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Hernández MA, Ledesma AE, Moncalián G, Alvarez HM. MLDSR, the transcriptional regulator of the major lipid droplets protein MLDS, is controlled by long-chain fatty acids and contributes to the lipid-accumulating phenotype in oleaginous Rhodococcus strains. FEBS J 2024; 291:1457-1482. [PMID: 38135896 DOI: 10.1111/febs.17043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 11/08/2023] [Accepted: 12/21/2023] [Indexed: 12/24/2023]
Abstract
Microorganism lipid droplet small regulator (MLDSR) is a transcriptional regulator of the major lipid droplet (LD)-associated protein MLDS in Rhodococcus jostii RHA1 and Rhodococcus opacus PD630. In this study, we investigated the role of MLDSR on lipid metabolism and triacylglycerol (TAG) accumulation in R. jostii RHA1 at physiological and molecular levels. MLDSR gene deletion promoted a significant decrease of TAG accumulation, whereas inhibition of de novo fatty acid biosynthesis by the addition of cerulenin significantly repressed the expression of the mldsr-mlds cluster under nitrogen-limiting conditions. In vitro and in vivo approaches revealed that MLDSR-DNA binding is inhibited by fatty acids and acyl-CoA residues through changes in the oligomeric or conformational state of the protein. RNAseq analysis indicated that MLDSR not only controls the expression of its own gene cluster but also of several genes involved in central, lipid, and redox metabolism, among others. We also identified putative MLDSR-binding sites on the upstream regions of genes coding for lipid catabolic enzymes and validated them by EMSA assays. Overexpression of mldsr gene under nitrogen-rich conditions promoted an increase of TAG accumulation, and further cell lysis with TAG release to the culture medium. Our results suggested that MLDSR is a fatty acid-responsive regulator that plays a dual role in cells by repression or activation of several metabolic genes in R. jostii RHA1. MLDSR seems to play an important role in the fine-tuning regulation of TAG accumulation, LD formation, and cellular lipid homeostasis, contributing to the oleaginous phenotype of R. jostii RHA1 and R. opacus PD630.
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Affiliation(s)
- Martín A Hernández
- INBIOP (Instituto de Biociencias de la Patagonia), Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Naturales, Universidad Nacional de la Patagonia San Juan Bosco, Comodoro Rivadavia, Argentina
| | - Ana E Ledesma
- CIBAAL (Centro de Investigación en Biofísica Aplicada y Alimentos), Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Santiago del Estero, Argentina
| | - Gabriel Moncalián
- Departamento de Biología Molecular, Universidad de Cantabria and Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), CSIC-Universidad de Cantabria, Santander, Spain
| | - Héctor M Alvarez
- INBIOP (Instituto de Biociencias de la Patagonia), Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Naturales, Universidad Nacional de la Patagonia San Juan Bosco, Comodoro Rivadavia, Argentina
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Herrero OM, Alvarez HM. Fruit residues as substrates for single-cell oil production by Rhodococcus species: physiology and genomics of carbohydrate catabolism. World J Microbiol Biotechnol 2024; 40:61. [PMID: 38177966 DOI: 10.1007/s11274-023-03866-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 12/03/2023] [Indexed: 01/06/2024]
Abstract
Strains belonging to R. opacus, R. jostii, R. fascians, R. erythropolis and R. equi exhibited differential ability to grow and produce lipids from fruit residues (grape marc and apple pomace), as well as single carbohydrates, such as glucose, gluconate, fructose and sucrose. The oleaginous species, R. opacus (strains PD630 and MR22) and R. jostii RHA1, produced higher yields of biomass (5.1-5.6 g L-1) and lipids (38-44% of CDW) from apple juice wastes, in comparison to R. erythropolis DSM43060, R. fascians F7 and R. equi ATCC6939 (4.1-4.3 g L-1 and less than 10% CDW of lipids). The production of cellular biomass and lipids were also higher in R. opacus and R. jostii (6.8-7.2 g L-1 and 33.9-36.5% of CDW of lipids) compared to R. erythropolis, R. fascians, and R. equi (3.0-3.6 g L-1 and less than 10% CDW of lipids), during cultivation of cells on wine grape waste. A genome-wide bioinformatic analysis of rhodococci indicated that oleaginous species possess a complete set of genes/proteins necessary for the efficient utilization of carbohydrates, whereas genomes from non-oleaginous rhodococcal strains lack relevant genes coding for transporters and/or enzymes for the uptake, catabolism and assimilation of carbohydrates, such as gntP, glcP, edd, eda, among others. Results of this study highlight the potential use of the oleaginous rhodococcal species to convert sugar-rich agro-industrial wastes, such as apple pomace and grape marc, into single-cell oils.
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Affiliation(s)
- O Marisa Herrero
- Instituto de Biociencias de la Patagonia (INBIOP), Universidad Nacional de la Patagonia San Juan Bosco y CONICET, Km 4-Ciudad Universitaria, 9000, Comodoro Rivadavia, Chubut, Argentina
| | - Héctor M Alvarez
- Instituto de Biociencias de la Patagonia (INBIOP), Universidad Nacional de la Patagonia San Juan Bosco y CONICET, Km 4-Ciudad Universitaria, 9000, Comodoro Rivadavia, Chubut, Argentina.
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Galván V, Pascutti F, Sandoval NE, Lanfranconi MP, Lozada M, Arabolaza AL, Mac Cormack WP, Alvarez HM, Gramajo HC, Dionisi HM. High wax ester and triacylglycerol biosynthesis potential in coastal sediments of Antarctic and Subantarctic environments. PLoS One 2023; 18:e0288509. [PMID: 37459319 PMCID: PMC10351704 DOI: 10.1371/journal.pone.0288509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 06/28/2023] [Indexed: 07/20/2023] Open
Abstract
The wax ester (WE) and triacylglycerol (TAG) biosynthetic potential of marine microorganisms is poorly understood at the microbial community level. The goal of this work was to uncover the prevalence and diversity of bacteria with the potential to synthesize these neutral lipids in coastal sediments of two high latitude environments, and to characterize the gene clusters related to this process. Homolog sequences of the key enzyme, the wax ester synthase/acyl-CoA:diacylglycerol acyltransferase (WS/DGAT) were retrieved from 13 metagenomes, including subtidal and intertidal sediments of a Subantarctic environment (Ushuaia Bay, Argentina), and subtidal sediments of an Antarctic environment (Potter Cove, Antarctica). The abundance of WS/DGAT homolog sequences in the sediment metagenomes was 1.23 ± 0.42 times the abundance of 12 single-copy genes encoding ribosomal proteins, higher than in seawater (0.13 ± 0.31 times in 338 metagenomes). Homolog sequences were highly diverse, and were assigned to the Pseudomonadota, Actinomycetota, Bacteroidota and Acidobacteriota phyla. The genomic context of WS/DGAT homologs included sequences related to WE and TAG biosynthesis pathways, as well as to other related pathways such as fatty-acid metabolism, suggesting carbon recycling might drive the flux to neutral lipid synthesis. These results indicate the presence of abundant and taxonomically diverse bacterial populations with the potential to synthesize lipid storage compounds in marine sediments, relating this metabolic process to bacterial survival.
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Affiliation(s)
- Virginia Galván
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET, FBIOyF–UNR), Rosario, Santa Fe, Argentina
| | - Federico Pascutti
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET, FBIOyF–UNR), Rosario, Santa Fe, Argentina
| | - Natalia E. Sandoval
- Instituto de Biociencias de la Patagonia (INBIOP-UNPSJB-CONICET), Comodoro Rivadavia, Chubut, Argentina
| | - Mariana P. Lanfranconi
- Instituto de Biociencias de la Patagonia (INBIOP-UNPSJB-CONICET), Comodoro Rivadavia, Chubut, Argentina
| | - Mariana Lozada
- Instituto de Biología de Organismos Marinos (IBIOMAR-CONICET), Puerto Madryn, Chubut, Argentina
| | - Ana L. Arabolaza
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET, FBIOyF–UNR), Rosario, Santa Fe, Argentina
| | - Walter P. Mac Cormack
- Instituto de Nanobiotecnología (NANOBIOTEC-UBA-CONICET), San Martín, Ciudad Autónoma de Buenos Aires, Argentina
- Instituto Antártico Argentino (IAA), San Martín, Buenos Aires, Argentina
| | - Héctor M. Alvarez
- Instituto de Biociencias de la Patagonia (INBIOP-UNPSJB-CONICET), Comodoro Rivadavia, Chubut, Argentina
| | - Hugo C. Gramajo
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET, FBIOyF–UNR), Rosario, Santa Fe, Argentina
| | - Hebe M. Dionisi
- Centro para el Estudio de Sistemas Marinos (CESIMAR-CONICET), Puerto Madryn, Chubut, Argentina
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Livieri AL, Colaccini F, Hernández MA, Gago G, Alvarez HM, Gramajo H, Rodriguez E. Genetic analysis of acyl-CoA carboxylases involved in lipid accumulation in Rhodococcus jostii RHA1. Appl Microbiol Biotechnol 2023:10.1007/s00253-023-12674-2. [PMID: 37439834 DOI: 10.1007/s00253-023-12674-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/06/2023] [Accepted: 06/15/2023] [Indexed: 07/14/2023]
Abstract
In actinomycetes, the acyl-CoA carboxylases, including the so-called acetyl-CoA carboxylases (ACCs), are biotin-dependent enzymes that exhibit broad substrate specificity and diverse domain and subunit arrangements. Bioinformatic analyses of the Rhodococcus jostii RHA1 genome found that this microorganism contains a vast arrange of putative acyl-CoA carboxylases domains and subunits. From the thirteen putative carboxyltransferase domains, only the carboxyltransferase subunit RO01202 and the carboxyltransferase domain present in the multidomain protein RO04222 are highly similar to well-known essential ACC subunits from other actinobacteria. Mutant strains in each of these genes showed that none of these enzymes is essential for R. jostii growth in rich or in minimal media with high nitrogen concentration, presumably because of their partial overlapping activities. A mutant strain in the ro04222 gene showed a decrease in triacylglycerol and mycolic acids accumulation in rich and minimal medium, highlighting the relevance of this multidomain ACC in the biosynthesis of these lipids. On the other hand, RO01202, a carboxyltransferase domain of a putative ACC complex, whose biotin carboxylase and biotin carboxyl carrier protein domain were not yet identified, was found to be essential for R. jostii growth only in minimal medium with low nitrogen concentration. The results of this study have identified a new component of the TAG-accumulating machinery in the oleaginous R. jostii RHA1. While non-essential for growth and TAG biosynthesis in RHA1, the activity of RO04222 significantly contributes to lipogenesis during single-cell oil production. Furthermore, this study highlights the high functional diversity of ACCs in actinobacteria, particularly regarding their essentiality under different environmental conditions. KEY POINTS: • R. jostii possess a remarkable heterogeneity in their acyl-carboxylase complexes. • RO04222 is a multidomain acetyl-CoA carboxylase involved in lipid accumulation. • RO01202 is an essential carboxyltransferase only at low nitrogen conditions.
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Affiliation(s)
- Andrea L Livieri
- Instituto de Biología Molecular y Celular de Rosario, Facultad de Ciencias Bioquímicas Y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain
| | - Facundo Colaccini
- Instituto de Biología Molecular y Celular de Rosario, Facultad de Ciencias Bioquímicas Y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Martin A Hernández
- Instituto de Biociencias de La Patagonia, Facultad de Ciencias Naturales y Ciencias de La Salud, Universidad Nacional de La Patagonia San Juan Bosco y CONICET, Comodoro Rivadavia, Argentina
| | - Gabriela Gago
- Instituto de Biología Molecular y Celular de Rosario, Facultad de Ciencias Bioquímicas Y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Héctor M Alvarez
- Instituto de Biociencias de La Patagonia, Facultad de Ciencias Naturales y Ciencias de La Salud, Universidad Nacional de La Patagonia San Juan Bosco y CONICET, Comodoro Rivadavia, Argentina
| | - Hugo Gramajo
- Instituto de Biología Molecular y Celular de Rosario, Facultad de Ciencias Bioquímicas Y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
| | - Eduardo Rodriguez
- Instituto de Biología Molecular y Celular de Rosario, Facultad de Ciencias Bioquímicas Y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
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Alvarez HM, Hernández MA, Lanfranconi MP, Silva RA, Villalba MS. Rhodococcus as Biofactories for Microbial Oil Production. Molecules 2021; 26:molecules26164871. [PMID: 34443455 PMCID: PMC8401914 DOI: 10.3390/molecules26164871] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/05/2021] [Accepted: 08/06/2021] [Indexed: 01/20/2023] Open
Abstract
Bacteria belonging to the Rhodococcus genus are frequent components of microbial communities in diverse natural environments. Some rhodococcal species exhibit the outstanding ability to produce significant amounts of triacylglycerols (TAG) (>20% of cellular dry weight) in the presence of an excess of the carbon source and limitation of the nitrogen source. For this reason, they can be considered as oleaginous microorganisms. As occurs as well in eukaryotic single-cell oil (SCO) producers, these bacteria possess specific physiological properties and molecular mechanisms that differentiate them from other microorganisms unable to synthesize TAG. In this review, we summarized several of the well-characterized molecular mechanisms that enable oleaginous rhodococci to produce significant amounts of SCO. Furthermore, we highlighted the ability of these microorganisms to degrade a wide range of carbon sources coupled to lipogenesis. The qualitative and quantitative oil production by rhodococci from diverse industrial wastes has also been included. Finally, we summarized the genetic and metabolic approaches applied to oleaginous rhodococci to improve SCO production. This review provides a comprehensive and integrating vision on the potential of oleaginous rhodococci to be considered as microbial biofactories for microbial oil production.
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Lanfranconi MP, Arabolaza A, Gramajo H, Alvarez HM. Insights into the evolutionary history of the virulent factor HBHA of Mycobacterium tuberculosis. Arch Microbiol 2021; 203:2171-2182. [PMID: 33620522 DOI: 10.1007/s00203-021-02192-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 12/23/2020] [Accepted: 02/04/2021] [Indexed: 12/20/2022]
Abstract
In Mycobacterium tuberculosis, heparin-binding hemagglutinin (HBHAMT) has a relevant role in infection. It is also present in non-virulent mycobacteria and ancient actinobacteria, such as Rhodococcus opacus. To have a better understanding of the underlying mechanisms that shaped the evolutionary divergence of these proteins, we performed a comprehensive phylogenetic analysis of the regulatory sequences that drive the expression of hbha in saprophytic and pathogenic mycobacterial species. The alignment of the hbha loci showed the appearance of intergenic sequences containing regulatory elements upstream the hbha gene; this sequence arrangement is present only in slow-growing pathogenic mycobacteria. The heterologous expression of HBHAMT in oleaginous R. opacus PD630 results in protein binding to lipid droplets, as it happens with HBHA proteins from saprophytic mycobacteria. We hypothesize that mycobacterial hbha gene cluster underwent functional divergence during the evolutionary differentiation of slow-growing pathogenic mycobacteria. We propose here an evolutionary scenario to explain the structural and functional divergence of HBHA in fast and slow-growing mycobacteria.
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Affiliation(s)
- Mariana P Lanfranconi
- Facultad de Ciencias Naturales y Ciencias de la Salud, INBIOP (Instituto de Biociencias de la Patagonia), Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de la Patagonia San Juan Bosco, Ruta Provincial N° 1, Km 4-Ciudad Universitaria, 9000, Comodoro Rivadavia, Chubut, Argentina
| | - Ana Arabolaza
- Facultad de Ciencias Bioquímicas y Farmacéuticas, IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Rosario, Ocampo y Esmeralda, 2000, Rosario, Santa Fe, Argentina
| | - Hugo Gramajo
- Facultad de Ciencias Bioquímicas y Farmacéuticas, IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Rosario, Ocampo y Esmeralda, 2000, Rosario, Santa Fe, Argentina
| | - Héctor M Alvarez
- Facultad de Ciencias Naturales y Ciencias de la Salud, INBIOP (Instituto de Biociencias de la Patagonia), Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de la Patagonia San Juan Bosco, Ruta Provincial N° 1, Km 4-Ciudad Universitaria, 9000, Comodoro Rivadavia, Chubut, Argentina.
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Cereijo AE, Kuhn ML, Hernández MA, Ballicora MA, Iglesias AA, Alvarez HM, Asencion Diez MD. Study of duplicated galU genes in Rhodococcus jostii and a putative new metabolic node for glucosamine-1P in rhodococci. Biochim Biophys Acta Gen Subj 2020; 1865:129727. [PMID: 32890704 DOI: 10.1016/j.bbagen.2020.129727] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 08/11/2020] [Accepted: 08/30/2020] [Indexed: 01/10/2023]
Abstract
BACKGOUND Studying enzymes that determine glucose-1P fate in carbohydrate metabolism is important to better understand microorganisms as biotechnological tools. One example ripe for discovery is the UDP-glucose pyrophosphorylase enzyme from Rhodococcus spp. In the R. jostii genome, this gene is duplicated, whereas R. fascians contains only one copy. METHODS We report the molecular cloning of galU genes from R. jostii and R. fascians to produce recombinant proteins RjoGalU1, RjoGalU2, and RfaGalU. Substrate saturation curves were conducted, kinetic parameters were obtained and the catalytic efficiency (kcat/Km) was used to analyze enzyme promiscuity. We also investigated the response of R. jostii GlmU pyrophosphorylase activity with different sugar-1Ps, which may compete for substrates with RjoGalU2. RESULTS All enzymes were active as pyrophosphorylases and exhibited substrate promiscuity toward sugar-1Ps. Remarkably, RjoGalU2 exhibited one order of magnitude higher activity with glucosamine-1P than glucose-1P, the canonical substrate. Glucosamine-1P activity was also significant in RfaGalU. The efficient use of the phospho-amino-sugar suggests the feasibility of the reaction to occur in vivo. Also, RjoGalU2 and RfaGalU represent enzymatic tools for the production of (amino)glucosyl precursors for the putative synthesis of novel molecules. CONCLUSIONS Results support the hypothesis that partitioning of glucosamine-1P includes an uncharacterized metabolic node in Rhodococcus spp., which could be important for producing diverse alternatives for carbohydrate metabolism in biotechnological applications. GENERAL SIGNIFICANCE Results presented here provide a model to study evolutionary enzyme promiscuity, which could be used as a tool to expand an organism's metabolic repertoire by incorporating non-canonical substrates into novel metabolic pathways.
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Affiliation(s)
- A E Cereijo
- Instituto de Agrobiotecnología del Litoral (UNL-CONICET), Facultad de Bioquímica y Ciencias Biológicas, CCT-Santa Fe, Colectora Ruta Nac 168 km 0, 3000 Santa Fe, Argentina
| | - M L Kuhn
- Department of Chemistry and Biochemistry, San Francisco State University, 1600 Holloway Ave., San Francisco, CA, United States
| | - M A Hernández
- Instituto de Biociencias de la Patagonia (INBIOP), Universidad Nacional de la Patagonia San Juan Bosco y CONICET, Km 4-Ciudad Universitaria 9000, Comodoro Rivadavia, Chubut, Argentina
| | - M A Ballicora
- Department of Chemistry and Biochemistry, Loyola University Chicago, 1068 W. Sheridan Rd., Chicago, IL 60660, United States
| | - A A Iglesias
- Instituto de Agrobiotecnología del Litoral (UNL-CONICET), Facultad de Bioquímica y Ciencias Biológicas, CCT-Santa Fe, Colectora Ruta Nac 168 km 0, 3000 Santa Fe, Argentina
| | - H M Alvarez
- Instituto de Biociencias de la Patagonia (INBIOP), Universidad Nacional de la Patagonia San Juan Bosco y CONICET, Km 4-Ciudad Universitaria 9000, Comodoro Rivadavia, Chubut, Argentina.
| | - M D Asencion Diez
- Instituto de Agrobiotecnología del Litoral (UNL-CONICET), Facultad de Bioquímica y Ciencias Biológicas, CCT-Santa Fe, Colectora Ruta Nac 168 km 0, 3000 Santa Fe, Argentina.
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Hernández MA, Alvarez HM. Increasing lipid production using an NADP +-dependent malic enzyme from Rhodococcus jostii. Microbiology (Reading) 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] [What about the content of this article? (0)] [Affiliation(s)] [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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Herrero OM, Villalba MS, Lanfranconi MP, Alvarez HM. Rhodococcus bacteria as a promising source of oils from olive mill wastes. World J Microbiol Biotechnol 2018; 34:114. [DOI: 10.1007/s11274-018-2499-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 07/07/2018] [Indexed: 10/28/2022]
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Hernández MA, Gleixner G, Sachse D, Alvarez HM. Carbon Allocation in Rhodococcus jostii RHA1 in Response to Disruption and Overexpression of nlpR Regulatory Gene, Based on 13C-labeling Analysis. Front Microbiol 2017; 8:1992. [PMID: 29075252 PMCID: PMC5641563 DOI: 10.3389/fmicb.2017.01992] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 09/27/2017] [Indexed: 12/23/2022] Open
Abstract
Nitrogen lipid regulator (NlpR) is a pleiotropic regulator that positively controls genes associated with both nitrogen and lipid metabolism in the oleaginous bacterium Rhodococcus jostii RHA1. In this study, we investigated the effect of nlpR disruption and overexpression on the assimilation of 13C-labeled glucose as carbon source, during cultivation of cells under nitrogen-limiting and nitrogen-rich conditions, respectively. Label incorporation into the total lipid extract (TLE) fraction was about 30% lower in the mutant strain in comparison with the wild type strain under low-nitrogen conditions. Moreover, a higher 13C abundance (∼60%) into the extracellular polymeric substance fraction was observed in the mutant strain. nlpR disruption also promoted a decrease in the label incorporation into several TLE-derivative fractions including neutral lipids (NL), glycolipids (GL), phospholipids (PL), triacylglycerols (TAG), diacylglycerols (DAG), and free fatty acids (FFA), with the DAG being the most affected. In contrast, the nlpR overexpression in RHA1 cells under nitrogen-rich conditions produced an increase of the label incorporation into the TLE and its derivative NL and PL fractions, the last one being the highest 13C enriched. In addition, a higher 13C enrichment occurred in the TAG, DAG, and FFA fractions after nlpR induction, with the FFA fraction being the most affected within the TLE. Isotopic-labeling experiments demonstrated that NlpR regulator is contributing in oleaginous phenotype of R. jostii RHA1 to the allocation of carbon into the different lipid fractions in response to nitrogen levels, increasing the rate of carbon flux into lipid metabolism.
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Affiliation(s)
- Martín A Hernández
- Instituto de Biociencias de la Patagonia, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Naturales, Universidad Nacional de la Patagonia San Juan Bosco, Comodoro Rivadavia, Argentina
| | - Gerd Gleixner
- Department of Biogeochemical Processes, Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Dirk Sachse
- Section 5.1: Geomorphology, GFZ German Research Centre for Geosciences, Potsdam, Germany.,Institute of Earth and Environmental Science, University of Potsdam, Potsdam, Germany
| | - Héctor M Alvarez
- Instituto de Biociencias de la Patagonia, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Naturales, Universidad Nacional de la Patagonia San Juan Bosco, Comodoro Rivadavia, Argentina
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Lanfranconi MP, Alvarez HM. Rewiring neutral lipids production for the de novo synthesis of wax esters in Rhodococcus opacus PD630. J Biotechnol 2017; 260:67-73. [DOI: 10.1016/j.jbiotec.2017.09.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 08/24/2017] [Accepted: 09/13/2017] [Indexed: 01/30/2023]
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Dávila Costa JS, Silva RA, Leichert L, Alvarez HM. Proteome analysis reveals differential expression of proteins involved in triacylglycerol accumulation by Rhodococcus jostii RHA1 after addition of methyl viologen. Microbiology (Reading) 2017; 163:343-354. [PMID: 28073401 DOI: 10.1099/mic.0.000424] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Rhodococcus jostii RHA1 is able to degrade toxic compounds and accumulate high amounts of triacylglycerols (TAG) upon nitrogen starvation. These NADPH-dependent processes are essential for the adaptation of rhodococci to fluctuating environmental conditions. In this study, we used an MS-based, label-free and quantitative proteomic approach to better understand the integral response of R. jostii RHA1 to the presence of methyl viologen (MV) in relation to the synthesis and accumulation of TAG. The addition of MV promoted a decrease of TAG accumulation in comparison to cells cultivated under nitrogen-limiting conditions in the absence of this pro-oxidant. Proteomic analyses revealed that the abundance of key proteins of fatty acid biosynthesis, the Kennedy pathway, glyceroneogenesis and methylmalonyl-CoA pathway, among others, decreased in the presence of MV. In contrast, some proteins involved in lipolysis and β-oxidation of fatty acids were upregulated. Some metabolic pathways linked to the synthesis of NADPH remained activated during oxidative stress as well as under nitrogen starvation conditions. Additionally, exposure to MV resulted in the activation of complete antioxidant machinery comprising superoxide dismutases, catalases, mycothiol biosynthesis, mycothione reductase and alkyl hydroperoxide reductases, among others. Our study suggests that oxidative stress response affects TAG accumulation under nitrogen-limiting conditions through programmed molecular mechanisms when both stresses occur simultaneously.
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Affiliation(s)
- José Sebastián Dávila Costa
- Instituto de Biociencias de la Patagonia (INBIOP), Universidad Nacional de la Patagonia San Juan Bosco y CONICET, Km 4-Ciudad Universitaria 9000, Comodoro Rivadavia (Chubut), Argentina.,Planta Piloto de Procesos Industriales Microbiológicos (PROIMI), CONICET, Av. Belgrano y Pasaje Caseros, 4000 Tucumán, Argentina
| | - Roxana A Silva
- Instituto de Biociencias de la Patagonia (INBIOP), Universidad Nacional de la Patagonia San Juan Bosco y CONICET, Km 4-Ciudad Universitaria 9000, Comodoro Rivadavia (Chubut), Argentina
| | - Lars Leichert
- Ruhr-Universität Bochum, Medizinisches Proteom-Center, Redox Proteomics Group, Bochum, Germany
| | - Héctor M Alvarez
- Instituto de Biociencias de la Patagonia (INBIOP), Universidad Nacional de la Patagonia San Juan Bosco y CONICET, Km 4-Ciudad Universitaria 9000, Comodoro Rivadavia (Chubut), Argentina
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Juarez A, Villa JA, Lanza VF, Lázaro B, de la Cruz F, Alvarez HM, Moncalián G. Nutrient starvation leading to triglyceride accumulation activates the Entner Doudoroff pathway in Rhodococcus jostii RHA1. Microb Cell Fact 2017; 16:35. [PMID: 28241831 PMCID: PMC5327559 DOI: 10.1186/s12934-017-0651-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Accepted: 02/22/2017] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Rhodococcus jostii RHA1 and other actinobacteria accumulate triglycerides (TAG) under nutrient starvation. This property has an important biotechnological potential in the production of sustainable oils. RESULTS To gain insight into the metabolic pathways involved in TAG accumulation, we analysed the transcriptome of R jostii RHA1 under nutrient-limiting conditions. We correlate these physiological conditions with significant changes in cell physiology. The main consequence was a global switch from catabolic to anabolic pathways. Interestingly, the Entner-Doudoroff (ED) pathway was upregulated in detriment of the glycolysis or pentose phosphate pathways. ED induction was independent of the carbon source (either gluconate or glucose). Some of the diacylglycerol acyltransferase genes involved in the last step of the Kennedy pathway were also upregulated. A common feature of the promoter region of most upregulated genes was the presence of a consensus binding sequence for the cAMP-dependent CRP regulator. CONCLUSION This is the first experimental observation of an ED shift under nutrient starvation conditions. Knowledge of this switch could help in the design of metabolomic approaches to optimize carbon derivation for single cell oil production.
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Affiliation(s)
- Antonio Juarez
- Institut de Bioenginyeria de Catalunya, Parc Científic de Barcelona, 08028, Barcelona, Spain.,Departamento de Microbiología, Facultad de Biología, Universidad de Barcelona, Avda Diagonal, 643., 08028, Barcelona, Spain
| | - Juan A Villa
- Departamento de Biología Molecular (Universidad de Cantabria) and Instituto de Biomedicina y Biotecnología de Cantabria IBBTEC (CSIC-UC), C/Albert Einstein 22, 39011, Santander, Spain
| | - Val F Lanza
- Departamento de Biología Molecular (Universidad de Cantabria) and Instituto de Biomedicina y Biotecnología de Cantabria IBBTEC (CSIC-UC), C/Albert Einstein 22, 39011, Santander, Spain
| | - Beatriz Lázaro
- Departamento de Biología Molecular (Universidad de Cantabria) and Instituto de Biomedicina y Biotecnología de Cantabria IBBTEC (CSIC-UC), C/Albert Einstein 22, 39011, Santander, Spain
| | - Fernando de la Cruz
- Departamento de Biología Molecular (Universidad de Cantabria) and Instituto de Biomedicina y Biotecnología de Cantabria IBBTEC (CSIC-UC), C/Albert Einstein 22, 39011, Santander, Spain
| | - Héctor M Alvarez
- INBIOP (Instituto de Biociencias de la Patagonia), Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Naturales, Universidad Nacional de la Patagonia San Juan Bosco, Ruta Provincial No 1, Km 4-Ciudad Universitaria 9000, Comodoro Rivadavia, Chubut, Argentina
| | - Gabriel Moncalián
- Departamento de Biología Molecular (Universidad de Cantabria) and Instituto de Biomedicina y Biotecnología de Cantabria IBBTEC (CSIC-UC), C/Albert Einstein 22, 39011, Santander, Spain.
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Day PA, Villalba MS, Herrero OM, Arancibia LA, Alvarez HM. Formation of indigoidine derived-pigments contributes to the adaptation of Vogesella sp. strain EB to cold aquatic iron-oxidizing environments. Antonie van Leeuwenhoek 2016; 110:415-428. [DOI: 10.1007/s10482-016-0814-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 11/26/2016] [Indexed: 01/18/2023]
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Hernández MA, Lara J, Gago G, Gramajo H, Alvarez HM. The pleiotropic transcriptional regulator NlpR contributes to the modulation of nitrogen metabolism, lipogenesis and triacylglycerol accumulation in oleaginous rhodococci. Mol Microbiol 2016; 103:366-385. [DOI: 10.1111/mmi.13564] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/22/2016] [Indexed: 01/04/2023]
Affiliation(s)
- Martín A. Hernández
- INBIOP (Instituto de Biociencias de la Patagonia), Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Naturales; Universidad Nacional de la Patagonia San Juan Bosco; Ruta Provincial N° 1, Km 4-Ciudad Universitaria 9000 Comodoro Rivadavia Chubut Argentina
| | - Julia Lara
- IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas. Facultad de Ciencias Bioquímicas y Farmacéuticas; Universidad Nacional de Rosario; Ocampo y Esmeralda 2000 Rosario Santa Fe Argentina
| | - Gabriela Gago
- IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas. Facultad de Ciencias Bioquímicas y Farmacéuticas; Universidad Nacional de Rosario; Ocampo y Esmeralda 2000 Rosario Santa Fe Argentina
| | - Hugo Gramajo
- IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas. Facultad de Ciencias Bioquímicas y Farmacéuticas; Universidad Nacional de Rosario; Ocampo y Esmeralda 2000 Rosario Santa Fe Argentina
| | - Héctor M. Alvarez
- INBIOP (Instituto de Biociencias de la Patagonia), Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Naturales; Universidad Nacional de la Patagonia San Juan Bosco; Ruta Provincial N° 1, Km 4-Ciudad Universitaria 9000 Comodoro Rivadavia Chubut Argentina
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Cereijo AE, Asencion Diez MD, Dávila Costa JS, Alvarez HM, Iglesias AA. On the Kinetic and Allosteric Regulatory Properties of the ADP-Glucose Pyrophosphorylase from Rhodococcus jostii: An Approach to Evaluate Glycogen Metabolism in Oleaginous Bacteria. Front Microbiol 2016; 7:830. [PMID: 27313571 PMCID: PMC4890535 DOI: 10.3389/fmicb.2016.00830] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 05/17/2016] [Indexed: 01/29/2023] Open
Abstract
Rhodococcus spp. are oleaginous bacteria that accumulate glycogen during exponential growth. Despite the importance of these microorganisms in biotechnology, little is known about the regulation of carbon and energy storage, mainly the relationship between glycogen and triacylglycerols metabolisms. Herein, we report the molecular cloning and heterologous expression of the gene coding for ADP-glucose pyrophosphorylase (EC 2.7.7.27) of Rhodococcus jostii, strain RHA1. The recombinant enzyme was purified to electrophoretic homogeneity to accurately characterize its oligomeric, kinetic, and regulatory properties. The R. jostii ADP-glucose pyrophosphorylase is a homotetramer of 190 kDa exhibiting low basal activity to catalyze synthesis of ADP-glucose, which is markedly influenced by different allosteric effectors. Glucose-6P, mannose-6P, fructose-6P, ribose-5P, and phosphoenolpyruvate were major activators; whereas, NADPH and 6P-gluconate behaved as main inhibitors of the enzyme. The combination of glucose-6P and other effectors (activators or inhibitors) showed a cross-talk effect suggesting that the different metabolites could orchestrate a fine regulation of ADP-glucose pyrophosphorylase in R. jostii. The enzyme exhibited some degree of affinity toward ATP, GTP, CTP, and other sugar-1P substrates. Remarkably, the use of glucosamine-1P was sensitive to allosteric activation. The relevance of the fine regulation of R. jostii ADP-glucose pyrophosphorylase is further analyzed in the framework of proteomic studies already determined for the bacterium. Results support a critical role for glycogen as a temporal reserve that provides a pool of carbon able of be re-routed to produce long-term storage of lipids under certain conditions.
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Affiliation(s)
- Antonela E Cereijo
- Laboratorio de Enzimología Molecular, Instituto de Agrobiotecnología del Litoral, CONICET, Centro Científico Tecnológico, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral Santa Fe, Argentina
| | - Matías D Asencion Diez
- Laboratorio de Enzimología Molecular, Instituto de Agrobiotecnología del Litoral, CONICET, Centro Científico Tecnológico, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral Santa Fe, Argentina
| | - José S Dávila Costa
- Centro Regional de Investigación y Desarrollo Científico Tecnológico, Facultad de Ciencias Naturales Universidad Nacional de la Patagonia San Juan Bosco Comodoro Rivadavia, Argentina
| | - Héctor M Alvarez
- Centro Regional de Investigación y Desarrollo Científico Tecnológico, Facultad de Ciencias Naturales Universidad Nacional de la Patagonia San Juan Bosco Comodoro Rivadavia, Argentina
| | - Alberto A Iglesias
- Laboratorio de Enzimología Molecular, Instituto de Agrobiotecnología del Litoral, CONICET, Centro Científico Tecnológico, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral Santa Fe, Argentina
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Herrero OM, Moncalián G, Alvarez HM. Physiological and genetic differences amongst Rhodococcus species for using glycerol as a source for growth and triacylglycerol production. Microbiology (Reading) 2016; 162:384-397. [DOI: 10.1099/mic.0.000232] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Affiliation(s)
- O. Marisa Herrero
- Centro Regional de Investigación y Desarrollo Científico Tecnológico, Facultad de Ciencias Naturales,Universidad Nacional de la Patagonia San Juan Bosco y CIT-CHUBUT CONICET, Km 4-Ciudad Universitaria, 9000 Comodoro Rivadavia (Chubut), Argentina
- Oil m&s, Avenida Hipólito Yrigoyen 4250, 9000 Comodoro Rivadavia (Chubut), Argentina
| | - Gabriel Moncalián
- Departamento de Biología Molecular e Instituto de Biomedicina y Biotecnología de Cantabria,Universidad de Cantabria-Consejo Superior de Investigaciones Científicas-SODERCAN, Calle Albert Einstein 22, 39011 Santander,Spain
| | - Héctor M. Alvarez
- Centro Regional de Investigación y Desarrollo Científico Tecnológico, Facultad de Ciencias Naturales,Universidad Nacional de la Patagonia San Juan Bosco y CIT-CHUBUT CONICET, Km 4-Ciudad Universitaria, 9000 Comodoro Rivadavia (Chubut), Argentina
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Lanfranconi MP, Alvarez AF, Alvarez HM. Identification of genes coding for putative wax ester synthase/diacylglycerol acyltransferase enzymes in terrestrial and marine environments. AMB Express 2015; 5:128. [PMID: 26228353 PMCID: PMC4520822 DOI: 10.1186/s13568-015-0128-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 07/06/2015] [Indexed: 11/29/2022] Open
Abstract
Synthesis of neutral lipids such as triacylglycerols (TAG) and wax esters (WE) is catalyzed in bacteria by wax ester synthase/diacylglycerol acyltransferase enzymes (WS/DGAT). We investigated
the diversity of genes encoding this enzyme in contrasting natural environments from Patagonia (Argentina). The content of petroleum hydrocarbons in samples collected from oil-producing areas was measured. PCR-based analysis covered WS/DGAT occurrence in marine sediments and soil. No product was obtained in seawater samples. All clones retrieved from marine sediments affiliated with gammaproteobacterial sequences and within them, most phylotypes formed a unique cluster related to putative WS/DGAT belonging to marine OM60 clade. In contrast, soils samples contained phylotypes only related to actinomycetes. Among them, phylotypes affiliated with representatives largely or recently reported as oleaginous bacteria, as well as with others considered as possible lipid-accumulating bacteria based on the analysis of their annotated genomes. Our study shows for the first time that the environment could contain a higher variety of ws/dgat than that reported from bacterial isolates. The results of this study highlight the relevance of the environment in a natural process such as the synthesis and accumulation of neutral lipids. Particularly, both marine sediments and soil may serve as a useful source for novel WS/DGAT with biotechnological interest.
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Abstract
Gram negative bacteria as well as Gram positive actinobacteria possess the ability to accumulate variable amounts of wax esters (WE) and/or triacylglycerols (TAG) under nitrogen limiting conditions. In recent years many advances have been made to obtain insight into neutral lipid biosynthesis and accumulation in prokaryotes. The clinical and industrial relevance of bacterial WE/TAG significantly promoted basic and applied research in this field. The recent integrated omic studies as well as the functional characterization of diverse genes are contributing to unravel the composition of the WE/TAG-accumulating machinery in bacteria. This will be a valuable data for designing new drugs against bacteria with clinical importance, such as Mycobacterium tuberculosis, or for transferring and optimizing lipid accumulation in bacterial hosts naturally unable to produce such lipids, such as Escherichia coli. In this article, recent investigations addressing WE/TAG biosynthesis and storage in prokaryotes are presented. A comprehensive view of the current knowledge on the different genes/proteins involved in WE/TAG biosynthesis is included.
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Affiliation(s)
- Héctor M Alvarez
- Centro Regional de Investigación y Desarrollo Científico Tecnológico (CRIDECIT), Facultad de Ciencias Naturales, Universidad Nacional de la Patagonia San Juan Bosco, CIT-CHUBUT, CONICET, Km 4-Ciudad Universitaria 9000, Comodoro Rivadavia, Chubut, Argentina.
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Herrero OM, Alvarez HM. Whey as a renewable source for lipid production byRhodococcusstrains: Physiology and genomics of lactose and galactose utilization. EUR J LIPID SCI TECH 2015. [DOI: 10.1002/ejlt.201500080] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- O. Marisa Herrero
- Centro Regional de Investigación y Desarrollo Científico Tecnológico, Facultad de Ciencias Naturales; Universidad Nacional de la Patagonia; San Juan Bosco, Comodoro Rivadavia Chubut Argentina
- Oil m&s; Comodoro Rivadavia Chubut Argentina
| | - Héctor M. Alvarez
- Centro Regional de Investigación y Desarrollo Científico Tecnológico, Facultad de Ciencias Naturales; Universidad Nacional de la Patagonia; San Juan Bosco, Comodoro Rivadavia Chubut Argentina
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Dávila Costa JS, Leichert L, Alvarez HM, Herrero OM. Label-free and redox proteomic analyses of the triacylglycerol-accumulating Rhodococcus jostii RHA1. Microbiology (Reading) 2015; 161:593-610. [DOI: 10.1099/mic.0.000028] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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Hernández MA, Comba S, Arabolaza A, Gramajo H, Alvarez HM. Overexpression of a phosphatidic acid phosphatase type 2 leads to an increase in triacylglycerol production in oleaginous Rhodococcus strains. Appl Microbiol Biotechnol 2014; 99:2191-207. [PMID: 25213912 DOI: 10.1007/s00253-014-6002-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 07/30/2014] [Accepted: 07/31/2014] [Indexed: 01/28/2023]
Abstract
Oleaginous Rhodococcus strains are able to accumulate large amounts of triacylglycerol (TAG). Phosphatidic acid phosphatase (PAP) enzyme catalyzes the dephosphorylation of phosphatidic acid (PA) to yield diacylglycerol (DAG), a key precursor for TAG biosynthesis. Studies to establish its role in lipid metabolism have been mainly focused in eukaryotes but not in bacteria. In this work, we identified and characterized a putative PAP type 2 (PAP2) encoded by the ro00075 gene in Rhodococcus jostii RHA1. Heterologous expression of ro00075 in Escherichia coli resulted in a fourfold increase in PAP activity and twofold in DAG content. The conditional deletion of ro00075 in RHA1 led to a decrease in the content of DAG and TAG, whereas its overexpression in both RHA1 and Rhodococcus opacus PD630 promoted an increase up to 10 to 15 % by cellular dry weight in TAG content. On the other hand, expression of ro00075 in the non-oleaginous strain Rhodococcus fascians F7 promoted an increase in total fatty acid content up to 7 % at the expense of free fatty acid (FFA), DAG, and TAG fractions. Moreover, co-expression of ro00075/atf2 genes resulted in a fourfold increase in total fatty acid content by a further increase of the FFA and TAG fractions. The results of this study suggest that ro00075 encodes for a PAP2 enzyme actively involved in TAG biosynthesis. Overexpression of this gene, as single one or with an atf gene, provides an alternative approach to increase the biosynthesis and accumulation of bacterial oils as a potential source of raw material for biofuel production.
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Affiliation(s)
- Martín A Hernández
- Centro Regional de Investigación y Desarrollo Científico Tecnológico, Facultad de Ciencias Naturales, Universidad Nacional de la Patagonia San Juan Bosco, Ruta Provincial N° 1, Km 4-Ciudad Universitaria, 9000, Comodoro Rivadavia, Chubut, Argentina
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Urbano SB, Di Capua C, Cortez N, Farías ME, Alvarez HM. Triacylglycerol accumulation and oxidative stress in Rhodococcus species: differential effects of pro-oxidants on lipid metabolism. Extremophiles 2014; 18:375-84. [DOI: 10.1007/s00792-013-0623-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Accepted: 12/29/2013] [Indexed: 11/28/2022]
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Hernández MA, Arabolaza A, Rodríguez E, Gramajo H, Alvarez HM. The atf2 gene is involved in triacylglycerol biosynthesis and accumulation in the oleaginous Rhodococcus opacus PD630. Appl Microbiol Biotechnol 2012; 97:2119-30. [DOI: 10.1007/s00253-012-4360-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 08/07/2012] [Accepted: 08/09/2012] [Indexed: 10/28/2022]
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Hernández MA, Alvarez HM. Glycogen formation by Rhodococcus species and the effect of inhibition of lipid biosynthesis on glycogen accumulation in Rhodococcus opacus PD630. FEMS Microbiol Lett 2010; 312:93-9. [DOI: 10.1111/j.1574-6968.2010.02108.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Alvarez HM, Steinbüchel A. Physiology, Biochemistry, and Molecular Biology of Triacylglycerol Accumulation by Rhodococcus. Biology of Rhodococcus 2010. [DOI: 10.1007/978-3-642-12937-7_10] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Alvarez HM, Silva RA, Cesari AC, Zamit AL, Peressutti SR, Reichelt R, Keller U, Malkus U, Rasch C, Maskow T, Mayer F, Steinbüchel A. Physiological and morphological responses of the soil bacterium Rhodococcus opacus strain PD630 to water stress. FEMS Microbiol Ecol 2009; 50:75-86. [PMID: 19712366 DOI: 10.1016/j.femsec.2004.06.002] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Rhodococcus opacus PD630 was investigated for physiological and morphological changes under water stress challenge. Gluconate- and hexadecane-grown cells were extremely resistant to these conditions, and survival accounted for up to 300 and 400 days; respectively, when they were subjected to slow air-drying. Results of this study suggest that strain PD630 has specific mechanisms to withstand water stress. Water-stressed cells were sensitive to the application of ethanol, high temperatures and oxidative stress, whereas they exhibited cross-protection solely against osmotic stress during the first hours of application. Results indicate that the resistance programme for water stress in R. opacus PD630 includes the following physiological and morphological changes, among others: (1) energetic adjustments with drastic reduction of the metabolic activity ( approximately 39% decrease during the first 24 h and about 90% after 190 days under dehydration), (2) endogenous metabolism using intracellular triacylglycerols for generating energy and precursors, (3) biosynthesis of different osmolytes such as trehalose, ectoine and hydroxyectoine, which may achieve a water balance through osmotic adjustment and may explain the overlap between water and osmotic stress, (4) adjustments of the cell-wall through the turnover of mycolic acid species, as preliminary experiments revealed no evident changes in the thickness of the cell envelope, (5) formation of short fragmenting-cells as probable resistance forms, (6) production of an extracellular slime covering the surface of colonies, which probably regulates internal and external changes in water potential, and (7) formation of compact masses of cells. This contributes to understanding the water stress resistance processes in the soil bacterium R. opacus PD630.
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Affiliation(s)
- Héctor M Alvarez
- Departamento de Bioquímica, Facultad de Ciencias Naturales, Universidad Nacional de la Patagonia San Juan Bosco, (9000) Comodoro Rivadavia, Argentina.
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Hernández MA, Mohn WW, Martínez E, Rost E, Alvarez AF, Alvarez HM. Biosynthesis of storage compounds by Rhodococcus jostii RHA1 and global identification of genes involved in their metabolism. BMC Genomics 2008; 9:600. [PMID: 19077282 PMCID: PMC2667194 DOI: 10.1186/1471-2164-9-600] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Accepted: 12/12/2008] [Indexed: 11/13/2022] Open
Abstract
Background Members of the genus Rhodococcus are frequently found in soil and other natural environments and are highly resistant to stresses common in those environments. The accumulation of storage compounds permits cells to survive and metabolically adapt during fluctuating environmental conditions. The purpose of this study was to perform a genome-wide bioinformatic analysis of key genes encoding metabolism of diverse storage compounds by Rhodococcus jostii RHA1 and to examine its ability to synthesize and accumulate triacylglycerols (TAG), wax esters, polyhydroxyalkanoates (PHA), glycogen and polyphosphate (PolyP). Results We identified in the RHA1 genome: 14 genes encoding putative wax ester synthase/acyl-CoA:diacylglycerol acyltransferase enzymes (WS/DGATs) likely involved in TAG and wax esters biosynthesis; a total of 54 genes coding for putative lipase/esterase enzymes possibly involved in TAG and wax ester degradation; 3 sets of genes encoding PHA synthases and PHA depolymerases; 6 genes encoding key enzymes for glycogen metabolism, one gene coding for a putative polyphosphate kinase and 3 putative exopolyphosphatase genes. Where possible, key amino acid residues in the above proteins (generally in active sites, effectors binding sites or substrate binding sites) were identified in order to support gene identification. RHA1 cells grown under N-limiting conditions, accumulated TAG as the main storage compounds plus wax esters, PHA (with 3-hydroxybutyrate and 3-hydroxyvalerate monomers), glycogen and PolyP. Rhodococcus members were previously known to accumulate TAG, wax esters, PHAs and polyP, but this is the first report of glycogen accumulation in this genus. Conclusion RHA1 possess key genes to accumulate diverse storage compounds. Under nitrogen-limiting conditions lipids are the principal storage compounds. An extensive capacity to synthesize and metabolize storage compounds appears to contribute versatility to RHA1 in its responses to environmental stresses.
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Affiliation(s)
- Martín A Hernández
- Centro Regional de Investigación y Desarrollo Científico Tecnológico, Facultad de Ciencias Naturales, Universidad Nacional de Patagonia San Juan Bosco, Km 4-Ciudad Universitaria, 9000 Comodoro Rivadavia, Chubut, Argentina.
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Peressutti SR, Olivera NL, Babay PA, Costagliola M, Alvarez HM. Degradation of linear alkylbenzene sulfonate by a bacterial consortium isolated from the aquatic environment of Argentina. J Appl Microbiol 2008; 105:476-84. [PMID: 18355233 DOI: 10.1111/j.1365-2672.2008.03771.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- S R Peressutti
- Instituto Nacional de Investigación y Desarrollo Pesquero, Mar del Plata, Argentina.
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Alvarez AF, Alvarez HM, Kalscheuer R, Wältermann M, Steinbüchel A. Cloning and characterization of a gene involved in triacylglycerol biosynthesis and identification of additional homologous genes in the oleaginous bacterium Rhodococcus opacus PD630. Microbiology (Reading) 2008; 154:2327-2335. [DOI: 10.1099/mic.0.2008/016568-0] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Adrian F. Alvarez
- Institut für Molekulare Mikrobiologie und Biotechnologie der Westfälischen Wilhelms-Universität Münster, Corrensstr. 3, 48149 Münster, Germany
| | - Héctor M. Alvarez
- Centro Regional de Investigación y Desarrollo Científico Tecnológico (CRIDECIT), Facultad de Ciencias Naturales, Universidad Nacional de la Patagonia San Juan Bosco, Comodoro Rivadavia, Argentina
| | - Rainer Kalscheuer
- Institut für Molekulare Mikrobiologie und Biotechnologie der Westfälischen Wilhelms-Universität Münster, Corrensstr. 3, 48149 Münster, Germany
| | - Marc Wältermann
- Institut für Molekulare Mikrobiologie und Biotechnologie der Westfälischen Wilhelms-Universität Münster, Corrensstr. 3, 48149 Münster, Germany
| | - Alexander Steinbüchel
- Institut für Molekulare Mikrobiologie und Biotechnologie der Westfälischen Wilhelms-Universität Münster, Corrensstr. 3, 48149 Münster, Germany
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Silva RA, Grossi V, Alvarez HM. Biodegradation of phytane (2,6,10,14-tetramethylhexadecane) and accumulation of related isoprenoid wax esters byMycobacterium ratisbonensestrain SD4 under nitrogen-starved conditions. FEMS Microbiol Lett 2007; 272:220-8. [PMID: 17521403 DOI: 10.1111/j.1574-6968.2007.00770.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
The accumulation of storage lipids during the biodegradation of 2,6,10,14-tetramethylhexadecane (phytane) by Mycobacterium ratisbonense strain SD4 grown under nitrogen-starved conditions was investigated. Detailed chemical analysis of intracellular metabolites revealed the existence of (at least) three different pathways for the catabolism of phytane, and the accumulation of significant proportions (39% of the total lipids) of several isoprenoid wax esters formed by condensation of oxidation products of the hydrocarbon. In contrast, triacylglycerols but no wax esters were accumulated by strain SD4 grown on hexadecane, the unbranched homologue of phytane.
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Affiliation(s)
- Roxana A Silva
- Centro Regional de Investigación y Desarrollo Científico--Tecnológico (CRIDECIT), Facultad de Ciencias Naturales, Universidad Nacional de la Patagonia San Juan Bosco, Chubut, Argentina
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Thevenet PS, Jensen O, Drut R, Cerrone GE, Grenóvero MS, Alvarez HM, Targovnik HM, Basualdo JA. Viability and infectiousness of eggs of Echinococcus granulosus aged under natural conditions of inferior arid climate. Vet Parasitol 2005; 133:71-7. [PMID: 15994009 DOI: 10.1016/j.vetpar.2005.05.048] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2005] [Revised: 05/13/2005] [Accepted: 05/18/2005] [Indexed: 11/27/2022]
Abstract
We studied the viability and infectiousness of aged Echinococcus granulosus eggs by in vivo evaluation in ovines. Our results demonstrated that after 41 months of ageing of the eggs under environmental conditions of an inferior arid climate (Patagonia, Argentina), they were still able to produce infection in 4/4 ovines challenged with 1200 eggs per ovine. In the ovines experimentally infected with these aged eggs, the occurrence of hepatic and pulmonary cysts was determined by necropsy, histologic and genetic studies. The eggs were found in a semi-senescent stage, thus keeping their capacity to generate an infection in the intermediary ovine host.
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Affiliation(s)
- Paula Sánchez Thevenet
- Departamento de Bioquímica, School of Natural Science, Facultad de Ciencias Naturales, Universidad Nacional de la Patagonia San Juan Bosco, Piso 2 Ciudad Universitaria Km. 4, Comodoro Rivadavia, Chubut 9000, Argentina.
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Ciarmela ML, Thevenet PS, Alvarez HM, Minvielle MC, Basualdo JA. Effect of Paecilomyces lilacinus on the viability of oncospheres of Taenia hydatigena. Vet Parasitol 2005; 131:61-4. [PMID: 15950384 DOI: 10.1016/j.vetpar.2005.04.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2005] [Revised: 04/05/2005] [Accepted: 04/26/2005] [Indexed: 10/25/2022]
Abstract
Paecilomyces lilacinus (Thom) Samson is a saprophytic hyphomycete from the soil with biological activity on helminth eggs. We evaluated the influence in vitro of P. lilacinus on the viability of the oncospheres from Taenia hydatigena, a parasite cestode of dogs and sheep. The eggs were exposed to the fungus strain in sterile distilled water and observed by light microscopy at days 4, 7 and 14 post-inoculation, and the viability was evaluated. The viability found in the exposed P. lilacinus oncospheres was significantly different in all observations. P. lilacinus exercised a negative biological activity on T. hydatigena eggs in vitro.
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Affiliation(s)
- M L Ciarmela
- Cátedra de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional de La Plata, 60 y 120 s/no (CP 1900), La Plata, Buenos Aires, Argentina
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Abstract
In this report we describe the isolation of a strain from soil contaminated with gas oil by taking bacteria from a chemotactic ring on gas oil-containing soft agar plates. Partial 16 S rDNA sequencing of the isolated strain showed 99.1% identity with Flavimonas oryzihabitans. It was not only able to degrade different aliphatic hydrocarbons but it was also chemotactic towards gas oil and hexadecane, as demonstrated by the use of three different chemotaxis methods, such as agarose plug and capillary assays and swarm plate analysis. In addition, the strain was chemotactic to a variety of carbon sources that serve as growth substrates, including glucose, arabinose, mannitol, glycerol, gluconate, acetate, succinate, citrate, malate, lactate and casaminoacids. This is the first report on chemotaxis of a hydrocarbon-degrading bacterium towards a pure alkane, such as hexadecane. The fact that environmental isolates show chemotaxis towards contaminant/s present in the site of isolation suggests that chemotaxis might enhance biodegradation by favouring contact between the degrading microorganism and its substrate.
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Affiliation(s)
- Mariana P Lanfranconi
- Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, CC 1245, 7600 Mar del Plata, Argentina
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Alvarez HM, Steinbüchel A. Triacylglycerols in prokaryotic microorganisms. Appl Microbiol Biotechnol 2002; 60:367-76. [PMID: 12466875 DOI: 10.1007/s00253-002-1135-0] [Citation(s) in RCA: 312] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2002] [Revised: 08/31/2002] [Accepted: 09/06/2002] [Indexed: 11/27/2022]
Abstract
Triacylglycerols (TAG) are fatty acid triesters of glycerol; there are diverse types of TAG with different properties depending on their fatty acid composition. The occurrence of TAG as reserve compounds is widespread among eukaryotic organisms such as yeast, fungi, plants and animals, whereas occurrence of TAG in bacteria has only rarely been described. However, accumulation of TAG seems to be widespread among bacteria belonging to the actinomycetes group, such as species of Mycobacterium, Streptomyces, Rhodococcus and Nocardia. Fatty acids in acylglycerols in cells of Rhodococcus opacus PD630 accounted for up to 87% of the cellular dry weight. TAG biosynthesis, justifying an oleaginous status, seems to be restricted mainly to this group of bacteria, but occurs to a minor extent also in a few other bacteria. The compositions and structures of bacterial TAG vary considerably depending on the microorganism and on the carbon source, and unusual acyl moieties, such as phenyldecanoic acid and 4,8,12 trimethyl tridecanoic acid, are also included. The principal function of bacterial TAG seems to be as a reserve compound. Other functions that have been discussed include regulation of cellular membrane fluidity by keeping unusual fatty acids away from membrane phospholipids, or acting as a sink for reducing equivalents. In recent years, basic aspects of the physiology and biochemistry of bacterial TAG accumulation, and the molecular biology of the lipid inclusion bodies have been reported. TAG are used for nutritional, therapeutic and pharmaceutical purposes and serve as a source of oleochemicals.
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Affiliation(s)
- H M Alvarez
- Departamento de Bioquímica, Facultad de Ciencias Naturales, Universidad Nacional de la Patagonia San Juan Bosco, (CC 1078) Km 4, 9000 Comodoro Rivadavia, Argentina.
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Alvarez HM, Luftmann H, Silva RA, Cesari AC, Viale A, Wältermann M, Steinbüchel A. Identification of phenyldecanoic acid as a constituent of triacylglycerols and wax ester produced by Rhodococcus opacus PD630. Microbiology (Reading) 2002; 148:1407-12. [PMID: 11988514 DOI: 10.1099/00221287-148-5-1407] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Phenyldecane supported growth and lipid accumulation of Rhodococcus opacus PD630 during cultivation under nitrogen-limiting conditions. The results of this study suggested that the hydrocarbon phenyldecane was degraded by monoterminal oxidation, followed by beta-oxidation of the alkyl side-chain to phenylacetic acid, and by an additional degradative route for the oxidation of the latter to intermediates of the central metabolism. alpha-Oxidation of phenyldecanoic acid also occurred to some extent. Phenyldecanoic acid, the monoterminal oxidation product, was also utilized for the biosynthesis of a novel wax ester and novel triacylglycerols. The formation of the wax ester phenyldecylphenyldecanoate probably resulted from the condensation of phenyldecanoic acid and phenyldecanol, which were produced as metabolites during the catabolism of phenyldecane. Two types of triacylglycerol were detected in phenyldecane-grown cells of strain PD630. Triacylglycerols containing only odd- and even-numbered aliphatic fatty acids, as well as triacylglycerols in which one fatty acid was replaced by a phenyldecanoic acid residue, occurred. Other phenyl intermediates, such as phenylacetic acid, phenylpropionic acid, 4-hydroxyphenylpropionic acid, protocatechuate and homogentisic acid, were excreted into the medium during cultivation on phenyldecane. On the basis of the results obtained, pathways for the catabolism and assimilation of phenyldecane by R. opacus PD630 are discussed.
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Affiliation(s)
- Héctor M Alvarez
- Departamento de Bioquímica, Facultad de Ciencias Naturales, Universidad Nacional de la Patagonia San Juan Bosco, CC 1078, Km 4, 9000 Comodoro Rivadavia, Chubut, Argentina.
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Alvarez HM, Krawiec M, Donovan-Merkert BT, Fouzi M, Rabinovich D. Modeling nickel hydrogenases: synthesis and structure of a distorted octahedral complex with an unprecedented [NiS(4)H(2)] core. Inorg Chem 2001; 40:5736-7. [PMID: 11681879 DOI: 10.1021/ic0155838] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- H M Alvarez
- Department of Chemistry, The University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, North Carolina 28223, USA
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Alvarez HM, Souto MF, Viale A, Pucci OH. Biosynthesis of fatty acids and triacylglycerols by 2,6,10,14-tetramethyl pentadecane-grown cells of Nocardia globerula 432. FEMS Microbiol Lett 2001; 200:195-200. [PMID: 11425475 DOI: 10.1111/j.1574-6968.2001.tb10715.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Nocardia globerula strain 432 was able to synthesize triacylglycerols (TAG) during cultivation on 2,6,10,14-tetramethyl pentadecane (pristane) under nitrogen-limiting conditions. Within these cells, 4,8,12-trimethyl tridecanoic acid was the major fatty acid detected. Fatty acids with an odd number of carbon atoms and minor amounts of even-numbered fatty acids were also observed. Experiments carried out with acrylic acid, an inhibitor of beta-oxidation, suggested that odd-numbered fatty acids such as C15:0, C17:0 and 10-methyl C17:0 were synthesized de novo using propionyl-CoA, the beta-oxidation product, as precursor. Although N. globerula 432 incorporated mainly straight chain fatty acids into TAG, the branched fatty acid 4,8,12-trimethyl tridecanoic acid also appeared, to some extent, in the acylglycerols. The importance of TAG biosynthesis by pristane-grown cells of N. globerula strain 432 is discussed.
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Affiliation(s)
- H M Alvarez
- CEIMA, Facultad de Ciencias Naturales, Universidad Nacional de la Patagonia SanJuan Bosco, Chubut, Argentina.
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Alvarez HM, Kalscheuer R, Steinbüchel A. Accumulation and mobilization of storage lipids by Rhodococcus opacus PD630 and Rhodococcus ruber NCIMB 40126. Appl Microbiol Biotechnol 2000; 54:218-23. [PMID: 10968636 DOI: 10.1007/s002530000395] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The time course of the accumulation of triacylglycerols (TAGs) in Rhodococcus opacus PD630 or of TAGs plus polyhydroxyalkanoates (PHA) in Rhodococcus ruber NCIMB 40126 with gluconate or glucose as carbon source, respectively, was studied. In addition, we examined the mobilization of these storage compounds in the absence of a carbon source. R. opacus accumulated TAGs only after the exhaustion of ammonium in the medium, and, with a fixed concentration of the carbon source, the amounts of TAGs in the cells increased with decreasing concentrations of ammonium in the medium. When these cells were incubated in the absence of an additional carbon source, about 90% of these TAGs were mobilized and used as endogenous carbon source, particularly if ammonium was available. R. ruber accumulated a copolyester consisting of 3-hydroxybutyrate and 3-hydroxyvalerate already during the early exponential growth phase, whereas TAGs were synthesized and accumulated mainly during the late exponential and stationary growth phases. In the stationary growth phase, synthesis of TAGs continued, whereas PHA was partially mobilized. In the absence of an additional carbon source but in the presence of ammonium, mobilization of TAGs started first and was then paralleled by the mobilization of PHA, resulting in an approximately 90% and 80% decrease of these storage compounds, respectively. During the accumulation phase, interesting shifts in the composition of the two storage compounds occurred, indicating that the substrates of the PHA synthase and the TAG synthesizing enzymes were provided to varying extents, depending on whether the cells were in the early or late exponential or in the stationary growth phase.
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Affiliation(s)
- H M Alvarez
- Institut für Mikrobiologie der Westfälischen Wilhelms-Universität Münster, Germany
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Abstract
An oleaginous hydrocarbon-degrading Rhodococcus opacus strain (PD630) was isolated from a soil sample. The cells were able to grow on a variety of substrates and to produce large amounts of three different types of intracellular inclusions during growth on alkanes, phenylalkanes, or non-hydrocarbon substrates. Electron microscopy revealed large numbers of electron-transparent inclusions with a sphere-like structure. In addition, electron-dense inclusions representing polyphosphate and electron-transparent inclusions with an elongated disc-shaped morphology occurred in small amounts. The electron-transparent inclusions of alkane- or gluconate-grown cells were composed of neutral lipids (98%, w/w), phospholipids (1.2%, w/w), and protein (0.8%, w/w). The major component of the cellular inclusions was triacylglycerols; minor amounts of diacylglycerols and probably also some free fatty acids were also present. Free fatty acids and/or fatty acids in acylglycerols in cells of R. opacus amounted up to 76 or 87% of the cellular dry weight in gluconate- or olive-oil-grown cells, respectively. The fatty acid composition of the inclusions depended on the substrate used for cultivation. In cells cultivated on n-alkanes, the composition of the fatty acids was related to the substrate, and intermediates of the beta-oxidation pathway, such as hexadecanoic or pentadecanoic acid, were among the acylglycerols. Hexadecanoic acid was also the major fatty acid (up 36% of total fatty acids) occurring in the lipid inclusions of gluconate-grown cells. This indicated that strain PD630 utilized beta-oxidation and de novo fatty acid biosynthesis for the synthesis of storage lipids. Inclusions isolated from phenyldecane-grown cells contained mainly the non-modified substrate and phenylalkanoic acids derived from the hydrocarbon oxidation, such as phenyldecanoic acid, phenyloctanoic acid, and phenylhexanoic acid, and approximately 5% (w/w) of diacylglycerols. The lipid inclusions seemed to have definite structures, probably with membranes at their surfaces, which allow them to maintain their shape, and with some associated proteins, probably involved in the inclusion formation.
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Affiliation(s)
- H M Alvarez
- CEIMA, Universidad Nacional de la Patagonia San Juan Bosco, km 4, 9000 Comodoro Rivadavia, Argentina
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