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Passoth V, Brandenburg J, Chmielarz M, Martín-Hernández GC, Nagaraj Y, Müller B, Blomqvist J. Oleaginous yeasts for biochemicals, biofuels and food from lignocellulose-hydrolysate and crude glycerol. Yeast 2023; 40:290-302. [PMID: 36597618 DOI: 10.1002/yea.3838] [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: 11/01/2022] [Revised: 12/21/2022] [Accepted: 12/31/2022] [Indexed: 01/05/2023] Open
Abstract
Microbial lipids produced from lignocellulose and crude glycerol (CG) can serve as sustainable alternatives to vegetable oils, whose production is, in many cases, accompanied by monocultures, land use changes or rain forest clearings. Our projects aim to understand the physiology of microbial lipid production by oleaginous yeasts, optimise the production and establish novel applications of microbial lipid compounds. We have established methods for fermentation and intracellular lipid quantification. Following the kinetics of lipid accumulation in different strains, we found high variability in lipid formation even between very closely related oleaginous yeast strains on both, wheat straw hydrolysate and CG. For example, on complete wheat straw hydrolysate, we saw that one Rhodotorula glutinis strain, when starting assimilating D-xylosealso assimilated the accumulated lipids, while a Rhodotorula babjevae strain could accumulate lipids on D-xylose. Two strains (Rhodotorula toruloides CBS 14 and R. glutinis CBS 3044) were found to be the best out of 27 tested to accumulate lipids on CG. Interestingly, the presence of hemicellulose hydrolysate stimulated glycerol assimilation in both strains. Apart from microbial oil, R. toruloides also produces carotenoids. The first attempts of extraction using the classical acetone-based method showed that β-carotene is the major carotenoid. However, there are indications that there are also substantial amounts of torulene and torularhodin, which have a very high potential as antioxidants.
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Affiliation(s)
- Volkmar Passoth
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Jule Brandenburg
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
- Klinisk Mikrobiologi Falun, Falun Lasarett, Falun, Sweden
| | - Mikołaj Chmielarz
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | | | - Yashaswini Nagaraj
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Bettina Müller
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Johanna Blomqvist
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Salvador López JM, Vandeputte M, Van Bogaert INA. Oleaginous yeasts: Time to rethink the definition? Yeast 2022; 39:553-606. [PMID: 36366783 DOI: 10.1002/yea.3827] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 10/21/2022] [Accepted: 11/08/2022] [Indexed: 11/12/2022] Open
Abstract
Oleaginous yeasts are typically defined as those able to accumulate more than 20% of their cell dry weight as lipids or triacylglycerides. Research on these yeasts has increased lately fuelled by an interest to use biotechnology to produce lipids and oleochemicals that can substitute those coming from fossil fuels or offer sustainable alternatives to traditional extractions (e.g., palm oil). Some oleaginous yeasts are attracting attention both in research and industry, with Yarrowia lipolytica one of the best-known and studied ones. Oleaginous yeasts can be found across several clades and different metabolic adaptations have been found, affecting not only fatty acid and neutral lipid synthesis, but also lipid particle stability and degradation. Recently, many novel oleaginous yeasts are being discovered, including oleaginous strains of the traditionally considered non-oleaginous Saccharomyces cerevisiae. In the face of this boom, a closer analysis of the definition of "oleaginous yeast" reveals that this term has instrumental value for biotechnology, while it does not give information about distinct types of yeasts. Having this perspective in mind, we propose to expand the term "oleaginous yeast" to those able to produce either intracellular or extracellular lipids, not limited to triacylglycerides, in at least one growth condition (including ex novo lipid synthesis). Finally, a critical look at Y. lipolytica as a model for oleaginous yeasts shows that the term "oleaginous" should be reserved only for strains and not species and that in the case of Y. lipolytica, it is necessary to distinguish clearly between the lipophilic and oleaginous phenotype.
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Affiliation(s)
- José Manuel Salvador López
- BioPort Group, Centre for Synthetic Biology (CSB), Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Meriam Vandeputte
- BioPort Group, Centre for Synthetic Biology (CSB), Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Inge N A Van Bogaert
- BioPort Group, Centre for Synthetic Biology (CSB), Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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Mota MN, Múgica P, Sá-Correia I. Exploring Yeast Diversity to Produce Lipid-Based Biofuels from Agro-Forestry and Industrial Organic Residues. J Fungi (Basel) 2022; 8:jof8070687. [PMID: 35887443 PMCID: PMC9315891 DOI: 10.3390/jof8070687] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 06/24/2022] [Accepted: 06/27/2022] [Indexed: 12/04/2022] Open
Abstract
Exploration of yeast diversity for the sustainable production of biofuels, in particular biodiesel, is gaining momentum in recent years. However, sustainable, and economically viable bioprocesses require yeast strains exhibiting: (i) high tolerance to multiple bioprocess-related stresses, including the various chemical inhibitors present in hydrolysates from lignocellulosic biomass and residues; (ii) the ability to efficiently consume all the major carbon sources present; (iii) the capacity to produce lipids with adequate composition in high yields. More than 160 non-conventional (non-Saccharomyces) yeast species are described as oleaginous, but only a smaller group are relatively well characterised, including Lipomyces starkeyi, Yarrowia lipolytica, Rhodotorula toruloides, Rhodotorula glutinis, Cutaneotrichosporonoleaginosus and Cutaneotrichosporon cutaneum. This article provides an overview of lipid production by oleaginous yeasts focusing on yeast diversity, metabolism, and other microbiological issues related to the toxicity and tolerance to multiple challenging stresses limiting bioprocess performance. This is essential knowledge to better understand and guide the rational improvement of yeast performance either by genetic manipulation or by exploring yeast physiology and optimal process conditions. Examples gathered from the literature showing the potential of different oleaginous yeasts/process conditions to produce oils for biodiesel from agro-forestry and industrial organic residues are provided.
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Affiliation(s)
- Marta N. Mota
- iBB—Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisbon, Portugal
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisbon, Portugal
- i4HB—Institute for Health and Bioeconomy, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisbon, Portugal
| | - Paula Múgica
- BIOREF—Collaborative Laboratory for Biorefineries, Rua da Amieira, Apartado 1089, São Mamede de Infesta, 4465-901 Matosinhos, Portugal
| | - Isabel Sá-Correia
- iBB—Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisbon, Portugal
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisbon, Portugal
- i4HB—Institute for Health and Bioeconomy, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisbon, Portugal
- Correspondence:
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Zhou W, Wang Y, Zhang J, Zhao M, Tang M, Zhou W, Gong Z. A metabolic model of Lipomyces starkeyi for predicting lipogenesis potential from diverse low-cost substrates. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:148. [PMID: 34210354 PMCID: PMC8247262 DOI: 10.1186/s13068-021-01997-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 06/17/2021] [Indexed: 05/08/2023]
Abstract
BACKGROUND Lipomyces starkeyi has been widely regarded as a promising oleaginous yeast with broad industrial application prospects because of its wide substrate spectrum, good adaption to fermentation inhibitors, excellent fatty acid composition for high-quality biodiesel, and negligible lipid remobilization. However, the currently low experimental lipid yield of L. starkeyi prohibits its commercial success. Metabolic model is extremely valuable to comprehend the complex biochemical processes and provide great guidance for strain modification to facilitate the lipid biosynthesis. RESULTS A small-scale metabolic model of L. starkeyi NRRL Y-11557 was constructed based on the genome annotation information. The theoretical lipid yields of glucose, cellobiose, xylose, glycerol, and acetic acid were calculated according to the flux balance analysis (FBA). The optimal flux distribution of the lipid synthesis showed that pentose phosphate pathway (PPP) independently met the necessity of NADPH for lipid synthesis, resulting in the relatively low lipid yields. Several targets (NADP-dependent oxidoreductases) beneficial for oleaginicity of L. starkeyi with significantly higher theoretical lipid yields were compared and elucidated. The combined utilization of acetic acid and other carbon sources and a hypothetical reverse β-oxidation (RBO) pathway showed outstanding potential for improving the theoretical lipid yield. CONCLUSIONS The lipid biosynthesis potential of L. starkeyi can be significantly improved through appropriate modification of metabolic network, as well as combined utilization of carbon sources according to the metabolic model. The prediction and analysis provide valuable guidance to improve lipid production from various low-cost substrates.
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Affiliation(s)
- Wei Zhou
- School of Chemistry and Chemical Engineering, Wuhan University of Science and Technology, 947 Heping Road, Wuhan, 430081 People’s Republic of China
| | - Yanan Wang
- State Key Laboratory Breeding Base of Dao-Di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700 People’s Republic of China
| | - Junlu Zhang
- School of Chemistry and Chemical Engineering, Wuhan University of Science and Technology, 947 Heping Road, Wuhan, 430081 People’s Republic of China
| | - Man Zhao
- School of Chemistry and Chemical Engineering, Wuhan University of Science and Technology, 947 Heping Road, Wuhan, 430081 People’s Republic of China
| | - Mou Tang
- School of Chemistry and Chemical Engineering, Wuhan University of Science and Technology, 947 Heping Road, Wuhan, 430081 People’s Republic of China
| | - Wenting Zhou
- School of Chemistry and Chemical Engineering, Wuhan University of Science and Technology, 947 Heping Road, Wuhan, 430081 People’s Republic of China
- HuBei Province Key Laboratory of Coal Conversion and New Carbon Materials, Wuhan University of Science and Technology, Wuhan, 430081 People’s Republic of China
| | - Zhiwei Gong
- School of Chemistry and Chemical Engineering, Wuhan University of Science and Technology, 947 Heping Road, Wuhan, 430081 People’s Republic of China
- HuBei Province Key Laboratory of Coal Conversion and New Carbon Materials, Wuhan University of Science and Technology, Wuhan, 430081 People’s Republic of China
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Chattopadhyay A, Maiti MK. Lipid production by oleaginous yeasts. ADVANCES IN APPLIED MICROBIOLOGY 2021; 116:1-98. [PMID: 34353502 DOI: 10.1016/bs.aambs.2021.03.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Microbial lipid production has been studied extensively for years; however, lipid metabolic engineering in many of the extraordinarily high lipid-accumulating yeasts was impeded by inadequate understanding of the metabolic pathways including regulatory mechanisms defining their oleaginicity and the limited genetic tools available. The aim of this review is to highlight the prominent oleaginous yeast genera, emphasizing their oleaginous characteristics, in conjunction with diverse other features such as cheap carbon source utilization, withstanding the effect of inhibitory compounds, commercially favorable fatty acid composition-all supporting their future development as economically viable lipid feedstock. The unique aspects of metabolism attributing to their oleaginicity are accentuated in the pretext of outlining the various strategies successfully implemented to improve the production of lipid and lipid-derived metabolites. A large number of in silico data generated on the lipid accumulation in certain oleaginous yeasts have been carefully curated, as suggestive evidences in line with the exceptional oleaginicity of these organisms. The different genetic elements developed in these yeasts to execute such strategies have been scrupulously inspected, underlining the major types of newly-found and synthetically constructed promoters, transcription terminators, and selection markers. Additionally, there is a plethora of advanced genetic toolboxes and techniques described, which have been successfully used in oleaginous yeasts in the recent years, promoting homologous recombination, genome editing, DNA assembly, and transformation at remarkable efficiencies. They can accelerate and effectively guide the rational designing of system-wide metabolic engineering approaches pinpointing the key targets for developing industrially suitable yeast strains.
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Affiliation(s)
- Atrayee Chattopadhyay
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, India
| | - Mrinal K Maiti
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, India.
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Chattopadhyay A, Mitra M, Maiti MK. Recent advances in lipid metabolic engineering of oleaginous yeasts. Biotechnol Adv 2021; 53:107722. [PMID: 33631187 DOI: 10.1016/j.biotechadv.2021.107722] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 02/15/2021] [Accepted: 02/15/2021] [Indexed: 01/12/2023]
Abstract
With the increasing demand to develop a renewable and sustainable biolipid feedstock, several species of non-conventional oleaginous yeasts are being explored. Apart from the platform oleaginous yeast Yarrowia lipolytica, the understanding of metabolic pathway and, therefore, exploiting the engineering prospects of most of the oleaginous species are still in infancy. However, in the past few years, enormous efforts have been invested in Rhodotorula, Rhodosporidium, Lipomyces, Trichosporon, and Candida genera of yeasts among others, with the rapid advancement of engineering strategies, significant improvement in genetic tools and techniques, generation of extensive bioinformatics and omics data. In this review, we have collated these recent progresses to make a detailed and insightful summary of the major developments in metabolic engineering of the prominent oleaginous yeast species. Such a comprehensive overview would be a useful resource for future strain improvement and metabolic engineering studies for enhanced production of lipid and lipid-derived chemicals in oleaginous yeasts.
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Affiliation(s)
- Atrayee Chattopadhyay
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Mohor Mitra
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Mrinal K Maiti
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
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Takaku H, Ebina S, Kasuga K, Sato R, Ara S, Kazama H, Matsuzawa T, Yaoi K, Araki H, Shida Y, Ogasawara W, Ishiya K, Aburatani S, Yamazaki H. Isolation and characterization of Lipomyces starkeyi mutants with greatly increased lipid productivity following UV irradiation. J Biosci Bioeng 2021; 131:613-621. [PMID: 33582014 DOI: 10.1016/j.jbiosc.2021.01.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/12/2021] [Accepted: 01/18/2021] [Indexed: 12/24/2022]
Abstract
The oleaginous yeast Lipomyces starkeyi is an intriguing lipid producer that can produce triacylglycerol (TAG), a feedstock for biodiesel production. We previously reported that the L. starkeyi mutant E15 with high levels of TAG production compared with the wild-type was efficiently obtained using Percoll density gradient centrifugation. However, considering its use for biodiesel production, it is necessary to further improve the lipid productivity of the mutant. In this study, we aimed to obtain mutants with better lipid productivity than E15, evaluate its lipid productivity, and analyze lipid synthesis-related gene expression in the wild-type and mutant strains. The mutants E15-11, E15-15, and E15-25 exhibiting higher lipid productivity than E15 were efficiently isolated from cells exposed to ultraviolet light using Percoll density gradient centrifugation. They exhibited approximately 4.5-fold higher lipid productivity than the wild-type on day 3. The obtained mutants did not exhibit significantly different fatty acid profiles than the wild-type and E15 mutant strains. E15-11, E15-15, and E15-25 exhibited higher expression of acyl-CoA synthesis- and Kennedy pathway-related genes than the wild-type and E15 mutant strains. Activation of the pentose phosphate pathway, which supplies NADPH, was also observed. These results suggested that the increased expression of acyl-CoA synthesis- and Kennedy pathway-related genes plays a vital role in lipid productivity in the oleaginous yeast L. starkeyi.
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Affiliation(s)
- Hiroaki Takaku
- Department of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, 265-1 Higashijima, Akiha-ku, Niigata 956-8603, Japan.
| | - Sayaka Ebina
- Department of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, 265-1 Higashijima, Akiha-ku, Niigata 956-8603, Japan
| | - Kotoha Kasuga
- Department of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, 265-1 Higashijima, Akiha-ku, Niigata 956-8603, Japan
| | - Rikako Sato
- Department of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, 265-1 Higashijima, Akiha-ku, Niigata 956-8603, Japan
| | - Satoshi Ara
- Department of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, 265-1 Higashijima, Akiha-ku, Niigata 956-8603, Japan
| | - Haruka Kazama
- Department of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, 265-1 Higashijima, Akiha-ku, Niigata 956-8603, Japan
| | - Tomohiko Matsuzawa
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
| | - Katsuro Yaoi
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
| | - Hideo Araki
- Research Institute for Creating the Future, Fuji Oil Holdings Inc., 4-3 Kinunodai, Tsukubamirai-shi, Ibaraki 300-2497, Japan
| | - Yosuke Shida
- Department of Bioengineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan
| | - Wataru Ogasawara
- Department of Bioengineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan
| | - Koji Ishiya
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
| | - Sachiyo Aburatani
- Computational Bio Big-Data Open Innovation Laboratory (CBBD-OIL), National Institute of Advanced Industrial Science and Technology (AIST), AIST Tokyo Waterfront Main Bldg. 2-3-26 Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Harutake Yamazaki
- Department of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, 265-1 Higashijima, Akiha-ku, Niigata 956-8603, Japan
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8
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Lipid metabolism of the oleaginous yeast Lipomyces starkeyi. Appl Microbiol Biotechnol 2020; 104:6141-6148. [DOI: 10.1007/s00253-020-10695-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/13/2020] [Accepted: 05/18/2020] [Indexed: 02/07/2023]
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Hernández MA, Alvarez HM. Increasing lipid production using an NADP +-dependent malic enzyme from Rhodococcus jostii. MICROBIOLOGY-SGM 2018; 165:4-14. [PMID: 30372408 DOI: 10.1099/mic.0.000736] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The occurrence of NADP+-dependent malic enzymes (NADP+-MEs) in several Rhodococcus strains was analysed. The NADP+-ME number in Rhodococcus genomes seemed to be a strain-dependent property. Total NADP+-ME activity increased by 1.8- and 2.6-fold in the oleaginous Rhodococcus jostii RHA1 and Rhodococcus opacus PD630 strains during cultivation under nitrogen-limiting conditions. Total NADP+-ME activity inhibition by sesamol resulted in a significant decrease of the cellular biomass and lipid production in oleaginous rhodococci. A non-redundant ME coded by the RHA1_RS44255 gene located in a megaplasmid (pRHL3) of R. jostii RHA1 was characterized and its heterologous expression in Escherichia coli resulted in a twofold increase in ME activity in an NADP+-dependent manner. The overexpression of RHA1_RS44255 in RHA1 and PD630 strains grown on glucose promoted an increase in total NADP+-ME activity and an up to 1.9-foldincrease in total fatty acid production without sacrificing cellular biomass. On the other hand, its expression in Rhodococcus fascians F7 grown on glycerol resulted in a 1.3-1.4-foldincrease in total fatty acid content. The results of this study confirmed the contribution of NADP+-MEs to TAG accumulation in oleaginous rhodococci and the utility of these enzymes as an alternative approach to increase bacterial oil production from different carbon sources.
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Affiliation(s)
- Martín A Hernández
- Facultad de Ciencias Naturales, Instituto de Biociencias de la Patagonia, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de la Patagonia San Juan Bosco, Ruta Provincial no. 1, Km 4-Ciudad Universitaria, 9000 Comodoro Rivadavia, Chubut, Argentina
| | - Héctor M Alvarez
- Facultad de Ciencias Naturales, Instituto de Biociencias de la Patagonia, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de la Patagonia San Juan Bosco, Ruta Provincial no. 1, Km 4-Ciudad Universitaria, 9000 Comodoro Rivadavia, Chubut, Argentina
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Middepogu A, Hou J, Gao X, Lin D. Effect and mechanism of TiO 2 nanoparticles on the photosynthesis of Chlorella pyrenoidosa. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 161:497-506. [PMID: 29913418 DOI: 10.1016/j.ecoenv.2018.06.027] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 06/07/2018] [Accepted: 06/09/2018] [Indexed: 05/15/2023]
Abstract
Titanium dioxide nanoparticles (n-TiO2) have been used in numerous applications, which results in their release into aquatic ecosystems and impact algal populations. A possible toxic mechanism of n-TiO2 on algae is via the disruption of the photosynthetic biochemical pathways, which yet remains to be demonstrated. In this study, Chlorella pyrenoidosa was exposed to different concentrations (0, 0.1, 1, 5, 10, and 20 mg/L) of a type of anatase n-TiO2, and the physiological, biochemical, and molecular responses involved in photosynthesis were investigated. The 96 h half growth inhibition concentration (IC50) of the n-TiO2 to algae was determined to be 9.1 mg/L. A variety of cellular and sub-cellular damages were observed, especially the blurry lamellar structure of thylakoids, indicating the n-TiO2 impaired the photosynthetic function of chloroplasts. Malondialdehyde (MDA) and glutathione disulfide (GSSG) significantly increased while the glutathione (GSH) content decreased. This implies the increased consumption of GSH by the increased intracellular oxidative stress upon n-TiO2 was insufficient to eliminate the lipid peroxidation. The contents of photosynthetic pigments, including chlorophyll a (Chl a) and phycobiliproteins (PBPs) in the exposed algal cells increased along with the up-regulation of genes encoding Chl a and photosystem II (PS II), which could be explained by a compensatory effect to overcome the toxicity induced by the n-TiO2. On the other hand, the photosynthetic activity was significantly inhibited, indicating the impairment on the photosynthesis via damaging the reaction center of PS II. In addition, lower productions of adenosine triphosphate (ATP) and glucose, together with the change of gene expressions suggested that the n-TiO2 disrupted the material and energy metabolisms in the photosynthesis. These findings support a paradigm shift of the toxic mechanism of n-TiO2 from physical and oxidative damages to metabolic disturbances, and emphasize the threat to the photosynthesis of algae in contaminated areas.
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Affiliation(s)
- Ayyaraju Middepogu
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Jie Hou
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Xuan Gao
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Daohui Lin
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Zhejiang University, Hangzhou 310058, China.
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11
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Zhu BH, Zhang RH, Lv NN, Yang GP, Wang YS, Pan KH. The Role of Malic Enzyme on Promoting Total Lipid and Fatty Acid Production in Phaeodactylum tricornutum. FRONTIERS IN PLANT SCIENCE 2018; 9:826. [PMID: 29971080 PMCID: PMC6018094 DOI: 10.3389/fpls.2018.00826] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 05/28/2018] [Indexed: 06/08/2023]
Abstract
To verify the function of malic enzyme (ME1), the ME1 gene was endogenously overexpressed in Phaeodactylum tricornutum. Overexpression of ME1 increased neutral and total lipid content and significantly increased saturated fatty acids (SFAs) and polyunsaturated fatty acids (PUFAs) in transformants, which varied between 23.19 and 25.32% in SFAs and between 49.02 and 54.04% in PUFAs, respectively. Additionally, increased ME1 activity was accompanied by elevated NADPH content in all three transformants, indicating that increased ME1 activity produced additional NADPH comparing with that of WT. These results indicated that ME1 activity is NADP-dependent and plays an important role in the NADPH levels required for lipid synthesis and fatty acid desaturation in P. tricornutum. Furthermore, our findings suggested that overexpression of endogenous ME1 represents a valid method for boosting neutral-lipid yield in diatom.
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Affiliation(s)
- Bao-Hua Zhu
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China
| | - Rui-Hao Zhang
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China
| | - Na-Na Lv
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China
| | - Guan-Pin Yang
- College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Yi-Sheng Wang
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China
| | - Ke-Hou Pan
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China
- Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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Li S, Li L, Xiong X, Ji X, Wei Y, Lin L, Zhang Q. A novel malic enzyme gene, Mime2, from Mortierella isabellina M6-22 contributes to lipid accumulation. Biotechnol Lett 2018; 40:1109-1118. [PMID: 29777513 DOI: 10.1007/s10529-018-2560-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 04/27/2018] [Indexed: 11/28/2022]
Abstract
OBJECTIVE This study was aimed at cloning and characterizing a novel malic enzyme (ME) gene of Mortierella isabellina M6-22 and identifying its relation with lipid accumulation. METHODS Mime2 was cloned from strain M6-22. Plasmid pET32aMIME2 was constructed to express ME of MIME2 in Escherichia coli BL21. After purification, the optimal pH and temperature of MIME2, as well as Km and Vmax for NADP+ were determined. The effects of EDTA or metal ions (Mn2+, Mg2+, Co2+, Cu2+, Ca2+, or Zn2+) on the enzymatic activity of MIME2 were evaluated. Besides, plasmid pRHMIME2 was created to express MIME2 in Rhodosporidium kratochvilovae YM25235, and its cell lipid content was measured by the acid-heating method. The optimal pH and temperature of MIME2 are 5.8 and 30 °C, respectively. RESULTS The act ivity of MIME2 was significantly increased by Mg2+, Ca2+, or Mn2+ at 0.5 mM but inhibited by Cu2+ or Zn2+ (p < 0.05). The optimal enzymatic activity of MIME2 is 177.46 U/mg, and the Km and Vmax for NADP+ are 0.703 mM and 156.25 μg/min, respectively. Besides, Mime2 transformation significantly increased the cell lipid content in strain YM25235 (3.15 ± 0.24 vs. 2.17 ± 0.31 g/L, p < 0.01). CONCLUSIONS The novel ME gene Mime2 isolated from strain M6-22 contributes to lipid accumulation in strain YM25235.
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Affiliation(s)
- Shan Li
- Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 South Jingming Road, Kunming, 650500, Yunnan, China
| | - Lingyan Li
- Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 South Jingming Road, Kunming, 650500, Yunnan, China
| | - Xiangfeng Xiong
- Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 South Jingming Road, Kunming, 650500, Yunnan, China
| | - Xiuling Ji
- Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 South Jingming Road, Kunming, 650500, Yunnan, China
| | - Yunlin Wei
- Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 South Jingming Road, Kunming, 650500, Yunnan, China
| | - Lianbing Lin
- Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 South Jingming Road, Kunming, 650500, Yunnan, China
| | - Qi Zhang
- Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 South Jingming Road, Kunming, 650500, Yunnan, China.
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13
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Critical steps in carbon metabolism affecting lipid accumulation and their regulation in oleaginous microorganisms. Appl Microbiol Biotechnol 2018; 102:2509-2523. [DOI: 10.1007/s00253-018-8813-z] [Citation(s) in RCA: 108] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 01/23/2018] [Accepted: 01/24/2018] [Indexed: 12/11/2022]
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14
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The boosted lipid accumulation in microalga Chlorella vulgaris by a heterotrophy and nutrition-limitation transition cultivation regime. World J Microbiol Biotechnol 2016; 32:202. [DOI: 10.1007/s11274-016-2164-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 10/23/2016] [Indexed: 10/20/2022]
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15
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High lipid accumulation in Yarrowia lipolytica cultivated under double limitation of nitrogen and magnesium. J Biotechnol 2016; 234:116-126. [PMID: 27498313 DOI: 10.1016/j.jbiotec.2016.08.001] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 06/26/2016] [Accepted: 08/02/2016] [Indexed: 12/16/2022]
Abstract
Yarrowia lipolytica cultivated under double nitrogen and magnesium limitation, but not under single nitrogen or single magnesium limitation, produced 12.2g/l biomass containing 47.5% lipids, which corresponds to a lipid production 5.8g/l. These yields are the higher described in the literature for wild strains of Y. lipolytica. Transcription of ACL1 and ACL2, encoding for ATP-citrate lyase (ATP:CL) was observed even under non-oleaginous conditions but high activity of ATP:CL was only detected under oleaginous conditions induced by low or zero activity of NAD(+) dependent isocitrate dehydrogenase. The low activity of malic enzyme (ME), a NADPH donor in typical oleaginous microorganisms, indicated that ME may not be implicated in lipid biosynthesis in this yeast, and NADPH may be provided by the pentose phosphate pathway (PPP). These findings underline the essential role of magnesium in lipogenesis, which is currently quite unexplored. The presence of organic nitrogen in low concentrations during lipogenesis was also required, and this peculiarity was probably related with the PPP functioning, being the NADPH donor of lipogenic machinery in Y. lipolytica.
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16
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Liang YJ, Jiang JG. Characterization of malic enzyme and the regulation of its activity and metabolic engineering on lipid production. RSC Adv 2015. [DOI: 10.1039/c5ra04635a] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Nowadays, microbial lipids are employed as the feedstock for biodiesel production, which has attracted great attention across the whole world.
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Affiliation(s)
- Ying-Jie Liang
- School of Biological Science & Engineering
- South China University of Technology
- Guangzhou
- China
| | - Jian-Guo Jiang
- School of Biological Science & Engineering
- South China University of Technology
- Guangzhou
- China
- College of Food Science and Engineering
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17
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Fan J, Cui Y, Zhou Y, Wan M, Wang W, Xie J, Li Y. The effect of nutrition pattern alteration on Chlorella pyrenoidosa growth, lipid biosynthesis-related gene transcription. BIORESOURCE TECHNOLOGY 2014; 164:214-220. [PMID: 24859213 DOI: 10.1016/j.biortech.2014.04.087] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 04/25/2014] [Accepted: 04/27/2014] [Indexed: 06/03/2023]
Abstract
Heterotrophy to photoautotrophy transition leads to the accumulation of lipids in Chlorella, which has potential to produce both healthy food and biofuels. Therefore, it is of key interest to study the metabolism shift and gene expression changes that influenced by the transition. Both total and neutral lipids contents were increased rapidly within 48 h after the switch to light environment, from 24.5% and 18.0% to 35.3% and 27.4%, respectively, along with the sharp decline of starch from 42.3% to 10.4% during 24h photoinduction phase. By analyzing the correlation between lipid content and gene expression, results revealed several genes viz. me g3137, me g6562, pepc g6833, dgat g3280 and dgat g7566, which encode corresponding enzymes in the de novo lipid biosynthesis pathway, are highly related to lipid accumulation and might be exploited as target genes for genetic modification. These results represented the feasibility of lipid production through trophic converting cultivation.
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Affiliation(s)
- Jianhua Fan
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
| | - Yanbin Cui
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
| | - Yang Zhou
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
| | - Minxi Wan
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
| | - Weiliang Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
| | - Jingli Xie
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
| | - Yuanguang Li
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
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18
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Ratledge C. The role of malic enzyme as the provider of NADPH in oleaginous microorganisms: a reappraisal and unsolved problems. Biotechnol Lett 2014; 36:1557-68. [PMID: 24752812 DOI: 10.1007/s10529-014-1532-3] [Citation(s) in RCA: 167] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 04/07/2014] [Indexed: 01/16/2023]
Abstract
Malic enzyme (ME; NADP(+)-dependent; EC 1.1.40) provides NADPH for lipid biosynthesis in oleaginous microorganisms. Its role in vivo depends on there being an adequate supply of NADH to drive malate dehydrogenase to convert oxaloacetate to malate as a component of a cycle of three reactions: pyruvate → oxaloacetate → malate and, by the action of ME, back to pyruvate. However, the availability of cytosolic NADH is limited and, consequently, ancillary means of producing NADPH are necessary. Stoichiometries are given for the conversion of glucose to triacylglycerols involving ME with and without the reactions of the pentose phosphate pathway (PPP) as an additional source of NADPH. Some oleaginous microorganisms (such as Yarrowia lipolytica), however, lack a cytosolic ME and, if the PPP is the sole provider of NADPH, the theoretical yield of triacylglycerol from glucose falls to 27.6 % (w/w) from 31.6 % when ME is present. An alternative route for NADPH generation via a cytosolic isocitrate dehydrogenase (NADP(+)-dependent) is then discussed.
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Affiliation(s)
- Colin Ratledge
- Department of Biological Sciences, University of Hull, Hull, HU6 7RX, UK,
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19
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Fan J, Cui Y, Wan M, Wang W, Li Y. Lipid accumulation and biosynthesis genes response of the oleaginous Chlorella pyrenoidosa under three nutrition stressors. BIOTECHNOLOGY FOR BIOFUELS 2014; 7:17. [PMID: 24479413 PMCID: PMC3916312 DOI: 10.1186/1754-6834-7-17] [Citation(s) in RCA: 166] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2013] [Accepted: 01/15/2014] [Indexed: 05/18/2023]
Abstract
BACKGROUND Microalgae can accumulate considerable amounts of lipids under different nutrient-deficient conditions, making them as one of the most promising sustainable sources for biofuel production. These inducible processes provide a powerful experimental basis for fully understanding the mechanisms of physiological acclimation, lipid hyperaccumulation and gene expression in algae. In this study, three nutrient-deficiency strategies, viz nitrogen-, phosphorus- and iron-deficiency were applied to trigger the lipid hyperaccumulation in an oleaginous Chlorella pyrenoidosa. Regular patterns of growth characteristics, lipid accumulation, physiological parameters, as well as the expression patterns of lipid biosynthesis-related genes were fully analyzed and compared. RESULTS Our results showed that all the nutrient stress conditions could enhance the lipid content considerably compared with the control. The total lipid and neutral lipid contents exhibit the most marked increment under nitrogen deficiency, achieving 50.32% and 34.29% of dry cell weight at the end of cultivation, respectively. Both photosynthesis indicators and reactive oxygen species parameters reveal that physiological stress turned up when exposed to nutrient depletions. Time-course transcript patterns of lipid biosynthesis-related genes showed that diverse expression dynamics probably contributes to the different lipidic phenotypes under stress conditions. By analyzing the correlation between lipid content and gene expression level, we pinpoint several genes viz. rbsL, me g6562, accA, accD, dgat g2354, dgat g3280 and dgat g7063, which encode corresponding enzymes or subunits of malic enzyme, ACCase and diacylglycerol acyltransferase in the de novo TAG biosynthesis pathway, are highly related to lipid accumulation and might be exploited as target genes for genetic modification. CONCLUSION This study provided us not only a comprehensive picture of adaptive mechanisms from physiological perspective, but also a number of targeted genes that can be used for a systematic metabolic engineering. Besides, our results also represented the feasibility of lipid production through trophic transition cultivation modes, throwing light on a two-stage microalgal lipid production strategy with which heterotrophy stage provides sufficient robust seed and nitrogen-starvation photoautotrophy stage enhances the overall lipid productivity.
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Affiliation(s)
- Jianhua Fan
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, 301 Mail box, Shanghai 200237, PR China
| | - Yanbin Cui
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, 301 Mail box, Shanghai 200237, PR China
| | - Minxi Wan
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, 301 Mail box, Shanghai 200237, PR China
| | - Weiliang Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, 301 Mail box, Shanghai 200237, PR China
| | - Yuanguang Li
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, 301 Mail box, Shanghai 200237, PR China
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20
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Vorapreeda T, Thammarongtham C, Cheevadhanarak S, Laoteng K. Repertoire of malic enzymes in yeast and fungi: insight into their evolutionary functional and structural significance. Microbiology (Reading) 2013; 159:2548-2557. [DOI: 10.1099/mic.0.065342-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Affiliation(s)
- Tayvich Vorapreeda
- Biochemical Engineering and Pilot Plant Research and Development Unit, National Center for Genetic Engineering and Biotechnology. King Mongkut’s University of Technology Thonburi, Bangkhuntien, Bangkok 10150, Thailand
| | - Chinae Thammarongtham
- Biochemical Engineering and Pilot Plant Research and Development Unit, National Center for Genetic Engineering and Biotechnology. King Mongkut’s University of Technology Thonburi, Bangkhuntien, Bangkok 10150, Thailand
| | - Supapon Cheevadhanarak
- Pilot Plant Development and Training Institute, King Mongkut’s University of Technology Thonburi, Bangkhuntien, Bangkok 10150, Thailand
- School of Bioresources and Technology, King Mongkut’s University of Technology Thonburi, Bangkhuntien, Bangkok 10150, Thailand
| | - Kobkul Laoteng
- Bioresources Technology Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Thailand Science Park, Pathum Thani 12120, Thailand
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21
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Zhang H, Zhang L, Chen H, Chen YQ, Ratledge C, Song Y, Chen W. Regulatory properties of malic enzyme in the oleaginous yeast, Yarrowia lipolytica, and its non-involvement in lipid accumulation. Biotechnol Lett 2013; 35:2091-8. [PMID: 23892983 DOI: 10.1007/s10529-013-1302-7] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 07/10/2013] [Indexed: 02/05/2023]
Abstract
Malic enzyme (EC 1.1.1.40) converts L-malate to pyruvate and CO2 providing NADPH for metabolism especially for lipid biosynthesis in oleaginous microorganisms. However, its role in the oleaginous yeast, Yarrowia lipolytica, is unclear. We have cloned the malic enzyme gene (YALI0E18634g) from Y. lipolytica into pET28a, expressed it in Escherichia coli and purified the recombinant protein (YlME). YlME used NAD(+) as the primary cofactor. Km values for NAD(+) and NADP(+) were 0.63 and 3.9 mM, respectively. Citrate, isocitrate and α-ketoglutaric acid (>5 mM) were inhibitory while succinate (5-15 mM) increased NADP(+)- but not NAD(+)-dependent activity. To determine if fatty acid biosynthesis could be increased in Y. lipolytica by providing additional NADPH from an NADP(+)-dependent malic enzyme, the malic enzyme gene (mce2) from an oleaginous fungus, Mortierella alpina, was expressed in Y. lipolytica. No significant changes occurred in lipid content or fatty acid profiles suggesting that malic enzyme is not the main source of NADPH for lipid accumulation in Y. lipolytica.
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Affiliation(s)
- Huaiyuan Zhang
- School of Food Science and Technology, Jiangnan University, Wuxi, 214122, Jiangsu, People's Republic of China,
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22
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Single cell oil production from low-cost substrates: The possibility and potential of its industrialization. Biotechnol Adv 2013; 31:129-39. [DOI: 10.1016/j.biotechadv.2012.08.010] [Citation(s) in RCA: 218] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 08/20/2012] [Accepted: 08/25/2012] [Indexed: 11/21/2022]
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23
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Beopoulos A, Nicaud JM, Gaillardin C. An overview of lipid metabolism in yeasts and its impact on biotechnological processes. Appl Microbiol Biotechnol 2011; 90:1193-206. [PMID: 21452033 DOI: 10.1007/s00253-011-3212-8] [Citation(s) in RCA: 227] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Accepted: 01/25/2011] [Indexed: 11/24/2022]
Abstract
High energy prices, depletion of crude oil supplies, and price imbalance created by the increasing demand of plant oils or animal fat for biodiesel and specific lipid derivatives such as lubricants, adhesives, and plastics have given rise to heated debates on land-use practices and to environmental concerns about oil production strategies. However, commercialization of microbial oils with similar composition and energy value to plant and animal oils could have many advantages, such as being non-competitive with food, having shorter process cycle and being independent of season and climate factors. This review focuses on the ongoing research on different oleaginous yeasts producing high added value lipids and on the prospects of such microbial oils to be used in different biotechnological processes and applications. It covers the basic biochemical mechanisms of lipid synthesis and accumulation in these organisms, along with the latest insights on the metabolic processes involved. The key elements of lipid accumulation, the mechanisms suspected to confer the oleaginous character of the cell, and the potential metabolic routes enhancing lipid production are also extensively discussed.
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Affiliation(s)
- Athanasios Beopoulos
- AgroParisTech, UMR1319, Micalis, Centre de Biotechnologie Agro-Industrielle, Thiverval-Grignon, France
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Kosa M, Ragauskas AJ. Lipids from heterotrophic microbes: advances in metabolism research. Trends Biotechnol 2010; 29:53-61. [PMID: 21146236 DOI: 10.1016/j.tibtech.2010.11.002] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Revised: 11/05/2010] [Accepted: 11/05/2010] [Indexed: 12/13/2022]
Abstract
Heterotrophic oleaginous microorganisms are capable of producing over 20% of their weight in single cell oils (SCOs) composed of triacylglycerols (TAGs). These TAGs contain fatty acids, such as palmitic, stearic and oleic acids, that are well-suited for biodiesel applications. Although some of these microbes are able to accumulate SCOs while growing on inexpensive agro-industrial biomass, the competition with plant oil resources means that a significant increase in productivity is desired. The present review aims to summarize recent details in lipid metabolism research and engineering (e.g. direct fatty acid ethyl ester production), as well as culture condition optimization and innovations, such as solid-state or semi-solid-state fermentation, that can all contribute to higher productivity and further advancement of the field.
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Affiliation(s)
- Matyas Kosa
- Department of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA
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Meng X, Yang J, Cao Y, Li L, Jiang X, Xu X, Liu W, Xian M, Zhang Y. Increasing fatty acid production in E. coli by simulating the lipid accumulation of oleaginous microorganisms. J Ind Microbiol Biotechnol 2010; 38:919-25. [PMID: 20972897 DOI: 10.1007/s10295-010-0861-z] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2010] [Accepted: 08/24/2010] [Indexed: 01/09/2023]
Abstract
Unlike many oleaginous microorganisms, E. coli only maintains a small amount of natural lipids in cells, impeding its utility to overproduce fatty acids. In this study, acetyl-CoA carboxylase (ACC) from Acinetobacter calcoaceticus was expressed in E. coli to redirect the carbon flux to the generation of malonyl-CoA, which resulted in a threefold increase in intracellular lipids. Moreover, providing a high level of NADPH by overexpressing malic enzyme and adding malate to the culture medium resulted in a fourfold increase in intracellular lipids (about 197.74 mg/g). Co-expression of ACC and malic enzyme resulted in 284.56 mg/g intracellular lipids, a 5.6-fold increase compared to the wild-type strain. This study provides some attractive strategies for increasing lipid production in E. coli by simulating the lipid accumulation of oleaginous microorganisms, which could aid the development of a prokaryotic fatty acid producer.
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Affiliation(s)
- Xin Meng
- Key Laboratory of Biofuel, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
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