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Beganovic S, Wittmann C. Medical properties, market potential, and microbial production of golden polyketide curcumin for food, biomedical, and cosmetic applications. Curr Opin Biotechnol 2024; 87:103112. [PMID: 38518404 DOI: 10.1016/j.copbio.2024.103112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 03/01/2024] [Accepted: 03/03/2024] [Indexed: 03/24/2024]
Abstract
Curcumin, a potent plant polyketide in turmeric, has gained recognition for its outstanding health benefits, including anti-inflammatory, antioxidant, and anticancer effects. Classical turmeric farming, which is widely used to produce curcumin, is linked to deforestation, soil degradation, excessive water use, and reduced biodiversity. In recent years, the microbial synthesis of curcumin has been achieved and optimized through novel strategies, offering increased safety, improved sustainability, and the potential to revolutionize production. Here, we discuss recent breakthroughs in microbial engineering and fermentation techniques, as well as their capacity to increase the yield, purity, and cost-effectiveness of curcumin production. The utilization of microbial systems not only addresses supply chain limitations but also helps meet the growing demand for curcumin in various industries, including pharmaceuticals, foods, and cosmetics.
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Affiliation(s)
- Selma Beganovic
- Institute of Systems Biotechnology, Saarland University, Germany
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Zhang YM, Qiao B, Shang W, Ding MZ, Xu QM, Duan TX, Cheng JS. Improving salt-tolerant artificial consortium of Bacillus amyloliquefaciens for bioconverting food waste to lipopeptides. WASTE MANAGEMENT (NEW YORK, N.Y.) 2024; 181:89-100. [PMID: 38598883 DOI: 10.1016/j.wasman.2024.04.006] [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: 12/06/2023] [Revised: 03/20/2024] [Accepted: 04/03/2024] [Indexed: 04/12/2024]
Abstract
High-salt content in food waste (FW) affects its resource utilization during biotransformation. In this study, adaptive laboratory evolution (ALE), gene editing, and artificial consortia were performed out to improve the salt-tolerance of Bacillus amyloliquefaciens for producing lipopeptide under FW and seawater. High-salt stress significantly decreased lipopeptide production in the B. amyloliquefaciens HM618 and ALE strains. The total lipopeptide production in the recombinant B. amyloliquefaciens HM-4KSMSO after overexpressing the ion transportor gene ktrA and proline transporter gene opuE and replacing the promoter of gene mrp was 1.34 times higher than that in the strain HM618 in medium containing 30 g/L NaCl. Lipopeptide production under salt-tolerant consortia containing two strains (HM-4KSMSO and Corynebacterium glutamicum) and three-strains (HM-4KSMSO, salt-tolerant C. glutamicum, and Yarrowia lipolytica) was 1.81- and 2.28-fold higher than that under pure culture in a medium containing FW or both FW and seawater, respectively. These findings provide a new strategy for using high-salt FW and seawater to produce value-added chemicals.
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Affiliation(s)
- Yu-Miao Zhang
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin 300350, People's Republic of China
| | - Bin Qiao
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin 300350, People's Republic of China
| | - Wei Shang
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin 300350, People's Republic of China
| | - Ming-Zhu Ding
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin 300350, People's Republic of China
| | - Qiu-Man Xu
- Tianjin Key Laboratory of Animal and Plant Resistance, College of Life Science, Tianjin Normal University, Binshuixi Road 393, Xiqing District, Tianjin 300387, People's Republic of China
| | - Tian-Xu Duan
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin 300350, People's Republic of China
| | - Jing-Sheng Cheng
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin 300350, People's Republic of China.
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Stegmüller J, Rodríguez Estévez M, Shu W, Gläser L, Myronovskyi M, Rückert-Reed C, Kalinowski J, Luzhetskyy A, Wittmann C. Systems metabolic engineering of the primary and secondary metabolism of Streptomyces albidoflavus enhances production of the reverse antibiotic nybomycin against multi-resistant Staphylococcus aureus. Metab Eng 2024; 81:123-143. [PMID: 38072358 DOI: 10.1016/j.ymben.2023.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 11/17/2023] [Accepted: 12/01/2023] [Indexed: 01/23/2024]
Abstract
Nybomycin is an antibiotic compound with proven activity against multi-resistant Staphylococcus aureus, making it an interesting candidate for combating these globally threatening pathogens. For exploring its potential, sufficient amounts of nybomycin and its derivatives must be synthetized to fully study its effectiveness, safety profile, and clinical applications. As native isolates only accumulate low amounts of the compound, superior producers are needed. The heterologous cell factory S. albidoflavus 4N24, previously derived from the cluster-free chassis S. albidoflavus Del14, produced 860 μg L-1 of nybomycin, mainly in the stationary phase. A first round of strain development modulated expression of genes involved in supply of nybomycin precursors under control of the common Perm* promoter in 4N24, but without any effect. Subsequent studies with mCherry reporter strains revealed that Perm* failed to drive expression during the product synthesis phase but that use of two synthetic promoters (PkasOP* and P41) enabled strong constitutive expression during the entire process. Using PkasOP*, several rounds of metabolic engineering successively streamlined expression of genes involved in the pentose phosphate pathway, the shikimic acid pathway, supply of CoA esters, and nybomycin biosynthesis and export, which more than doubled the nybomycin titer to 1.7 mg L-1 in the sixth-generation strain NYB-6B. In addition, we identified the minimal set of nyb genes needed to synthetize the molecule using single-gene-deletion strains. Subsequently, deletion of the regulator nybW enabled nybomycin production to begin during the growth phase, further boosting the titer and productivity. Based on RNA sequencing along the created strain genealogy, we discovered that the nyb gene cluster was unfavorably downregulated in all advanced producers. This inspired removal of a part and the entire set of the four regulatory genes at the 3'-end nyb of the cluster. The corresponding mutants NYB-8 and NYB-9 exhibited marked further improvement in production, and the deregulated cluster was combined with all beneficial targets from primary metabolism. The best strain, S. albidoflavus NYB-11, accumulated up to 12 mg L-1 nybomycin, fifteenfold more than the basic strain. The absence of native gene clusters in the host and use of a lean minimal medium contributed to a selective production process, providing an important next step toward further development of nybomycin.
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Affiliation(s)
- Julian Stegmüller
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | | | - Wei Shu
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Lars Gläser
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Maksym Myronovskyi
- Department of Pharmaceutical Biotechnology, Saarland University, Saarbrücken, Germany
| | | | - Jörn Kalinowski
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Andriy Luzhetskyy
- Department of Pharmaceutical Biotechnology, Saarland University, Saarbrücken, Germany
| | - Christoph Wittmann
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany.
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Seo K, Shu W, Rückert-Reed C, Gerlinger P, Erb TJ, Kalinowski J, Wittmann C. From waste to health-supporting molecules: biosynthesis of natural products from lignin-, plastic- and seaweed-based monomers using metabolically engineered Streptomyces lividans. Microb Cell Fact 2023; 22:262. [PMID: 38114944 PMCID: PMC10731712 DOI: 10.1186/s12934-023-02266-0] [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: 11/02/2023] [Accepted: 12/05/2023] [Indexed: 12/21/2023] Open
Abstract
BACKGROUND Transforming waste and nonfood materials into bulk biofuels and chemicals represents a major stride in creating a sustainable bioindustry to optimize the use of resources while reducing environmental footprint. However, despite these advancements, the production of high-value natural products often continues to depend on the use of first-generation substrates, underscoring the intricate processes and specific requirements of their biosyntheses. This is also true for Streptomyces lividans, a renowned host organism celebrated for its capacity to produce a wide array of natural products, which is attributed to its genetic versatility and potent secondary metabolic activity. Given this context, it becomes imperative to assess and optimize this microorganism for the synthesis of natural products specifically from waste and nonfood substrates. RESULTS We metabolically engineered S. lividans to heterologously produce the ribosomally synthesized and posttranslationally modified peptide bottromycin, as well as the polyketide pamamycin. The modified strains successfully produced these compounds using waste and nonfood model substrates such as protocatechuate (derived from lignin), 4-hydroxybenzoate (sourced from plastic waste), and mannitol (from seaweed). Comprehensive transcriptomic and metabolomic analyses offered insights into how these substrates influenced the cellular metabolism of S. lividans. In terms of production efficiency, S. lividans showed remarkable tolerance, especially in a fed-batch process using a mineral medium containing the toxic aromatic 4-hydroxybenzoate, which led to enhanced and highly selective bottromycin production. Additionally, the strain generated a unique spectrum of pamamycins when cultured in mannitol-rich seaweed extract with no additional nutrients. CONCLUSION Our study showcases the successful production of high-value natural products based on the use of varied waste and nonfood raw materials, circumventing the reliance on costly, food-competing resources. S. lividans exhibited remarkable adaptability and resilience when grown on these diverse substrates. When cultured on aromatic compounds, it displayed a distinct array of intracellular CoA esters, presenting promising avenues for polyketide production. Future research could be focused on enhancing S. lividans substrate utilization pathways to process the intricate mixtures commonly found in waste and nonfood sources more efficiently.
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Affiliation(s)
- Kyoyoung Seo
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Wei Shu
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | | | | | - Tobias J Erb
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | | | - Christoph Wittmann
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany.
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Beganovic S, Rückert-Reed C, Sucipto H, Shu W, Gläser L, Patschkowski T, Struck B, Kalinowski J, Luzhetskyy A, Wittmann C. Systems biology of industrial oxytetracycline production in Streptomyces rimosus: the secrets of a mutagenized hyperproducer. Microb Cell Fact 2023; 22:222. [PMID: 37898787 PMCID: PMC10612213 DOI: 10.1186/s12934-023-02215-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 09/26/2023] [Indexed: 10/30/2023] Open
Abstract
BACKGROUND Oxytetracycline which is derived from Streptomyces rimosus, inhibits a wide range of bacteria and is industrially important. The underlying biosynthetic processes are complex and hinder rational engineering, so industrial manufacturing currently relies on classical mutants for production. While the biochemistry underlying oxytetracycline synthesis is known to involve polyketide synthase, hyperproducing strains of S. rimosus have not been extensively studied, limiting our knowledge on fundamental mechanisms that drive production. RESULTS In this study, a multiomics analysis of S. rimosus is performed and wild-type and hyperproducing strains are compared. Insights into the metabolic and regulatory networks driving oxytetracycline formation were obtained. The overproducer exhibited increased acetyl-CoA and malonyl CoA supply, upregulated oxytetracycline biosynthesis, reduced competing byproduct formation, and streamlined morphology. These features were used to synthesize bhimamycin, an antibiotic, and a novel microbial chassis strain was created. A cluster deletion derivative showed enhanced bhimamycin production. CONCLUSIONS This study suggests that the precursor supply should be globally increased to further increase the expression of the oxytetracycline cluster while maintaining the natural cluster sequence. The mutagenized hyperproducer S. rimosus HP126 exhibited numerous mutations, including large genomic rearrangements, due to natural genetic instability, and single nucleotide changes. More complex mutations were found than those typically observed in mutagenized bacteria, impacting gene expression, and complicating rational engineering. Overall, the approach revealed key traits influencing oxytetracycline production in S. rimosus, suggesting that similar studies for other antibiotics could uncover general mechanisms to improve production.
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Affiliation(s)
- Selma Beganovic
- Institute of Systems Biotechnology, Saarland University, Campus A1 5, 66123, Saarbrücken, Germany
| | | | - Hilda Sucipto
- Department of Pharmacy, Saarland University, Saarbrücken, Germany
| | - Wei Shu
- Institute of Systems Biotechnology, Saarland University, Campus A1 5, 66123, Saarbrücken, Germany
| | - Lars Gläser
- Institute of Systems Biotechnology, Saarland University, Campus A1 5, 66123, Saarbrücken, Germany
| | | | - Ben Struck
- Centre for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Jörn Kalinowski
- Centre for Biotechnology, Bielefeld University, Bielefeld, Germany
| | | | - Christoph Wittmann
- Institute of Systems Biotechnology, Saarland University, Campus A1 5, 66123, Saarbrücken, Germany. *
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Dietrich D, Jovanovic-Gasovic S, Cao P, Kohlstedt M, Wittmann C. Refactoring the architecture of a polyketide gene cluster enhances docosahexaenoic acid production in Yarrowia lipolytica through improved expression and genetic stability. Microb Cell Fact 2023; 22:199. [PMID: 37773137 PMCID: PMC10540379 DOI: 10.1186/s12934-023-02209-9] [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: 08/15/2023] [Accepted: 09/20/2023] [Indexed: 10/01/2023] Open
Abstract
BACKGROUND Long-chain polyunsaturated fatty acids (LC-PUFAs), such as docosahexaenoic acid (DHA), are essential for human health and have been widely used in the food and pharmaceutical industries. However, the limited availability of natural sources, such as oily fish, has led to the pursuit of microbial production as a promising alternative. Yarrowia lipolytica can produce various PUFAs via genetic modification. A recent study upgraded Y. lipolytica for DHA production by expressing a four-gene cluster encoding a myxobacterial PKS-like PUFA synthase, reducing the demand for redox power. However, the genetic architecture of gene expression in Y. lipolytica is complex and involves various control elements, offering space for additional improvement of DHA production. This study was designed to optimize the expression of the PUFA cluster using a modular cloning approach. RESULTS Expression of the monocistronic cluster with each gene under the control of the constitutive TEF promoter led to low-level DHA production. By using the minLEU2 promoter instead and incorporating additional upstream activating UAS1B4 sequences, 5' promoter introns, and intergenic spacers, DHA production was increased by 16-fold. The producers remained stable over 185 h of cultivation. Beneficially, the different genetic control elements acted synergistically: UAS1B elements generally increased expression, while the intron caused gene-specific effects. Mutants with UAS1B16 sequences within 2-8 kb distance, however, were found to be genetically unstable, which limited production performance over time, suggesting the avoidance of long repetitive sequence blocks in synthetic multigene clusters and careful monitoring of genetic stability in producing strains. CONCLUSIONS Overall, the results demonstrate the effectiveness of synthetic heterologous gene clusters to drive DHA production in Y. lipolytica. The combinatorial exploration of different genetic control elements allowed the optimization of DHA production. These findings have important implications for developing Y. lipolytica strains for the industrial-scale production of valuable polyunsaturated fatty acids.
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Affiliation(s)
- Demian Dietrich
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | | | - Peng Cao
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Michael Kohlstedt
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Christoph Wittmann
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany.
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Liu L, Li G, Cao H. The Multiomics Response of Bacillus subtilis to Simultaneous Genetic and Environmental Perturbations. Microorganisms 2023; 11:1949. [PMID: 37630509 PMCID: PMC10458161 DOI: 10.3390/microorganisms11081949] [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: 06/25/2023] [Revised: 07/16/2023] [Accepted: 07/27/2023] [Indexed: 08/27/2023] Open
Abstract
How bacteria respond at the systems level to both genetic and environmental perturbations imposed at the same time is one fundamental yet open question in biology. Bioengineering or synthetic biology provides an ideal system for studying such responses, as engineered strains always have genetic changes as opposed to wildtypes and are grown in conditions which often change during growth for maximal yield of desired products. So, engineered strains were used to address the outstanding question. Two Bacillus subtilis strains (MT1 and MT2) were created previously for the overproduction of N-acetylglucosamine (GlcNAc), which were grown in an environment with a carbon shift from glucose to glucose and xylose in the same culture system. We had four groups: (1) a wildtype (WT) grown with glucose at t1; (2) a WT with glucose and xylose at t2; (3) a mutant (MT1) grown with glucose at t1; and (4) MT1 with glucose and xylose at t2. By measuring transcriptomes and metabolomes, we found that GlcNAc-producing mutants, particularly MT2, had a higher yield of N-acetylglucosamine than WT but displayed a smaller maximum growth rate than the wildtype, despite MT1 reaching higher carrying capacity. Underlying the observed growth, the engineered pathways leading to N-acetylglucosamine had both higher gene expression and associated metabolite concentrations in MT1 than WT at both t1 and t2; in bioenergetics, there was higher energy supply in terms of ATP and GTP, with the energy state metric higher in MT1 than WT at both timepoints. Additionally, most top key precursor metabolites were equally abundant in MT1 and WT at either timepoints. Besides that, one prominent feature was the high consistency between transcriptomics and metabolomics in revealing the response. First, both metabolomes and transcriptomes revealed the same PCA clusters of the four groups. Second, we found that the important functions enriched both by metabolomes and transcriptomes overlapped, such as amino acid metabolism and ABC transport. Strikingly, these functions overlapped those enriched by the genes showing a high (positive or negative) correlation with metabolites. Furthermore, these functions also overlapped the enriched KEGG pathways identified using weighted gene coexpression network analysis. All these findings suggest that the responses to simultaneous genetic and environmental perturbations are well coordinated at the metabolic and transcriptional levels: they rely heavily on bioenergetics, but core metabolism does not differ much, while amino acid metabolism and ABC transport are important. This serves as a design guide for bioengineering, synthetic biology, and systems biology.
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Affiliation(s)
| | | | - Huansheng Cao
- Division of Natural and Applied Sciences, Duke Kunshan University, Suzhou 215316, China; (L.L.); (G.L.)
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Pauli S, Kohlstedt M, Lamber J, Weiland F, Becker J, Wittmann C. Systems metabolic engineering upgrades Corynebacterium glutamicum for selective high-level production of the chiral drug precursor and cell-protective extremolyte L-pipecolic acid. Metab Eng 2023; 77:100-117. [PMID: 36931556 DOI: 10.1016/j.ymben.2023.03.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 03/02/2023] [Accepted: 03/14/2023] [Indexed: 03/17/2023]
Abstract
The nonproteinogenic cyclic metabolite l-pipecolic acid is a chiral precursor for the synthesis of various commercial drugs and functions as a cell-protective extremolyte and mediator of defense in plants, enabling high-value applications in the pharmaceutical, medical, cosmetic, and agrochemical markets. To date, the production of the compound is unfavorably fossil-based. Here, we upgraded the strain Corynebacterium glutamicum for l-pipecolic acid production using systems metabolic engineering. Heterologous expression of the l-lysine 6-dehydrogenase pathway, apparently the best route to be used in the microbe, yielded a family of strains that enabled successful de novo synthesis from glucose but approached a limit of performance at a yield of 0.18 mol mol-1. Detailed analysis of the producers at the transcriptome, proteome, and metabolome levels revealed that the requirements of the introduced route were largely incompatible with the cellular environment, which could not be overcome after several further rounds of metabolic engineering. Based on the gained knowledge, we based the strain design on l-l-lysine 6-aminotransferase instead, which enabled a substantially higher in vivo flux toward l-pipecolic acid. The tailormade producer C. glutamicum PIA-7 formed l-pipecolic acid up to a yield of 562 mmol mol-1, representing 75% of the theoretical maximum. Ultimately, the advanced mutant PIA-10B achieved a titer of 93 g L-1 in a fed-batch process on glucose, outperforming all previous efforts to synthesize this valuable molecule de novo and even approaching the level of biotransformation from l-lysine. Notably, the use of C. glutamicum allows the safe production of GRAS-designated l-pipecolic acid, providing extra benefit toward addressing the high-value pharmaceutical, medical, and cosmetic markets. In summary, our development sets a milestone toward the commercialization of biobased l-pipecolic acid.
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Affiliation(s)
- Sarah Pauli
- Institute for Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Michael Kohlstedt
- Institute for Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Jessica Lamber
- Institute for Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Fabia Weiland
- Institute for Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Judith Becker
- Institute for Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Christoph Wittmann
- Institute for Systems Biotechnology, Saarland University, Saarbrücken, Germany.
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Jungmann L, Hoffmann SL, Lang C, De Agazio R, Becker J, Kohlstedt M, Wittmann C. High-efficiency production of 5-hydroxyectoine using metabolically engineered Corynebacterium glutamicum. Microb Cell Fact 2022; 21:274. [PMID: 36578077 PMCID: PMC9798599 DOI: 10.1186/s12934-022-02003-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 12/17/2022] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Extremolytes enable microbes to withstand even the most extreme conditions in nature. Due to their unique protective properties, the small organic molecules, more and more, become high-value active ingredients for the cosmetics and the pharmaceutical industries. While ectoine, the industrial extremolyte flagship, has been successfully commercialized before, an economically viable route to its highly interesting derivative 5-hydroxyectoine (hydroxyectoine) is not existing. RESULTS Here, we demonstrate high-level hydroxyectoine production, using metabolically engineered strains of C. glutamicum that express a codon-optimized, heterologous ectD gene, encoding for ectoine hydroxylase, to convert supplemented ectoine in the presence of sucrose as growth substrate into the desired derivative. Fourteen out of sixteen codon-optimized ectD variants from phylogenetically diverse bacterial and archaeal donors enabled hydroxyectoine production, showing the strategy to work almost regardless of the origin of the gene. The genes from Pseudomonas stutzeri (PST) and Mycobacterium smegmatis (MSM) worked best and enabled hydroxyectoine production up to 97% yield. Metabolic analyses revealed high enrichment of the ectoines inside the cells, which, inter alia, reduced the synthesis of other compatible solutes, including proline and trehalose. After further optimization, C. glutamicum Ptuf ectDPST achieved a titre of 74 g L-1 hydroxyectoine at 70% selectivity within 12 h, using a simple batch process. In a two-step procedure, hydroxyectoine production from ectoine, previously synthesized fermentatively with C. glutamicum ectABCopt, was successfully achieved without intermediate purification. CONCLUSIONS C. glutamicum is a well-known and industrially proven host, allowing the synthesis of commercial products with granted GRAS status, a great benefit for a safe production of hydroxyectoine as active ingredient for cosmetic and pharmaceutical applications. Because ectoine is already available at commercial scale, its use as precursor appears straightforward. In the future, two-step processes might provide hydroxyectoine de novo from sugar.
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Affiliation(s)
- Lukas Jungmann
- grid.11749.3a0000 0001 2167 7588Institute of Systems Biotechnology, Saarland University, Campus A1.5, Saarbrücken, Germany
| | - Sarah Lisa Hoffmann
- grid.11749.3a0000 0001 2167 7588Institute of Systems Biotechnology, Saarland University, Campus A1.5, Saarbrücken, Germany
| | - Caroline Lang
- grid.11749.3a0000 0001 2167 7588Institute of Systems Biotechnology, Saarland University, Campus A1.5, Saarbrücken, Germany
| | - Raphaela De Agazio
- grid.11749.3a0000 0001 2167 7588Institute of Systems Biotechnology, Saarland University, Campus A1.5, Saarbrücken, Germany
| | - Judith Becker
- grid.11749.3a0000 0001 2167 7588Institute of Systems Biotechnology, Saarland University, Campus A1.5, Saarbrücken, Germany
| | - Michael Kohlstedt
- grid.11749.3a0000 0001 2167 7588Institute of Systems Biotechnology, Saarland University, Campus A1.5, Saarbrücken, Germany
| | - Christoph Wittmann
- grid.11749.3a0000 0001 2167 7588Institute of Systems Biotechnology, Saarland University, Campus A1.5, Saarbrücken, Germany
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How To Deal with Toxic Amino Acids: the Bipartite AzlCD Complex Exports Histidine in Bacillus subtilis. J Bacteriol 2022; 204:e0035322. [PMID: 36377869 PMCID: PMC9765041 DOI: 10.1128/jb.00353-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The Gram-positive model bacterium Bacillus subtilis can use several amino acids as sources of carbon and nitrogen. However, some amino acids inhibit the growth of this bacterium. This amino acid toxicity is often enhanced in strains lacking the second messenger cyclic dimeric adenosine 3',5'-monophosphate (c-di-AMP). We observed that the presence of histidine is also toxic for a B. subtilis strain that lacks all three c-di-AMP synthesizing enzymes. However, suppressor mutants emerged, and whole-genome sequencing revealed mutations in the azlB gene that encode the repressor of the azl operon. This operon encodes an exporter and an importer for branched-chain amino acids. The suppressor mutations result in an overexpression of the azl operon. Deletion of the azlCD genes encoding the branched-chain amino acid exporter restored the toxicity of histidine, indicating that this exporter is required for histidine export and for resistance to otherwise toxic levels of the amino acid. The higher abundance of the amino acid exporter AzlCD increased the extracellular concentration of histidine, thus confirming the new function of AzlCD as a histidine exporter. Unexpectedly, the AzlB-mediated repression of the operon remains active even in the presence of amino acids, suggesting that the expression of the azl operon requires the mutational inactivation of AzlB. IMPORTANCE Amino acids are building blocks for protein biosynthesis in each living cell. However, due to their reactivity and the similarity between several amino acids, they may also be involved in harmful reactions or in noncognate interactions and thus may be toxic. Bacillus subtilis can deal with otherwise toxic histidine by overexpressing the bipartite amino acid exporter AzlCD. Although encoded in an operon that also contains a gene for an amino acid importer, the corresponding genes are not expressed, irrespective of the availability of amino acids in the medium. This suggests that the azl operon is a last resort by which to deal with histidine stress that can be expressed due to the mutational inactivation of the cognate repressor AzlB.
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Methylocystis sp. Strain SC2 Acclimatizes to Increasing NH 4+ Levels by a Precise Rebalancing of Enzymes and Osmolyte Composition. mSystems 2022; 7:e0040322. [PMID: 36154142 PMCID: PMC9600857 DOI: 10.1128/msystems.00403-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
A high NH4+ load is known to inhibit bacterial methane oxidation. This is due to a competition between CH4 and NH3 for the active site of particulate methane monooxygenase (pMMO), which converts CH4 to CH3OH. Here, we combined global proteomics with amino acid profiling and nitrogen oxides measurements to elucidate the cellular acclimatization response of Methylocystis sp. strain SC2 to high NH4+ levels. Relative to 1 mM NH4+, a high (50 mM and 75 mM) NH4+ load under CH4-replete conditions significantly increased the lag phase duration required for proteome adjustment. The number of differentially regulated proteins was highly significantly correlated with an increasing NH4+ load. The cellular responses to increasing ionic and osmotic stress involved a significant upregulation of stress-responsive proteins, the K+ "salt-in" strategy, the synthesis of compatible solutes (glutamate and proline), and the induction of the glutathione metabolism pathway. A significant increase in the apparent Km value for CH4 oxidation during the growth phase was indicative of increased pMMO-based oxidation of NH3 to toxic hydroxylamine. The detoxifying activity of hydroxlyamine oxidoreductase (HAO) led to a significant accumulation of NO2- and, upon decreasing O2 tension, N2O. Nitric oxide reductase and hybrid cluster proteins (Hcps) were the candidate enzymes for the production of N2O. In summary, strain SC2 has the capacity to precisely rebalance enzymes and osmolyte composition in response to increasing NH4+ exposure, but the need to simultaneously combat both ionic-osmotic stress and the toxic effects of hydroxylamine may be the reason why its acclimatization capacity is limited to 75 mM NH4+. IMPORTANCE In addition to reducing CH4 emissions from wetlands and landfills, the activity of alphaproteobacterial methane oxidizers of the genus Methylocystis contributes to the sink capacity of forest and grassland soils for atmospheric methane. The methane-oxidizing activity of Methylocystis spp. is, however, sensitive to high NH4+ concentrations. This is due to the competition of CH4 and NH3 for the active site of particulate methane monooxygenase, thereby resulting in the production of toxic hydroxylamine with an increasing NH4+ load. An understanding of the physiological and molecular response mechanisms of Methylocystis spp. is therefore of great importance. Here, we combined global proteomics with amino acid profiling and NOx measurements to disentangle the cellular mechanisms underlying the acclimatization of Methylocystis sp. strain SC2 to an increasing NH4+ load.
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Stecker D, Hoffmann T, Link H, Commichau FM, Bremer E. L-Proline Synthesis Mutants of Bacillus subtilis Overcome Osmotic Sensitivity by Genetically Adapting L-Arginine Metabolism. Front Microbiol 2022; 13:908304. [PMID: 35783388 PMCID: PMC9245794 DOI: 10.3389/fmicb.2022.908304] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 05/17/2022] [Indexed: 11/30/2022] Open
Abstract
The accumulation of the compatible solute L-proline by Bacillus subtilis via synthesis is a cornerstone in the cell’s defense against high salinity as the genetic disruption of this biosynthetic process causes osmotic sensitivity. To understand how B. subtilis could potentially cope with high osmolarity surroundings without the functioning of its natural osmostress adaptive L-proline biosynthetic route (ProJ-ProA-ProH), we isolated suppressor strains of proA mutants under high-salinity growth conditions. These osmostress-tolerant strains carried mutations affecting either the AhrC transcriptional regulator or its operator positioned in front of the argCJBD-carAB-argF L-ornithine/L-citrulline/L-arginine biosynthetic operon. Osmostress protection assays, molecular analysis and targeted metabolomics showed that these mutations, in conjunction with regulatory mutations affecting rocR-rocDEF expression, connect and re-purpose three different physiological processes: (i) the biosynthetic pathway for L-arginine, (ii) the RocD-dependent degradation route for L-ornithine, and (iii) the last step in L-proline biosynthesis. Hence, osmostress adaptation without a functional ProJ-ProA-ProH route is made possible through a naturally existing, but inefficient, metabolic shunt that allows to substitute the enzyme activity of ProA by feeding the RocD-formed metabolite γ-glutamate-semialdehyde/Δ1-pyrroline-5-carboxylate into the biosynthetic route for the compatible solute L-proline. Notably, in one class of mutants, not only substantial L-proline pools but also large pools of L-citrulline were accumulated, a rather uncommon compatible solute in microorganisms. Collectively, our data provide an example of the considerable genetic plasticity and metabolic resourcefulness of B. subtilis to cope with everchanging environmental conditions.
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Affiliation(s)
- Daniela Stecker
- Faculty of Biology, Philipps-University Marburg, Marburg, Germany
| | - Tamara Hoffmann
- Faculty of Biology, Philipps-University Marburg, Marburg, Germany
- SYNMIKRO Research Center, Philipps-University Marburg, Marburg, Germany
| | - Hannes Link
- SYNMIKRO Research Center, Philipps-University Marburg, Marburg, Germany
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Fabian M. Commichau
- Insitute of Microbiology and Genetics, Georg-August-University Göttingen, Göttingen, Germany
- Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
| | - Erhard Bremer
- Faculty of Biology, Philipps-University Marburg, Marburg, Germany
- SYNMIKRO Research Center, Philipps-University Marburg, Marburg, Germany
- *Correspondence: Erhard Bremer,
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13
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Yunus IS, Lee TS. Applications of targeted proteomics in metabolic engineering: advances and opportunities. Curr Opin Biotechnol 2022; 75:102709. [DOI: 10.1016/j.copbio.2022.102709] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 02/15/2022] [Accepted: 02/23/2022] [Indexed: 12/22/2022]
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14
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Morawska LP, Detert Oude Weme RGJ, Frenzel E, Dirkzwager M, Hoffmann T, Bremer E, Kuipers OP. Stress-induced activation of the proline biosynthetic pathway in Bacillus subtilis: a population-wide and single-cell study of the osmotically controlled proHJ promoter. Microb Biotechnol 2022; 15:2411-2425. [PMID: 35593133 PMCID: PMC9437891 DOI: 10.1111/1751-7915.14073] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 04/20/2022] [Accepted: 04/27/2022] [Indexed: 12/01/2022] Open
Abstract
Bacillus subtilis, in its natural habitat, is regularly exposed to rapid changes in the osmolarity of its surrounding. As its primary survival strategy, it accumulates large amounts of the compatible solute proline by activating the de novo proline biosynthesis pathway and exploiting the glutamate pools. This osmotically‐induced biosynthesis requires activation of a SigA‐type promoter that drives the expression of the proHJ operon. Population‐wide studies have shown that the activity of the proHJ promoter correlates with the increased osmotic pressure of the environment. Therefore, the activation of the proHJ transcription should be an adequate measure of the adaptation to osmotic stress through proline synthesis in the absence of other osmoprotectants. In this study, we investigate the kinetics of the proHJ promoter activation and the early adaptation to mild osmotic upshift at the single‐cell level. Under these conditions, we observed a switching point and heterogeneous proline biosynthesis gene expression, where the subpopulation of cells showing active proHJ transcription is able to continuously divide, and those unresponsive to osmotic stress remain dormant. Additionally, we demonstrate that bactericidal antibiotics significantly upregulate proHJ transcription in the absence of externally imposed osmotic pressure, suggesting that the osmotically‐controlled proline biosynthesis pathway is also involved in the antibiotic‐mediated stress response.
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Affiliation(s)
- Luiza P Morawska
- Molecular Genetics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Ruud G J Detert Oude Weme
- Molecular Genetics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Elrike Frenzel
- Molecular Genetics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Maarten Dirkzwager
- Molecular Genetics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Tamara Hoffmann
- Department of Biology, Laboratory for Microbiology, Philipps University Marburg, Karl-von-Frisch-Str.8, D-35032, Marburg, Germany.,Center for Synthetic Microbiology (SYNMIKRO), Philipps-University Marburg, Karl-von-Frisch Strasse 14, 35043, Marburg, Germany
| | - Erhard Bremer
- Department of Biology, Laboratory for Microbiology, Philipps University Marburg, Karl-von-Frisch-Str.8, D-35032, Marburg, Germany.,Center for Synthetic Microbiology (SYNMIKRO), Philipps-University Marburg, Karl-von-Frisch Strasse 14, 35043, Marburg, Germany
| | - Oscar P Kuipers
- Molecular Genetics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
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15
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Kohlstedt M, Weimer A, Weiland F, Stolzenberger J, Selzer M, Sanz M, Kramps L, Wittmann C. Biobased PET from lignin using an engineered cis, cis-muconate-producing Pseudomonas putida strain with superior robustness, energy and redox properties. Metab Eng 2022; 72:337-352. [DOI: 10.1016/j.ymben.2022.05.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 04/18/2022] [Accepted: 05/04/2022] [Indexed: 11/26/2022]
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16
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Schulze D, Kohlstedt M, Becker J, Cahoreau E, Peyriga L, Makowka A, Hildebrandt S, Gutekunst K, Portais JC, Wittmann C. GC/MS-based 13C metabolic flux analysis resolves the parallel and cyclic photomixotrophic metabolism of Synechocystis sp. PCC 6803 and selected deletion mutants including the Entner-Doudoroff and phosphoketolase pathways. Microb Cell Fact 2022; 21:69. [PMID: 35459213 PMCID: PMC9034593 DOI: 10.1186/s12934-022-01790-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 04/05/2022] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Cyanobacteria receive huge interest as green catalysts. While exploiting energy from sunlight, they co-utilize sugar and CO2. This photomixotrophic mode enables fast growth and high cell densities, opening perspectives for sustainable biomanufacturing. The model cyanobacterium Synechocystis sp. PCC 6803 possesses a complex architecture of glycolytic routes for glucose breakdown that are intertwined with the CO2-fixing Calvin-Benson-Bassham (CBB) cycle. To date, the contribution of these pathways to photomixotrophic metabolism has remained unclear. RESULTS Here, we developed a comprehensive approach for 13C metabolic flux analysis of Synechocystis sp. PCC 6803 during steady state photomixotrophic growth. Under these conditions, the Entner-Doudoroff (ED) and phosphoketolase (PK) pathways were found inactive but the microbe used the phosphoglucoisomerase (PGI) (63.1%) and the oxidative pentose phosphate pathway (OPP) shunts (9.3%) to fuel the CBB cycle. Mutants that lacked the ED pathway, the PK pathway, or phosphofructokinases were not affected in growth under metabolic steady-state. An ED pathway-deficient mutant (Δeda) exhibited an enhanced CBB cycle flux and increased glycogen formation, while the OPP shunt was almost inactive (1.3%). Under fluctuating light, ∆eda showed a growth defect, different to wild type and the other deletion strains. CONCLUSIONS The developed approach, based on parallel 13C tracer studies with GC-MS analysis of amino acids, sugars, and sugar derivatives, optionally adding NMR data from amino acids, is valuable to study fluxes in photomixotrophic microbes to detail. In photomixotrophic cells, PGI and OPP form glycolytic shunts that merge at switch points and result in synergistic fueling of the CBB cycle for maximized CO2 fixation. However, redirected fluxes in an ED shunt-deficient mutant and the impossibility to delete this shunt in a GAPDH2 knockout mutant, indicate that either minor fluxes (below the resolution limit of 13C flux analysis) might exist that could provide catalytic amounts of regulatory intermediates or alternatively, that EDA possesses additional so far unknown functions. These ideas require further experiments.
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Affiliation(s)
- Dennis Schulze
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Michael Kohlstedt
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Judith Becker
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Edern Cahoreau
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France.,MetaboHUB-MetaToul, National Infrastructure of Metabolomics & Fluxomics, Toulouse, France.,RESTORE, Université de Toulouse, Inserm U1031, CNRS 5070, UPS, EFS, Toulouse, France
| | - Lindsay Peyriga
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France.,MetaboHUB-MetaToul, National Infrastructure of Metabolomics & Fluxomics, Toulouse, France.,RESTORE, Université de Toulouse, Inserm U1031, CNRS 5070, UPS, EFS, Toulouse, France
| | | | | | - Kirstin Gutekunst
- Institute of Botany, Christian-Albrecht University, Kiel, Germany.,Molecular Plant Physiology, Bioenergetics in Photoautotrophs, University of Kassel, Kassel, Germany
| | - Jean-Charles Portais
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France.,MetaboHUB-MetaToul, National Infrastructure of Metabolomics & Fluxomics, Toulouse, France.,RESTORE, Université de Toulouse, Inserm U1031, CNRS 5070, UPS, EFS, Toulouse, France
| | - Christoph Wittmann
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany.
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17
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Tangyu M, Fritz M, Ye L, Aragão Börner R, Morin-Rivron D, Campos-Giménez E, Bolten CJ, Bogicevic B, Wittmann C. Co-cultures of Propionibacterium freudenreichii and Bacillus amyloliquefaciens cooperatively upgrade sunflower seed milk to high levels of vitamin B 12 and multiple co-benefits. Microb Cell Fact 2022; 21:48. [PMID: 35346203 PMCID: PMC8959080 DOI: 10.1186/s12934-022-01773-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 03/02/2022] [Indexed: 01/12/2023] Open
Abstract
Background Sunflower seeds (Helianthus annuus) display an attractive source for the rapidly increasing market of plant-based human nutrition. Of particular interest are press cakes of the seeds, cheap residuals from sunflower oil manufacturing that offer attractive sustainability and economic benefits. Admittedly, sunflower seed milk, derived therefrom, suffers from limited nutritional value, undesired flavor, and the presence of indigestible sugars. Of specific relevance is the absence of vitamin B12. This vitamin is required for development and function of the central nervous system, healthy red blood cell formation, and DNA synthesis, and displays the most important micronutrient for vegans to be aware of. Here we evaluated the power of microbes to enrich sunflower seed milk nutritionally as well as in flavor. Results Propionibacterium freudenreichii NCC 1177 showed highest vitamin B12 production in sunflower seed milk out of a range of food-grade propionibacteria. Its growth and B12 production capacity, however, were limited by a lack of accessible carbon sources and stimulants of B12 biosynthesis in the plant milk. This was overcome by co-cultivation with Bacillus amyloliquefaciens NCC 156, which supplied lactate, amino acids, and vitamin B7 for growth of NCC 1177 plus vitamins B2 and B3, potentially supporting vitamin B12 production by the Propionibacterium. After several rounds of optimization, co-fermentation of ultra-high-temperature pre-treated sunflower seed milk by the two microbes, enabled the production of 17 µg (100 g)−1 vitamin B12 within four days without any further supplementation. The fermented milk further revealed significantly enriched levels of l-lysine, the most limiting essential amino acid, vitamin B3, vitamin B6, improved protein quality and flavor, and largely eliminated indigestible sugars. Conclusion The fermented sunflower seed milk, obtained by using two food-grade microbes without further supplementation, displays an attractive, clean-label product with a high level of vitamin B12 and multiple co-benefits. The secret of the successfully upgraded plant milk lies in the multifunctional cooperation of the two microbes, which were combined, based on their genetic potential and metabolic signatures found in mono-culture fermentations. This design by knowledge approach appears valuable for future development of plant-based milk products. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-022-01773-w.
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Affiliation(s)
- Muzi Tangyu
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Michel Fritz
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Lijuan Ye
- Nestlé Research Center, Lausanne, Switzerland
| | | | | | | | - Christoph J Bolten
- Nestlé Research Center, Lausanne, Switzerland.,Nestlé Product Technology Center Food, Singen, Germany
| | | | - Christoph Wittmann
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany.
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18
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Effects of pH and Osmotic Changes on the Metabolic Expressions of Bacillus subtilis Strain 168 in Metabolite Pathways including Leucine Metabolism. Metabolites 2022; 12:metabo12020112. [PMID: 35208188 PMCID: PMC8880083 DOI: 10.3390/metabo12020112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 01/20/2022] [Accepted: 01/21/2022] [Indexed: 11/25/2022] Open
Abstract
Bacillus subtilis is often exposed to diverse culture conditions with the aim of improving hygiene or food quality. This can lead to changes in the volatile metabolite profiles related to the quality of fermented foods. To comprehensively interpret the associated metabolic expressions, changes in intracellular primary and extracellular secondary volatile metabolites were investigated by exposing B. subtilis to an alkaline pH (BP, pH 8.0) and a high salt concentration (BS, 1 M). In particular, B. subtilis was cultured in a leucine-enriched medium to investigate the formation of leucine-derived volatile metabolites. This study observed metabolic changes in several metabolic pathways, including carbohydrate metabolism, amino acid metabolism, fatty acid metabolism, and leucine degradation. The formation of proline (an osmolyte), furans, pyrrole, and monosaccharide sugars (glucose, galactose, and fructose) was enhanced in BS, whereas fatty acid derivatives (ketones and alcohols) increased in BP. In the case of leucine degradation, 3-methyl-butanal and 3-methylbutanol could be salt-specific metabolites, while the contents of 3-methylbutanoic acid and 3-methylbutylacetate increased in BP. These results show culture condition-specific metabolic changes, especially secondary volatile metabolites related to the sensory property of foods, in B. subtilis.
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Strategies to increase tolerance and robustness of industrial microorganisms. Synth Syst Biotechnol 2022; 7:533-540. [PMID: 35024480 PMCID: PMC8718811 DOI: 10.1016/j.synbio.2021.12.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 12/17/2021] [Accepted: 12/17/2021] [Indexed: 01/06/2023] Open
Abstract
The development of a cost-competitive bioprocess requires that the cell factory converts the feedstock into the product of interest at high rates and yields. However, microbial cell factories are exposed to a variety of different stresses during the fermentation process. These stresses can be derived from feedstocks, metabolism, or industrial production processes, limiting production capacity and diminishing competitiveness. Improving stress tolerance and robustness allows for more efficient production and ultimately makes a process more economically viable. This review summarises general trends and updates the most recent developments in technologies to improve the stress tolerance of microorganisms. We first look at evolutionary, systems biology and computational methods as examples of non-rational approaches. Then we review the (semi-)rational approaches of membrane and transcription factor engineering for improving tolerance phenotypes. We further discuss challenges and perspectives associated with these different approaches.
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Three Microbial Musketeers of the Seas: Shewanella baltica, Aliivibrio fischeri and Vibrio harveyi, and Their Adaptation to Different Salinity Probed by a Proteomic Approach. Int J Mol Sci 2022; 23:ijms23020619. [PMID: 35054801 PMCID: PMC8775919 DOI: 10.3390/ijms23020619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 01/01/2022] [Accepted: 01/04/2022] [Indexed: 11/17/2022] Open
Abstract
Osmotic changes are common challenges for marine microorganisms. Bacteria have developed numerous ways of dealing with this stress, including reprogramming of global cellular processes. However, specific molecular adaptation mechanisms to osmotic stress have mainly been investigated in terrestrial model bacteria. In this work, we aimed to elucidate the basis of adjustment to prolonged salinity challenges at the proteome level in marine bacteria. The objects of our studies were three representatives of bacteria inhabiting various marine environments, Shewanella baltica, Vibrio harveyi and Aliivibrio fischeri. The proteomic studies were performed with bacteria cultivated in increased and decreased salinity, followed by proteolytic digestion of samples which were then subjected to liquid chromatography with tandem mass spectrometry analysis. We show that bacteria adjust at all levels of their biological processes, from DNA topology through gene expression regulation and proteasome assembly, to transport and cellular metabolism. The finding that many similar adaptation strategies were observed for both low- and high-salinity conditions is particularly striking. The results show that adaptation to salinity challenge involves the accumulation of DNA-binding proteins and increased polyamine uptake. We hypothesize that their function is to coat and protect the nucleoid to counteract adverse changes in DNA topology due to ionic shifts.
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21
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Microbial protein cell factories fight back? Trends Biotechnol 2021; 40:576-590. [PMID: 34924209 DOI: 10.1016/j.tibtech.2021.10.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 10/01/2021] [Accepted: 10/01/2021] [Indexed: 01/26/2023]
Abstract
The biopharmaceutical market is growing faster than ever, with two production systems competing for market dominance: mammalian cells and microorganisms. In recent years, based on the rise of antibody-based therapies, new biotherapeutic approvals have favored mammalian hosts. However, not only has extensive research elevated our understanding of microbes to new levels, but emerging therapeutic molecules also facilitate their use; thus, is it time for microbes to fight back? In this review, we answer this timely question by cross-comparing four microbial production hosts and examining the innovations made to both their secretion and post-translational modification (PTM) capabilities. Furthermore, we discuss the impact of tools, such as omics and systems biology, as well as alternative production systems and emerging biotherapeutics.
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22
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Advances in metabolic engineering of Corynebacterium glutamicum to produce high-value active ingredients for food, feed, human health, and well-being. Essays Biochem 2021; 65:197-212. [PMID: 34096577 PMCID: PMC8313993 DOI: 10.1042/ebc20200134] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 04/26/2021] [Accepted: 04/27/2021] [Indexed: 12/12/2022]
Abstract
The soil microbe Corynebacterium glutamicum is a leading workhorse in industrial biotechnology and has become famous for its power to synthetise amino acids and a range of bulk chemicals at high titre and yield. The product portfolio of the microbe is continuously expanding. Moreover, metabolically engineered strains of C. glutamicum produce more than 30 high value active ingredients, including signature molecules of raspberry, savoury, and orange flavours, sun blockers, anti-ageing sugars, and polymers for regenerative medicine. Herein, we highlight recent advances in engineering of the microbe into novel cell factories that overproduce these precious molecules from pioneering proofs-of-concept up to industrial productivity.
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23
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Becker J, Wittmann C. Metabolic Engineering of
Corynebacterium glutamicum. Metab Eng 2021. [DOI: 10.1002/9783527823468.ch12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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24
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Appelbaum M, Schweder T. Metabolic Engineering of
Bacillus
– New Tools, Strains, and Concepts. Metab Eng 2021. [DOI: 10.1002/9783527823468.ch13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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25
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Tangyu M, Fritz M, Aragao-Börner R, Ye L, Bogicevic B, Bolten CJ, Wittmann C. Genome-based selection and application of food-grade microbes for chickpea milk fermentation towards increased L-lysine content, elimination of indigestible sugars, and improved flavour. Microb Cell Fact 2021; 20:109. [PMID: 34049541 PMCID: PMC8161961 DOI: 10.1186/s12934-021-01595-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 05/15/2021] [Indexed: 01/01/2023] Open
Abstract
Background Plant-based milk alternatives are more popular than ever, and chickpea-based milks are among the most commercially relevant products. Unfortunately, limited nutritional value because of low levels of the essential amino acid l-lysine, low digestibility and unpleasant taste are challenges that must be addressed to improve product quality and meet consumer expectations. Results Using in-silico screening and food safety classifications, 31 strains were selected as potential l-lysine producers from approximately 2,500 potential candidates. Beneficially, 30% of the isolates significantly accumulated amino acids (up to 1.4 mM) during chickpea milk fermentation, increasing the natural level by up to 43%. The best-performing strains, B. amyloliquefaciens NCC 156 and L. paracasei subsp. paracasei NCC 2511, were tested further. De novo lysine biosynthesis was demonstrated in both strains by 13C metabolic pathway analysis. Spiking small amounts of citrate into the fermentation significantly activated l-lysine biosynthesis in NCC 156 and stimulated growth. Both microbes revealed additional benefits in eliminating indigestible sugars such as stachyose and raffinose and converting off-flavour aldehydes into the corresponding alcohols and acids with fruity and sweet notes. Conclusions B. amyloliquefaciens NCC 156 and L. paracasei subsp. paracasei NCC 2511 emerged as multi-benefit microbes for chickpea milk fermentation with strong potential for industrial processing of the plant material. Given the high number of l-lysine-producing isolates identified in silico, this concept appears promising to support strain selection for food fermentation. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-021-01595-2.
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Affiliation(s)
- Muzi Tangyu
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Michel Fritz
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | | | - Lijuan Ye
- Nestlé Research Center, Lausanne, Switzerland
| | | | | | - Christoph Wittmann
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany.
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Kuhl M, Rückert C, Gläser L, Beganovic S, Luzhetskyy A, Kalinowski J, Wittmann C. Microparticles enhance the formation of seven major classes of natural products in native and metabolically engineered actinobacteria through accelerated morphological development. Biotechnol Bioeng 2021; 118:3076-3093. [PMID: 33974270 DOI: 10.1002/bit.27818] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 04/17/2021] [Accepted: 04/30/2021] [Indexed: 11/09/2022]
Abstract
Actinobacteria provide a rich spectrum of bioactive natural products and therefore display an invaluable source towards commercially valuable pharmaceuticals and agrochemicals. Here, we studied the use of inorganic talc microparticles (hydrous magnesium silicate, 3MgO·4SiO2 ·H2 O, 10 µm) as a general supplement to enhance natural product formation in this important class of bacteria. Added to cultures of recombinant Streptomyces lividans, talc enhanced production of the macrocyclic peptide antibiotic bottromycin A2 and its methylated derivative Met-bottromycin A2 up to 109 mg L-1 , the highest titer reported so far. Hereby, the microparticles fundamentally affected metabolism. With 10 g L-1 talc, S. lividans grew to 40% smaller pellets and, using RNA sequencing, revealed accelerated morphogenesis and aging, indicated by early upregulation of developmental regulator genes such as ssgA, ssgB, wblA, sigN, and bldN. Furthermore, the microparticles re-balanced the expression of individual bottromycin cluster genes, resulting in a higher macrocyclization efficiency at the level of BotAH and correspondingly lower levels of non-cyclized shunt by-products, driving the production of mature bottromycin. Testing a variety of Streptomyces species, talc addition resulted in up to 13-fold higher titers for the RiPPs bottromycin and cinnamycin, the alkaloid undecylprodigiosin, the polyketide pamamycin, the tetracycline-type oxytetracycline, and the anthramycin-analogs usabamycins. Moreover, talc addition boosted production in other actinobacteria, outside of the genus of Streptomyces: vancomycin (Amycolatopsis japonicum DSM 44213), teicoplanin (Actinoplanes teichomyceticus ATCC 31121), and the angucyclinone-type antibiotic simocyclinone (Kitasatospora sp.). For teicoplanin, the microparticles were even crucial to activate production. Taken together, the use of talc was beneficial in 75% of all tested cases and optimized natural and heterologous hosts forming the substance of interest with clusters under native and synthetic control. Given its simplicity and broad benefits, microparticle-supplementation appears as an enabling technology in natural product research of these most important microbes.
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Affiliation(s)
- Martin Kuhl
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | | | - Lars Gläser
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Selma Beganovic
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Andriy Luzhetskyy
- Department of Pharmaceutical Biotechnology, Saarland University, Saarbrücken, Germany
| | - Jörn Kalinowski
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Christoph Wittmann
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
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Sustained Control of Pyruvate Carboxylase by the Essential Second Messenger Cyclic di-AMP in Bacillus subtilis. mBio 2021; 13:e0360221. [PMID: 35130724 PMCID: PMC8822347 DOI: 10.1128/mbio.03602-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
In Bacillus subtilis and other Gram-positive bacteria, cyclic di-AMP is an essential second messenger that signals potassium availability by binding to a variety of proteins. In some bacteria, c-di-AMP also binds to the pyruvate carboxylase to inhibit its activity. We have discovered that in B. subtilis the c-di-AMP target protein DarB, rather than c-di-AMP itself, specifically binds to pyruvate carboxylase both in vivo and in vitro. This interaction stimulates the activity of the enzyme, as demonstrated by in vitro enzyme assays and in vivo metabolite determinations. Both the interaction and the activation of enzyme activity require apo-DarB and are inhibited by c-di-AMP. Under conditions of potassium starvation and corresponding low c-di-AMP levels, the demand for citric acid cycle intermediates is increased. Apo-DarB helps to replenish the cycle by activating both pyruvate carboxylase gene expression and enzymatic activity via triggering the stringent response as a result of its interaction with the (p)ppGpp synthetase Rel and by direct interaction with the enzyme, respectively. IMPORTANCE If bacteria experience a starvation for potassium, by far the most abundant metal ion in every living cell, they have to activate high-affinity potassium transporters, switch off growth activities such as translation and transcription of many genes or replication, and redirect the metabolism in a way that the most essential functions of potassium can be taken over by metabolites. Importantly, potassium starvation triggers a need for glutamate-derived amino acids. In many bacteria, the responses to changing potassium availability are orchestrated by a nucleotide second messenger, cyclic di-AMP. c-di-AMP binds to factors involved directly in potassium homeostasis and to dedicated signal transduction proteins. Here, we demonstrate that in the Gram-positive model organism Bacillus subtilis, the c-di-AMP receptor protein DarB can bind to and, thus, activate pyruvate carboxylase, the enzyme responsible for replenishing the citric acid cycle. This interaction takes place under conditions of potassium starvation if DarB is present in the apo form and the cells are in need of glutamate. Thus, DarB links potassium availability to the control of central metabolism.
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Krüger L, Herzberg C, Rath H, Pedreira T, Ischebeck T, Poehlein A, Gundlach J, Daniel R, Völker U, Mäder U, Stülke J. Essentiality of c-di-AMP in Bacillus subtilis: Bypassing mutations converge in potassium and glutamate homeostasis. PLoS Genet 2021; 17:e1009092. [PMID: 33481774 PMCID: PMC7857571 DOI: 10.1371/journal.pgen.1009092] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 02/03/2021] [Accepted: 12/14/2020] [Indexed: 12/14/2022] Open
Abstract
In order to adjust to changing environmental conditions, bacteria use nucleotide second messengers to transduce external signals and translate them into a specific cellular response. Cyclic di-adenosine monophosphate (c-di-AMP) is the only known essential nucleotide second messenger. In addition to the well-established role of this second messenger in the control of potassium homeostasis, we observed that glutamate is as toxic as potassium for a c-di-AMP-free strain of the Gram-positive model bacterium Bacillus subtilis. In this work, we isolated suppressor mutants that allow growth of a c-di-AMP-free strain under these toxic conditions. Characterization of glutamate resistant suppressors revealed that they contain pairs of mutations, in most cases affecting glutamate and potassium homeostasis. Among these mutations, several independent mutations affected a novel glutamate transporter, AimA (Amino acid importer A, formerly YbeC). This protein is the major transporter for glutamate and serine in B. subtilis. Unexpectedly, some of the isolated suppressor mutants could suppress glutamate toxicity by a combination of mutations that affect phospholipid biosynthesis and a specific gain-of-function mutation of a mechanosensitive channel of small conductance (YfkC) resulting in the acquisition of a device for glutamate export. Cultivation of the c-di-AMP-free strain on complex medium was an even greater challenge because the amounts of potassium, glutamate, and other osmolytes are substantially higher than in minimal medium. Suppressor mutants viable on complex medium could only be isolated under anaerobic conditions if one of the two c-di-AMP receptor proteins, DarA or DarB, was absent. Also on complex medium, potassium and osmolyte toxicity are the major bottlenecks for the growth of B. subtilis in the absence of c-di-AMP. Our results indicate that the essentiality of c-di-AMP in B. subtilis is caused by the global impact of the second messenger nucleotide on different aspects of cellular physiology.
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Affiliation(s)
- Larissa Krüger
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Christina Herzberg
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Hermann Rath
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Tiago Pedreira
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Till Ischebeck
- Department of Plant Biochemistry, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Anja Poehlein
- Department of Genomic and Applied Microbiology, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Jan Gundlach
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Rolf Daniel
- Department of Genomic and Applied Microbiology, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Uwe Völker
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Ulrike Mäder
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Jörg Stülke
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Göttingen, Germany
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Slomka S, Françoise I, Hornung G, Asraf O, Biniashvili T, Pilpel Y, Dahan O. Experimental Evolution of Bacillus subtilis Reveals the Evolutionary Dynamics of Horizontal Gene Transfer and Suggests Adaptive and Neutral Effects. Genetics 2020; 216:543-558. [PMID: 32847815 PMCID: PMC7536860 DOI: 10.1534/genetics.120.303401] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 08/16/2020] [Indexed: 12/18/2022] Open
Abstract
Tracing evolutionary processes that lead to fixation of genomic variation in wild bacterial populations is a prime challenge in molecular evolution. In particular, the relative contribution of horizontal gene transfer (HGT) vs.de novo mutations during adaptation to a new environment is poorly understood. To gain a better understanding of the dynamics of HGT and its effect on adaptation, we subjected several populations of competent Bacillus subtilis to a serial dilution evolution on a high-salt-containing medium, either with or without foreign DNA from diverse pre-adapted or naturally salt tolerant species. Following 504 generations of evolution, all populations improved growth yield on the medium. Sequencing of evolved populations revealed extensive acquisition of foreign DNA from close Bacillus donors but not from more remote donors. HGT occurred in bursts, whereby a single bacterial cell appears to have acquired dozens of fragments at once. In the largest burst, close to 2% of the genome has been replaced by HGT. Acquired segments tend to be clustered in integration hotspots. Other than HGT, genomes also acquired spontaneous mutations. Many of these mutations occurred within, and seem to alter, the sequence of flagellar proteins. Finally, we show that, while some HGT fragments could be neutral, others are adaptive and accelerate evolution.
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Affiliation(s)
- Shai Slomka
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Itamar Françoise
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Gil Hornung
- The Nancy and Stephen Grand Israel National Center for Personalized Medicine, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Omer Asraf
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Tammy Biniashvili
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yitzhak Pilpel
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Orna Dahan
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
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Developing rapid growing Bacillus subtilis for improved biochemical and recombinant protein production. Metab Eng Commun 2020; 11:e00141. [PMID: 32874915 PMCID: PMC7452210 DOI: 10.1016/j.mec.2020.e00141] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 08/05/2020] [Accepted: 08/10/2020] [Indexed: 12/28/2022] Open
Abstract
Bacillus subtilis is a model Gram-positive bacterium, which has been widely used as industrially important chassis in synthetic biology and metabolic engineering. Rapid growth of chassis is beneficial for shortening the fermentation period and enhancing production of target product. However, engineered B. subtilis with faster growth phenotype is lacking. Here, fast-growing B. subtilis were constructed through rational gene knockout and adaptive laboratory evolution using wild type strain B. subtilis 168 (BS168) as starting strain. Specifically, strains BS01, BS02, and BS03 were obtained through gene knockout of oppD, hag, and flgD genes, respectively, resulting 15.37%, 24.18% and 36.46% increases of specific growth rate compared with BS168. Next, strains A28 and A40 were obtained through adaptive laboratory evolution, whose specific growth rates increased by 39.88% and 43.53% compared to BS168, respectively. Then these two methods were combined via deleting oppD, hag, and flgD genes respectively on the basis of evolved strain A40, yielding strain A4003 with further 7.76% increase of specific growth rate, reaching 0.75 h-1 in chemical defined M9 medium. Finally, bioproduction efficiency of intracellular product (ribonucleic acid, RNA), extracellular product (acetoin), and recombinant proteins (green fluorescent protein (GFP) and ovalbumin) by fast-growing strain A4003 was tested. And the production of RNA, acetoin, GFP, and ovalbumin increased 38.09%, 5.40%, 9.47% and 19.79% using fast-growing strain A4003 as chassis compared with BS168, respectively. The developed fast-growing B. subtilis strains and strategies used for developing these strains should be useful for improving bioproduction efficiency and constructing other industrially important bacterium with faster growth phenotype. Fast-growing Bacillus subtilis were constructed through rational gene knockout and adaptive laboratory evolution. Specific growth rate of engineered B. subtilis increased 53.06% compared with B. subtilis 168, reaching 0.75 h-1 in M9 medium. Production of RNA, acetoin, and ovalbumin increased 38.09%, 5.40%, and 19.79% using fast-growing strain as chassis.
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Abstract
The second messenger molecule cyclic di-AMP (c-di-AMP) is formed by many bacteria and archaea. In many species that produce c-di-AMP, this second messenger is essential for viability on rich medium. Recent research has demonstrated that c-di-AMP binds to a large number of proteins and riboswitches, which are often involved in potassium and osmotic homeostasis. c-di-AMP becomes dispensable if the bacteria are cultivated on minimal media with low concentrations of osmotically active compounds. Thus, the essentiality of c-di-AMP does not result from an interaction with a single essential target but rather from the multilevel control of complex homeostatic processes. This review summarizes current knowledge on the homeostasis of c-di-AMP and its function(s) in the control of cellular processes.
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Affiliation(s)
- Jörg Stülke
- Department of General Microbiology, Göttingen Center for Molecular Biosciences (GZMB), Georg-August-University Göttingen, 37077 Göttingen, Germany;
| | - Larissa Krüger
- Department of General Microbiology, Göttingen Center for Molecular Biosciences (GZMB), Georg-August-University Göttingen, 37077 Göttingen, Germany;
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32
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Rath H, Sappa PK, Hoffmann T, Gesell Salazar M, Reder A, Steil L, Hecker M, Bremer E, Mäder U, Völker U. Impact of high salinity and the compatible solute glycine betaine on gene expression of Bacillus subtilis. Environ Microbiol 2020; 22:3266-3286. [PMID: 32419322 DOI: 10.1111/1462-2920.15087] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 04/30/2020] [Accepted: 05/13/2020] [Indexed: 12/15/2022]
Abstract
The Gram-positive bacterium Bacillus subtilis is frequently exposed to hyperosmotic conditions. In addition to the induction of genes involved in the accumulation of compatible solutes, high salinity exerts widespread effects on B. subtilis physiology, including changes in cell wall metabolism, induction of an iron limitation response, reduced motility and suppression of sporulation. We performed a combined whole-transcriptome and proteome analysis of B. subtilis 168 cells continuously cultivated at low or high (1.2 M NaCl) salinity. Our study revealed significant changes in the expression of more than one-fourth of the protein-coding genes and of numerous non-coding RNAs. New aspects in understanding the impact of high salinity on B. subtilis include a sustained low-level induction of the SigB-dependent general stress response and strong repression of biofilm formation under high-salinity conditions. The accumulation of compatible solutes such as glycine betaine aids the cells to cope with water stress by maintaining physiologically adequate levels of turgor and also affects multiple cellular processes through interactions with cellular components. Therefore, we additionally analysed the global effects of glycine betaine on the transcriptome and proteome of B. subtilis and revealed that it influences gene expression not only under high-salinity, but also under standard growth conditions.
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Affiliation(s)
- Hermann Rath
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Praveen K Sappa
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Tamara Hoffmann
- Laboratory for Microbiology, Department of Biology, Philipps-University Marburg, Marburg, Germany
| | - Manuela Gesell Salazar
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Alexander Reder
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Leif Steil
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Michael Hecker
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany.,Institute of Marine Biotechnology e.V. (IMaB), Greifswald, Germany
| | - Erhard Bremer
- Laboratory for Microbiology, Department of Biology, Philipps-University Marburg, Marburg, Germany
| | - Ulrike Mäder
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Uwe Völker
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany.,Institute of Marine Biotechnology e.V. (IMaB), Greifswald, Germany
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Contextual Flexibility in Pseudomonas aeruginosa Central Carbon Metabolism during Growth in Single Carbon Sources. mBio 2020; 11:mBio.02684-19. [PMID: 32184246 PMCID: PMC7078475 DOI: 10.1128/mbio.02684-19] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic human pathogen that is well known for causing infections in the airways of people with cystic fibrosis. Although it is clear that P. aeruginosa is metabolically well adapted to life in the CF lung, little is currently known about how the organism metabolizes the nutrients available in the airways. In this work, we used a combination of gene expression and isotope tracer (“fluxomic”) analyses to find out exactly where the input carbon goes during growth on two CF-relevant carbon sources, acetate and glycerol (derived from the breakdown of lung surfactant). We found that carbon is routed (“fluxed”) through very different pathways during growth on these substrates and that this is accompanied by an unexpected remodeling of the cell’s electron transfer pathways. Having access to this “blueprint” is important because the metabolism of P. aeruginosa is increasingly being recognized as a target for the development of much-needed antimicrobial agents. Pseudomonas aeruginosa is an opportunistic human pathogen, particularly noted for causing infections in the lungs of people with cystic fibrosis (CF). Previous studies have shown that the gene expression profile of P. aeruginosa appears to converge toward a common metabolic program as the organism adapts to the CF airway environment. However, we still have only a limited understanding of how these transcriptional changes impact metabolic flux at the systems level. To address this, we analyzed the transcriptome, proteome, and fluxome of P. aeruginosa grown on glycerol or acetate. These carbon sources were chosen because they are the primary breakdown products of an airway surfactant, phosphatidylcholine, which is known to be a major carbon source for P. aeruginosa in CF airways. We show that the fluxes of carbon throughout central metabolism are radically different among carbon sources. For example, the newly recognized “EDEMP cycle” (which incorporates elements of the Entner-Doudoroff [ED] pathway, the Embden-Meyerhof-Parnas [EMP] pathway, and the pentose phosphate [PP] pathway) plays an important role in supplying NADPH during growth on glycerol. In contrast, the EDEMP cycle is attenuated during growth on acetate, and instead, NADPH is primarily supplied by the reaction catalyzed by isocitrate dehydrogenase(s). Perhaps more importantly, our proteomic and transcriptomic analyses revealed a global remodeling of gene expression during growth on the different carbon sources, with unanticipated impacts on aerobic denitrification, electron transport chain architecture, and the redox economy of the cell. Collectively, these data highlight the remarkable metabolic plasticity of P. aeruginosa; that plasticity allows the organism to seamlessly segue between different carbon sources, maximizing the energetic yield from each.
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Godard T, Zühlke D, Richter G, Wall M, Rohde M, Riedel K, Poblete-Castro I, Krull R, Biedendieck R. Metabolic Rearrangements Causing Elevated Proline and Polyhydroxybutyrate Accumulation During the Osmotic Adaptation Response of Bacillus megaterium. Front Bioeng Biotechnol 2020; 8:47. [PMID: 32161752 PMCID: PMC7053513 DOI: 10.3389/fbioe.2020.00047] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Accepted: 01/21/2020] [Indexed: 12/15/2022] Open
Abstract
For many years now, Bacillus megaterium serves as a microbial workhorse for the high-level production of recombinant proteins in the g/L-scale. However, efficient and stable production processes require the knowledge of the molecular adaptation strategies of the host organism to establish optimal environmental conditions. Here, we interrogated the osmotic stress response of B. megaterium using transcriptome, proteome, metabolome, and fluxome analyses. An initial transient adaptation consisted of potassium import and glutamate counterion synthesis. The massive synthesis of the compatible solute proline constituted the second longterm adaptation process. Several stress response enzymes involved in iron scavenging and reactive oxygen species (ROS) fighting proteins showed higher levels under prolonged osmotic stress induced by 1.8 M NaCl. At the same time, the downregulation of the expression of genes of the upper part of glycolysis resulted in the activation of the pentose phosphate pathway (PPP), generating an oversupply of NADPH. The increased production of lactate accompanied by the reduction of acetate secretion partially compensate for the unbalanced (NADH/NAD+) ratio. Besides, the tricarboxylic acid cycle (TCA) mainly supplies the produced NADH, as indicated by the higher mRNA and protein levels of involved enzymes, and further confirmed by 13C flux analyses. As a consequence of the metabolic flux toward acetyl-CoA and the generation of an excess of NADPH, B. megaterium redirected the produced acetyl-CoA toward the polyhydroxybutyrate (PHB) biosynthetic pathway accumulating around 30% of the cell dry weight (CDW) as PHB. This direct relation between osmotic stress and intracellular PHB content has been evidenced for the first time, thus opening new avenues for synthesizing this valuable biopolymer using varying salt concentrations under non-limiting nutrient conditions.
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Affiliation(s)
- Thibault Godard
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Braunschweig, Germany
| | - Daniela Zühlke
- Institute of Microbiology, Universität Greifswald, Greifswald, Germany
| | - Georg Richter
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Braunschweig, Germany
| | - Melanie Wall
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Braunschweig, Germany
| | - Manfred Rohde
- Central Facility for Microscopy, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Katharina Riedel
- Institute of Microbiology, Universität Greifswald, Greifswald, Germany
| | - Ignacio Poblete-Castro
- Biosystems Engineering Laboratory, Center for Bioinformatics and Integrative Biology, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
| | - Rainer Krull
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Braunschweig, Germany.,Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Braunschweig, Germany.,Center of Pharmaceutical Engineering (PVZ), Technische Universität Braunschweig, Braunschweig, Germany
| | - Rebekka Biedendieck
- Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Braunschweig, Germany.,Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
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Comparative genomics analysis of Nitriliruptoria reveals the genomic differences and salt adaptation strategies. Extremophiles 2019; 24:249-264. [PMID: 31820112 DOI: 10.1007/s00792-019-01150-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 11/25/2019] [Indexed: 12/22/2022]
Abstract
The group Nitriliruptoria, recently classified as a separate class of phylum Actinobacteria, has five members at present, which belong to halophilic or halotolerant Actinobacteria. Here, we sequenced the genomes of Egicoccus halophilus EGI 80432T and Egibacter rhizosphaerae EGI 80759T, and performed a comparative genomics approach to analyze the genomic differences and salt adaptation mechanisms in Nitriliruptoria. Phylogenetic analysis suggested that Euzebya tangerina F10T has a closer phylogenetic relationship to Euzebya rosea DSW09T, while genomic analysis revealed highest genomic similarity with Nitriliruptor alkaliphilus ANL-iso2T and E. halophilus EGI 80432T. Genomic differences of Nitriliruptoria were mainly observed in genome size, gene contents, and the amounts of gene in per functional categories. Furthermore, our analysis also revealed that Nitriliruptoria possess similar synthesis systems of solutes, such as trehalose, glutamine, glutamate, and proline. On the other hand, each member of Nitriliruptoria species possesses specific mechanisms, K+ influx and efflux, betaine and ectoine synthesis, and compatible solutes transport to survive in various high-salt environments.
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Tangyu M, Muller J, Bolten CJ, Wittmann C. Fermentation of plant-based milk alternatives for improved flavour and nutritional value. Appl Microbiol Biotechnol 2019; 103:9263-9275. [PMID: 31686143 PMCID: PMC6867983 DOI: 10.1007/s00253-019-10175-9] [Citation(s) in RCA: 154] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 09/21/2019] [Accepted: 10/03/2019] [Indexed: 12/11/2022]
Abstract
Non-dairy milk alternatives (or milk analogues) are water extracts of plants and have become increasingly popular for human nutrition. Over the years, the global market for these products has become a multi-billion dollar business and will reach a value of approximately 26 billion USD within the next 5 years. Moreover, many consumers demand plant-based milk alternatives for sustainability, health-related, lifestyle and dietary reasons, resulting in an abundance of products based on nuts, seeds or beans. Unfortunately, plant-based milk alternatives are often nutritionally unbalanced, and their flavour profiles limit their acceptance. With the goal of producing more valuable and tasty products, fermentation can help to the improve sensory profiles, nutritional properties, texture and microbial safety of plant-based milk alternatives so that the amendment with additional ingredients, often perceived as artificial, can be avoided. To date, plant-based milk fermentation mainly uses mono-cultures of microbes, such as lactic acid bacteria, bacilli and yeasts, for this purpose. More recently, new concepts have proposed mixed-culture fermentations with two or more microbial species. These approaches promise synergistic effects to enhance the fermentation process and improve the quality of the final products. Here, we review the plant-based milk market, including nutritional, sensory and manufacturing aspects. In addition, we provide an overview of the state-of-the-art fermentation of plant materials using mono- and mixed-cultures. Due to the rapid progress in this field, we can expect well-balanced and naturally fermented plant-based milk alternatives in the coming years.
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Affiliation(s)
- Muzi Tangyu
- Institute of Systems Biotechnology, Saarland University, Campus A1.5, 66123, Saarbrücken, Germany
| | - Jeroen Muller
- Institute of Material Sciences, Department of Biology, Nestlé Research, Lausanne, Switzerland
| | - Christoph J Bolten
- Institute of Material Sciences, Department of Biology, Nestlé Research, Lausanne, Switzerland
| | - Christoph Wittmann
- Institute of Systems Biotechnology, Saarland University, Campus A1.5, 66123, Saarbrücken, Germany.
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Becker J, Wittmann C. A field of dreams: Lignin valorization into chemicals, materials, fuels, and health-care products. Biotechnol Adv 2019; 37:107360. [DOI: 10.1016/j.biotechadv.2019.02.016] [Citation(s) in RCA: 207] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/18/2019] [Accepted: 02/22/2019] [Indexed: 02/07/2023]
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GC-MS-based 13C metabolic flux analysis resolves the parallel and cyclic glucose metabolism of Pseudomonas putida KT2440 and Pseudomonas aeruginosa PAO1. Metab Eng 2019; 54:35-53. [DOI: 10.1016/j.ymben.2019.01.008] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 01/16/2019] [Accepted: 01/16/2019] [Indexed: 01/05/2023]
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Improvement of stress tolerance and riboflavin production of Bacillus subtilis by introduction of heat shock proteins from thermophilic bacillus strains. Appl Microbiol Biotechnol 2019; 103:4455-4465. [PMID: 30968162 DOI: 10.1007/s00253-019-09788-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 03/12/2019] [Accepted: 03/19/2019] [Indexed: 10/27/2022]
Abstract
In this study, stress tolerance devices consisting of heat shock protein (HSP) genes from thermophiles Geobacillus and Parageobacillus were introduced into riboflavin-producing strain Bacillus subtilis 446 to improve its stress tolerance and riboflavin production. The 12 HSP homologs were selected from 28 Geobacillus and Parageobacillus genomes according to their sequence clustering and phylogenetically analysis which represents the diversity of HSPs from thermophilic bacillus. The 12 HSP genes and 2 combinations of them (PtdnaK-PtdnaJ-PtgrpE and PtgroeL-PtgroeS) were heterologously expressed in B. subtilis 446 under the control of a strong constitutive promoter P43. Most of the 14 engineered strains showed increased cell density at 44 to 48 °C and less cell death at 50 °C compared with the control strains. Among them, strains B.s446-HSP20-3, B.s446-HSP20-2, and B.s446-PtDnaK-PtDnaJ-PtGrpE increased their cell densities over 25% at 44 to 48 °C. They also showed 5-, 4-, and 4-fold improved cell survivals after the 10-h heat shock treatment at 50 °C, respectively. These three strains also showed reduced cell death rates under osmotic stress of 10% NaCl, indicating that the introduction of HSPs improved not only the heat tolerance of B. subtilis 446 but also its osmotic tolerance. Fermentation of these three strains at higher temperatures of 39 and 43 °C showed 23-66% improved riboflavin titers, as well as 24-h shortened fermentation period. These results indicated that implanting HSPs from thermophiles to B. subtilis 446 would be an efficient approach to improve its stress tolerance and riboflavin production.
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Poblete-Castro I, Wittmann C, Nikel PI. Biochemistry, genetics and biotechnology of glycerol utilization in Pseudomonas species. Microb Biotechnol 2019; 13:32-53. [PMID: 30883020 PMCID: PMC6922529 DOI: 10.1111/1751-7915.13400] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 02/17/2019] [Accepted: 02/23/2019] [Indexed: 11/30/2022] Open
Abstract
The use of renewable waste feedstocks is an environment‐friendly choice contributing to the reduction of waste treatment costs and increasing the economic value of industrial by‐products. Glycerol (1,2,3‐propanetriol), a simple polyol compound widely distributed in biological systems, constitutes a prime example of a relatively cheap and readily available substrate to be used in bioprocesses. Extensively exploited as an ingredient in the food and pharmaceutical industries, glycerol is also the main by‐product of biodiesel production, which has resulted in a progressive drop in substrate price over the years. Consequently, glycerol has become an attractive substrate in biotechnology, and several chemical commodities currently produced from petroleum have been shown to be obtained from this polyol using whole‐cell biocatalysts with both wild‐type and engineered bacterial strains. Pseudomonas species, endowed with a versatile and rich metabolism, have been adopted for the conversion of glycerol into value‐added products (ranging from simple molecules to structurally complex biopolymers, e.g. polyhydroxyalkanoates), and a number of metabolic engineering strategies have been deployed to increase the number of applications of glycerol as a cost‐effective substrate. The unique genetic and metabolic features of glycerol‐grown Pseudomonas are presented in this review, along with relevant examples of bioprocesses based on this substrate – and the synthetic biology and metabolic engineering strategies implemented in bacteria of this genus aimed at glycerol valorization.
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Affiliation(s)
- Ignacio Poblete-Castro
- Biosystems Engineering Laboratory, Center for Bioinformatics and Integrative Biology, Faculty of Natural Sciences, Universidad Andrés Bello, Santiago de Chile, Chile
| | - Christoph Wittmann
- Institute of Systems Biotechnology, Universität des Saarlandes, Saarbrücken, Germany
| | - Pablo I Nikel
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs Lyngby, Denmark
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Jiang X, Beust A, Sappa PK, Völker U, Dinse T, Herglotz J, Reinhold-Hurek B. Two Functionally Deviating Type 6 Secretion Systems Occur in the Nitrogen-Fixing Endophyte Azoarcus olearius BH72. Front Microbiol 2019; 10:459. [PMID: 30915056 PMCID: PMC6423157 DOI: 10.3389/fmicb.2019.00459] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 02/21/2019] [Indexed: 12/18/2022] Open
Abstract
Type VI protein secretion systems (T6SSs) have been identified in many plant-associated bacteria. However, despite the fact that effector proteins may modulate host responses or interbacterial competition, only a few have been functionally dissected in detail. We dissected the T6SS in Azoarcus olearius strain BH72, a nitrogen-fixing model endophyte of grasses. The genome harbors two gene clusters encoding putative T6SSs, tss-1 and tss-2, of which only T6SS-2 shared genetic organization and functional homology with the H1-T6SS of Pseudomonas aeruginosa. While tss-2 genes were constitutively expressed, tss-1 genes were strongly up-regulated under conditions of nitrogen fixation. A comparative analysis of the wild type and mutants lacking either functional tss-1 or tss-2 allowed to differentiate the functions of both secretion systems. Abundance of Hcp in the culture supernatant as an indication for T6SS activity revealed that only T6SS-2 was active, either under aerobic or nitrogen-fixing conditions. Our data show that T6SS-2 but not T6SS-1 is post-translationally regulated by phosphorylation mediated by TagE/TagG (PpkA/PppA), and by the phosphorylation-independent inhibitory protein TagF, similar to published work in Pseudomonas. Therefore, T6SS-1 appears to be post-translationally regulated by yet unknown mechanisms. Thus, both T6SS systems appear to perform different functions in Azoarcus, one of them specifically adapted to the nitrogen-fixing lifestyle.
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Affiliation(s)
- Xun Jiang
- Department of Microbe-Plant Interactions, Faculty of Biology and Chemistry, Center for Biomolecular Interactions Bremen, University of Bremen, Bremen, Germany
| | - Andreas Beust
- Department of Microbe-Plant Interactions, Faculty of Biology and Chemistry, Center for Biomolecular Interactions Bremen, University of Bremen, Bremen, Germany
| | - Praveen K. Sappa
- Interfaculty Institute of Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Uwe Völker
- Interfaculty Institute of Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Theresa Dinse
- Department of Microbe-Plant Interactions, Faculty of Biology and Chemistry, Center for Biomolecular Interactions Bremen, University of Bremen, Bremen, Germany
| | - Julia Herglotz
- Department of Microbe-Plant Interactions, Faculty of Biology and Chemistry, Center for Biomolecular Interactions Bremen, University of Bremen, Bremen, Germany
| | - Barbara Reinhold-Hurek
- Department of Microbe-Plant Interactions, Faculty of Biology and Chemistry, Center for Biomolecular Interactions Bremen, University of Bremen, Bremen, Germany
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42
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Metabolically engineered Corynebacterium glutamicum for bio-based production of chemicals, fuels, materials, and healthcare products. Metab Eng 2018; 50:122-141. [DOI: 10.1016/j.ymben.2018.07.008] [Citation(s) in RCA: 138] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 07/17/2018] [Accepted: 07/18/2018] [Indexed: 01/15/2023]
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43
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Becker J, Wittmann C. From systems biology to metabolically engineered cells — an omics perspective on the development of industrial microbes. Curr Opin Microbiol 2018; 45:180-188. [DOI: 10.1016/j.mib.2018.06.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 06/06/2018] [Accepted: 06/08/2018] [Indexed: 10/28/2022]
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Long X, Tian J, Liao X, Tian Y. Adaptations of Bacillus shacheensis HNA-14 required for long-term survival under osmotic challenge: a multi-omics perspective. RSC Adv 2018; 8:27525-27536. [PMID: 35540019 PMCID: PMC9083893 DOI: 10.1039/c8ra05472j] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 07/26/2018] [Indexed: 01/28/2023] Open
Abstract
Genomic sequence, transcriptomic, metabolomic and fatty acid analyses of strain HNA-14 were performed to understand the mechanism of salt tolerance for long-term survival. The results indicated that strain HNA-14 has different osmotic resistance mechanisms for long-term survival and short-term salt stress. The cells mainly synthesized compatible solutes to resist osmotic pressure when cultured under nutrient deficient conditions, while they can slow down the synthesis rate and uptake from the environment when cultured under a nutritionally rich environment. Also, the amounts of branched and unsaturated fatty acids in the cell membrane are maintained to a high degree (>50%) to maintain the fluidity of the cell membrane; when the cells are cultured in a high osmotic environment for long-term survival, they may increase the content of branched fatty acids and phosphoric fatty acids to increase the fluidity of the cell membrane to resist the high osmotic pressure.
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Affiliation(s)
- Xiufeng Long
- Department of Biomass and Leather Engineering, Sichuan University Chengdu 610065 PR China
| | - Jiewei Tian
- Department of Biomass and Leather Engineering, Sichuan University Chengdu 610065 PR China
| | - Xuepin Liao
- Department of Biomass and Leather Engineering, Sichuan University Chengdu 610065 PR China
- National Engineering Laboratory for Clean Technology of Leather Manufacture, Sichuan University Chengdu 610065 PR China
| | - Yongqiang Tian
- Department of Biomass and Leather Engineering, Sichuan University Chengdu 610065 PR China
- National Engineering Laboratory for Clean Technology of Leather Manufacture, Sichuan University Chengdu 610065 PR China
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45
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Liu D, Mao Z, Guo J, Wei L, Ma H, Tang Y, Chen T, Wang Z, Zhao X. Construction, Model-Based Analysis, and Characterization of a Promoter Library for Fine-Tuned Gene Expression in Bacillus subtilis. ACS Synth Biol 2018; 7:1785-1797. [PMID: 29944832 DOI: 10.1021/acssynbio.8b00115] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Promoters are among the most-important and most-basic tools for the control of metabolic pathways. However, previous research mainly focused on the screening and characterization of some native promoters in Bacillus subtilis. To develop a broadly applicable promoter system for this important platform organism, we created a de novo synthetic promoter library (SPL) based on consensus sequences by analyzing the microarray transcriptome data of B. subtilis 168. A total of 214 potential promoters spanning a gradient of strengths was isolated and characterized by a green fluorescence assay. Among these, a detailed intensity analysis was conducted on nine promoters with different strengths by reverse-transcription polymerase chain reaction (RT-PCR) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Furthermore, reconstructed promoters and promoter cassettes (tandem promoter cluster) were designed via statistical model-based analysis and tandem dual promoters, which showed strength that was increased 1.2- and 2.77-fold compared to that of promoter P43, respectively. Finally, the SPL was employed in the production of inosine and acetoin by repressing and over-expressing the relevant metabolic pathways, yielding a 700% and 44% increase relative to the respective control strains. This is the first report of a de novo synthetic promoter library for B. subtilis, which is independent of any native promoter. The strategy of improving and fine-tuning promoter strengths will contribute to future metabolic engineering and synthetic biology projects in B. subtilis.
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Affiliation(s)
| | - Zhitao Mao
- Key Laboratory of System Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | | | | | - Hongwu Ma
- Key Laboratory of System Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yajie Tang
- Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Hubei University of Technology, Wuhan 430068, China
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46
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Jiménez-Munguía I, Calderón-Santiago M, Rodríguez-Franco A, Priego-Capote F, Rodríguez-Ortega MJ. Multi-omic profiling to assess the effect of iron starvation in Streptococcus pneumoniae TIGR4. PeerJ 2018; 6:e4966. [PMID: 29915696 PMCID: PMC6004102 DOI: 10.7717/peerj.4966] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/23/2018] [Indexed: 11/20/2022] Open
Abstract
We applied multi-omics approaches (transcriptomics, proteomics and metabolomics) to study the effect of iron starvation on the Gram-positive human pathogen Streptococcus pneumoniae to elucidate global changes in the bacterium in a condition similar to what can be found in the host during an infectious episode. We treated the reference strain TIGR4 with the iron chelator deferoxamine mesylate. DNA microarrays revealed changes in the expression of operons involved in multiple biological processes, with a prevalence of genes coding for ion binding proteins. We also studied the changes in protein abundance by 2-DE followed by MALDI-TOF/TOF analysis of total cell extracts and secretome fractions. The main proteomic changes were found in proteins related to the primary and amino sugar metabolism, especially in enzymes with divalent cations as cofactors. Finally, the metabolomic analysis of intracellular metabolites showed altered levels of amino sugars involved in the cell wall peptidoglycan metabolism. This work shows the utility of multi-perspective studies that can provide complementary results for the comprehension of how a given condition can influence global physiological changes in microorganisms.
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Affiliation(s)
- Irene Jiménez-Munguía
- Departamento de Bioquímica y Biología Molecular, Universidad de Córdoba; Campus de Excelencia Internacional CeiA3, Córdoba, Spain
| | - Mónica Calderón-Santiago
- Departamento de Química Analítica, Universidad de Córdoba; Campus de Excelencia Internacional CeiA3, Córdoba, Spain
| | - Antonio Rodríguez-Franco
- Departamento de Bioquímica y Biología Molecular, Universidad de Córdoba; Campus de Excelencia Internacional CeiA3, Córdoba, Spain
| | - Feliciano Priego-Capote
- Departamento de Química Analítica, Universidad de Córdoba; Campus de Excelencia Internacional CeiA3, Córdoba, Spain
| | - Manuel J Rodríguez-Ortega
- Departamento de Bioquímica y Biología Molecular, Universidad de Córdoba; Campus de Excelencia Internacional CeiA3, Córdoba, Spain
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47
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Schwechheimer SK, Becker J, Peyriga L, Portais JC, Sauer D, Müller R, Hoff B, Haefner S, Schröder H, Zelder O, Wittmann C. Improved riboflavin production with Ashbya gossypii from vegetable oil based on 13C metabolic network analysis with combined labeling analysis by GC/MS, LC/MS, 1D, and 2D NMR. Metab Eng 2018; 47:357-373. [PMID: 29654833 DOI: 10.1016/j.ymben.2018.04.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 02/13/2018] [Accepted: 04/11/2018] [Indexed: 11/29/2022]
Abstract
The fungus Ashbya gossypii is an important industrial producer of riboflavin, i.e. vitamin B2. In order to meet the constantly increasing demands for improved production processes, it appears essential to better understand the underlying metabolic pathways of the vitamin. Here, we used a highly sophisticated set-up of parallel 13C tracer studies with labeling analysis by GC/MS, LC/MS, 1D, and 2D NMR to resolve carbon fluxes in the overproducing strain A. gossypii B2 during growth and subsequent riboflavin production from vegetable oil as carbon source, yeast extract, and supplemented glycine. The studies provided a detailed picture of the underlying metabolism. Glycine was exclusively used as carbon-two donor of the vitamin's pyrimidine ring, which is part of its isoalloxazine ring structure, but did not contribute to the carbon-one metabolism due to the proven absence of a functional glycine cleavage system. The pools of serine and glycine were closely connected due to a highly reversible serine hydroxymethyltransferase. Transmembrane formate flux simulations revealed that the one-carbon metabolism displayed a severe bottleneck during initial riboflavin production, which was overcome in later phases of the cultivation by intrinsic formate accumulation. The transiently limiting carbon-one pool was successfully replenished by time-resolved feeding of small amounts of formate and serine, respectively. This increased the intracellular availability of glycine, serine, and formate and resulted in a final riboflavin titer increase of 45%.
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Affiliation(s)
| | - Judith Becker
- Institute of Systems Biotechnology, Saarland University, Germany
| | - Lindsay Peyriga
- Université de Toulouse; INSA, UPS, INP, Toulouse, France; INRA, UMR792 Ingénerie des Systèmes Biologiques et des Procédés, Toulouse, France; CNRS, UMR5504, Toulouse, France
| | - Jean-Charles Portais
- Université de Toulouse; INSA, UPS, INP, Toulouse, France; INRA, UMR792 Ingénerie des Systèmes Biologiques et des Procédés, Toulouse, France; CNRS, UMR5504, Toulouse, France
| | - Daniel Sauer
- Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Centre for Infection Research and Department of Pharmaceutical Biotechnology, Saarland University, Campus E8.1, 66123 Saarbrücken, Germany
| | - Rolf Müller
- Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Centre for Infection Research and Department of Pharmaceutical Biotechnology, Saarland University, Campus E8.1, 66123 Saarbrücken, Germany
| | - Birgit Hoff
- BASF SE, White Biotechnology Research, Ludwigshafen, Germany
| | - Stefan Haefner
- BASF SE, White Biotechnology Research, Ludwigshafen, Germany
| | | | - Oskar Zelder
- BASF SE, White Biotechnology Research, Ludwigshafen, Germany
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48
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Manes NP, Nita-Lazar A. Application of targeted mass spectrometry in bottom-up proteomics for systems biology research. J Proteomics 2018; 189:75-90. [PMID: 29452276 DOI: 10.1016/j.jprot.2018.02.008] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 01/25/2018] [Accepted: 02/07/2018] [Indexed: 02/08/2023]
Abstract
The enormous diversity of proteoforms produces tremendous complexity within cellular proteomes, facilitates intricate networks of molecular interactions, and constitutes a formidable analytical challenge for biomedical researchers. Currently, quantitative whole-proteome profiling often relies on non-targeted liquid chromatography-mass spectrometry (LC-MS), which samples proteoforms broadly, but can suffer from lower accuracy, sensitivity, and reproducibility compared with targeted LC-MS. Recent advances in bottom-up proteomics using targeted LC-MS have enabled previously unachievable identification and quantification of target proteins and posttranslational modifications within complex samples. Consequently, targeted LC-MS is rapidly advancing biomedical research, especially systems biology research in diverse areas that include proteogenomics, interactomics, kinomics, and biological pathway modeling. With the recent development of targeted LC-MS assays for nearly the entire human proteome, targeted LC-MS is positioned to enable quantitative proteomic profiling of unprecedented quality and accessibility to support fundamental and clinical research. Here we review recent applications of bottom-up proteomics using targeted LC-MS for systems biology research. SIGNIFICANCE: Advances in targeted proteomics are rapidly advancing systems biology research. Recent applications include systems-level investigations focused on posttranslational modifications (such as phosphoproteomics), protein conformation, protein-protein interaction, kinomics, proteogenomics, and metabolic and signaling pathways. Notably, absolute quantification of metabolic and signaling pathway proteins has enabled accurate pathway modeling and engineering. Integration of targeted proteomics with other technologies, such as RNA-seq, has facilitated diverse research such as the identification of hundreds of "missing" human proteins (genes and transcripts that appear to encode proteins but direct experimental evidence was lacking).
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Affiliation(s)
- Nathan P Manes
- Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Aleksandra Nita-Lazar
- Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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49
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Current Knowledge and Recent Advances in Marine Dinoflagellate Transcriptomic Research. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2018. [DOI: 10.3390/jmse6010013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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50
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Kim KH, Jia B, Jeon CO. Identification of Trans-4-Hydroxy-L-Proline as a Compatible Solute and Its Biosynthesis and Molecular Characterization in Halobacillus halophilus. Front Microbiol 2017; 8:2054. [PMID: 29104571 PMCID: PMC5655121 DOI: 10.3389/fmicb.2017.02054] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Accepted: 10/06/2017] [Indexed: 12/17/2022] Open
Abstract
Halobacillus halophilus, a moderately halophilic bacterium, accumulates a variety of compatible solutes including glycine betaine, glutamate, glutamine, proline, and ectoine to cope with osmotic stress. Non-targeted analysis of intracellular organic compounds using 1H-NMR showed that a large amount of trans-4-hydroxy-L-proline (Hyp), which has not been reported as a compatible solute in H. halophilus, was accumulated in response to high NaCl salinity, suggesting that Hyp may be an important compatible solute in H. halophilus. Candidate genes encoding proline 4-hydroxylase (PH-4), which hydroxylates L-proline to generate Hyp, were retrieved from the genome of H. halophilus through domain searches based on the sequences of known PH-4 proteins. A gene, HBHAL_RS11735, which was annotated as a multidrug DMT transporter permease in GenBank, was identified as the PH-4 gene through protein expression analysis in Escherichia coli. The PH-4 gene constituted a transcriptional unit with a promoter and a rho-independent terminator, and it was distantly located from the proline biosynthetic gene cluster (pro operon). Transcriptional analysis showed that PH-4 gene expression was NaCl concentration-dependent, and was specifically induced by chloride anion, similar to the pro operon. Accumulation of intracellular Hyp was also observed in other bacteria, suggesting that Hyp may be a widespread compatible solute in halophilic and halotolerant bacteria.
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Affiliation(s)
| | | | - Che Ok Jeon
- Department of Life Science, Chung-Ang University, Seoul, South Korea
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