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Malafatti-Picca L, de Barros Chaves MR, de Castro AM, Valoni É, de Oliveira VM, Marsaioli AJ, de Franceschi de Angelis D, Attili-Angelis D. Hydrocarbon-associated substrates reveal promising fungi for poly (ethylene terephthalate) (PET) depolymerization. Braz J Microbiol 2019; 50:633-648. [PMID: 31175657 PMCID: PMC6863199 DOI: 10.1007/s42770-019-00093-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 04/03/2019] [Indexed: 12/11/2022] Open
Abstract
Recalcitrant characteristics and insolubility in water make the disposal of synthetic polymers a great environmental problem to be faced by modern society. Strategies towards the recycling of post-consumer polymers, like poly (ethylene terephthalate, PET) degradation/depolymerization have been studied but still need improvement. To contribute with this purpose, 100 fungal strains from hydrocarbon-associated environments were screened for lipase and esterase activities by plate assays and high-throughput screening (HTS), using short- and long-chain fluorogenic probes. Nine isolates were selected for their outstanding hydrolytic activity, comprising the genera Microsphaeropsis, Mucor, Trichoderma, Westerdykella, and Pycnidiophora. Two strains of Microsphaeropsis arundinis were able to convert 2-3% of PET nanoparticle into terephthalic acid, and when cultured with two kinds of commercial PET bottle fragments, they also promoted weight loss, surface and chemical changes, increased lipase and esterase activities, and led to PET depolymerization with release of terephthalic acid at concentrations above 20.0 ppm and other oligomers over 0.6 ppm. The results corroborate that hydrocarbon-associated areas are important source of microorganisms for application in environmental technologies, and the sources investigated revealed important strains with potential for PET depolymerization.
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Affiliation(s)
- Lusiane Malafatti-Picca
- Environmental Studies Center, UNESP, São Paulo State University, 24-A Av., 1515, Bela Vista, Rio Claro, SP, 13506-900, Brazil.
| | | | - Aline Machado de Castro
- Biotechnology Department, R&D Center, PETROBRAS, Av. Horácio Macedo, 950, Ilha do Fundão, Rio de Janeiro, RJ, 21941-915, Brazil
| | - Érika Valoni
- Biotechnology Department, R&D Center, PETROBRAS, Av. Horácio Macedo, 950, Ilha do Fundão, Rio de Janeiro, RJ, 21941-915, Brazil
| | - Valéria Maia de Oliveira
- Division of Microbial Resources, CPQBA - State University of Campinas, Alexandre Cazellato Str., 999, Paulínia, SP, 13148-218, Brazil
| | - Anita Jocelyne Marsaioli
- Institute of Chemistry, State University of Campinas, PO Box 6154, Campinas, SP, 13084-971, Brazil
| | - Dejanira de Franceschi de Angelis
- Department of Biochemistry and Microbiology, UNESP, São Paulo State University, 24-A Av., 1515, Bela Vista, Rio Claro, SP, 13506-900, Brazil
| | - Derlene Attili-Angelis
- Environmental Studies Center, UNESP, São Paulo State University, 24-A Av., 1515, Bela Vista, Rio Claro, SP, 13506-900, Brazil
- Division of Microbial Resources, CPQBA - State University of Campinas, Alexandre Cazellato Str., 999, Paulínia, SP, 13148-218, Brazil
- Department of Biochemistry and Microbiology, UNESP, São Paulo State University, 24-A Av., 1515, Bela Vista, Rio Claro, SP, 13506-900, Brazil
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Koshinsky HA, Schappert KT, Khachatourians GG. Isolation and characterization of Saccharomyces cerevisiae mutants resistant to T-2 toxin. Curr Genet 1988; 13:363-8. [PMID: 3042165 DOI: 10.1007/bf00365656] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
T-2 toxin, a trichothecene mycotoxin, inhibits the growth of Saccharomyces cerevisiae. We have isolated nine spontaneous S. cerevisiae mutants resistant to this toxin. The mutants were distinguished from the wild type according to their degree of resistance to T-2 toxin on media with dextrose or glycerol as the carbon source. Generation time, mutation stability and level of cross-resistance to roridin A, another trichothecene, were determined for each mutant. The T-2 toxin resistant mutants were further characterized by subsequent tests involving cross-resistance and collateral sensitivity to chlorampenicol, neomycin, paromomycin, ethidium bromide and thiolutin. Mutants have been placed into three subgroups and the mechanism of T-2 toxin resistance in each group has been postulated. Mutant HK1 is the first S. cerevisiae isolate resistant to roridin A. One particular isolate, mutant HK11, carries a single recessive nuclear mutation. This mutation was termed ttt (for T-2 toxin resistant).
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Affiliation(s)
- H A Koshinsky
- Department of Applied Microbiology and Food Science, University of Saskatchewan, Saskatoon, Canada
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Shearer G, Sypherd PS. Cycloheximide efflux in antibiotic-adapted cells of the fungus Mucor racemosus. Antimicrob Agents Chemother 1988; 32:341-5. [PMID: 3364951 PMCID: PMC172172 DOI: 10.1128/aac.32.3.341] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Mucor racemosus cells adapted to either cycloheximide or trichodermin were approximately 40-fold more resistant to cycloheximide than nonadapted cells. Ribosomes isolated from adapted and nonadapted cells were equally sensitive to cycloheximide in an in vitro poly(U) translation assay. There was no detectable modification of cycloheximide by adapted cells. Uptake of drug by nonadapted and adapted cells was characterized by a rapid initial accumulation during the first 2 min of incubation with [3H]cycloheximide, followed by a steady-state intracellular drug concentration well below that of the medium. The steady-state drug concentration was approximately 10-fold lower in adapted cells than in nonadapted cells. Treatment of cells with sodium azide or dinitrophenol abolished the difference between uptake of drug by nonadapted and adapted cells and resulted in intracellular drug levels equal to that of the medium. Direct efflux measurements showed that adapted cells loaded with cycloheximide were able to excrete the drug far more rapidly than nonadapted cells. These results suggest that both nonadapted and adapted cells possess an energy-dependent efflux mechanism for transporting cycloheximide and that resistance in adapted cells is due to increased efficiency of transport.
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Affiliation(s)
- G Shearer
- Department of Microbiology and Molecular Genetics, College of Medicine, University of California, Irvine 92717
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