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Hassane AMA, Eldiehy KSH, Saha D, Mohamed H, Mosa MA, Abouelela ME, Abo-Dahab NF, El-Shanawany ARA. Oleaginous fungi: a promising source of biofuels and nutraceuticals with enhanced lipid production strategies. Arch Microbiol 2024; 206:338. [PMID: 38955856 DOI: 10.1007/s00203-024-04054-9] [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: 05/11/2024] [Revised: 06/13/2024] [Accepted: 06/14/2024] [Indexed: 07/04/2024]
Abstract
Oleaginous fungi have attracted a great deal of interest for their potency to accumulate high amounts of lipids (more than 20% of biomass dry weight) and polyunsaturated fatty acids (PUFAs), which have a variety of industrial and biological applications. Lipids of plant and animal origin are related to some restrictions and thus lead to attention towards oleaginous microorganisms as reliable substitute resources. Lipids are traditionally biosynthesized intra-cellularly and involved in the building structure of a variety of cellular compartments. In oleaginous fungi, under certain conditions of elevated carbon ratio and decreased nitrogen in the growth medium, a change in metabolic pathway occurred by switching the whole central carbon metabolism to fatty acid anabolism, which subsequently resulted in high lipid accumulation. The present review illustrates the bio-lipid structure, fatty acid classes and biosynthesis within oleaginous fungi with certain key enzymes, and the advantages of oleaginous fungi over other lipid bio-sources. Qualitative and quantitative techniques for detecting the lipid accumulation capability of oleaginous microbes including visual, and analytical (convenient and non-convenient) were debated. Factors affecting lipid production, and different approaches followed to enhance the lipid content in oleaginous yeasts and fungi, including optimization, utilization of cost-effective wastes, co-culturing, as well as metabolic and genetic engineering, were discussed. A better understanding of the oleaginous fungi regarding screening, detection, and maximization of lipid content using different strategies could help to discover new potent oleaginous isolates, exploit and recycle low-cost wastes, and improve the efficiency of bio-lipids cumulation with biotechnological significance.
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Affiliation(s)
- Abdallah M A Hassane
- Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, P.O. Box 71524, Assiut, Egypt.
| | - Khalifa S H Eldiehy
- Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, P.O. Box 71524, Assiut, Egypt
| | - Debanjan Saha
- Department of Molecular Biology and Biotechnology, Tezpur University, P.O. Box 784028, Assam, India
| | - Hassan Mohamed
- Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, P.O. Box 71524, Assiut, Egypt
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, P.O. Box 255000, Zibo, China
| | - Mohamed A Mosa
- Nanotechnology and Advanced Nano-Materials Laboratory (NANML), Plant Pathology Research Institute, Agricultural Research Center, P.O. Box 12619, Giza, Egypt
| | - Mohamed E Abouelela
- Department of Pharmacognosy, Faculty of Pharmacy, Al-Azhar University, P.O. Box 11884, Cairo, Egypt
| | - Nageh F Abo-Dahab
- Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, P.O. Box 71524, Assiut, Egypt
| | - Abdel-Rehim A El-Shanawany
- Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, P.O. Box 71524, Assiut, Egypt
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Muñoz-Fernández G, Martínez-Buey R, Revuelta JL, Jiménez A. Metabolic engineering of Ashbya gossypii for limonene production from xylose. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:79. [PMID: 35841062 PMCID: PMC9284773 DOI: 10.1186/s13068-022-02176-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 07/05/2022] [Indexed: 05/28/2023]
Abstract
BACKGROUND Limonene is a cyclic monoterpene that has applications in the food, cosmetic, and pharmaceutical industries. The industrial production of limonene and its derivatives through plant extraction presents important drawbacks such as seasonal and climate issues, feedstock limitations, low efficiency and environmental concerns. Consequently, the implementation of efficient and eco-friendly bioprocesses for the production of limonene and other terpenes constitutes an attractive goal for microbial biotechnology. In this context, novel biocatalysts with the ability to produce limonene from alternative carbon sources will help to meet the industrial demands of limonene. RESULTS Engineered strains of the industrial fungus Ashbya gossypii have been developed to produce limonene from xylose. The limonene synthase (LS) from Citrus limon was initially overexpressed together with the native HMG1 gene (coding for HMG-CoA reductase) to establish a limonene-producing platform from a xylose-utilizing A. gossypii strain. In addition, several strategies were designed to increase the production of limonene. Hence, the effect of mutant alleles of ERG20 (erg20F95W and erg20F126W) were evaluated together with a synthetic orthogonal pathway using a heterologous neryl diphosphate synthase. The lethality of the A. gossypii double mutant erg20F95W-F126W highlights the indispensability of farnesyl diphosphate for the synthesis of essential sterols. In addition, the utilization of the orthogonal pathway, bypassing the Erg20 activity through neryl diphosphate, triggered a substantial increase in limonene titer (33.6 mg/L), without critically altering the fitness of the engineered strain. Finally, the overexpression of the native ERG12 gene further enhanced limonene production, which reached 336.4 mg/L after 96 h in flask cultures using xylose as the carbon source. CONCLUSIONS The microbial production of limonene can be carried out using engineered strains of A. gossypii from xylose-based carbon sources. The utilization of a synthetic orthogonal pathway together with the overexpression of ERG12 is a highly beneficial strategy for the production of limonene in A. gossypii. The strains presented in this work constitute a proof of principle for the production of limonene and other terpenes from agro-industrial wastes such as xylose-rich hydrolysates in A. gossypii.
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Affiliation(s)
- Gloria Muñoz-Fernández
- Metabolic Engineering Group, Department of Microbiology and Genetics, Universidad de Salamanca, Campus Miguel de Unamuno, 37007, Salamanca, Spain
| | - Rubén Martínez-Buey
- Metabolic Engineering Group, Department of Microbiology and Genetics, Universidad de Salamanca, Campus Miguel de Unamuno, 37007, Salamanca, Spain
| | - José Luis Revuelta
- Metabolic Engineering Group, Department of Microbiology and Genetics, Universidad de Salamanca, Campus Miguel de Unamuno, 37007, Salamanca, Spain
| | - Alberto Jiménez
- Metabolic Engineering Group, Department of Microbiology and Genetics, Universidad de Salamanca, Campus Miguel de Unamuno, 37007, Salamanca, Spain.
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Joshi A, Verma KK, D Rajput V, Minkina T, Arora J. Recent advances in metabolic engineering of microorganisms for advancing lignocellulose-derived biofuels. Bioengineered 2022; 13:8135-8163. [PMID: 35297313 PMCID: PMC9161965 DOI: 10.1080/21655979.2022.2051856] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Combating climate change and ensuring energy supply to a rapidly growing global population has highlighted the need to replace petroleum fuels with clean, and sustainable renewable fuels. Biofuels offer a solution to safeguard energy security with reduced ecological footprint and process economics. Over the past years, lignocellulosic biomass has become the most preferred raw material for the production of biofuels, such as fuel, alcohol, biodiesel, and biohydrogen. However, the cost-effective conversion of lignocellulose into biofuels remains an unsolved challenge at the industrial scale. Recently, intensive efforts have been made in lignocellulose feedstock and microbial engineering to address this problem. By improving the biological pathways leading to the polysaccharide, lignin, and lipid biosynthesis, limited success has been achieved, and still needs to improve sustainable biofuel production. Impressive success is being achieved by the retouring metabolic pathways of different microbial hosts. Several robust phenotypes, mostly from bacteria and yeast domains, have been successfully constructed with improved substrate spectrum, product yield and sturdiness against hydrolysate toxins. Cyanobacteria is also being explored for metabolic advancement in recent years, however, it also remained underdeveloped to generate commercialized biofuels. The bacterium Escherichia coli and yeast Saccharomyces cerevisiae strains are also being engineered to have cell surfaces displaying hydrolytic enzymes, which holds much promise for near-term scale-up and biorefinery use. Looking forward, future advances to achieve economically feasible production of lignocellulosic-based biofuels with special focus on designing more efficient metabolic pathways coupled with screening, and engineering of novel enzymes.
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Affiliation(s)
- Abhishek Joshi
- Laboratory of Biomolecular Technology, Department of Botany, Mohanlal Sukhadia University, Udaipur313001, India
| | - Krishan K. Verma
- Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs/Guangxi Key Laboratory of Sugarcane Genetic improvement/Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning - 530007, China
| | - Vishnu D Rajput
- Academy of Biology and Biotechnology, Southern Federal University, 344090, Russia
| | - Tatiana Minkina
- Academy of Biology and Biotechnology, Southern Federal University, 344090, Russia
| | - Jaya Arora
- Laboratory of Biomolecular Technology, Department of Botany, Mohanlal Sukhadia University, Udaipur313001, India,CONTACT Jaya Arora Laboratory of Biomolecular Technology, Department of Botany, Mohanlal Sukhadia University, Udaipur313001, India
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New Promoters for Metabolic Engineering of Ashbya gossypii. J Fungi (Basel) 2021; 7:jof7110906. [PMID: 34829195 PMCID: PMC8618306 DOI: 10.3390/jof7110906] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 10/21/2021] [Accepted: 10/24/2021] [Indexed: 11/22/2022] Open
Abstract
Ashbya gossypii is a filamentous fungus that is currently exploited for the industrial production of riboflavin. In addition, metabolically engineered strains of A. gossypii have also been described as valuable biocatalysts for the production of different metabolites such as folic acid, nucleosides, and biolipids. Hence, bioproduction in A. gossypii relies on the availability of well-performing gene expression systems both for endogenous and heterologous genes. In this regard, the identification of novel promoters, which are critical elements for gene expression, decisively helps to expand the A. gossypii molecular toolbox. In this work, we present an adaptation of the Dual Luciferase Reporter (DLR) Assay for promoter analysis in A. gossypii using integrative cassettes. We demonstrate the efficiency of the analysis through the identification of 10 new promoters with different features, including carbon source-regulatable abilities, that will highly improve the gene expression platforms used in A. gossypii. Three novel strong promoters (PCCW12, PSED1, and PTSA1) and seven medium/weak promoters (PHSP26, PAGL366C, PTMA10, PCWP1, PAFR038W, PPFS1, and PCDA2) are presented. The functionality of the promoters was further evaluated both for the overexpression and for the underexpression of the A. gossypii MSN2 gene, which induced significant changes in the sporulation ability of the mutant strains.
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Nieland S, Barig S, Salzmann J, Gehrau F, Zamani AI, Richter A, Ibrahim J, Gräser Y, Ng CL, Stahmann K. Aspergillus fumigatus AR04 obeys Arrhenius' rule in cultivation temperature shifts from 30 to 40°C. Microb Biotechnol 2021; 14:1422-1432. [PMID: 33421319 PMCID: PMC8313250 DOI: 10.1111/1751-7915.13739] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 12/11/2020] [Accepted: 12/11/2020] [Indexed: 01/01/2023] Open
Abstract
To set a benchmark in fungal growth rate, a differential analysis of prototrophic Aspergillus fumigatus AR04 with three ascomycetes applied in > 103 t year-1 scale was performed, i.e. Ashbya gosspyii (riboflavin), Aspergillus niger (citric acid) and Aspergillus oryzae (food-processing). While radial colony growth decreased 0.5-fold when A. gossypii was cultivated at 40°C instead of 28°C, A. fumigatus AR04 responded with 1.7-fold faster hyphal growth. A. niger and A. oryzae formed colonies at 40°C, but not at 43°C. Moreover, all A. fumigatus strains tested grew even at 49°C. In chemostat experiments, A. fumigatus AR04 reached steady state at a dilution rate of 0.7 h-1 at 40°C, 120% more than reported for A. gossypii at 28°C. To study mycelial growth rates under unlimited conditions, carbon dioxide increase rates were calculated from concentrations detected online in the exhaust of batch fermentations for 3 h only. All rates calculated suggest that A. fumigatus AR04 approximates Arrhenius' rule when comparing short cultivations at 30°C with those at 40°C. Linearization of the exponential phase and comparison of the slopes revealed an increase to 192% by the 10°C up-shift.
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Affiliation(s)
- Susanne Nieland
- Institute of BiotechnologyBrandenburg University of Technology Cottbus ‐ SenftenbergUniversitätsplatz 1SenftenbergD‐01958Germany
| | - Susann Barig
- Institute of BiotechnologyBrandenburg University of Technology Cottbus ‐ SenftenbergUniversitätsplatz 1SenftenbergD‐01958Germany
| | - Julian Salzmann
- Institute of BiotechnologyBrandenburg University of Technology Cottbus ‐ SenftenbergUniversitätsplatz 1SenftenbergD‐01958Germany
| | - Frauke Gehrau
- Institute of BiotechnologyBrandenburg University of Technology Cottbus ‐ SenftenbergUniversitätsplatz 1SenftenbergD‐01958Germany
| | - Arief Izzairy Zamani
- Institute of Systems BiologyUniversiti Kebangsaan MalaysiaBangiSelangor43600 UKMMalaysia
| | - Annabell Richter
- Institute of BiotechnologyBrandenburg University of Technology Cottbus ‐ SenftenbergUniversitätsplatz 1SenftenbergD‐01958Germany
| | - Julia Ibrahim
- Sime Darby Technology CentreUPM‐MTDC Technology Centre IIILebuh Silikon1st Floor Block BUPM 43400SerdangSelangorMalaysia
| | - Yvonne Gräser
- Institute of Microbiology and ImmunologyCharité ‐ Universitätsmedizin BerlinCorporate Member of Freie Universität BerlinHumboldt‐Universität zu BerlinBerlinGermany
- Berlin Institute of HealthHindenburgdamm 30BerlinD‐12203Germany
| | - Chyan Leong Ng
- Institute of Systems BiologyUniversiti Kebangsaan MalaysiaBangiSelangor43600 UKMMalaysia
| | - Klaus‐Peter Stahmann
- Institute of BiotechnologyBrandenburg University of Technology Cottbus ‐ SenftenbergUniversitätsplatz 1SenftenbergD‐01958Germany
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Lv X, Wu Y, Gong M, Deng J, Gu Y, Liu Y, Li J, Du G, Ledesma-Amaro R, Liu L, Chen J. Synthetic biology for future food: Research progress and future directions. FUTURE FOODS 2021. [DOI: 10.1016/j.fufo.2021.100025] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
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Mhlongo SI, Ezeokoli OT, Roopnarain A, Ndaba B, Sekoai PT, Habimana O, Pohl CH. The Potential of Single-Cell Oils Derived From Filamentous Fungi as Alternative Feedstock Sources for Biodiesel Production. Front Microbiol 2021; 12:637381. [PMID: 33584636 PMCID: PMC7876240 DOI: 10.3389/fmicb.2021.637381] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 01/07/2021] [Indexed: 11/13/2022] Open
Abstract
Microbial lipids, also known as single-cell oils (SCOs), are highly attractive feedstocks for biodiesel production due to their fast production rates, minimal labor requirements, independence from seasonal and climatic changes, and ease of scale-up for industrial processing. Among the SCO producers, the less explored filamentous fungi (molds) exhibit desirable features such as a repertoire of hydrolyzing enzymes and a unique pellet morphology that facilitates downstream harvesting. Although several oleaginous filamentous fungi have been identified and explored for SCO production, high production costs and technical difficulties still make the process less attractive compared to conventional lipid sources for biodiesel production. This review aims to highlight the ability of filamentous fungi to hydrolyze various organic wastes for SCO production and explore current strategies to enhance the efficiency and cost-effectiveness of the SCO production and recovery process. The review also highlights the mechanisms and components governing lipogenic pathways, which can inform the rational designs of processing conditions and metabolic engineering efforts for increasing the quality and accumulation of lipids in filamentous fungi. Furthermore, we describe other process integration strategies such as the co-production with hydrogen using advanced fermentation processes as a step toward a biorefinery process. These innovative approaches allow for integrating upstream and downstream processing units, thus resulting in an efficient and cost-effective method of simultaneous SCO production and utilization for biodiesel production.
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Affiliation(s)
- Sizwe I. Mhlongo
- Discipline of Medical Microbiology, School of Laboratory Medicine and Medical Sciences, Medical School, University of KwaZulu-Natal, Durban, South Africa
| | - Obinna T. Ezeokoli
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
| | - Ashira Roopnarain
- Microbiology and Environmental Biotechnology Research Group, Institute for Soil, Climate and Water, Agricultural Research Council, Pretoria, South Africa
| | - Busiswa Ndaba
- Microbiology and Environmental Biotechnology Research Group, Institute for Soil, Climate and Water, Agricultural Research Council, Pretoria, South Africa
| | - Patrick T. Sekoai
- The School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Olivier Habimana
- The School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Carolina H. Pohl
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
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8
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Sporulation in Ashbya gossypii. J Fungi (Basel) 2020; 6:jof6030157. [PMID: 32872517 PMCID: PMC7558398 DOI: 10.3390/jof6030157] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 08/26/2020] [Accepted: 08/28/2020] [Indexed: 12/28/2022] Open
Abstract
Ashbya gossypii is a filamentous ascomycete belonging to the yeast family of Saccharomycetaceae. At the end of its growth phase Ashbya generates abundant amounts of riboflavin and spores that form within sporangia derived from fragmented cellular compartments of hyphae. The length of spores differs within species of the genus. Needle-shaped Ashbya spores aggregate via terminal filaments. A. gossypii is a homothallic fungus which may possess a and α mating types. However, the solo-MATa type strain is self-fertile and sporulates abundantly apparently without the need of prior mating. The central components required for the regulation of sporulation, encoded by IME1, IME2, IME4, KAR4, are conserved with Saccharomyces cerevisiae. Nutrient depletion generates a strong positive signal for sporulation via the cAMP-PKA pathway and SOK2, which is also essential for sporulation. Strong inhibitors of sporulation besides mutations in the central regulatory genes are the addition of exogenous cAMP or the overexpression of the mating type gene MATα2. Sporulation has been dissected using gene-function analyses and global RNA-seq transcriptomics. This revealed a role of Msn2/4, another potential PKA-target, for spore wall formation and a key dual role of the protein A kinase Tpk2 at the onset of sporulation as well as for breaking the dormancy of spores to initiate germination. Recent work has provided an overview of ascus development, regulation of sporulation and spore maturation. This will be summarized in the current review with a focus on the central regulatory genes. Current research and open questions will also be discussed.
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Jiménez A, Hoff B, Revuelta JL. Multiplex genome editing in Ashbya gossypii using CRISPR-Cpf1. N Biotechnol 2020; 57:29-33. [DOI: 10.1016/j.nbt.2020.02.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 02/04/2020] [Accepted: 02/11/2020] [Indexed: 12/11/2022]
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Díaz-Fernández D, Aguiar TQ, Martín VI, Romaní A, Silva R, Domingues L, Revuelta JL, Jiménez A. Microbial lipids from industrial wastes using xylose-utilizing Ashbya gossypii strains. BIORESOURCE TECHNOLOGY 2019; 293:122054. [PMID: 31487616 DOI: 10.1016/j.biortech.2019.122054] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 08/21/2019] [Accepted: 08/22/2019] [Indexed: 05/08/2023]
Abstract
This work presents the exploitation of waste industrial by-products as raw materials for the production of microbial lipids in engineered strains of the filamentous fungus Ashbya gossypii. A lipogenic xylose-utilizing strain was used to apply a metabolic engineering approach aiming at relieving regulatory mechanisms to further increase the biosynthesis of lipids. Three genomic manipulations were applied: the overexpression of a feedback resistant form of the acetyl-CoA carboxylase enzyme; the expression of a truncated form of Mga2, a regulator of the main Δ9 desaturase gene; and the overexpression of an additional copy of DGA1 that codes for diacylglycerol acyltransferase. The performance of the engineered strain was evaluated in culture media containing mixed formulations of corn-cob hydrolysates, sugarcane molasses or crude glycerol. Our results demonstrate the efficiency of the engineered strains, which were able to accumulate about 40% of cell dry weight (CDW) in lipid content using organic industrial wastes as feedstocks.
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Affiliation(s)
- David Díaz-Fernández
- Metabolic Engineering Group, Department of Microbiology and Genetics, University of Salamanca, Campus Miguel de Unamuno, E-37007 Salamanca, Spain
| | - Tatiana Q Aguiar
- CEB - Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
| | - Victoria Isabel Martín
- Metabolic Engineering Group, Department of Microbiology and Genetics, University of Salamanca, Campus Miguel de Unamuno, E-37007 Salamanca, Spain
| | - Aloia Romaní
- CEB - Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
| | - Rui Silva
- CEB - Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
| | - Lucília Domingues
- CEB - Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
| | - José Luis Revuelta
- Metabolic Engineering Group, Department of Microbiology and Genetics, University of Salamanca, Campus Miguel de Unamuno, E-37007 Salamanca, Spain.
| | - 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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Jiménez A, Muñoz‐Fernández G, Ledesma‐Amaro R, Buey RM, Revuelta JL. One-vector CRISPR/Cas9 genome engineering of the industrial fungus Ashbya gossypii. Microb Biotechnol 2019; 12:1293-1301. [PMID: 31055883 PMCID: PMC6801137 DOI: 10.1111/1751-7915.13425] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 04/23/2019] [Accepted: 04/24/2019] [Indexed: 11/30/2022] Open
Abstract
The filamentous fungus Ashbya gossypii is currently used for the industrial production of vitamin B2. Furthermore, the ability of A. gossypii to grow using low-cost substrates together with the inexpensive downstream processing makes this fungus an attractive biotechnological chassis. Indeed, the production in A. gossypii of other high-added value compounds such as folic acid, nucleosides and biolipids has been described. Hence, the development of new methods to expand the molecular toolkit for A. gossypii genomic manipulation constitutes an important issue for the biotechnology of this fungus. In this work, we present a one-vector CRISPR/Cas9 system for genomic engineering of A. gossypii. We demonstrate the efficiency of the system as a marker-less approach for nucleotide deletions and substitutions both with visible and invisible phenotypes. Particularly, the system has been validated for three types of genomic editions: gene inactivation, the genomic erasure of loxP scars and the introduction of point mutations. We anticipate that the use of the CRISPR/Cas9 system for A. gossypii will largely contribute to facilitate the genomic manipulations of this industrial fungus in a marker-less manner.
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Affiliation(s)
- Alberto Jiménez
- Metabolic Engineering GroupDepartamento de Microbiología y GenéticaUniversidad de SalamancaCampus Miguel de UnamunoE‐37007SalamancaSpain
| | - Gloria Muñoz‐Fernández
- Metabolic Engineering GroupDepartamento de Microbiología y GenéticaUniversidad de SalamancaCampus Miguel de UnamunoE‐37007SalamancaSpain
| | - Rodrigo Ledesma‐Amaro
- Metabolic Engineering GroupDepartamento de Microbiología y GenéticaUniversidad de SalamancaCampus Miguel de UnamunoE‐37007SalamancaSpain
- Imperial College Centre for Synthetic Biology and Department of BioengineeringImperial College LondonLondonSW7 2AZUK
| | - Rubén M. Buey
- Metabolic Engineering GroupDepartamento de Microbiología y GenéticaUniversidad de SalamancaCampus Miguel de UnamunoE‐37007SalamancaSpain
| | - José L. Revuelta
- Metabolic Engineering GroupDepartamento de Microbiología y GenéticaUniversidad de SalamancaCampus Miguel de UnamunoE‐37007SalamancaSpain
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Song R, Zhai Q, Sun L, Huang E, Zhang Y, Zhu Y, Guo Q, Tian Y, Zhao B, Lu H. CRISPR/Cas9 genome editing technology in filamentous fungi: progress and perspective. Appl Microbiol Biotechnol 2019; 103:6919-6932. [PMID: 31332488 PMCID: PMC6690858 DOI: 10.1007/s00253-019-10007-w] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 06/28/2019] [Accepted: 07/01/2019] [Indexed: 12/16/2022]
Abstract
Filamentous fungi play an important role in human health and industrial/agricultural production. With the increasing number of full genomes available for fungal species, the study of filamentous fungi has brought about a wider range of genetic manipulation opportunities. However, the utilization of traditional methods to study fungi is time consuming and laborious. Recent rapid progress and wide application of a versatile genome editing technology, i.e., the CRISPR (clustered regularly interspaced short palindromic repeat)-Cas9 (CRISPR-related nuclease 9) system, has revolutionized biological research and has many innovative applications in a wide range of fields showing great promise in research and application of filamentous fungi. In this review, we introduce the CRISPR/Cas9 genome editing technology focusing on its application in research of filamentous fungi and we discuss the general considerations of genome editing using CRISPR/Cas9 system illustrating vector construction, multiple editing strategies, technical consideration of different sizes of homology arms on genome editing efficiency, off-target effects, and different transformation methodologies. In addition, we discuss the challenges encountered using CRISPR/Cas9 technology and give the perspectives of future applications of CRISPR/Cas9 technology for basic research and practical application of filamentous fungi.
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Affiliation(s)
- Runjie Song
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Qing Zhai
- Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa, 850000, Tibet, China
| | - Lu Sun
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Enxia Huang
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Yu Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Yanli Zhu
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Qingyun Guo
- Qinghai Academy of Agriculture and Forestry Sciences, Qinghai University/Key Laboratory of Agricultural Integrated Pest Management, Qinghai Province/State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, 810016, Qinghai, China.
| | - Yanan Tian
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine, Texas A&M University, College Station, TX, 77843, USA
| | - Baoyu Zhao
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Hao Lu
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China.
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Ledesma-Amaro R, Jiménez A, Revuelta JL. Pathway Grafting for Polyunsaturated Fatty Acids Production in Ashbya gossypii through Golden Gate Rapid Assembly. ACS Synth Biol 2018; 7:2340-2347. [PMID: 30261136 DOI: 10.1021/acssynbio.8b00287] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Here we present a Golden Gate assembly system adapted for the rapid genomic engineering of the industrial fungus Ashbya gossypii. This biocatalyst is an excellent biotechnological chassis for synthetic biology applications and is currently used for the industrial production of riboflavin. Other bioprocesses such as the production of folic acid, nucleosides, amino acids and biolipids have been recently reported in A. gossypii. In this work, an efficient assembly system for the expression of heterologous complex pathways has been designed. The expression platform comprises interchangeable DNA modules, which provides flexibility for the use of different loci for integration, selection markers and regulatory sequences. The functionality of the system has been applied to engineer strains able to synthesize polyunsaturated fatty acids (up to 35% of total fatty acids). The production of the industrially relevant arachidonic, eicosapentanoic and docosahexanoic acids remarks the potential of A. gossypii to produce these functional lipids.
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Affiliation(s)
- Rodrigo Ledesma-Amaro
- Imperial College Centre for Synthetic Biology and Department of Bioengineering, Imperial College London, London SW7 2AZ, U.K
- Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, E-37007 Salamanca, Spain
| | - Alberto Jiménez
- Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, E-37007 Salamanca, Spain
| | - José Luis Revuelta
- Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, E-37007 Salamanca, Spain
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14
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Xie D. Integrating Cellular and Bioprocess Engineering in the Non-Conventional Yeast Yarrowia lipolytica for Biodiesel Production: A Review. Front Bioeng Biotechnol 2017; 5:65. [PMID: 29090211 PMCID: PMC5650997 DOI: 10.3389/fbioe.2017.00065] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 10/02/2017] [Indexed: 12/14/2022] Open
Abstract
As one of the major biofuels to replace fossil fuel, biodiesel has now attracted more and more attention due to its advantages in higher energy density and overall less greenhouse gas generation. Biodiesel (fatty acid alkyl esters) is produced by chemically or enzymatically catalyzed transesterification of lipids from microbial cells, microalgae, oil crops, or animal fats. Currently, plant oils or waste cooking oils/fats remain the major source for biodiesel production via enzymatic route, but the production capacity is limited either by the uncertain supplement of plant oils or by the low or inconsistent quality of waste oils/fats. In the past decades, significant progresses have been made on synthesis of microalgae oils directly from CO2via a photosynthesis process, but the production cost from any current technologies is still too high to be commercialized due to microalgae’s slow growth rate on CO2, inefficiency in photo-bioreactors, lack of efficient contamination control methods, and high cost in downstream recovery. At the same time, many oleaginous microorganisms have been studied to produce lipids via the fatty acid synthesis pathway under aerobic fermentation conditions, among them one of the most studied is the non-conventional yeast, Yarrowia lipolytica, which is able to produce fatty acids at very high titer, rate, and yield from various economical substrates. This review summarizes the recent research progresses in both cellular and bioprocess engineering in Y. lipolytica to produce lipids at a low cost that may lead to commercial-scale biodiesel production. Specific technologies include the strain engineering for using various substrates, metabolic engineering in high-yield lipid synthesis, cell morphology study for efficient substrate uptake and product formation, free fatty acid formation and secretion for improved downstream recovery, and fermentation engineering for higher productivities and less operating cost. To further improve the economics of the microbial oil-based biodiesel, production of lipid-related or -derived high-value products are also discussed.
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Affiliation(s)
- Dongming Xie
- Massachusetts Biomanufacturing Center, Department of Chemical Engineering, University of Massachusetts Lowell, Lowell, MA, United States
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15
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Díaz-Fernández D, Lozano-Martínez P, Buey RM, Revuelta JL, Jiménez A. Utilization of xylose by engineered strains of Ashbya gossypii for the production of microbial oils. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:3. [PMID: 28053663 PMCID: PMC5209892 DOI: 10.1186/s13068-016-0685-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Accepted: 12/09/2016] [Indexed: 05/24/2023]
Abstract
BACKGROUND Ashbya gossypii is a filamentous fungus that is currently exploited for the industrial production of riboflavin. The utilization of A. gossypii as a microbial biocatalyst is further supported by its ability to grow in low-cost feedstocks, inexpensive downstream processing and the availability of an ease to use molecular toolbox for genetic and genomic modifications. Consequently, A. gossypii has been also introduced as an ideal biotechnological chassis for the production of inosine, folic acid, and microbial oils. However, A. gossypii cannot use xylose, the most common pentose in hydrolysates of plant biomass. RESULTS In this work, we aimed at designing A. gossypii strains able to utilize xylose as the carbon source for the production of biolipids. An endogenous xylose utilization pathway was identified and overexpressed, resulting in an A. gossypii xylose-metabolizing strain showing prominent conversion rates of xylose to xylitol (up to 97% after 48 h). In addition, metabolic flux channeling from xylulose-5-phosphate to acetyl-CoA, using aheterologous phosphoketolase pathway, increased the lipid content in the xylose-metabolizing strain a 54% over the parental strain growing in glucose-based media. This increase raised to 69% when lipid accumulation was further boosted by blocking the beta-oxidation pathway. CONCLUSIONS Ashbya gossypii has been engineered for the utilization of xylose. We present here a proof-of-concept study for the production of microbial oils from xylose in A. gossypii, thus introducing a novel biocatalyst with very promising properties in developing consolidated bioprocessing to produce fine chemicals and biofuels from xylose-rich hydrolysates of plant biomass.
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Affiliation(s)
- David Díaz-Fernández
- Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| | - Patricia Lozano-Martínez
- Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| | - Rubén M. Buey
- Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| | - José Luis Revuelta
- Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| | - Alberto Jiménez
- Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
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16
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Lozano-Martínez P, Buey RM, Ledesma-Amaro R, Jiménez A, Revuelta JL. Engineering Ashbya gossypii strains for de novo lipid production using industrial by-products. Microb Biotechnol 2016; 10:425-433. [PMID: 28008713 PMCID: PMC5328814 DOI: 10.1111/1751-7915.12487] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 11/14/2016] [Accepted: 11/16/2016] [Indexed: 11/27/2022] Open
Abstract
Ashbya gossypii is a filamentous fungus that naturally overproduces riboflavin, and it is currently exploited for the industrial production of this vitamin. The utilization of A. gossypii for biotechnological applications presents important advantages such as the utilization of low-cost culture media, inexpensive downstream processing and a wide range of molecular tools for genetic manipulation, thus making A. gossypii a valuable biotechnological chassis for metabolic engineering. A. gossypii has been shown to accumulate high levels of lipids in oil-based culture media; however, the lipid biosynthesis capacity is rather limited when grown in sugar-based culture media. In this study, by altering the fatty acyl-CoA pool and manipulating the regulation of the main ∆9 desaturase gene, we have obtained A. gossypii strains with significantly increased (up to fourfold) de novo lipid biosynthesis using glucose as the only carbon source in the fermentation broth. Moreover, these strains were efficient biocatalysts for the conversion of carbohydrates from sugarcane molasses to biolipids, able to accumulate lipids up to 25% of its cell dry weight. Our results represent a proof of principle showing the promising potential of A. gossypii as a competitive microorganism for industrial biolipid production using cost-effective feed stocks.
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Affiliation(s)
- Patricia Lozano-Martínez
- Metabolic Engineering Group, Departamento de Microbiología y Genética, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, 37007, Salamanca, Spain
| | - Rubén M Buey
- Metabolic Engineering Group, Departamento de Microbiología y Genética, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, 37007, Salamanca, Spain
| | - Rodrigo Ledesma-Amaro
- Metabolic Engineering Group, Departamento de Microbiología y Genética, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, 37007, Salamanca, Spain
| | - Alberto Jiménez
- Metabolic Engineering Group, Departamento de Microbiología y Genética, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, 37007, Salamanca, Spain
| | - José Luis Revuelta
- Metabolic Engineering Group, Departamento de Microbiología y Genética, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, 37007, Salamanca, Spain
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Aguiar TQ, Silva R, Domingues L. New biotechnological applications for Ashbya gossypii: Challenges and perspectives. Bioengineered 2016; 8:309-315. [PMID: 27791453 DOI: 10.1080/21655979.2016.1234543] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The filamentous fungus Ashbya gossypii has long been considered a paradigm of the White Biotechnology in what concerns riboflavin production. Its industrial relevance led to the development of a significant molecular and in silico modeling toolbox for its manipulation. This, together with the increasing knowledge of its genome and metabolism has helped designing effective metabolic engineering strategies for optimizing riboflavin production, but also for developing new A. gossypii strains for novel biotechnological applications, such as production of recombinant proteins, single cell oils (SCOs), and flavour compounds. With the recent availability of its genome-scale metabolic model, the exploration of the full biotechnological potential of A. gossypii is now in the spotlight. Here, we will discuss some of the challenges that these emerging A. gossypii applications still need to overcome to become economically attractive and will present future perspectives for these and other possible biotechnological applications for A. gossypii.
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Affiliation(s)
- Tatiana Q Aguiar
- a CEB - Centre of Biological Engineering , University of Minho , Braga , Portugal
| | - Rui Silva
- a CEB - Centre of Biological Engineering , University of Minho , Braga , Portugal
| | - Lucília Domingues
- a CEB - Centre of Biological Engineering , University of Minho , Braga , Portugal
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18
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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: 24] [Impact Index Per Article: 3.0] [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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Bioproduction of riboflavin: a bright yellow history. J Ind Microbiol Biotechnol 2016; 44:659-665. [PMID: 27696023 DOI: 10.1007/s10295-016-1842-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 09/23/2016] [Indexed: 10/20/2022]
Abstract
Riboflavin (vitamin B2) is an essential nutrient for humans and animals that must be obtained from the diet. To ensure an optimal supply, riboflavin is used on a large scale as additive in the food and feed industries. Here, we describe a historical overview of the industrial process of riboflavin production starting from its discovery and the need to produce the vitamin in bulk at prices that would allow for their use in human and animal nutrition. Riboflavin was produced industrially by chemical synthesis for many decades. At present, the development of economical and eco-efficient fermentation processes, which are mainly based on Bacillus subtilis and Ashbya gossypii strains, has replaced the synthetic process at industrial scale. A detailed account is given of the development of the riboflavin overproducer strains as well as future prospects for its improvement.
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20
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Ledesma-Amaro R, Nicaud JM. Yarrowia lipolytica as a biotechnological chassis to produce usual and unusual fatty acids. Prog Lipid Res 2016; 61:40-50. [DOI: 10.1016/j.plipres.2015.12.001] [Citation(s) in RCA: 165] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 12/02/2015] [Accepted: 12/08/2015] [Indexed: 10/22/2022]
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