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Genetic Engineering of Talaromyces marneffei to Enhance Siderophore Production and Preliminary Testing for Medical Application Potential. J Fungi (Basel) 2022; 8:jof8111183. [DOI: 10.3390/jof8111183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 11/02/2022] [Accepted: 11/07/2022] [Indexed: 11/11/2022] Open
Abstract
Siderophores are compounds with low molecular weight with a high affinity and specificity for ferric iron, which is produced by bacteria and fungi. Fungal siderophores have been characterized and their feasibility for clinical applications has been investigated. Fungi may be limited in slow growth and low siderophore production; however, they have advantages of high diversity and affinity. Hence, the purpose of this study was to generate a genetically modified strain in Talaromyces marneffei that enhanced siderophore production and to identify the characteristics of siderophore to guide its medical application. SreA is a transcription factor that negatively controls iron acquisition mechanisms. Therefore, we deleted the sreA gene to enhance the siderophore production and found that the null mutant of sreA (ΔsreA) produced a high amount of extracellular siderophores. The produced siderophore was characterized using HPLC-MS, HPLC-DAD, FTIR, and 1H- and 13C-NMR techniques and identified as a coprogen B. The compound showed a powerful iron-binding activity and could reduce labile iron pool levels in iron-loaded hepatocellular carcinoma (Huh7) cells. In addition, the coprogen B showed no toxicity to the Huh7 cells, demonstrating its potential to serve as an ideal iron chelator. Moreover, it inhibits the growth of Candida albicans and Escherichia coli in a dose-dependent manner. Thus, we have generated the siderophore-enhancing strain of T. marneffei, and the coprogen B isolated from this strain could be useful in the development of a new iron-chelating agent or other medical applications.
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Potor L, Sikura KÉ, Hegedűs H, Pethő D, Szabó Z, Szigeti ZM, Pócsi I, Trencsényi G, Szikra D, Garai I, Gáll T, Combi Z, Kappelmayer J, Balla G, Balla J. The Fungal Iron Chelator Desferricoprogen Inhibits Atherosclerotic Plaque Formation. Int J Mol Sci 2020; 21:ijms21134746. [PMID: 32635347 PMCID: PMC7369830 DOI: 10.3390/ijms21134746] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 06/26/2020] [Accepted: 07/01/2020] [Indexed: 12/14/2022] Open
Abstract
Hemoglobin, heme and iron are implicated in the progression of atherosclerosis. Therefore, we investigated whether the hydrophobic fungal iron chelator siderophore, desferricoprogen (DFC) inhibits atherosclerosis. DFC reduced atherosclerotic plaque formation in ApoE-/- mice on an atherogenic diet. It lowered the plasma level of oxidized LDL (oxLDL) and inhibited lipid peroxidation in aortic roots. The elevated collagen/elastin content and enhanced expression of adhesion molecule VCAM-1 were decreased. DFC diminished oxidation of Low-density Lipoprotein (LDL) and plaque lipids catalyzed by heme or hemoglobin. Formation of foam cells, uptake of oxLDL by macrophages, upregulation of CD36 and increased expression of TNF-α were reduced by DFC in macrophages. TNF-triggered endothelial cell activation (vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecules (ICAMs), E-selectin) and increased adhesion of monocytes to endothelium were attenuated. The increased endothelial permeability and intracellular gap formation provoked by TNF-α was also prevented by DFC. DFC acted as a cytoprotectant in endothelial cells and macrophages challenged with a lethal dose of oxLDL and lowered the expression of stress-responsive heme oxygenase-1 as sublethal dose was employed. Saturation of desferrisiderophore with iron led to the loss of the beneficial effects. We demonstrated that DFC accumulated within the atheromas of the aorta in ApoE-/- mice. DFC represents a novel therapeutic approach to control the progression of atherosclerosis.
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Affiliation(s)
- László Potor
- HAS-UD Vascular Biology and Myocardial Pathophysiology Research Group, Hungarian Academy of Sciences, University of Debrecen, 4012 Debrecen, Hungary; (L.P.); (K.É.S.); (T.G.)
- Department of Pediatrics, Faculty of Medicine, University of Debrecen, 4012 Debrecen, Hungary
- Division of Nephrology, Department of Medicine, Faculty of Medicine, University of Debrecen, 4012 Debrecen, Hungary; (H.H.); (D.P.); (Z.C.)
| | - Katalin Éva Sikura
- HAS-UD Vascular Biology and Myocardial Pathophysiology Research Group, Hungarian Academy of Sciences, University of Debrecen, 4012 Debrecen, Hungary; (L.P.); (K.É.S.); (T.G.)
- Department of Pediatrics, Faculty of Medicine, University of Debrecen, 4012 Debrecen, Hungary
- Division of Nephrology, Department of Medicine, Faculty of Medicine, University of Debrecen, 4012 Debrecen, Hungary; (H.H.); (D.P.); (Z.C.)
| | - Hajnalka Hegedűs
- Division of Nephrology, Department of Medicine, Faculty of Medicine, University of Debrecen, 4012 Debrecen, Hungary; (H.H.); (D.P.); (Z.C.)
| | - Dávid Pethő
- Division of Nephrology, Department of Medicine, Faculty of Medicine, University of Debrecen, 4012 Debrecen, Hungary; (H.H.); (D.P.); (Z.C.)
| | - Zsuzsa Szabó
- Department of Molecular Biotechnology and Microbiology, Institute of Technology, Faculty of Science and Technology, University of Debrecen, 4012 Debrecen, Hungary; (Z.S.); (Z.M.S.); (I.P.)
| | - Zsuzsa M Szigeti
- Department of Molecular Biotechnology and Microbiology, Institute of Technology, Faculty of Science and Technology, University of Debrecen, 4012 Debrecen, Hungary; (Z.S.); (Z.M.S.); (I.P.)
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Institute of Technology, Faculty of Science and Technology, University of Debrecen, 4012 Debrecen, Hungary; (Z.S.); (Z.M.S.); (I.P.)
| | - György Trencsényi
- Scanomed Ltd., University of Debrecen, 4012 Debrecen, Hungary; (G.T.); (D.S.); (I.G.)
| | - Dezső Szikra
- Scanomed Ltd., University of Debrecen, 4012 Debrecen, Hungary; (G.T.); (D.S.); (I.G.)
| | - Ildikó Garai
- Scanomed Ltd., University of Debrecen, 4012 Debrecen, Hungary; (G.T.); (D.S.); (I.G.)
| | - Tamás Gáll
- HAS-UD Vascular Biology and Myocardial Pathophysiology Research Group, Hungarian Academy of Sciences, University of Debrecen, 4012 Debrecen, Hungary; (L.P.); (K.É.S.); (T.G.)
- Division of Nephrology, Department of Medicine, Faculty of Medicine, University of Debrecen, 4012 Debrecen, Hungary; (H.H.); (D.P.); (Z.C.)
| | - Zsolt Combi
- Division of Nephrology, Department of Medicine, Faculty of Medicine, University of Debrecen, 4012 Debrecen, Hungary; (H.H.); (D.P.); (Z.C.)
| | - János Kappelmayer
- Department of Laboratory Medicine, Faculty of Medicine, University of Debrecen, 4012 Debrecen, Hungary;
| | - György Balla
- HAS-UD Vascular Biology and Myocardial Pathophysiology Research Group, Hungarian Academy of Sciences, University of Debrecen, 4012 Debrecen, Hungary; (L.P.); (K.É.S.); (T.G.)
- Department of Pediatrics, Faculty of Medicine, University of Debrecen, 4012 Debrecen, Hungary
- Correspondence: (G.B.); (J.B.)
| | - József Balla
- HAS-UD Vascular Biology and Myocardial Pathophysiology Research Group, Hungarian Academy of Sciences, University of Debrecen, 4012 Debrecen, Hungary; (L.P.); (K.É.S.); (T.G.)
- Division of Nephrology, Department of Medicine, Faculty of Medicine, University of Debrecen, 4012 Debrecen, Hungary; (H.H.); (D.P.); (Z.C.)
- Correspondence: (G.B.); (J.B.)
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Farkas E, Szabó O, Gyémánt G, Szaniszló S, Szabó Z, Pócsi I. Complexation of hydroxamate-based siderophores with cobalt(II/III): growth inhibitory effect of cobalt(III)-desferricoprogen complex on fungi. TRANSIT METAL CHEM 2018. [DOI: 10.1007/s11243-018-0225-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Szigeti Z, Szaniszló S, Fazekas E, Gyémánt G, Szabon J, Antal K, Emri T, Balla J, Balla G, Csernoch L, Pócsi I. Optimization of triacetylfusarinine C and ferricrocin productions in Aspergillus fumigatus. Acta Microbiol Immunol Hung 2014; 61:107-19. [PMID: 24939680 DOI: 10.1556/amicr.61.2014.2.2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Iron is an essential element for all microorganisms. Bacteria and fungi produce versatile siderophores for binding and storing this essential transition metal when its availability is limited in the environment. The aim of the study was to optimize the fermentation medium of Aspergillus fumigatus for siderophore production. Triacetyl-fusarinine C and ferricrocin yields were dependent on glucose and glycine supplementations as well as the initial pH of the culture media. The optimal fermentation medium for triacetylfusarinine C production contained 8% glucose, 0.4% glycine and the initial pH was set to 5.9. Meanwhile, maximal ferricrocin yields were recorded in the presence of 10% glucose, 0.5% glycine and at an initial pH of 7.4. Under optimized fermentation conditions, the yields for triacetylfusarinine C and ferricrocin increased up to 2.9 g/l culture medium and 18.9 mg/g mycelium, respectively.
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Affiliation(s)
- Zsuzsa Szigeti
- 1 University of Debrecen Department of Microbial Biotechnology and Cell Biology, Faculty of Science and Technology Debrecen Hungary
| | - Szilvia Szaniszló
- 1 University of Debrecen Department of Microbial Biotechnology and Cell Biology, Faculty of Science and Technology Debrecen Hungary
| | - Erika Fazekas
- 2 University of Debrecen Department of Inorganic and Analytical Chemistry, Faculty of Science and Technology Debrecen Hungary
| | - Gyöngyi Gyémánt
- 2 University of Debrecen Department of Inorganic and Analytical Chemistry, Faculty of Science and Technology Debrecen Hungary
| | - Judit Szabon
- 1 University of Debrecen Department of Microbial Biotechnology and Cell Biology, Faculty of Science and Technology Debrecen Hungary
| | - Károly Antal
- 3 Eszterházy Károly College Department of Zoology, Faculty of Sciences Eger Hungary
| | - Tamás Emri
- 1 University of Debrecen Department of Microbial Biotechnology and Cell Biology, Faculty of Science and Technology Debrecen Hungary
| | | | | | - László Csernoch
- 7 University of Debrecen Department of Physiology, Medical and Health Science Center Debrecen Hungary
| | - István Pócsi
- 1 University of Debrecen Department of Microbial Biotechnology and Cell Biology, Faculty of Science and Technology Debrecen Hungary
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Tircsó G, Garda Z, Kálmán FK, Baranyai Z, Pócsi I, Balla G, Tóth I. Lanthanide(III) complexes of some natural siderophores: A thermodynamic, kinetic and relaxometric study. J Inorg Biochem 2013; 127:53-61. [DOI: 10.1016/j.jinorgbio.2013.06.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Revised: 06/09/2013] [Accepted: 06/10/2013] [Indexed: 11/25/2022]
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Emri T, Tóth V, Nagy CT, Nagy G, Pócsi I, Gyémánt G, Antal K, Balla J, Balla G, Román G, Kovács I, Pócsi I. Towards high-siderophore-content foods: optimisation of coprogen production in submerged cultures of Penicillium nalgiovense. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2013; 93:2221-2228. [PMID: 23349056 DOI: 10.1002/jsfa.6029] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 10/25/2012] [Accepted: 12/06/2012] [Indexed: 06/01/2023]
Abstract
BACKGROUND Fungal siderophores are likely to possess atheroprotective effects in humans, and therefore studies are needed to develop siderophore-rich food additives or functional foods to increase the siderophore uptake in people prone to cardiovascular diseases. In this study the siderophore contents of mould-ripened cheeses and meat products were analysed and the coprogen production by Penicillium nalgiovense was characterised. RESULTS High concentrations of hexadentate fungal siderophores were detected in penicillia-ripened Camembert- and Roquefort-type cheeses and also in some sausages. In one sausage fermented by P. nalgiovense, the siderophore content was comparable to those found in cheeses. Penicillium nalgiovense produced high concentrations of coprogen in submerged cultures, which were affected predominantly by the available carbon and nitrogen sources under iron starvation. Considerable coprogen yields were still detectable in the presence of iron when the fermentation medium was supplemented with the iron chelator Na₂-EDTA or when P. nalgiovense was co-cultivated with Saccharomyces cerevisiae. CONCLUSION These data may be exploitable in the future development of high-siderophore-content foods and/or food additives. Nevertheless, the use of P. nalgiovense fermentation broths for these purposes may be limited by the instability of coprogen in fermentation media and by the β-lactam production by the fungus.
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Affiliation(s)
- Tamás Emri
- Department of Microbial Biotechnology and Cell Biology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
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Szabó O, Farkas E. Characterization of Mn(II) and Mn(III) binding capability of natural siderophores desferrioxamine B and desferricoprogen as well as model hydroxamic acids. Inorganica Chim Acta 2011. [DOI: 10.1016/j.ica.2011.07.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Smidák R, Jopcík M, Kralovicová M, Gajdosíková J, Kormanec J, Timko J, Turna J. Core promoters of the penicillin biosynthesis genes and quantitative RT-PCR analysis of these genes in high and low production strain of Penicillium chrysogenum. Folia Microbiol (Praha) 2010; 55:126-32. [PMID: 20490754 DOI: 10.1007/s12223-010-0019-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Revised: 12/09/2009] [Indexed: 11/30/2022]
Abstract
The transcription start points of the penicillin biosynthesis genes from Penicillium chrysogenum were mapped using the primer extension method. For each of the three genes consensus sequences of the core promoter elements were identified, supporting the notion that the basal transcription of these genes is mediated separately. Interestingly, transcription start of the pcbC gene is located within the potential Inr element with no TATA box-like sequence being found at expected position. This is in contrast to pcbAB and penDE genes with proposed TATA boxes or even to Aspergillus nidulans ipnA (pcbC) gene indicating possible differences in basal transcription regulation. Using the quantitative RT-PCR analysis the expression of all three biosynthesis genes was monitored in both the high and low production strain of P. chrysogenum during a 3-d cultivation under production conditions. The differences were found between the strains in time regulation and transcript levels of the biosynthesis genes. Furthermore, we showed that the effect of higher gene dosage on productivity in the production strain is amplified by more efficient transcription of the biosynthesis genes with the RNA levels approximately 37- and 12-times higher, respectively, than in a low production strain.
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Affiliation(s)
- R Smidák
- Institute of Molecular Biology, Slovak Academy of Sciences, 845 51, Bratislava 45, Slovak Republic.
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Pócsi I, Jeney V, Kertai P, Pócsi I, Emri T, Gyémánt G, Fésüs L, Balla J, Balla G. Fungal siderophores function as protective agents of LDL oxidation and are promising anti-atherosclerotic metabolites in functional food. Mol Nutr Food Res 2008; 52:1434-47. [DOI: 10.1002/mnfr.200700467] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Pócsi I, Miskei M, Karányi Z, Emri T, Ayoubi P, Pusztahelyi T, Balla G, Prade RA. Comparison of gene expression signatures of diamide, H2O2 and menadione exposed Aspergillus nidulans cultures--linking genome-wide transcriptional changes to cellular physiology. BMC Genomics 2005; 6:182. [PMID: 16368011 PMCID: PMC1352360 DOI: 10.1186/1471-2164-6-182] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2005] [Accepted: 12/20/2005] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In addition to their cytotoxic nature, reactive oxygen species (ROS) are also signal molecules in diverse cellular processes in eukaryotic organisms. Linking genome-wide transcriptional changes to cellular physiology in oxidative stress-exposed Aspergillus nidulans cultures provides the opportunity to estimate the sizes of peroxide (O2(2-)), superoxide (O2*-) and glutathione/glutathione disulphide (GSH/GSSG) redox imbalance responses. RESULTS Genome-wide transcriptional changes triggered by diamide, H2O2 and menadione in A. nidulans vegetative tissues were recorded using DNA microarrays containing 3533 unique PCR-amplified probes. Evaluation of LOESS-normalized data indicated that 2499 gene probes were affected by at least one stress-inducing agent. The stress induced by diamide and H2O2 were pulse-like, with recovery after 1 h exposure time while no recovery was observed with menadione. The distribution of stress-responsive gene probes among major physiological functional categories was approximately the same for each agent. The gene group sizes solely responsive to changes in intracellular O2(2-), O2*- concentrations or to GSH/GSSG redox imbalance were estimated at 7.7, 32.6 and 13.0 %, respectively. Gene groups responsive to diamide, H2O2 and menadione treatments and gene groups influenced by GSH/GSSG, O2(2-) and O2*- were only partly overlapping with distinct enrichment profiles within functional categories. Changes in the GSH/GSSG redox state influenced expression of genes coding for PBS2 like MAPK kinase homologue, PSK2 kinase homologue, AtfA transcription factor, and many elements of ubiquitin tagging, cell division cycle regulators, translation machinery proteins, defense and stress proteins, transport proteins as well as many enzymes of the primary and secondary metabolisms. Meanwhile, a separate set of genes encoding transport proteins, CpcA and JlbA amino acid starvation-responsive transcription factors, and some elements of sexual development and sporulation was ROS responsive. CONCLUSION The existence of separate O2(2-), O2*- and GSH/GSSG responsive gene groups in a eukaryotic genome has been demonstrated. Oxidant-triggered, genome-wide transcriptional changes should be analyzed considering changes in oxidative stress-responsive physiological conditions and not correlating them directly to the chemistry and concentrations of the oxidative stress-inducing agent.
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Affiliation(s)
- István Pócsi
- Department of Microbiology and Biotechnology, Faculty of Science, University of Debrecen, P.O.Box 63, H-4010 Debrecen, Hungary
| | - Márton Miskei
- Department of Microbiology and Biotechnology, Faculty of Science, University of Debrecen, P.O.Box 63, H-4010 Debrecen, Hungary
| | - Zsolt Karányi
- Department of Medicine, Faculty of Medicine, University of Debrecen, P.O. Box 19, H-4012 Debrecen, Hungary
| | - Tamás Emri
- Department of Microbiology and Biotechnology, Faculty of Science, University of Debrecen, P.O.Box 63, H-4010 Debrecen, Hungary
| | - Patricia Ayoubi
- Department of Biochemistry and Molecular Biology, Oklahoma State University, 348E Noble Research Center, Stillwater, OK 74078, USA
| | - Tünde Pusztahelyi
- Department of Microbiology and Biotechnology, Faculty of Science, University of Debrecen, P.O.Box 63, H-4010 Debrecen, Hungary
| | - György Balla
- Department of Neonatology, Faculty of Medicine, University of Debrecen, P.O.Box 37; H-4012 Debrecen, Hungary
| | - Rolf A Prade
- Department of Microbiology and Molecular Genetics, Oklahoma State University, 307 LSE, Stillwater, OK 74078, USA
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Enyedy EA, Pócsi I, Farkas E. Complexation of desferricoprogen with trivalent Fe, Al, Ga, In and divalent Fe, Ni, Cu, Zn metal ions: effects of the linking chain structure on the metal binding ability of hydroxamate based siderophores. J Inorg Biochem 2005; 98:1957-66. [PMID: 15522421 DOI: 10.1016/j.jinorgbio.2004.08.017] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2004] [Revised: 08/10/2004] [Accepted: 08/24/2004] [Indexed: 11/17/2022]
Abstract
Complexes of the natural siderophore, desferricoprogen (DFC), with several trivalent and divalent metal ions in aqueous solution were studied by pH-potentiometry, UV-Vis spectrophotometry and cyclic voltammetry. DFC was found to be an effective metal binding ligand, which, in addition to Fe(III), forms complexes of high stability with Ga(III), Al(III), In(III), Cu(II), Ni(II) and Zn(II). Fe(II), however, is oxidized by DFC under anaerobic conditions and Fe(III) complexes are formed. By comparing the results with those of desferrioxamine B (DFB), it can be concluded that the conjugated beta-double bond slightly increases the stability of the hydroxamate chelates, consequently increases the stability of mono-chelated complexes of DFC. Any steric effect by the connecting chains arises only in the bis- and tris-chelated complexes. With metal ions possessing a relatively big ionic radius (Cu(II), Ni(II), Zn(II), In(III)) DFC, containing a bit longer chains than DFB, forms slightly more stable complexes. With smaller metal ions the trend is the opposite. Also a notable difference is that stable trinuclear complex, [Cu(3)L(2)], is formed with DFC but not with DFB. Possible bio-relevance of the Fe(II)/Fe(III) results is also discussed in the paper.
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Affiliation(s)
- Eva A Enyedy
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem ter 1, P.O. Box 21, H-4010 Debrecen, Hungary
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Emri T, Molnár Z, Pusztahelyi T, Pócsi I. Physiological and morphological changes in autolyzingAspergillus nidulans cultures. Folia Microbiol (Praha) 2004; 49:277-84. [PMID: 15259768 DOI: 10.1007/bf02931043] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Physiological and morphological changes in carbon-limited autolyzing cultures of Aspergillus nidulans were described. The carbon starvation arrested conidiation while the formation of filamentous and "yeast-like" hyphal fragments with profoundly altered metabolism enabled the fungus to survive the nutritional stress. The morphological and physiological stress responses, which maintained the cellular integrity of surviving hyphal fragments at the expense of autolyzing cells, were highly concerted and regulated. Moreover, sublethal concentrations of the protein synthesis inhibitor cycloheximide or the mitochondrial uncoupler 2,4-dinitrophenol completely blocked the autolysis. In accordance with the propositions of the free-radical theory of ageing reactive oxygen species accumulated in the surviving fragments with a concomitant increase in the specific superoxide dismutase activity and a continuous decrease in cell viability. Glutathione was degraded extensively in carbon-starving cells due to the action of gamma-glutamyltranspeptidase, which resulted in a glutathione-glutathione disulfide redox imbalance during autolysis.
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Affiliation(s)
- T Emri
- Department of Microbiology and Biotechnology, Faculty of Science, University of Debrecen, 4010 Debrecen, Hungary.
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Sámi L, Karaffa L, Emri T, Pócsi I. Autolysis and ageing of Penicillium chrysogenum under carbon starvation: respiration and glucose oxidase production. Acta Microbiol Immunol Hung 2003; 50:67-76. [PMID: 12793202 DOI: 10.1556/amicr.50.2003.1.7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
During the exponential growth phase of Penicillium chrysogenum NCAIM 00237 the effective conversion of glucose and O2 to gluconate and H2O2 by glucose oxidase (GOX) was the most likely source of intracellular ROS measured. In glucose-supplemented autolysing cultures, the increased of intracellular ROS concentration was attributed to respiration in the absence of any significant GOX activity. The induction of GOX and catalase by glucose and H2O2 was clearly age-dependent in P. chrysogenum. In ageing cryptic growth phase cultures, superoxide dismutase and cyanide-resistant respiration were the major elements of antioxidative defence but these activities were insufficient to prevent the progressive accumulation of ROS and the concomitant decrease in cell vitality.
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Affiliation(s)
- L Sámi
- Department of Microbiology and Biotechnology, Faculty of Sciences, University of Debrecen, P.O. Box 63, H-4010 Debrecen, Hungary
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Pócsi I, Emri T, Sámi L, Leiter E, Szentirmai A. The glutathione metabolism of the beta-lactam producer filamentous fungus Penicillium chrysogenum. Acta Microbiol Immunol Hung 2002; 48:393-411. [PMID: 11791340 DOI: 10.1556/amicr.48.2001.3-4.9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Glutathione (gamma-L-glutamyl-L-cysteinyl-glycine; GSH) shares structural similarities with the beta-lactam biosynthetic intermediate ACV-tripeptide (delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine). Not surprisingly, GSH has been reported to inhibit the beta-lactam biosynthetic machinery quite effectively and, hence, strategies to decrease the intracellular GSH concentrations without influencing negatively the physiological status of idiophasic mycelia would attract industrial interests. Here we present a detailed map of the GSH metabolic network of P. chrysogenum and show a promising way to keep the GSH pool selectively down under penicillin producing conditions. This procedure includes a well-controlled and transient lowering of pH at the beginning of the production phase, and it relies on the GSH-dependent detoxification of the protonophore penicillin side-chain precursors phenoxyacetic acid (POA) and phenylacetic acid (PA). Encouraging preliminary fed-batch fermentation experiments have been performed to test this technological proposal. Interestingly, the mechanism of the activation of POA and PA to the appropriate CoA derivatives has remained yet to be answered but the involvement of GSH seems to be rather unlikely in this case. Our data also challenge the hypothesis that the formation of different kinds of penicillins would be an alternative to GSH-dependent detoxification processes in P. chrysogenum.
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Affiliation(s)
- I Pócsi
- Department of Microbiology and Biotechnology, Faculty of Sciences, University of Debrecen, P.O. Box 63, H-4010 Debrecen, Hungary
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