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Bin Hafeez A, Pełka K, Worobo R, Szweda P. In Silico Safety Assessment of Bacillus Isolated from Polish Bee Pollen and Bee Bread as Novel Probiotic Candidates. Int J Mol Sci 2024; 25:666. [PMID: 38203838 PMCID: PMC10780176 DOI: 10.3390/ijms25010666] [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: 12/11/2023] [Revised: 12/23/2023] [Accepted: 12/25/2023] [Indexed: 01/12/2024] Open
Abstract
Bacillus species isolated from Polish bee pollen (BP) and bee bread (BB) were characterized for in silico probiotic and safety attributes. A probiogenomics approach was used, and in-depth genomic analysis was performed using a wide array of bioinformatics tools to investigate the presence of virulence and antibiotic resistance properties, mobile genetic elements, and secondary metabolites. Functional annotation and Carbohydrate-Active enZYmes (CAZYme) profiling revealed the presence of genes and a repertoire of probiotics properties promoting enzymes. The isolates BB10.1, BP20.15 (isolated from bee bread), and PY2.3 (isolated from bee pollen) genome mining revealed the presence of several genes encoding acid, heat, cold, and other stress tolerance mechanisms, adhesion proteins required to survive and colonize harsh gastrointestinal environments, enzymes involved in the metabolism of dietary molecules, antioxidant activity, and genes associated with the synthesis of vitamins. In addition, genes responsible for the production of biogenic amines (BAs) and D-/L-lactate, hemolytic activity, and other toxic compounds were also analyzed. Pan-genome analyses were performed with 180 Bacillus subtilis and 204 Bacillus velezensis genomes to mine for any novel genes present in the genomes of our isolates. Moreover, all three isolates also consisted of gene clusters encoding secondary metabolites.
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Affiliation(s)
- Ahmer Bin Hafeez
- Department of Pharmaceutical Technology and Biochemistry, Faculty of Chemistry, Gdańsk University of Technology, Ul. G. Narutowicza 11/12, 80-233 Gdańsk, Poland; (A.B.H.); (K.P.)
| | - Karolina Pełka
- Department of Pharmaceutical Technology and Biochemistry, Faculty of Chemistry, Gdańsk University of Technology, Ul. G. Narutowicza 11/12, 80-233 Gdańsk, Poland; (A.B.H.); (K.P.)
| | - Randy Worobo
- Department of Food Science, Cornell University, Ithaca, NY 14853, USA;
| | - Piotr Szweda
- Department of Pharmaceutical Technology and Biochemistry, Faculty of Chemistry, Gdańsk University of Technology, Ul. G. Narutowicza 11/12, 80-233 Gdańsk, Poland; (A.B.H.); (K.P.)
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2
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Das S, Bhattacharjee MJ, Mukherjee AK, Khan MR. Comprehensive bacterial-metabolite profiles of Hawaijar, Bekang, and Akhone: a comparative study on traditional fermented soybeans of north-east India. World J Microbiol Biotechnol 2023; 39:315. [PMID: 37736853 DOI: 10.1007/s11274-023-03773-3] [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: 06/02/2023] [Accepted: 09/19/2023] [Indexed: 09/23/2023]
Abstract
Preparation of traditionally fermented soybeans varies across ethnicities with distinct tastes, flavour, and nutritional values. The fermented soybean varieties Hawaijar, Bekang, and Akhone of north-east India are associated with diverse ethnic groups from Manipur, Mizoram, and Nagaland, respectively. These varieties differ in substrate and traditional practice that exerts differential bacterial-metabolite profile, which needs an in-depth analysis i. Culture-dependent and independent techniques investigated the bacterial diversity of the fermented soybean varieties. Gas chromatography and mass spectroscopy (GC-MS) studied these varieties' metabolite profiles. The common dominant bacterial genera detected in Hawaijar, Bekang, and Akhone were Bacillus, Ignatzschinaria, and Corynebacterium, with the presence of Brevibacillus and Staphylococcus exclusively in Hawaijar and Oceanobacillus in Bekang and Akhone. The metabolite analysis identified a higher abundance of essential amino acids, amino and nucleotide sugars, and vitamins in Hawaijar, short-chain fatty acids in Bekang, polyunsaturated fatty acids in Akhone and Hawaijar, and prebiotics in Akhone. The bacteria-metabolite correlation analysis predicted four distinct bacterial clusters associated with the differential synthesis of the functional metabolites. While B. subtilis is ubiquitous, cluster-1 comprised B. thermoamylovorans/B. amyloliquefaciens, cluster-2 comprised B. tropicus, cluster-3 comprised B. megaterium/B. borstelensis, and cluster-4 comprised B. rugosus. To the best of our knowledge, this is the first comparative study on traditional fermented soybean varieties of north-east India linking bacterial-metabolite profiles which may help in designing starters for desired functionalities in the future.
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Affiliation(s)
- Sushmita Das
- Division of Life Science, Institute of Advanced Study in Science and Technology, Paschim Boragaon, Guwahati, Assam, 781035, India
- Department of Biotechnology, Gauhati University, Guwahati, Assam, 781014, India
| | - Maloyjo Joyraj Bhattacharjee
- Division of Life Science, Institute of Advanced Study in Science and Technology, Paschim Boragaon, Guwahati, Assam, 781035, India
| | - Ashis K Mukherjee
- Division of Life Science, Institute of Advanced Study in Science and Technology, Paschim Boragaon, Guwahati, Assam, 781035, India
| | - Mojibur Rohman Khan
- Division of Life Science, Institute of Advanced Study in Science and Technology, Paschim Boragaon, Guwahati, Assam, 781035, India.
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3
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Susanti D, Volland A, Tawari N, Baxter N, Gangaiah D, Plata G, Nagireddy A, Hawkins T, Mane SP, Kumar A. Multi-Omics Characterization of Host-Derived Bacillus spp. Probiotics for Improved Growth Performance in Poultry. Front Microbiol 2021; 12:747845. [PMID: 34745051 PMCID: PMC8563996 DOI: 10.3389/fmicb.2021.747845] [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] [Received: 07/26/2021] [Accepted: 09/24/2021] [Indexed: 01/04/2023] Open
Abstract
Microbial feed ingredients or probiotics have been used widely in the poultry industry to improve production efficiency. Spore-forming Bacillus spp. offer advantages over traditional probiotic strains as Bacillus spores are resilient to high temperature, acidic pH, and desiccation. This results in increased strain viability during manufacturing and feed-pelleting processes, extended product shelf-life, and increased stability within the animal’s gastrointestinal tract. Despite numerous reports on the use of Bacillus spores as feed additives, detailed characterizations of Bacillus probiotic strains are typically not published. Insufficient characterizations can lead to misidentification of probiotic strains in product labels, and the potential application of strains carrying virulence factors, toxins, antibiotic resistance, or toxic metabolites. Hence, it is critical to characterize in detail the genomic and phenotypic properties of these strains to screen out undesirable properties and to tie individual traits to clinical outcomes and possible mechanisms. Here, we report a screening workflow and comprehensive multi-omics characterization of Bacillus spp. for use in broiler chickens. Host-derived Bacillus strains were isolated and screened for desirable probiotic properties. The phenotypic, genomic and metabolomic analyses of three probiotic candidates, two Bacillus amyloliquefaciens (Ba ATCC PTA126784 and ATCC PTA126785), and a Bacillus subtilis (Bs ATCC PTA126786), showed that all three strains had promising probiotic traits and safety profiles. Inclusion of Ba ATCC PTA12684 (Ba-PTA84) in the feed of broiler chickens resulted in improved growth performance, as shown by a significantly improved feed conversion ratio (3.3%), increased of European Broiler Index (6.2%), and increased average daily gain (ADG) (3.5%). Comparison of the cecal microbiomes from Ba PTA84-treated and control animals suggested minimal differences in microbiome structure, indicating that the observed growth promotion presumably was not mediated by modulation of cecal microbiome.
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Affiliation(s)
- Dwi Susanti
- Division of Discovery Biology, Bacteriology and Microbiome, Elanco Animal Health, Greenfield, IN, United States
| | - Alyssa Volland
- Division of Discovery Biology, Bacteriology and Microbiome, Elanco Animal Health, Greenfield, IN, United States
| | - Nilesh Tawari
- Division of Global Computational Sciences, Elanco Animal Health, Greenfield, IN, United States
| | - Nielson Baxter
- Division of Nutritional Health, Elanco Animal Health, Greenfield, IN, United States
| | - Dharanesh Gangaiah
- Division of Discovery Biology, Bacteriology and Microbiome, Elanco Animal Health, Greenfield, IN, United States
| | - Germán Plata
- Division of Global Computational Sciences, Elanco Animal Health, Greenfield, IN, United States
| | - Akshitha Nagireddy
- Division of Global Computational Sciences, Elanco Animal Health, Greenfield, IN, United States
| | - Troy Hawkins
- Division of Global Computational Sciences, Elanco Animal Health, Greenfield, IN, United States
| | - Shrinivasrao P Mane
- Division of Global Computational Sciences, Elanco Animal Health, Greenfield, IN, United States
| | - Arvind Kumar
- Division of Discovery Biology, Bacteriology and Microbiome, Elanco Animal Health, Greenfield, IN, United States
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4
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Lu C, Liu Y, Li J, Liu L, Du G. Engineering of Biosynthesis Pathway and NADPH Supply for Improved L-5-Methyltetrahydrofolate Production by Lactococcus lactis. J Microbiol Biotechnol 2021; 31:154-162. [PMID: 31893598 PMCID: PMC9705839 DOI: 10.4014/jmb.1910.10069] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 12/17/2019] [Indexed: 12/15/2022]
Abstract
L-5-methyltetrahydrofolate (5-MTHF) is one of the biological active forms of folate, which is widely used as a nutraceutical. However, low yield and serious pollution associated with the chemical synthesis of 5-MTHF hampers its sustainable supply. In this study, 5-MTHF production was improved by engineering the 5-MTHF biosynthesis pathway and NADPH supply in Lactococcus lactis for developing a green and sustainable biosynthesis approach. Specifically, overexpressing the key rate-limiting enzyme methylenetetrahydrofolate reductase led to intracellular 5-MTHF accumulation, reaching 18 μg/l. Next, 5-MTHF synthesis was further enhanced by combinatorial overexpression of 5-MTHF synthesis pathway enzymes with methylenetetrahydrofolate reductase, resulting in 1.7-fold enhancement. The folate supply pathway was strengthened by expressing folE encoding GTP cyclohydrolase I, which increased 5-MTHF production 2.4-fold to 72 μg/l. Furthermore, glucose-6-phosphate dehydrogenase was overexpressed to improve the redox cofactor NADPH supply for 5-MTHF biosynthesis, which led to a 60% increase in intracellular NADPH and a 35% increase in 5-MTHF production (97 μg/l). To reduce formation of the by-product 5-formyltetrahydrofolate, overexpression of 5-formyltetrahydrofolate cyclo-ligase converted 5-formyltetrahydrofolate to 5,10-methyltetrahydrofolate, which enhanced the 5-MTHF titer to 132 μg/l. Finally, combinatorial addition of folate precursors to the fermentation medium boosted 5-MTHF production, reaching 300 μg/l. To the best of our knowledge, this titer is the highest achieved by L. lactis. This study lays the foundation for further engineering of L. lactis for efficient 5-MTHF biosynthesis.
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Affiliation(s)
- Chuanchuan Lu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 2422, P.R. China,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 141, P.R. China
| | - Yanfeng Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 2422, P.R. China,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 141, P.R. China,Corresponding authors Y.Liu Phone: +86-510-85197117 Fax: +86-510-85918309 E-mail:
| | - Jianghua Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 2422, P.R. China,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 141, P.R. China
| | - Long Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 2422, P.R. China,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 141, P.R. China
| | - Guocheng Du
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 2422, P.R. China,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 141, P.R. China,G.Du Phone: +86-510-85918309 Fax: +86-510-85918309 E-mail:
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5
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Yang H, Liu Y, Li J, Liu L, Du G, Chen J. Systems metabolic engineering of
Bacillus subtilis
for efficient biosynthesis of 5‐methyltetrahydrofolate. Biotechnol Bioeng 2020; 117:2116-2130. [DOI: 10.1002/bit.27332] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 02/11/2020] [Accepted: 03/12/2020] [Indexed: 12/21/2022]
Affiliation(s)
- Han Yang
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of EducationJiangnan University Wuxi China
- Key Laboratory of Industrial Biotechnology, Ministry of EducationJiangnan University Wuxi China
| | - Yanfeng Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of EducationJiangnan University Wuxi China
- Key Laboratory of Industrial Biotechnology, Ministry of EducationJiangnan University Wuxi China
| | - Jianghua Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of EducationJiangnan University Wuxi China
- Key Laboratory of Industrial Biotechnology, Ministry of EducationJiangnan University Wuxi China
| | - Long Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of EducationJiangnan University Wuxi China
- Key Laboratory of Industrial Biotechnology, Ministry of EducationJiangnan University Wuxi China
| | - Guocheng Du
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of EducationJiangnan University Wuxi China
- Key Laboratory of Industrial Biotechnology, Ministry of EducationJiangnan University Wuxi China
| | - Jian Chen
- Key Laboratory of Industrial Biotechnology, Ministry of EducationJiangnan University Wuxi China
- National Engineering Laboratory for Cereal Fermentation TechnologyJiangnan University Wuxi China
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6
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Khatri I, Sharma G, Subramanian S. Composite genome sequence of Bacillus clausii, a probiotic commercially available as Enterogermina ®, and insights into its probiotic properties. BMC Microbiol 2019; 19:307. [PMID: 31888501 PMCID: PMC6937992 DOI: 10.1186/s12866-019-1680-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 12/11/2019] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Some of the spore-forming strains of Bacillus probiotics are marketed commercially as they survive harsh gastrointestinal conditions and bestow health benefits to the host. RESULTS We report the composite genome of Bacillus clausii ENTPro from a commercially available probiotic Enterogermina® and compare it with the genomes of other Bacillus probiotics. We find that the members of B. clausii species harbor high heterogeneity at the species as well as genus level. The genes conferring resistance to chloramphenicol, streptomycin, rifampicin, and tetracycline in the B. clausii ENTPro strain could be identified. The genes coding for the bacteriocin gallidermin, which prevents biofilm formation in the pathogens Staphylococcus aureus and S. epidermidis, were also identified. KEGG Pathway analysis suggested that the folate biosynthesis pathway, which depicts one of the important roles of probiotics in the host, is conserved completely in B. subtilis and minimally in B. clausii and other probiotics. CONCLUSIONS We identified various antibiotic resistance, bacteriocins, stress-related, and adhesion-related domains, and industrially-relevant pathways, in the genomes of these probiotic bacteria that are likely to help them survive in the harsh gastrointestinal tract, facilitating adhesion to host epithelial cells, persistence during antibiotic treatment and combating bacterial infections.
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Affiliation(s)
- Indu Khatri
- CSIR-Institute of Microbial Technology, Sector-39A, Chandigarh, 160036, India.,Leiden University Medical Center, Leiden, the Netherlands
| | - Gaurav Sharma
- CSIR-Institute of Microbial Technology, Sector-39A, Chandigarh, 160036, India.,Institute of Bioinformatics and Applied Biotechnology, Bengaluru, Karnataka, India
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7
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Lyu X, Zhao G, Ng KR, Mark R, Chen WN. Metabolic Engineering of Saccharomyces cerevisiae for De Novo Production of Kaempferol. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:5596-5606. [PMID: 30957490 DOI: 10.1021/acs.jafc.9b01329] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Kaempferol is a polyphenolic compound with various reported health benefits and thus harbors considerable potential for food-engineering applications. In this study, a high-yield kaempferol-producing cell factory was constructed by multiple strategies, including gene screening, elimination of the phenylethanol biosynthetic branch, optimizing the core flavonoid synthetic pathway, supplementation of precursor PEP/E4P, and mitochondrial engineering of F3H and FLS. A total of 86 mg/L of kaempferol was achieved in strain YL-4, to date the highest production titer in yeast. Furthermore, a coculture system and supplementation of surfactants were investigated, to relieve the metabolic burden as well as the low solubility/possible transport limitations of flavonoids, respectively. In the coculture system, the whole pathway was divided across two strains, resulting in 50% increased cell growth. Meanwhile, supplementation of Tween 80 in our engineered strains yielded 220 mg/L of naringenin and 200 mg/L of mixed flavonoids-among the highest production titer reported via de novo production in yeast.
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Affiliation(s)
- Xiaomei Lyu
- School of Chemical and Biomedical Engineering, College of Engineering , Nanyang Technological University , 62 Nanyang Drive , Singapore 637459 , Singapore
| | - Guili Zhao
- School of Chemical and Biomedical Engineering, College of Engineering , Nanyang Technological University , 62 Nanyang Drive , Singapore 637459 , Singapore
| | - Kuan Rei Ng
- School of Chemical and Biomedical Engineering, College of Engineering , Nanyang Technological University , 62 Nanyang Drive , Singapore 637459 , Singapore
| | - Rita Mark
- School of Chemical and Biomedical Engineering, College of Engineering , Nanyang Technological University , 62 Nanyang Drive , Singapore 637459 , Singapore
| | - Wei Ning Chen
- School of Chemical and Biomedical Engineering, College of Engineering , Nanyang Technological University , 62 Nanyang Drive , Singapore 637459 , Singapore
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8
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Microbial cell factories for the sustainable manufacturing of B vitamins. Curr Opin Biotechnol 2018; 56:18-29. [PMID: 30138794 DOI: 10.1016/j.copbio.2018.07.006] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Revised: 07/20/2018] [Accepted: 07/23/2018] [Indexed: 12/16/2022]
Abstract
Vitamins are essential compounds in human and animal diets. Their demand is increasing globally in food, feed, cosmetics, chemical and pharmaceutical industries. Most current production methods are unsustainable because they use non-renewable sources and often generate hazardous waste. Many microorganisms produce vitamins naturally, but their corresponding metabolic pathways are tightly regulated since vitamins are needed only in catalytic amounts. Metabolic engineering is accelerating the development of microbial cell factories for vitamins that could compete with chemical methods that have been optimized over decades, but scientific hurdles remain. Additional technological and regulatory issues need to be overcome for innovative bioprocesses to reach the market. Here, we review the current state of development and challenges for fermentative processes for the B vitamin group.
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9
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Revuelta JL, Serrano-Amatriain C, Ledesma-Amaro R, Jiménez A. Formation of folates by microorganisms: towards the biotechnological production of this vitamin. Appl Microbiol Biotechnol 2018; 102:8613-8620. [PMID: 30073396 PMCID: PMC6153639 DOI: 10.1007/s00253-018-9266-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/23/2018] [Accepted: 07/24/2018] [Indexed: 01/12/2023]
Abstract
Folates (vitamin B9) are essential micronutrients which function as cofactors in one-carbon transfer reactions involved in the synthesis of nucleotides and amino acids. Folate deficiency is associated with important diseases such as cancer, anemia, cardiovascular diseases, or neural tube defects. Epidemiological data show that folate deficiency is still highly prevalent in many populations. Hence, food fortification with synthetic folic acid (i.e., folic acid supplementation) has become mandatory in many developed countries. However, folate biofortification of staple crops and dairy products as well as folate bioproduction using metabolically engineered microorganisms are promising alternatives to folic acid supplementation. Here, we review the current strategies aimed at overproducing folates in microorganisms, in view to implement an economic feasible process for the biotechnological production of the vitamin.
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Affiliation(s)
- José Luis Revuelta
- Metabolic Engineering Group, Department of Microbiology and Genetics, University of Salamanca, Campus Miguel de Unamuno, E-37007, Salamanca, Spain.
| | - Cristina Serrano-Amatriain
- Metabolic Engineering Group, Department of Microbiology and Genetics, University of Salamanca, Campus Miguel de Unamuno, E-37007, Salamanca, Spain
| | - Rodrigo Ledesma-Amaro
- Imperial College Centre for Synthetic Biology and Department of Bioengineering, Imperial College London, London, UK
| | - Alberto Jiménez
- Metabolic Engineering Group, Department of Microbiology and Genetics, University of Salamanca, Campus Miguel de Unamuno, E-37007, Salamanca, Spain
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10
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Gao M, Cao M, Suástegui M, Walker J, Rodriguez Quiroz N, Wu Y, Tribby D, Okerlund A, Stanley L, Shanks JV, Shao Z. Innovating a Nonconventional Yeast Platform for Producing Shikimate as the Building Block of High-Value Aromatics. ACS Synth Biol 2017; 6:29-38. [PMID: 27600996 DOI: 10.1021/acssynbio.6b00132] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The shikimate pathway serves an essential role in many organisms. Not only are the three aromatic amino acids synthesized through this pathway, but many secondary metabolites also derive from it. Decades of effort have been invested into engineering Saccharomyces cerevisiae to produce shikimate and its derivatives. In addition to the ability to express cytochrome P450, S. cerevisiae is generally recognized as safe for producing compounds with nutraceutical and pharmaceutical applications. However, the intrinsically complicated regulations involved in central metabolism and the low precursor availability in S. cerevisiae has limited production levels. Here we report the development of a new platform based on Scheffersomyces stipitis, whose superior xylose utilization efficiency makes it particularly suited to produce the shikimate group of compounds. Shikimate was produced at 3.11 g/L, representing the highest level among shikimate pathway products in yeasts. Our work represents a new exploration toward expanding the current collection of microbial factories.
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Affiliation(s)
- Meirong Gao
- Department of Chemical and Biological
Engineering, ‡NSF Engineering Research Center
for Biorenewable Chemicals (CBiRC), §Department of Chemistry, ∥Interdepartmental Microbiology
Program, Iowa State University, Ames, Iowa 50011, United States
| | - Mingfeng Cao
- Department of Chemical and Biological
Engineering, ‡NSF Engineering Research Center
for Biorenewable Chemicals (CBiRC), §Department of Chemistry, ∥Interdepartmental Microbiology
Program, Iowa State University, Ames, Iowa 50011, United States
| | - Miguel Suástegui
- Department of Chemical and Biological
Engineering, ‡NSF Engineering Research Center
for Biorenewable Chemicals (CBiRC), §Department of Chemistry, ∥Interdepartmental Microbiology
Program, Iowa State University, Ames, Iowa 50011, United States
| | - James Walker
- Department of Chemical and Biological
Engineering, ‡NSF Engineering Research Center
for Biorenewable Chemicals (CBiRC), §Department of Chemistry, ∥Interdepartmental Microbiology
Program, Iowa State University, Ames, Iowa 50011, United States
| | - Natalia Rodriguez Quiroz
- Department of Chemical and Biological
Engineering, ‡NSF Engineering Research Center
for Biorenewable Chemicals (CBiRC), §Department of Chemistry, ∥Interdepartmental Microbiology
Program, Iowa State University, Ames, Iowa 50011, United States
| | - Yutong Wu
- Department of Chemical and Biological
Engineering, ‡NSF Engineering Research Center
for Biorenewable Chemicals (CBiRC), §Department of Chemistry, ∥Interdepartmental Microbiology
Program, Iowa State University, Ames, Iowa 50011, United States
| | - Dana Tribby
- Department of Chemical and Biological
Engineering, ‡NSF Engineering Research Center
for Biorenewable Chemicals (CBiRC), §Department of Chemistry, ∥Interdepartmental Microbiology
Program, Iowa State University, Ames, Iowa 50011, United States
| | - Adam Okerlund
- Department of Chemical and Biological
Engineering, ‡NSF Engineering Research Center
for Biorenewable Chemicals (CBiRC), §Department of Chemistry, ∥Interdepartmental Microbiology
Program, Iowa State University, Ames, Iowa 50011, United States
| | - Levi Stanley
- Department of Chemical and Biological
Engineering, ‡NSF Engineering Research Center
for Biorenewable Chemicals (CBiRC), §Department of Chemistry, ∥Interdepartmental Microbiology
Program, Iowa State University, Ames, Iowa 50011, United States
| | - Jacqueline V. Shanks
- Department of Chemical and Biological
Engineering, ‡NSF Engineering Research Center
for Biorenewable Chemicals (CBiRC), §Department of Chemistry, ∥Interdepartmental Microbiology
Program, Iowa State University, Ames, Iowa 50011, United States
| | - Zengyi Shao
- Department of Chemical and Biological
Engineering, ‡NSF Engineering Research Center
for Biorenewable Chemicals (CBiRC), §Department of Chemistry, ∥Interdepartmental Microbiology
Program, Iowa State University, Ames, Iowa 50011, United States
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11
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Serrano-Amatriain C, Ledesma-Amaro R, López-Nicolás R, Ros G, Jiménez A, Revuelta JL. Folic Acid Production by Engineered Ashbya gossypii. Metab Eng 2016; 38:473-482. [PMID: 27989803 DOI: 10.1016/j.ymben.2016.10.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 09/13/2016] [Accepted: 10/25/2016] [Indexed: 11/17/2022]
Abstract
Folic acid (vitamin B9) is the common name of a number of chemically related compounds (folates), which play a central role as cofactors in one-carbon transfer reactions. Folates are involved in the biosynthesis and metabolism of nucleotides and amino acids, as well as supplying methyl groups to a broad range of substrates, such as hormones, DNA, proteins, and lipids, as part of the methyl cycle. Humans and animals cannot synthesize folic acid and, therefore, need them in the diet. Folic acid deficiency is an important and underestimated problem of micronutrient malnutrition affecting billions of people worldwide. Therefore, the addition of folic acid as food additive has become mandatory in many countries thus contributing to a growing demand of the vitamin. At present, folic acid is exclusively produced by chemical synthesis despite its associated environmental burdens. In this work, we have metabolically engineered the industrial fungus Ashbya gossypii in order to explore its potential as a natural producer of folic acid. Overexpression of FOL genes greatly enhanced the synthesis of folates and identified GTP cyclohydrolase I as the limiting step. Metabolic flux redirection from competing pathways also stimulated folic acid production. Finally, combinatorial engineering synergistically increased the production of different bioactive forms of the folic vitamin. Overall, strains were constructed which produce 146-fold (6595µg/L) more vitamin than the wild-type and by far represents the highest yield reported.
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Affiliation(s)
- Cristina Serrano-Amatriain
- Metabolic Engineering Group, Department of Microbiology and Genetics, University of Salamanca, Campus Miguel de Unamuno, E-37007 Salamanca, Spain
| | - Rodrigo Ledesma-Amaro
- Metabolic Engineering Group, Department of Microbiology and Genetics, University of Salamanca, Campus Miguel de Unamuno, E-37007 Salamanca, Spain
| | - Rubén López-Nicolás
- Department of Food Science and Nutrition, Faculty of Veterinary Sciences, University of Murcia, Campus de Espinardo, 30071 Espinardo (Murcia), Spain
| | - Gaspar Ros
- Department of Food Science and Nutrition, Faculty of Veterinary Sciences, University of Murcia, Campus de Espinardo, 30071 Espinardo (Murcia), Spain
| | - Alberto Jiménez
- Metabolic Engineering Group, Department of Microbiology and Genetics, University of Salamanca, Campus Miguel de Unamuno, E-37007 Salamanca, Spain
| | - José Luis Revuelta
- Metabolic Engineering Group, Department of Microbiology and Genetics, University of Salamanca, Campus Miguel de Unamuno, E-37007 Salamanca, Spain.
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Suástegui M, Guo W, Feng X, Shao Z. Investigating strain dependency in the production of aromatic compounds in
Saccharomyces cerevisiae. Biotechnol Bioeng 2016; 113:2676-2685. [DOI: 10.1002/bit.26037] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 05/16/2016] [Accepted: 06/13/2016] [Indexed: 12/13/2022]
Affiliation(s)
- Miguel Suástegui
- Department of Chemical and Biological EngineeringIowa State UniversityAmesIowa
- NSF Engineering Research Center for Biorenewable Chemicals (CBiRC)AmesIowa
| | - Weihua Guo
- Department of Biological Systems EngineeringVirginia Polytechnic Institute and State UniversityBlacksburgVirginia
| | - Xueyang Feng
- Department of Biological Systems EngineeringVirginia Polytechnic Institute and State UniversityBlacksburgVirginia
| | - Zengyi Shao
- Department of Chemical and Biological EngineeringIowa State UniversityAmesIowa
- NSF Engineering Research Center for Biorenewable Chemicals (CBiRC)AmesIowa
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13
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Galaction AI, Bompa AS, Kloetzer L, Turnea MA, Caşcaval D. Synergic Extraction and Transport of Folic Acid through Liquid Membranes. SOLVENT EXTRACTION AND ION EXCHANGE 2015. [DOI: 10.1080/07366299.2015.1010887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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14
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15
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Liu DF, Ai GM, Zheng QX, Liu C, Jiang CY, Liu LX, Zhang B, Liu YM, Yang C, Liu SJ. Metabolic flux responses to genetic modification for shikimic acid production by Bacillus subtilis strains. Microb Cell Fact 2014; 13:40. [PMID: 24628944 PMCID: PMC4003833 DOI: 10.1186/1475-2859-13-40] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Accepted: 02/21/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Shikimic acid (SA) is a key chiral starting molecule for the synthesis of the neuramidase inhibitor GS4104 against viral influenza. Microbial production of SA has been extensively investigated in Escherichia coli, and to a less extent in Bacillus subtilis. However, metabolic flux of the high SA-producing strains has not been explored. In this study, we constructed with genetic manipulation and further determined metabolic flux with 13C-labeling test of high SA-producing B. subtilis strains. RESULTS B. subtilis 1A474 had a mutation in SA kinase gene (aroI) and accumulated 1.5 g/L of SA. Overexpression of plasmid-encoded aroA, aroB, aroC or aroD in B. subtilis revealed that aroD had the most significantly positive effects on SA production. Simultaneous overexpression of genes for 3-deoxy-D-arabinoheptulosonate-7-phosphate synthase (aroA) and SA dehydrogenase (aroD) in B. subtilis BSSA/pSAAroA/pDGSAAroD resulted in SA production of 3.2 g/L. 13C-Metabolic flux assay (MFA) on the two strains BSSA/pHCMC04/pDG148-stu and BSSA/pSAAroA/pDGSAAroD indicated the carbon flux from glucose to SA increased to 4.6% in BSSA/pSAAroA/pDGSAAroD from 1.9% in strain BSSA/pHCMC04/pDG148-stu. The carbon flux through tricarboxylic acid cycle significantly reduced, while responses of the pentose phosphate pathway and the glycolysis to high SA production were rather weak, in the strain BSSA/pSAAroA/pDGSAAroD. Based on the results from MFA, two potential targets for further optimization of SA production were identified. Experiments on genetic deletion of phosphoenoylpyruvate kinase gene confirmed its positive influence on SA production, while the overexpression of the transketolase gene did not lead to increase in SA production. CONCLUSION Of the genes involved in shikimate pathway in B. subtilis, aroD exerted most significant influence on SA accumulation. Overexpression of plasmid-encoded aroA and aroD doubled SA production than its parent strain. MFA revealed metabolic flux redistribution among phosphate pentose pathway, glycolysis, TCA cycle in the low and high SA-producing B. subtilis strains. The high SA producing strain BSSA/pSAAroA/pDGSAAroD had increased carbon flux into shikimate pathway and reduced flux into TCA cycle.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Chen Yang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
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16
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Licona-Cassani C, Lara AR, Cabrera-Valladares N, Escalante A, Hernández-Chávez G, Martinez A, Bolívar F, Gosset G. Inactivation of Pyruvate Kinase or the Phosphoenolpyruvate: Sugar Phosphotransferase System Increases Shikimic and Dehydroshikimic Acid Yields from Glucose inBacillus subtilis. J Mol Microbiol Biotechnol 2014; 24:37-45. [DOI: 10.1159/000355264] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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17
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Kanmani P, Satish Kumar R, Yuvaraj N, Paari KA, Pattukumar V, Arul V. Probiotics and its functionally valuable products-a review. Crit Rev Food Sci Nutr 2013; 53:641-58. [PMID: 23627505 DOI: 10.1080/10408398.2011.553752] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
During the past two decades probiotic bacteria have been increasingly proposed as health promoting bacteria in variety of food system, because of its safety, functional, and technological characteristics. Commonly, Lactobacillus spp., Bifidobacterium spp., Saccharomyces boulardii, and some other microorganisms have been considered as probiotic strains. Possibly these bacterial strains exerted several beneficial effects into gastrointestinal tract of host while administered with variety of food system. Lactic acid bacteria (LAB) usually produce antimicrobial substances like bacteriocin which have broad spectrum of antagonist effect against closely related Gram positive and Gram negative pathogens. LAB strains often produce polymeric substances such as exopolysaccharides (EPS) which increase the colonization of probiotic bacteria by cell-cell interactions in gastrointestinal tract. LAB also produces biosurfactant which showed that the wide range of antimicrobial activity against bacterial pathogen as well as its antiadhesive properties reduces the adhesion of pathogens into gastric wall membrane. Furthermore, LAB strains have also been reported for production of antioxidants which are ability to scavenge the free radicals such as superoxide anions and hydroxyl radicals. For this sense, this review article is mainly focused on the ecology, biosynthesis, genetics, target sites, and applications of bacteriocins and EPS from LAB strains. Moreover, this review discusses about the production and functions of nutritive essential element folate and iron chelating agent such as siderophores from LAB.
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Affiliation(s)
- Paulraj Kanmani
- Department of Biotechnology, School of Life Sciences, Pondicherry University, Pondicherry, 605014, India
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18
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Song GC, Choi HK, Ryu CM. The folate precursor para-aminobenzoic acid elicits induced resistance against Cucumber mosaic virus and Xanthomonas axonopodis. ANNALS OF BOTANY 2013; 111:925-34. [PMID: 23471007 PMCID: PMC3631333 DOI: 10.1093/aob/mct049] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Accepted: 01/21/2013] [Indexed: 05/19/2023]
Abstract
BACKGROUND AND AIMS The use of vitamins including vitamin B1, B2 and K3 for the induction of systemic acquired resistance (SAR) to protect crops against plant pathogens has been evaluated previously. The use of vitamins is beneficial because it is cost effective and safe for the environment. The use of folate precursors, including ortho-aminobenzoic acid, to induce SAR against a soft-rot pathogen in tobacco has been reported previously. METHODS In the present study, para-aminobenzoic acid (PABA, also referred to as vitamin Bx) was selected owing to its effect on the induction of SAR against Xanthomonas axonopodis pv. vesicatoria in pepper plants through greenhouse screening. KEY RESULTS Dipping of pepper seedlings in a 1 mm PABA solution in field trials induced SAR against artificially infiltrated X. axonopodis pv. vesicatoria and naturally occurring cucumber mosaic virus. Expression of the Capsicum annuum pathogenesis-related 4 gene was primed in response to pathogen infection as assessed by quantitative real-time PCR. The accumulation of cucumber mosaic virus RNA was reduced in PABA-treated pepper plants at 40 and 105 d post-treatment. Unexpectedly, fruit yield was increased in PABA-treated plants, indicating that PABA-mediated SAR successfully protected pepper plants from infection by bacterial and viral pathogens without significant fitness allocation costs. CONCLUSIONS The present study is the first to demonstrate the effective elicitation of SAR by a folate precursor under field conditions.
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Affiliation(s)
- Geun Cheol Song
- Molecular Phytobacteriology Laboratory, Systems & Synthetic Biology Research Center, KRIBB, Daejeon 305-806, South Korea
- Biosystems and Bioengineering Program, University of Science and Technology, Daejeon, 305-350, South Korea
| | - Hye Kyung Choi
- Molecular Phytobacteriology Laboratory, Systems & Synthetic Biology Research Center, KRIBB, Daejeon 305-806, South Korea
| | - Choong-Min Ryu
- Molecular Phytobacteriology Laboratory, Systems & Synthetic Biology Research Center, KRIBB, Daejeon 305-806, South Korea
- Biosystems and Bioengineering Program, University of Science and Technology, Daejeon, 305-350, South Korea
- * For correspondence. E-mail
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Lactic acid bacteria producing B-group vitamins: a great potential for functional cereals products. Appl Microbiol Biotechnol 2012; 96:1383-94. [PMID: 23093174 DOI: 10.1007/s00253-012-4440-2] [Citation(s) in RCA: 146] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 09/07/2012] [Accepted: 09/10/2012] [Indexed: 10/27/2022]
Abstract
Wheat contains various essential nutrients including the B group of vitamins. However, B group vitamins, normally present in cereals-derived products, are easily removed or destroyed during milling, food processing or cooking. Lactic acid bacteria (LAB) are widely used as starter cultures for the fermentation of a large variety of foods and can improve the safety, shelf life, nutritional value, flavor and overall quality of the fermented products. In this regard, the identification and application of strains delivering health-promoting compounds is a fascinating field. Besides their key role in food fermentations, several LAB found in the gastrointestinal tract of humans and animals are commercially used as probiotics and possess generally recognized as safe status. LAB are usually auxotrophic for several vitamins although certain strains of LAB have the capability to synthesize water-soluble vitamins such as those included in the B group. In recent years, a number of biotechnological processes have been explored to perform a more economical and sustainable vitamin production than that obtained via chemical synthesis. This review article will briefly report the current knowledge on lactic acid bacteria synthesis of vitamins B2, B11 and B12 and the potential strategies to increase B-group vitamin content in cereals-based products, where vitamins-producing LAB have been leading to the elaboration of novel fermented functional foods. In addition, the use of genetic strategies to increase vitamin production or to create novel vitamin-producing strains will be also discussed.
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Cabrera-Valladares N, Martínez LM, Flores N, Hernández-Chávez G, Martínez A, Bolívar F, Gosset G. Physiologic Consequences of Glucose Transport and Phosphoenolpyruvate Node Modifications inBacillus subtilis168. J Mol Microbiol Biotechnol 2012; 22:177-97. [DOI: 10.1159/000339973] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
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21
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Trausch JJ, Ceres P, Reyes FE, Batey RT. The structure of a tetrahydrofolate-sensing riboswitch reveals two ligand binding sites in a single aptamer. Structure 2011; 19:1413-23. [PMID: 21906956 DOI: 10.1016/j.str.2011.06.019] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2011] [Revised: 06/14/2011] [Accepted: 06/15/2011] [Indexed: 12/16/2022]
Abstract
Transport and biosynthesis of folate and its derivatives are frequently controlled by the tetrahydrofolate (THF) riboswitch in Firmicutes. We have solved the crystal structure of the THF riboswitch aptamer in complex with folinic acid, a THF analog. Uniquely, this structure reveals two molecules of folinic acid binding to a single structured domain. These two sites interact with ligand in a similar fashion, primarily through recognition of the reduced pterin moiety. 7-deazaguanine, a soluble analog of guanine, binds the riboswitch with nearly the same affinity as its natural effector. However, 7-deazaguanine effects transcriptional termination to a substantially lesser degree than folinic acid, suggesting that the cellular guanine pool does not act upon the THF riboswitch. Under physiological conditions the ligands display strong cooperative binding, with one of the two sites playing a greater role in eliciting the regulatory response, which suggests that the second site may play another functional role.
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Affiliation(s)
- Jeremiah J Trausch
- Department of Chemistry and Biochemistry, University of Colorado, UCB 215, Boulder, CO 80309-0215, USA
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22
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'Unknown' proteins and 'orphan' enzymes: the missing half of the engineering parts list--and how to find it. Biochem J 2009; 425:1-11. [PMID: 20001958 DOI: 10.1042/bj20091328] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Like other forms of engineering, metabolic engineering requires knowledge of the components (the 'parts list') of the target system. Lack of such knowledge impairs both rational engineering design and diagnosis of the reasons for failures; it also poses problems for the related field of metabolic reconstruction, which uses a cell's parts list to recreate its metabolic activities in silico. Despite spectacular progress in genome sequencing, the parts lists for most organisms that we seek to manipulate remain highly incomplete, due to the dual problem of 'unknown' proteins and 'orphan' enzymes. The former are all the proteins deduced from genome sequence that have no known function, and the latter are all the enzymes described in the literature (and often catalogued in the EC database) for which no corresponding gene has been reported. Unknown proteins constitute up to about half of the proteins in prokaryotic genomes, and much more than this in higher plants and animals. Orphan enzymes make up more than a third of the EC database. Attacking the 'missing parts list' problem is accordingly one of the great challenges for post-genomic biology, and a tremendous opportunity to discover new facets of life's machinery. Success will require a co-ordinated community-wide attack, sustained over years. In this attack, comparative genomics is probably the single most effective strategy, for it can reliably predict functions for unknown proteins and genes for orphan enzymes. Furthermore, it is cost-efficient and increasingly straightforward to deploy owing to a proliferation of databases and associated tools.
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Fujii K, Nakashima H, Hashidzume Y. Isolation of folate-producing microalgae, from oligotrophic ponds in Yamaguchi, Japan. J Appl Microbiol 2009; 108:1421-9. [PMID: 19796121 DOI: 10.1111/j.1365-2672.2009.04542.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
AIMS Folate (FA) is a B-vitamin that plays an important role in the prevention of several disorders. Although synthetic FA currently dominates the market, consumers tend to demand natural FA. Because microalgae can produce organic compounds photoautotrophically, we isolated and characterized FA-producing microalgal strains. METHODS AND RESULTS To isolate microalgae that produce vitamins de novo, fresh water samples were cultivated in a mineral salts medium without any vitamins. After repeated subculture, 11 isolates were obtained. A biological assay revealed that four isolates accumulated FA at significantly higher levels (15-36 mg kg(-1) in dry biomass) than any known commercial microalgae. Thiamine content of the isolates was also remarkably high (71-90 mg kg(-1) in dry biomass). Phylogenetic studies based on SSU-rDNA suggested that one isolate was Chlamydomonas reinhardtii, while others were likely novel species of Chlorococcum. CONCLUSION There are no reports of toxicity associated with Chlamydomonas and Chlorococcum; therefore, the isolates are expected to be safe and useful not only as a promising alternative source of FA and thiamine but also as nutraceuticals for humans and animals. SIGNIFICANCE AND IMPACT OF THE STUDY The present results advance our understanding of FA-producing microalgae in aquatic environments and suggest their potentials for application to biotechnological vitamin production.
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Affiliation(s)
- K Fujii
- Department of Agriculture, Yamaguchi University, Yoshida, Yamaguchi, Japan.
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Cunningham DS, Koepsel RR, Ataai MM, Domach MM. Factors affecting plasmid production in Escherichia coli from a resource allocation standpoint. Microb Cell Fact 2009; 8:27. [PMID: 19463175 PMCID: PMC2702362 DOI: 10.1186/1475-2859-8-27] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2009] [Accepted: 05/22/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Plasmids are being reconsidered as viable vector alternatives to viruses for gene therapies and vaccines because they are safer, non-toxic, and simpler to produce. Accordingly, there has been renewed interest in the production of plasmid DNA itself as the therapeutic end-product of a bioprocess. Improvement to the best current yields and productivities of such emerging processes would help ensure economic feasibility on the industrial scale. Our goal, therefore, was to develop a stoichiometric model of Escherichia coli metabolism in order to (1) determine its maximum theoretical plasmid-producing capacity, and to (2) identify factors that significantly impact plasmid production. RESULTS Such a model was developed for the production of a high copy plasmid under conditions of batch aerobic growth on glucose minimal medium. The objective of the model was to maximize plasmid production. By employing certain constraints and examining the resulting flux distributions, several factors were determined that significantly impact plasmid yield. Acetate production and constitutive expression of the plasmid's antibiotic resistance marker exert negative effects, while low pyruvate kinase (Pyk) flux and the generation of NADPH by transhydrogenase activity offer positive effects. The highest theoretical yield (592 mg/g) resulted under conditions of no marker or acetate production, nil Pyk flux, and the maximum allowable transhydrogenase activity. For comparison, when these four fluxes were constrained to wild-type values, yields on the order of tens of mg/g resulted, which are on par with the best experimental yields reported to date. CONCLUSION These results suggest that specific plasmid yields can theoretically reach 12 times their current experimental maximum (51 mg/g). Moreover, they imply that abolishing Pyk activity and/or transhydrogenase up-regulation would be useful strategies to implement when designing host strains for plasmid production; mutations that reduce acetate production would also be advantageous. The results further suggest that using some other means for plasmid selection than antibiotic resistance, or at least weakening the marker's expression, would be beneficial because it would allow more precursor metabolites, energy, and reducing power to be put toward plasmid production. Thus far, the impact of eliminating Pyk activity has been explored experimentally, with significantly higher plasmid yields resulting.
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Affiliation(s)
- Drew S Cunningham
- Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | - Richard R Koepsel
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Mohammad M Ataai
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Michael M Domach
- Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
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Bacterial vitamin B2, B11 and B12 overproduction: An overview. Int J Food Microbiol 2009; 133:1-7. [PMID: 19467724 DOI: 10.1016/j.ijfoodmicro.2009.04.012] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2008] [Revised: 04/12/2009] [Accepted: 04/14/2009] [Indexed: 11/20/2022]
Abstract
Consumers are becoming increasingly health conscious and therefore more discerning in their food choices. The production of fermented food products with elevated levels of B-vitamins increase both their commercial and nutritional value, and eliminate the need for subsequent fortification with these essential vitamins. Such novel products could reduce the incidence of inadequate vitamin intake which is common in many parts of the world, not only in developing countries, but also in many industrialised countries. Moreover, the concept of in situ fortification by bacterial fermentation opens the way for development of food products targeted at specific groups in society such as the elderly and adolescents. This review looks at how vitamin overproduction strategies have been developed, some of which have successfully been tested in animal models. Such innovative strategies could be relatively easily adapted by the food industry to develop novel vitamin-enhanced functional foods with enhanced consumer appeal.
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26
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Pan Z, Zhu T, Domagalski N, Khan S, Koepsel RR, Domach MM, Ataai MM. Regulating Expression of Pyruvate Kinase in Bacillus subtilis for Control of Growth Rate and Formation of Acidic Byproducts. Biotechnol Prog 2008; 22:1451-5. [PMID: 17022686 DOI: 10.1021/bp060049u] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Our prior work has shown that a pyk mutant of Bacillus subtilis exhibited diminished acidic byproduct accumulation, dramatically elevated phosphoenolpyruvate (PEP) pool, and reduced growth rate. To determine if a low acetate-producing but fast-growing strain of B. subtilis could be developed, we placed the expression of the pyk gene under the control of an inducible promoter. Enzyme measurements proved that PYK activity of the inducible PYK mutant (iPYK) increases with the isopropyl-beta-d-thiogalactopyranoside concentration. Batch growth experiments showed that growth rate and acid formation are closely related to the induction level of pyk. Measurements of cell growth rate and acetate formation of the iPYK mutant at different induction levels revealed that a PYK activity of about 12% of wild-type allows for good growth rate (0.4 h(-)(1) versus 0.63 h(-)(1) of wild-type) and low acetate production (0.26 g/L versus 1.05 g/L of wild-type). This is the first report to our knowledge of a metabolically engineered B. subtilis strain that allows good growth rate and low acid production in batch cultures. Finally, it was found that, by varying the pyk induction level, intracellular PEP concentration can be controlled over a wide range. The intracellular PEP concentration is intimately connected to the regulation of the transport of phosphotransferase system (PTS) sugars in the presence of glucose. Because there is no other method for modulating intracellular PEP levels, this finding represents a major advance in one's ability to dissect the function of the PTS and sugar metabolism in bacteria.
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Affiliation(s)
- Zhiwei Pan
- Department of Chemical Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
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27
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Campbell WC. History of the Discovery of Sulfaquinoxaline as a Coccidiostat. J Parasitol 2008; 94:934-45. [DOI: 10.1645/ge-1413.1] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2007] [Accepted: 02/06/2008] [Indexed: 11/10/2022] Open
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28
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Bekaert S, Storozhenko S, Mehrshahi P, Bennett MJ, Lambert W, Gregory JF, Schubert K, Hugenholtz J, Van Der Straeten D, Hanson AD. Folate biofortification in food plants. TRENDS IN PLANT SCIENCE 2008; 13:28-35. [PMID: 18083061 DOI: 10.1016/j.tplants.2007.11.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2007] [Revised: 10/27/2007] [Accepted: 11/05/2007] [Indexed: 05/10/2023]
Abstract
Folate deficiency is a global health problem affecting many people in the developing and developed world. Current interventions (industrial food fortification and supplementation by folic acid pills) are effective if they can be used but might not be possible in less developed countries. Recent advances demonstrate that folate biofortification of food crops is now a feasible complementary strategy to fight folate deficiency worldwide. The genes and enzymes of folate synthesis are sufficiently understood to enable metabolic engineering of the pathway, and results from pilot engineering studies in plants (and bacteria) are encouraging. Here, we review the current status of investigations in the field of folate enhancement on the eve of a new era in food fortification.
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Affiliation(s)
- Samir Bekaert
- Department of Molecular Genetics, Ghent University, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium
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