- Email: [email protected]
Molecular biology of biodegradation
Abstracts
Molecular Biology of Biodegradation M.A.Z. Ayub Centro de Biotecnologia,
UFRGS, Porto Alegre, RS, Brazil
Organochlorines are greatly used, principally as herbicides, fungicides, wood preservatives, paint removers, solvents, etc. Apart from this, industrial efiluents from the chemical, petrochemical and paper industries, among others, contribute an enormous level of pollution in terms of biochemical and chemical oxygen demand. Using molecular biology techniques, it is possible to identify and isolate the genetic elements responsible for the metabolic steps involved in biodegradation. This basic scientific knowledge will be applied to the development of biotechnological tools to produce controlled, optimised processes for the biodegradation of effluents and other pollutants (insecticides, pesticides, fuels, etc.) using adapted or genetically modified microorganisms.
119
Most of the halogenated compounds in industrial effluents are toxic for biological life and recalcitrant for the environment. The purpose of our research is to investigate the biological mechanisms involved in the biodegradation of organochlorinated compounds. In the course of our work, we have been able to identify several types of aerobic bacteria isolated from cellulose pulp production effluents. These microorganisms exhibit the ability to survive and grow, possibly utilizing 4,5,6-trichloroguaiacol, usually found in this kind of effluent, as carbon source after enzymatic breakdown of the molecule. After isolating and characterizing these organisms we were able to identify two bacteria which show very high ability to survive and grow on amounts of trichloroguaiacol 3 x lo4 times higher than those found in cellulose pulp mill effluent. We are now investigating the physiology of trichloroguaiacol degradation and its relation to the structures of the plasmids we have found. (Supported by: GENOTOX, FAPERGS and CNPq.)
Oil Degrading Microorganisms E.G.C. Rodrigues, E.P. Menezes, L.M.M. Santa Anna, R.L. Vital and G.V. Shstian PetrobraslCENPES, RJ, Brazil
This paper is based on the selection and identification of rnicroorganisms that metabolize oil and its products as a source of carbon and energy. The microorganisms were selected from soils where oil had been spilled and from contaminated fuels. The change in composition in the hydrocarbon feed due to the microbial activity was analyzed by gas chromatography. Respirometric evaluation was used in the studies of oil degradation in soil and a great CO2 rate was detected. The strains Pseudomonas sp, Acinetobacter sp, Candida sp, Hormoconis resinae were identified, coni%ming their activity as good oil degraders, as reported in the current literature. Several products and research programs in biotechnology were derived directly from these studies, such as bioremediation of oil contaminated ground, prevention of microbial contamination in fuel, oil recovery and production of biosurfactants applied to the oil industry.
Anaerobic Degradation of a Pulp Mill Solid Waste E. Ratnieks” and C.C. Gaylarde6 “Technology Centre, RIOCELL S.A., Porto Alegre, Brazil and bDepartamento Solos, Faculdad, AgronomialUFRGS, Porto Alegre, Brazil
This experiment investigates the anaerobic degradation of complex organic compounds. The object of study is the solid sludge from a pulp mill waste-water treatment plant. The aim is to enhance the degradation of chlorinated organics, handling physical-chemical parameters of the sludge digestion in an anaerobic environment. The chlorinated organics are analyzed by the EOX (Extractable Organic Halogen) analysis. The degradation of organic matter is analyzed by COD,, values. The main enhancement factors studied were the pH of the degrading sludge and the use of surfactants. Distinct classes of surfactants and pH adjustment strategies were monitored in 20-l-lab vessels during a 6-month period. Each strategy displays distinct behavior, due to non-synchronic degradation rates over the time. The degradation or organic matter in the sludge is slow, and exceeds the time evaluated in this work.
Biodegradation of 4,5,6-Trichloroguaiacol by a Consortium of Aerobic Bacteria Isolated from Cellulose Pulp Mill Effluent E.C. Tondo, A.C.R. Cm&a and M.A.Z. Ayub Centro de Biotecnologia/UFRGS, Porto Alegre, RS, Brazil
Physiological Responses of Rhizophora mangle to Oil Spills: Possible Recovery on Transplantation N. Pereira”, A. Quilicib, H. Bricefio” and C. Infanteb “PALMICHAL, S.C., Estacidn Experimental Agricola El Tablazo, Pequiven, Zulia, and bINTEVEP, S.A., Gerencia General de Investigaciones Ecoldgicas y Ambientales, Caracas, Venezuela
Seedlings of R. mangle were submitted to oil spill conditions. applied were: petroleum (CR); petroTreatments leum + fertiliser (CR + F); petroleum + beach cleanser (CR + L); control (C). An ANOVA analysis was applied to the results of measurements of rate of photosynthesis (A), stomata1 conductance (Gs), rate of transpiration (E), internal concentration of CO2 (Ci) and efficiency of water use (EUA). The results were assessed after 5 months. For A, treatments CRfF and CR+L were not significantly different, both being higher than the control. Parameters E, Gs, Ci and EUA gave different results depending on the treatment. CR+L gave the least Ci and the greatest EUA. No significant differences in relative growth rate or in the ratio root/aerial mass were found. The resuls seem to indicate that treatment with fertilisers or with beach cleanser could be an alternative for the recovery of mangroves affected by hydrocarbons.
Biomass and Lactase Production by Trametes versicolor, Trametes villosa and Pycnoporus sanguineus G.A. Piva and R.W.S.P. Thomas Agronomy Faculty, UFRGS, Porto Alegre, RS, Brazil
The basidiomycete fungi Trametes versicolor, Trametes villosa and Pycnoporus sanguineus were grown with and without the lactase inducer resorcinol, in malt-extract broth and in wheybased liquid media in shake flask cultures at 28”C, pH 5.5, and an agitation rate of 90 rpm. Lactase production was monitored by the syringaldazine assay after 21 days of incubation. The results showed that P. sanguineus produced higher levels of lactase (800 units) than the Trametes species (350 units) when growing in malt-extract broth. Lactase was not detected in the whey-based media. Biomass production was assessed using the same media in a 1.5 1 bench fermentor with an aeration rate of 1 v/v/min and minimal agitation. Average biomass production in the malt-extract medium was 50% less than growth in whey.
Molecular Biology of Biodegradation M.A.Z. Ayub Centro de Biotecnologia,
UFRGS, Porto Alegre, RS, Brazil
Organochlorines are greatly used, principally as herbicides, fungicides, wood preservatives, paint removers, solvents, etc. Apart from this, industrial efiluents from the chemical, petrochemical and paper industries, among others, contribute an enormous level of pollution in terms of biochemical and chemical oxygen demand. Using molecular biology techniques, it is possible to identify and isolate the genetic elements responsible for the metabolic steps involved in biodegradation. This basic scientific knowledge will be applied to the development of biotechnological tools to produce controlled, optimised processes for the biodegradation of effluents and other pollutants (insecticides, pesticides, fuels, etc.) using adapted or genetically modified microorganisms.
119
Most of the halogenated compounds in industrial effluents are toxic for biological life and recalcitrant for the environment. The purpose of our research is to investigate the biological mechanisms involved in the biodegradation of organochlorinated compounds. In the course of our work, we have been able to identify several types of aerobic bacteria isolated from cellulose pulp production effluents. These microorganisms exhibit the ability to survive and grow, possibly utilizing 4,5,6-trichloroguaiacol, usually found in this kind of effluent, as carbon source after enzymatic breakdown of the molecule. After isolating and characterizing these organisms we were able to identify two bacteria which show very high ability to survive and grow on amounts of trichloroguaiacol 3 x lo4 times higher than those found in cellulose pulp mill effluent. We are now investigating the physiology of trichloroguaiacol degradation and its relation to the structures of the plasmids we have found. (Supported by: GENOTOX, FAPERGS and CNPq.)
Oil Degrading Microorganisms E.G.C. Rodrigues, E.P. Menezes, L.M.M. Santa Anna, R.L. Vital and G.V. Shstian PetrobraslCENPES, RJ, Brazil
This paper is based on the selection and identification of rnicroorganisms that metabolize oil and its products as a source of carbon and energy. The microorganisms were selected from soils where oil had been spilled and from contaminated fuels. The change in composition in the hydrocarbon feed due to the microbial activity was analyzed by gas chromatography. Respirometric evaluation was used in the studies of oil degradation in soil and a great CO2 rate was detected. The strains Pseudomonas sp, Acinetobacter sp, Candida sp, Hormoconis resinae were identified, coni%ming their activity as good oil degraders, as reported in the current literature. Several products and research programs in biotechnology were derived directly from these studies, such as bioremediation of oil contaminated ground, prevention of microbial contamination in fuel, oil recovery and production of biosurfactants applied to the oil industry.
Anaerobic Degradation of a Pulp Mill Solid Waste E. Ratnieks” and C.C. Gaylarde6 “Technology Centre, RIOCELL S.A., Porto Alegre, Brazil and bDepartamento Solos, Faculdad, AgronomialUFRGS, Porto Alegre, Brazil
This experiment investigates the anaerobic degradation of complex organic compounds. The object of study is the solid sludge from a pulp mill waste-water treatment plant. The aim is to enhance the degradation of chlorinated organics, handling physical-chemical parameters of the sludge digestion in an anaerobic environment. The chlorinated organics are analyzed by the EOX (Extractable Organic Halogen) analysis. The degradation of organic matter is analyzed by COD,, values. The main enhancement factors studied were the pH of the degrading sludge and the use of surfactants. Distinct classes of surfactants and pH adjustment strategies were monitored in 20-l-lab vessels during a 6-month period. Each strategy displays distinct behavior, due to non-synchronic degradation rates over the time. The degradation or organic matter in the sludge is slow, and exceeds the time evaluated in this work.
Biodegradation of 4,5,6-Trichloroguaiacol by a Consortium of Aerobic Bacteria Isolated from Cellulose Pulp Mill Effluent E.C. Tondo, A.C.R. Cm&a and M.A.Z. Ayub Centro de Biotecnologia/UFRGS, Porto Alegre, RS, Brazil
Physiological Responses of Rhizophora mangle to Oil Spills: Possible Recovery on Transplantation N. Pereira”, A. Quilicib, H. Bricefio” and C. Infanteb “PALMICHAL, S.C., Estacidn Experimental Agricola El Tablazo, Pequiven, Zulia, and bINTEVEP, S.A., Gerencia General de Investigaciones Ecoldgicas y Ambientales, Caracas, Venezuela
Seedlings of R. mangle were submitted to oil spill conditions. applied were: petroleum (CR); petroTreatments leum + fertiliser (CR + F); petroleum + beach cleanser (CR + L); control (C). An ANOVA analysis was applied to the results of measurements of rate of photosynthesis (A), stomata1 conductance (Gs), rate of transpiration (E), internal concentration of CO2 (Ci) and efficiency of water use (EUA). The results were assessed after 5 months. For A, treatments CRfF and CR+L were not significantly different, both being higher than the control. Parameters E, Gs, Ci and EUA gave different results depending on the treatment. CR+L gave the least Ci and the greatest EUA. No significant differences in relative growth rate or in the ratio root/aerial mass were found. The resuls seem to indicate that treatment with fertilisers or with beach cleanser could be an alternative for the recovery of mangroves affected by hydrocarbons.
Biomass and Lactase Production by Trametes versicolor, Trametes villosa and Pycnoporus sanguineus G.A. Piva and R.W.S.P. Thomas Agronomy Faculty, UFRGS, Porto Alegre, RS, Brazil
The basidiomycete fungi Trametes versicolor, Trametes villosa and Pycnoporus sanguineus were grown with and without the lactase inducer resorcinol, in malt-extract broth and in wheybased liquid media in shake flask cultures at 28”C, pH 5.5, and an agitation rate of 90 rpm. Lactase production was monitored by the syringaldazine assay after 21 days of incubation. The results showed that P. sanguineus produced higher levels of lactase (800 units) than the Trametes species (350 units) when growing in malt-extract broth. Lactase was not detected in the whey-based media. Biomass production was assessed using the same media in a 1.5 1 bench fermentor with an aeration rate of 1 v/v/min and minimal agitation. Average biomass production in the malt-extract medium was 50% less than growth in whey.