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Effect of an oil spill on fungal biomass in an estuarine mangrove of Lake Maracaibo, Venzuela, and its bioremediation
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Abstracts
BIOREMEDIATION A Comparison of Bacterial Immobilization Substrata and their use as Bioremediation Agents N.G. Wilson and G. Bradley University of Plymouth, Plymouth, UK Polyesterpolyurethane and a commercially available support (Biofix) and biosorbant (Drizit) were compared as immobilization substrata and bioremediation agents. Pseudomonas jkorescens was immobilized to each substratum and examined by scanning electron microscopy. Bacterial loading capacity was examined over eight days and the absorbancy of Ekofisk crude per gram of substrata estimated. Effectiveness in enhancing degradation of alkanes (C,+&) in crude Ekofisk or Petrol (Slovene diesel) at room temperature, in sea water or minimal media, was compared to a free system for up to 30 days. Drizit exhibited an enhanced level of degradation of alkanes C&& in diesel, had a comparable level of absorbancy of oil and a stable loading capacity relative to polyurethane and Biotix. These results indicate Drizit was the most suitable immobilization substratum used as a bioremediation agent under the conditions stated.
Biodegradation of Lignocellulosic Materials by Facultatively Anaerobic Soil Fungi L.R. Durrant Faculdad Engenharia de Alimentos, UNICAMP,
SP, Brazil
The production of ethanol through direct fermentation of lignocellulosic materials by two soil fungi isolated under anaerobic conditions was investigated. The strains (QlO and H2) were cultured under anaerobic, microaeropbiic and aerobic conditions on a medium containing ball-milled filter paper as the cellulose source and after its complete degradation, lignocellulases and fermentation products were determined. For both strains, high levels of xylanase activity followed by CMCase activity were present in the culture supematants. B-glucosidase and avicelase were also detected. Highest activities for Trichocladium canadense (strain QlO) and strain H2 (a basidiomycete species) were obtained when cultures were incubated under microaerophilic conditions and air, respectively. Ethanol was the major non-gaseous fermentation product. Highest conversion of cellulose to ethanol was obtained with strain QlO (g&96%), under non-aerated conditions. Strain H2 showed 81% under aerated conditions. Ethanol production decreased when microcrystalline cellulose and lignocellulosic substrates were used.
Effect of an Oil Spill on Fungal Biomass in an Estuarine Mangrove of Lake Maracaibo, Venzuela, and its Bioremediation M.B. Gonzalez’, R. Sala.@, N. Pereirab and H. Briceiio* “Universidad de1 Zulia, Fact&ad de Ciencias, Maracaibo and bPALMICHAL S.C., Estacidn Experimental Agricola, El Tablazo, Pequiven, Venezuela In order to seek remediation alternatives for a mangrove soil disturbed by hydrocarbons, the effect of a simulated oil spill on fungal biomass in an estuarine mangrove was evaluated. The following treatments were applied in randomly selected parcels containing Rhizophora mangle trees: oil (CR), oil plus fertilizer
(CR + F), oil plus shoreline cleaner (CR + L), and control (C). Physical-chemical parameters and biomass counts were determined over six months. Results were analysed by ANOVA and LSD tests, establishing two groups: C, CR + F and CR, CR + F, CR + L. Similar fungal biomass values in treatments C and CR + F indicate that use of fertilizers represents a valuable alternative for accelerating oil biodegradation processes, contributing in this way to the recuperation of the ecosystem. Also, a variation in biodiversity of the population affected was observed, probably as a result of the treatments applied.
Screening of Liininolytic Fungi for Soil Remediation. II - Production of Peroxidases and Phenoloxidases K.M.G. Machado”, W.R.F. Silva” and V.L.R. Bononib “CETEC, Belo Horizonte, MG, Brazil and bbtstituto de Botdnica, S&o Paulo, SP. Brazil Evidence suggests that the ability of white rot fungi to degrade an extremely diverse range of very persistent or toxic environmental pollutants is due, at least partially, to their lignin degrading system. This study aims to evaluate the ability of 44 basidiomycetes isolated in Brazil to produce ligninolytic enzymes. The production of enzymes was assessed in solid medium with sugar cane bagasse. Peroxidase activity was measured by the decolorization of Remazol Brilliant Blue and phenoloxidase using o-dianisidine as a substrate. Phanerochaete chrysosporium ATCC 28326 was used as control. Among the basidiomycetes tested, 12 and 7 failed to produce detectable peroxidases and phenoloxidases, respectively. Eleven have shown good production and belong to the genera Lentinus, Melanoporia, Peniophora, Trametes, Trichaptum and Trogia. Further examination of the enzymatic system of some of them is being conducted. The presence of lignin peroxidase, Manganese Peroxidase and Lactase will be evaluated. (Supported in part by RHODIA and CETEC.)
“Clean up” of Aeration Ponds in the Petrochemical Industry by Microbial Processes M.C. Maciel Souza”, A.G.T. Volponb, A.C. Quinteiro’, R.C. TorresCand A. Drozdowiczb ninstituto de Microbiologia, UFRJ, bCENPES, Petrobras and ‘REDUC, Petrobras, RJ, Brazil One of the problems in the petrochemical industry is environmental pollution caused by industrial wastes. Biodegradation is a decisive factor in the reduction of pollutant levels in aeration ponds. In this study of the aeration ponds in REDUC, the microbial population density was considered one of the most important parameters for characterising the clean up potential of this community. Microbiological counts on water and sludge were performed by the MPN method for total aerobic heterotrophs, total anaerobic heterotrophs, SRB, ammonifying and denitrifying hydrocarbon consumers, bacteria. Other organisms isolated were nitrogen fixers, cellulolytic microorganisms and bacteria which survive at high ammonia concentrations. Experiments with organic fertiliser were carried out in vitro in attempts to reduce the concentration of ammonia in the system and the efficiency of this treatment was shown by the increase in C : N ratio.
Abstracts
BIOREMEDIATION A Comparison of Bacterial Immobilization Substrata and their use as Bioremediation Agents N.G. Wilson and G. Bradley University of Plymouth, Plymouth, UK Polyesterpolyurethane and a commercially available support (Biofix) and biosorbant (Drizit) were compared as immobilization substrata and bioremediation agents. Pseudomonas jkorescens was immobilized to each substratum and examined by scanning electron microscopy. Bacterial loading capacity was examined over eight days and the absorbancy of Ekofisk crude per gram of substrata estimated. Effectiveness in enhancing degradation of alkanes (C,+&) in crude Ekofisk or Petrol (Slovene diesel) at room temperature, in sea water or minimal media, was compared to a free system for up to 30 days. Drizit exhibited an enhanced level of degradation of alkanes C&& in diesel, had a comparable level of absorbancy of oil and a stable loading capacity relative to polyurethane and Biotix. These results indicate Drizit was the most suitable immobilization substratum used as a bioremediation agent under the conditions stated.
Biodegradation of Lignocellulosic Materials by Facultatively Anaerobic Soil Fungi L.R. Durrant Faculdad Engenharia de Alimentos, UNICAMP,
SP, Brazil
The production of ethanol through direct fermentation of lignocellulosic materials by two soil fungi isolated under anaerobic conditions was investigated. The strains (QlO and H2) were cultured under anaerobic, microaeropbiic and aerobic conditions on a medium containing ball-milled filter paper as the cellulose source and after its complete degradation, lignocellulases and fermentation products were determined. For both strains, high levels of xylanase activity followed by CMCase activity were present in the culture supematants. B-glucosidase and avicelase were also detected. Highest activities for Trichocladium canadense (strain QlO) and strain H2 (a basidiomycete species) were obtained when cultures were incubated under microaerophilic conditions and air, respectively. Ethanol was the major non-gaseous fermentation product. Highest conversion of cellulose to ethanol was obtained with strain QlO (g&96%), under non-aerated conditions. Strain H2 showed 81% under aerated conditions. Ethanol production decreased when microcrystalline cellulose and lignocellulosic substrates were used.
Effect of an Oil Spill on Fungal Biomass in an Estuarine Mangrove of Lake Maracaibo, Venzuela, and its Bioremediation M.B. Gonzalez’, R. Sala.@, N. Pereirab and H. Briceiio* “Universidad de1 Zulia, Fact&ad de Ciencias, Maracaibo and bPALMICHAL S.C., Estacidn Experimental Agricola, El Tablazo, Pequiven, Venezuela In order to seek remediation alternatives for a mangrove soil disturbed by hydrocarbons, the effect of a simulated oil spill on fungal biomass in an estuarine mangrove was evaluated. The following treatments were applied in randomly selected parcels containing Rhizophora mangle trees: oil (CR), oil plus fertilizer
(CR + F), oil plus shoreline cleaner (CR + L), and control (C). Physical-chemical parameters and biomass counts were determined over six months. Results were analysed by ANOVA and LSD tests, establishing two groups: C, CR + F and CR, CR + F, CR + L. Similar fungal biomass values in treatments C and CR + F indicate that use of fertilizers represents a valuable alternative for accelerating oil biodegradation processes, contributing in this way to the recuperation of the ecosystem. Also, a variation in biodiversity of the population affected was observed, probably as a result of the treatments applied.
Screening of Liininolytic Fungi for Soil Remediation. II - Production of Peroxidases and Phenoloxidases K.M.G. Machado”, W.R.F. Silva” and V.L.R. Bononib “CETEC, Belo Horizonte, MG, Brazil and bbtstituto de Botdnica, S&o Paulo, SP. Brazil Evidence suggests that the ability of white rot fungi to degrade an extremely diverse range of very persistent or toxic environmental pollutants is due, at least partially, to their lignin degrading system. This study aims to evaluate the ability of 44 basidiomycetes isolated in Brazil to produce ligninolytic enzymes. The production of enzymes was assessed in solid medium with sugar cane bagasse. Peroxidase activity was measured by the decolorization of Remazol Brilliant Blue and phenoloxidase using o-dianisidine as a substrate. Phanerochaete chrysosporium ATCC 28326 was used as control. Among the basidiomycetes tested, 12 and 7 failed to produce detectable peroxidases and phenoloxidases, respectively. Eleven have shown good production and belong to the genera Lentinus, Melanoporia, Peniophora, Trametes, Trichaptum and Trogia. Further examination of the enzymatic system of some of them is being conducted. The presence of lignin peroxidase, Manganese Peroxidase and Lactase will be evaluated. (Supported in part by RHODIA and CETEC.)
“Clean up” of Aeration Ponds in the Petrochemical Industry by Microbial Processes M.C. Maciel Souza”, A.G.T. Volponb, A.C. Quinteiro’, R.C. TorresCand A. Drozdowiczb ninstituto de Microbiologia, UFRJ, bCENPES, Petrobras and ‘REDUC, Petrobras, RJ, Brazil One of the problems in the petrochemical industry is environmental pollution caused by industrial wastes. Biodegradation is a decisive factor in the reduction of pollutant levels in aeration ponds. In this study of the aeration ponds in REDUC, the microbial population density was considered one of the most important parameters for characterising the clean up potential of this community. Microbiological counts on water and sludge were performed by the MPN method for total aerobic heterotrophs, total anaerobic heterotrophs, SRB, ammonifying and denitrifying hydrocarbon consumers, bacteria. Other organisms isolated were nitrogen fixers, cellulolytic microorganisms and bacteria which survive at high ammonia concentrations. Experiments with organic fertiliser were carried out in vitro in attempts to reduce the concentration of ammonia in the system and the efficiency of this treatment was shown by the increase in C : N ratio.