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Zhao J, Li X, He R, Wang Y, Wang Z. Construction and Application of a Multienzyme System for Synthesis of L-malate. Appl Biochem Biotechnol 2024:10.1007/s12010-024-05026-x. [PMID: 39088025 DOI: 10.1007/s12010-024-05026-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/23/2024] [Indexed: 08/02/2024]
Abstract
This study aimed to develop a multienzymatic system for synthesis of L-malate. First, recombinant Escherichia coli strains were constructed expressing maleic acid cis-trans isomerase (MaiA) or fumarase C (FumC) from different sources. Serratia marcescens MaiA (SMaiA) and E. coli FumC (ECFumC) showed good catalytic performance. Next, six co-expression systems for SMaiA and ECFumC were constructed. E. coli BL21 (DE3)-pRSFDuet-1-ecfumC-smaiA (named strain pFM2) had the highest L-malate catalytic activity. In 7-L fed-batch fermentation, the SMaiA and ECFumC activities of strain pFM2 wet cells were 43.4 and 154.5 U/g, respectively, 2.4- and 10.7-fold the values that were obtained in shaken flasks. Finally, a whole-cell catalytic process was established for the production of L-malate by strain pFM2 with maleate as the substrate. When the dose of pFM2 wet cells was 0.5 g/100 mL and 1 mol/L maleate was the substrate, the catalytic process was completed within 4 h. Notably, the intermediate fumarate was almost absent during the conversion process. The concentration of L-malate reached 143.8 g/L with a yield of 0.60 g/(L·min). The molar conversion rate of the substrate was 98.4%. These findings lay a foundation for the industrial application of multienzymatic synthesis of L-malate.
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Affiliation(s)
- Jielin Zhao
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China
- College of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
- Key Laboratory of Biopharmaceutical Preparation and Delivery (Chinese Academy of Sciences), Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China
| | - Xiaolian Li
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China
- Key Laboratory of Biopharmaceutical Preparation and Delivery (Chinese Academy of Sciences), Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China
| | - Ranfeng He
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China
- Key Laboratory of Biopharmaceutical Preparation and Delivery (Chinese Academy of Sciences), Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yunshan Wang
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China
- Key Laboratory of Biopharmaceutical Preparation and Delivery (Chinese Academy of Sciences), Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China
| | - Ziqiang Wang
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China.
- Key Laboratory of Biopharmaceutical Preparation and Delivery (Chinese Academy of Sciences), Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China.
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Sun Z, Wu Y, Long S, Feng S, Jia X, Hu Y, Ma M, Liu J, Zeng B. Aspergillus oryzae as a Cell Factory: Research and Applications in Industrial Production. J Fungi (Basel) 2024; 10:248. [PMID: 38667919 PMCID: PMC11051239 DOI: 10.3390/jof10040248] [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: 02/08/2024] [Revised: 03/15/2024] [Accepted: 03/15/2024] [Indexed: 04/28/2024] Open
Abstract
Aspergillus oryzae, a biosafe strain widely utilized in bioproduction and fermentation technology, exhibits a robust hydrolytic enzyme secretion system. Therefore, it is frequently employed as a cell factory for industrial enzyme production. Moreover, A. oryzae has the ability to synthesize various secondary metabolites, such as kojic acid and L-malic acid. Nevertheless, the complex secretion system and protein expression regulation mechanism of A. oryzae pose challenges for expressing numerous heterologous products. By leveraging synthetic biology and novel genetic engineering techniques, A. oryzae has emerged as an ideal candidate for constructing cell factories. In this review, we provide an overview of the latest advancements in the application of A. oryzae-based cell factories in industrial production. These studies suggest that metabolic engineering and optimization of protein expression regulation are key elements in realizing the widespread industrial application of A. oryzae cell factories. It is anticipated that this review will pave the way for more effective approaches and research avenues in the future implementation of A. oryzae cell factories in industrial production.
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Affiliation(s)
- Zeao Sun
- College of Chemistry and Chemical Engineering, Jiangxi Science and Technology Normal University, Nanchang 330013, China; (Z.S.); (S.F.)
- College of Pharmacy, Shenzhen Technology University, Shenzhen 518118, China; (Y.W.); (S.L.); (X.J.); (Y.H.); (M.M.)
| | - Yijian Wu
- College of Pharmacy, Shenzhen Technology University, Shenzhen 518118, China; (Y.W.); (S.L.); (X.J.); (Y.H.); (M.M.)
| | - Shihua Long
- College of Pharmacy, Shenzhen Technology University, Shenzhen 518118, China; (Y.W.); (S.L.); (X.J.); (Y.H.); (M.M.)
| | - Sai Feng
- College of Chemistry and Chemical Engineering, Jiangxi Science and Technology Normal University, Nanchang 330013, China; (Z.S.); (S.F.)
- College of Pharmacy, Shenzhen Technology University, Shenzhen 518118, China; (Y.W.); (S.L.); (X.J.); (Y.H.); (M.M.)
| | - Xiao Jia
- College of Pharmacy, Shenzhen Technology University, Shenzhen 518118, China; (Y.W.); (S.L.); (X.J.); (Y.H.); (M.M.)
| | - Yan Hu
- College of Pharmacy, Shenzhen Technology University, Shenzhen 518118, China; (Y.W.); (S.L.); (X.J.); (Y.H.); (M.M.)
| | - Maomao Ma
- College of Pharmacy, Shenzhen Technology University, Shenzhen 518118, China; (Y.W.); (S.L.); (X.J.); (Y.H.); (M.M.)
| | - Jingxin Liu
- College of Pharmacy, Shenzhen Technology University, Shenzhen 518118, China; (Y.W.); (S.L.); (X.J.); (Y.H.); (M.M.)
| | - Bin Zeng
- College of Pharmacy, Shenzhen Technology University, Shenzhen 518118, China; (Y.W.); (S.L.); (X.J.); (Y.H.); (M.M.)
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Jiang Z, Jiang Y, Wu H, Zhang W, Xin F, Ma J, Jiang M. Cofactor Metabolic Engineering of Escherichia coli for Aerobic L-Malate Production with Lower CO 2 Emissions. Bioengineering (Basel) 2023; 10:881. [PMID: 37627766 PMCID: PMC10451681 DOI: 10.3390/bioengineering10080881] [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: 05/22/2023] [Revised: 06/16/2023] [Accepted: 06/23/2023] [Indexed: 08/27/2023] Open
Abstract
Escherichia coli has been engineered for L-malate production via aerobic cultivation. However, the maximum yield obtained through this mode is inferior to that of anaerobic fermentation due to massive amounts of CO2 emissions. Here, we aim to address this issue by reducing CO2 emissions of recombinant E. coli during aerobic L-malate production. Our findings indicated that NADH oxidation and ATP-synthesis-related genes were down-regulated with 2 g/L of YE during aerobic cultivations of E. coli E23, as compared to 5 g/L of YE. Then, E23 was engineered via the knockout of nuoA and the introduction of the nonoxidative glycolysis (NOG) pathway, resulting in a reduction of NAD+ and ATP supplies. The results demonstrate that E23 (ΔnuoA, NOG) exhibited decreased CO2 emissions, and it produced 21.3 g/L of L-malate from glucose aerobically with the improved yield of 0.43 g/g. This study suggests that a restricted NAD+ and ATP supply can prompt E. coli to engage in incomplete oxidization of glucose, leading to the accumulation of metabolites instead of utilizing them in cellular respiration.
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Affiliation(s)
| | | | | | | | | | - Jiangfeng Ma
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, China
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Zuo H, Ji L, Pan J, Chen X, Gao C, Liu J, Wei W, Wu J, Song W, Liu L. Engineering growth phenotypes of Aspergillus oryzae for L-malate production. BIORESOUR BIOPROCESS 2023; 10:25. [PMID: 38647943 PMCID: PMC10991988 DOI: 10.1186/s40643-023-00642-7] [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: 12/24/2022] [Accepted: 03/09/2023] [Indexed: 04/09/2023] Open
Abstract
Improving the growth status of Aspergillus oryzae is an efficient way to enhance L-malate production. However, the growth mechanism of filamentous fungi is relatively complex, which limits A. oryzae as a cell factory to produce L-malate industrially. This study determined the relationship between growth status and L-malate production. The optimal ranges of colony diameter, percentage of vegetative mycelia, and pellet number of A. oryzae were determined to be 26-30 mm, 35-40%, and 220-240/mL, respectively. To achieve this optimum range, adaptive evolution was used to obtain the evolved strain Z07 with 132.54 g/L L-malate and a productivity of 1.1 g/L/h. Finally, a combination of transcriptome analysis and morphological characterization was used to identify the relevant pathway genes that affect the growth mechanism of A. oryzae. The strategies used in this study and the growth mechanism provide a good basis for efficient L-malate production by filamentous fungi.
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Affiliation(s)
- Huiyun Zuo
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Lihao Ji
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Jingyu Pan
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Xiulai Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Cong Gao
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Jia Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Wanqing Wei
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Jing Wu
- School of Pharmaceutical Science, Jiangnan University, Wuxi, 214122, Jiangsu, China
| | - Wei Song
- School of Pharmaceutical Science, Jiangnan University, Wuxi, 214122, Jiangsu, China
| | - Liming Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China.
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Ding Q, Ye C. Recent advances in producing food additive L-malate: Chassis, substrate, pathway, fermentation regulation and application. Microb Biotechnol 2023; 16:709-725. [PMID: 36604311 PMCID: PMC10034640 DOI: 10.1111/1751-7915.14206] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Accepted: 12/22/2022] [Indexed: 01/07/2023] Open
Abstract
In addition to being an important intermediate in the TCA cycle, L-malate is also widely used in the chemical and beverage industries. Due to the resulting high demand, numerous studies investigated chemical methods to synthesize L-malate from petrochemical resources, but such approaches are hampered by complex downstream processing and environmental pollution. Accordingly, there is an urgent need to develop microbial methods for environmentally-friendly and economical L-malate biosynthesis. The rapid progress and understanding of DNA manipulation, cell physiology, and cell metabolism can improve industrial L-malate biosynthesis by applying intelligent biochemical strategies and advanced synthetic biology tools. In this paper, we mainly focused on biotechnological approaches for enhancing L-malate synthesis, encompassing the microbial chassis, substrate utilization, synthesis pathway, fermentation regulation, and industrial application. This review emphasizes the application of novel metabolic engineering strategies and synthetic biology tools combined with a deep understanding of microbial physiology to improve industrial L-malate biosynthesis in the future.
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Affiliation(s)
- Qiang Ding
- School of Life Sciences, Anhui University, Hefei, China
- Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei, China
- Anhui Key Laboratory of Modern Biomanufacturing, Hefei, China
| | - Chao Ye
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
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Ding Q, Ye C. Microbial cell factories based on filamentous bacteria, yeasts, and fungi. Microb Cell Fact 2023; 22:20. [PMID: 36717860 PMCID: PMC9885587 DOI: 10.1186/s12934-023-02025-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 01/20/2023] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Advanced DNA synthesis, biosensor assembly, and genetic circuit development in synthetic biology and metabolic engineering have reinforced the application of filamentous bacteria, yeasts, and fungi as promising chassis cells for chemical production, but their industrial application remains a major challenge that needs to be solved. RESULTS As important chassis strains, filamentous microorganisms can synthesize important enzymes, chemicals, and niche pharmaceutical products through microbial fermentation. With the aid of metabolic engineering and synthetic biology, filamentous bacteria, yeasts, and fungi can be developed into efficient microbial cell factories through genome engineering, pathway engineering, tolerance engineering, and microbial engineering. Mutant screening and metabolic engineering can be used in filamentous bacteria, filamentous yeasts (Candida glabrata, Candida utilis), and filamentous fungi (Aspergillus sp., Rhizopus sp.) to greatly increase their capacity for chemical production. This review highlights the potential of using biotechnology to further develop filamentous bacteria, yeasts, and fungi as alternative chassis strains. CONCLUSIONS In this review, we recapitulate the recent progress in the application of filamentous bacteria, yeasts, and fungi as microbial cell factories. Furthermore, emphasis on metabolic engineering strategies involved in cellular tolerance, metabolic engineering, and screening are discussed. Finally, we offer an outlook on advanced techniques for the engineering of filamentous bacteria, yeasts, and fungi.
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Affiliation(s)
- Qiang Ding
- grid.252245.60000 0001 0085 4987School of Life Sciences, Anhui University, Hefei, 230601 China ,grid.252245.60000 0001 0085 4987Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei, 230601 Anhui China ,Anhui Key Laboratory of Modern Biomanufacturing, Hefei, 230601 Anhui China
| | - Chao Ye
- grid.260474.30000 0001 0089 5711School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210023 China
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Wu N, Zhang J, Chen Y, Xu Q, Song P, Li Y, Li K, Liu H. Recent advances in microbial production of L-malic acid. Appl Microbiol Biotechnol 2022; 106:7973-7992. [PMID: 36370160 DOI: 10.1007/s00253-022-12260-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 10/19/2022] [Accepted: 10/23/2022] [Indexed: 11/14/2022]
Abstract
Over the last few decades, increasing concerns regarding fossil fuel depletion and excessive CO2 emissions have led to extensive fundamental studies and industrial trials regarding microbial chemical production. As an additive or precursor, L-malic acid has been shown to exhibit distinctive properties in the food, pharmaceutical, and daily chemical industries. L-malic acid is currently mainly fabricated through a fumarate hydratase-based biocatalytic conversion route, wherein petroleum-derived fumaric acid serves as a substrate. In this review, for the first time, we comprehensively describe the methods of malic acid strain transformation, raw material utilization, malic acid separation, etc., especially recent progress and remaining challenges for industrial applications. First, we summarize the various pathways involved in L-malic acid biosynthesis using different microorganisms. We also discuss several strain engineering strategies for improving the titer, yield, and productivity of L-malic acid. We illustrate the currently available alternatives for reducing production costs and the existing strategies for optimizing the fermentation process. Finally, we summarize the present challenges and future perspectives regarding the development of microbial L-malic acid production. KEY POINTS: • A range of wild-type, mutant, laboratory-evolved, and metabolically engineered strains which could produce L-malic acid were comprehensively described. • Alternative raw materials for reducing production costs and the existing strategies for optimizing the fermentation were sufficiently summarized. • The present challenges and future perspectives regarding the development of microbial L-malic acid production were elaboratively discussed.
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Affiliation(s)
- Na Wu
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Jiahui Zhang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Yaru Chen
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Qing Xu
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Ping Song
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Yingfeng Li
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Ke Li
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China.
| | - Hao Liu
- MOE Key Laboratory of Industrial Fermentation Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China. .,Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, Tianjin University of Science & Technology, Tianjin, China.
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Kövilein A, Aschmann V, Zadravec L, Ochsenreither K. Optimization of l-malic acid production from acetate with Aspergillus oryzae DSM 1863 using a pH-coupled feeding strategy. Microb Cell Fact 2022; 21:242. [DOI: 10.1186/s12934-022-01961-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 11/01/2022] [Indexed: 11/25/2022] Open
Abstract
Abstract
Background
Malic acid, a dicarboxylic acid mainly used in the food industry, is currently produced from fossil resources. The utilization of low-cost substrates derived from biomass could render microbial processes economic. Such feedstocks, like lignocellulosic hydrolysates or condensates of fast pyrolysis, can contain high concentrations of acetic acid. Acetate is a suitable substrate for l-malic acid production with the filamentous fungus Aspergillus oryzae DSM 1863, but concentrations obtained so far are low. An advantage of this carbon source is that it can be used for pH control and simultaneous substrate supply in the form of acetic acid. In this study, we therefore aimed to enhance l-malate production from acetate with A. oryzae by applying a pH-coupled feeding strategy.
Results
In 2.5-L bioreactor fermentations, several feeding strategies were evaluated. Using a pH-coupled feed consisting of 10 M acetic acid, the malic acid concentration was increased about 5.3-fold compared to the batch process without pH control, resulting in a maximum titer of 29.53 ± 1.82 g/L after 264 h. However, it was not possible to keep both the pH and the substrate concentration constant during this fermentation. By using 10 M acetic acid set to a pH of 4.5, or with the repeated addition of NaOH, the substrate concentration could be maintained within a constant range, but these strategies did not prove beneficial as lower maximum titers and yields were obtained. Since cessation of malic acid production was observed in later fermentation stages despite carbon availability, a possible product inhibition was evaluated in shake flask cultivations. In these experiments, malate and succinate, which is a major by-product during malic acid production, were added at concentrations of up to 50 g/L, and it was found that A. oryzae is capable of organic acid production even at high product concentrations.
Conclusions
This study demonstrates that a suitable feeding strategy is necessary for efficient malic acid production from acetate. It illustrates the potential of acetate as carbon source for microbial production of the organic acid and provides useful insights which can serve as basis for further optimization.
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Kövilein A, Zadravec L, Hohmann S, Umpfenbach J, Ochsenreither K. Effect of process mode, nitrogen source and temperature on L-malic acid production with Aspergillus oryzae DSM 1863 using acetate as carbon source. Front Bioeng Biotechnol 2022; 10:1033777. [PMID: 36312560 PMCID: PMC9614319 DOI: 10.3389/fbioe.2022.1033777] [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: 08/31/2022] [Accepted: 10/04/2022] [Indexed: 11/21/2022] Open
Abstract
Malic acid, mainly used as acidulant and taste enhancer in the food industry, is currently produced from fossil resources. In this study, microbial L-malate production with the filamentous fungus A. oryzae using the carbon source acetate was evaluated. Acetate is for example contained in biomass-derived substrates such as lignocellulosic hydrolysates and condensates of fast pyrolysis, thus avoiding competition with food production. Since research on malic acid synthesis from acetate is limited and reported productivities and yields are low, this work aimed to improve the process. First, different cultivation temperatures were tested. This parameter was found to affect the ratio between malic and succinic acid, which is the major by-product of organic acid production with A. oryzae. At 32°C, the malate share was highest (53.7 ± 1.6%), while it was lowest at 38°C (43.3 ± 1.1%) whereas succinate represented the main product (51.5 ± 1.0%). Besides the temperature, the type of nitrogen source was also found to affect malate synthesis as well as biomass production. In the pre-culture, the biomass concentration was increased by a factor of 3.4–3.9, and germination started earlier with the complex nitrogen sources yeast extract, casein hydrolysate and peptone compared to the defined nitrogen source (NH4)2SO4. Especially with yeast extract, malate synthesis in the main culture was accelerated and the titer obtained after 48 h was about 2.6 times higher than that quantified with (NH4)2SO4. To reduce substrate inhibition in acetate medium, fed-batch and repeated-batch processes were evaluated using (NH4)2SO4 or yeast extract as nitrogen source. In the fed-batch process, the period of malate production was extended, and the maximum product concentration was increased to 11.49 ± 1.84 g/L with (NH4)2SO4 and 12.08 ± 1.25 g/L with yeast extract. In the repeated-batch process, the total acid production was highest within the first 240 h of fermentation, but optimization is required to maintain high production rates in later cycles. The lessons learned in this study will help in the development of further process strategies to maximize malate production using acetate as alternative substrate to the commonly used glucose.
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Schmitt V, Derenbach L, Ochsenreither K. Enhanced l-Malic Acid Production by Aspergillus oryzae DSM 1863 Using Repeated-Batch Cultivation. Front Bioeng Biotechnol 2022; 9:760500. [PMID: 35083199 PMCID: PMC8784810 DOI: 10.3389/fbioe.2021.760500] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 11/11/2021] [Indexed: 11/16/2022] Open
Abstract
l-Malic acid is a C4-dicarboxylic acid and a potential key building block for a bio-based economy. At present, malic acid is synthesized petrochemically and its major market is the food and beverages industry. In future, malic acid might also serve as a building block for biopolymers or even replace the commodity chemical maleic anhydride. For a sustainable production of l-malic acid from renewable resources, the microbial synthesis by the mold Aspergillus oryzae is one possible route. As CO2 fixation is involved in the biosynthesis, high yields are possible, and at the same time greenhouse gases can be reduced. In order to enhance the production potential of the wild-type strain Aspergillus oryzae DSM 1863, process characteristics were studied in shake flasks, comparing batch, fed-batch, and repeated-batch cultivations. In the batch process, a prolonged cultivation time led to malic acid consumption. Keeping carbon source concentration on a high level by pulsed feeding could prolong cell viability and cultivation time, however, did not result in significant higher product levels. In contrast, continuous malic acid production could be achieved over six exchange cycles and a total fermentation time of 19 days in repeated-batch cultivations. Up to 178 g/L l-malic acid was produced. The maximum productivity (0.90 ± 0.05 g/L/h) achieved in the repeated-batch cultivation had more than doubled than that achieved in the batch process and also the average productivity (0.42 ± 0.03 g/L/h for five exchange cycles and 16 days) was increased considerably. Further repeated-batch experiments confirmed a positive effect of regular calcium carbonate additions on pH stability and malic acid synthesis. Besides calcium carbonate, nitrogen supplementation proved to be essential for the prolonged malic acid production in repeated-batch. As prolonged malic acid production was only observed in cultivations with product removal, product inhibition seems to be the major limiting factor for malic acid production by the wild-type strain. This study provides a systematic comparison of different process strategies under consideration of major influencing factors and thereby delivers important insights into natural l-malic acid production.
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Affiliation(s)
- Vanessa Schmitt
- Institute of Process Engineering in Life Sciences 2: Technical Biology, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Laura Derenbach
- Institute of Process Engineering in Life Sciences 2: Technical Biology, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Katrin Ochsenreither
- Institute of Process Engineering in Life Sciences 2: Technical Biology, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
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Daba GM, Mostafa FA, Elkhateeb WA. The ancient koji mold (Aspergillus oryzae) as a modern biotechnological tool. BIORESOUR BIOPROCESS 2021; 8:52. [PMID: 38650252 PMCID: PMC10992763 DOI: 10.1186/s40643-021-00408-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 06/16/2021] [Indexed: 01/07/2023] Open
Abstract
Aspergillus oryzae (A. oryzae) is a filamentous micro-fungus that is used from centuries in fermentation of different foods in many countries all over the world. This valuable fungus is also a rich source of many bioactive secondary metabolites. Moreover, A. oryzae has a prestigious secretory system that allows it to secrete high concentrations of proteins into its culturing medium, which support its use as biotechnological tool in veterinary, food, pharmaceutical, and industrial fields. This review aims to highlight the significance of this valuable fungus in food industry, showing its generosity in production of nutritional and bioactive metabolites that enrich food fermented by it. Also, using A. oryzae as a biotechnological tool in the field of enzymes production was described. Furthermore, domestication, functional genomics, and contributions of A. oryzae in functional production of human pharmaceutical proteins were presented. Finally, future prospects in order to get more benefits from A. oryzae were discussed.
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Affiliation(s)
- Ghoson M Daba
- Chemistry of Natural and Microbial Products Department, Pharmaceutical Industries Researches Division, National Research Centre, El Buhouth Street, Dokki, Giza, 12311, Egypt.
| | - Faten A Mostafa
- Chemistry of Natural and Microbial Products Department, Pharmaceutical Industries Researches Division, National Research Centre, El Buhouth Street, Dokki, Giza, 12311, Egypt.
| | - Waill A Elkhateeb
- Chemistry of Natural and Microbial Products Department, Pharmaceutical Industries Researches Division, National Research Centre, El Buhouth Street, Dokki, Giza, 12311, Egypt
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