucose, nitrogen source, and EAA were optimized. An increase of 80% compared to a previously performed experiment with similar initial conditions was achieved for the E3HB concentration.
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11
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Engineering of the 2,3-butanediol pathway of Paenibacillus polymyxa DSM 365. Metab Eng 2020; 61:381-388. [DOI: 10.1016/j.ymben.2020.07.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/12/2020] [Accepted: 07/27/2020] [Indexed: 02/06/2023]
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Meng W, Zhang Y, Cao M, Zhang W, Lü C, Yang C, Gao C, Xu P, Ma C. Efficient 2,3-butanediol production from whey powder using metabolically engineered Klebsiella oxytoca. Microb Cell Fact 2020; 19:162. [PMID: 32778112 PMCID: PMC7419187 DOI: 10.1186/s12934-020-01420-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 08/05/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Whey is a major pollutant generated by the dairy industry. To decrease environmental pollution caused by the industrial release of whey, new prospects for its utilization need to be urgently explored. Here, we investigated the possibility of using whey powder to produce 2,3-butanediol (BDO), an important platform chemical. RESULTS Klebsiella oxytoca strain PDL-0 was selected because of its ability to efficiently produce BDO from lactose, the major fermentable sugar in whey. After deleting genes pox, pta, frdA, ldhD, and pflB responding for the production of by-products acetate, succinate, lactate, and formate, a recombinant strain K. oxytoca PDL-K5 was constructed. Fed-batch fermentation using K. oxytoca PDL-K5 produced 74.9 g/L BDO with a productivity of 2.27 g/L/h and a yield of 0.43 g/g from lactose. In addition, when whey powder was used as the substrate, 65.5 g/L BDO was produced within 24 h with a productivity of 2.73 g/L/h and a yield of 0.44 g/g. CONCLUSION This study demonstrated the efficiency of K. oxytoca PDL-0 for BDO production from whey. Due to its non-pathogenicity and efficient lactose utilization, K. oxytoca PDL-0 might also be used in the production of other important chemicals using whey as the substrate.
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Affiliation(s)
- Wensi Meng
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Yongjia Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Menghao Cao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Wen Zhang
- Center for Gene and Immunotherapy, The Second Hospital of Shandong University, Jinan, 250033, People's Republic of China
| | - Chuanjuan Lü
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China.
| | - Chunyu Yang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Chao Gao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China
| | - Cuiqing Ma
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China.
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