Polymerization study of the aromatic amines generated by the biodegradation of azo dyes using the laccase enzyme

Four different azo dyes were decolorized (color reduction >90%) by bacteria isolated from a textile wastewater effluent. Dye decolorizing was carried out under microaerobic conditions until completion, after which the aromatic amine concentration was determined. A laccase from Myceliophthora thermophila was used to catalyze coupling reactions of the aromatic amines produced from decolorizing the dyes. The reaction was carried out with stirring (100 rpm) in a weak acidic buffer solution (pH 5.0) at 45 °C for 3 days. The presence of aromatic amines in the samples after bacterial decolorizing confirmed the azo bond was reduced in the process. In addition, the UV–vis spectrum was shifted significantly after the sequential bacterial-laccase treatment also indicating a chemical transformation of the dyes. After laccase treatment the solutions formed colored soluble and precipitated products. The particles sizes making up the precipitates formed after laccase treatment varied between 105 and 483 nm as determined by Photon Correlation Spectroscopy (PCS). The laccase treatment also reduced the COD of the dye solutions by ∼20%. We show that successive bacterial-laccase treatment is effective in decolorized azo dyes by reduction of the azo bonds, and promoting coupling reactions between the aromatic amines formed. Promoting coupling reactions between the aromatic amines using enzymes may prove useful for the physical removal and reuse of these amines.The authors would like to thank the Brazilian Foundation Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior of the Ministry of Education (CAPES) and the National Counsel for Technological and Scientific Development (CNPq) for providing grants to Elisangela Franciscon

Enhanced reduction of COD and aromatics in petroleum-produced water using indigenous microorganisms and nutrient addition

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Petroleum reservoir produced water is a high volume waste stream that is frequently hypersaline with a high chemical oxygen demand (COD) as well as containing water soluble aromatic compounds such as phenols. Biological treatment of produced water is problematic due to the high saline content, which inhibits conventional wastewater treatment systems. Phenol, benzoic acid, and para-hydroxybenzoic acid degrading Halomonas sp. were isolated from hypersaline produced water (100 g l(-1) NaCl) from a standard storage facility demonstrating that the indigenous microbial population had the potential to degrade aromatic compounds. Addition of specific nitrogen, phosphorous, and carbon sources under aerobic conditions was shown to stimulate the indigenous population. Chemical oxygen demand reduction increased from 20% without additions to as much as 65-80% with the addition of low levels of phosphate combined with alanine or glucuronic acid, or tryptone in combination with glucuronic acid. Phenol and benzoic acid were also shown to be significantly reduced in those cultures where significant improvement in COD reduction was observed. The results indicated that the indigenous microbial population in hypersaline produced water can be used to successfully reduce the COD and remove aromatic compounds using nutrient addition without dilution of the saline content. (C) 2012 Elsevier Ltd. All rights reserved.687884Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Phylogenetic Analysis Of The Microbial Community In Hypersaline Petroleum Produced Water From The Campos Basin

In this work the archaea and eubacteria community of a hypersaline produced water from the Campos Basin that had been transported and discharged to an onshore storage facility was evaluated by 16S recombinant RNA (rRNA) gene sequence analysis. The produced water had a hypersaline salt content of 10 (w/v), had a carbon oxygen demand (COD) of 4,300 mg/l and contains phenol and other aromatic compounds. The high salt and COD content and the presence of toxic phenolic compounds present a problem for conventional discharge to open seawater. In previous studies, we demonstrated that the COD and phenolic content could be largely removed under aerobic conditions, without dilution, by either addition of phenol degrading Haloarchaea or the addition of nutrients alone. In this study our goal was to characterize the microbial community to gain further insight into the persistence of reservoir community members in the produced water and the potential for bioremediation of COD and toxic contaminants. Members of the archaea community were consistent with previously identified communities from mesothermic reservoirs. All identified archaea were located within the phylum Euryarchaeota, with 98 % being identified as methanogens while 2 % could not be affiliated with any known genus. Of the identified archaea, 37 % were identified as members of the strictly carbon-dioxide-reducing genus Methanoplanus and 59 % as members of the acetoclastic genus Methanosaeta. No Haloarchaea were detected, consistent with the need to add these organisms for COD and aromatic removal. Marinobacter and Halomonas dominated the eubacterial community. The presence of these genera is consistent with the ability to stimulate COD and aromatic removal with nutrient addition. In addition, anaerobic members of the phyla Thermotogae, Firmicutes, and unclassified eubacteria were identified and may represent reservoir organisms associated with the conversion hydrocarbons to methane. © 2014 Springer-Verlag Berlin Heidelberg

Identification And Characterization Of Aromatic Degrading Halomonas In Hypersaline Produced Water And Cod Reduction By Bioremediation By The Indigenous Microbial Population Using Nutrient Addition

Hypersaline produced water is a high volume waste stream that is typically contaminated by toxic low molecular weight aromatic compounds exemplified by phenol. Aromatic compound degrading Halomonas were isolated from hypersaline produced water obtained from offshore operations in Brazil, which had a chemical oxygen demand (COD) of 4300 mg/L. These isolates were able to aerobically degrade the oxygenated aromatics phenol, benzoic acid, para-hydroxybenzoic acid and some isolates were shown to produce aromatic dioxygenase activities associated with highly conserved aromatic degradation pathways utilized by a broad range of aromatic degrading bacteria. The presence of aromatic degrading bacteria in the hypersaline produced water suggested that the COD content could be reduced by bioremediation using the indigenous microbial population by the addition of nutrients. Using this approach a variety of nitrogen, phosphorous and carbons sources were identified that individually or in combination significantly improved the reduction in COD after aerobic incubation. These results demonstrate the potential of applying bioremediation to undiluted hypersaline produced water for COD reduction and aromatic compound removal. Copyright © 2012, AIDIC Servizi S.r.l.27385390Arnold, R., Burnett, D.B., Elphick, J., Feeley III, T.J., Galbrun, M., Hightower, M., Jiang, Z., Verbeek, P., Managing water-from waste to resource (2004) Oilfield Review, 16 (2), pp. 26-41Ausubel, F.M.R., Kinston, R.E., Moore, D.D., Seidman, J.G., Smith, J.A., Strhl, K., (1989) Current Protocols in Molecular Biology, , John Wiley & Sons, New York, USAClark, C.E., Veil, J.A., (2009) A White Paper Describing Produced Water Volumes and Managements Pratices in the United States, , Prepared by Argonne National Laboratory, Argonne, Illinois for the U.S. Department of Energy, National Energy Technology Laboratory, USAFairley, D.J., Boyd, D.R., Sharma, N.D., Allen, C.C., Morgan, P., Larkin, M.J., Aerobic metabolism of 4-hydroxybenzoic acid in Archaea via an unusual pathway involving an intramolecular migration (NIH shift) (2002) Applied Environmental Microbiology, 68, pp. 6246-6255García, M.T., Ventosa, A., Mellado, E., Catabolic versatility of aromatic compound-degrading halophilic bacteria (2005) FEMS Microbiology Ecology, 54 (1), pp. 97-109Lefebvre, O., Moletta, R., Treatment of organic pollution in industrial saline wastewater: A literature review (2006) Water Research, 40, pp. 3671-3682Masai, E., Yamada, A., Healey, J.M., Hatta, T., Kimbara, K., Fukuda, M., Yano, K., Characterization of biphenyl catabolic genes of Gram-positive polychlorinated biphenyl degrader Rhodococcus sp. strain RHA1 (1995) Applied Environmental Microbiology, 61, pp. 2079-2085Oie, C.S., Albaugh, C.E., Peyton, B.M., Benzoate and salicylate degradation by Halomonas campisalis, an alkaliphilic and moderately halophilic microorganism (2007) Water Research, 41, pp. 1235-1242Ornston, L.N., Stanier, R.Y., The conversion of catechol and protocatechuate to β- Ketoadipate by Pseudomonas putida (1966) Journal of Biological Chemistry, 241, pp. 3776-3786Speight, J.G., (2007) The Chemistry and Technology of Petroleum, , 4th edn. Marcel Dekker, New York,USAVeil, J.A., Puder, M., Elcock, D., Redweik, R.Jr., (2004) A White Paper Describing Produced Water from Production of Crude Oil, Natural Gas, and Coal Bed Methane, , Prepared by Argonne National Laboratory, Argonne, Illinois for the U.S. Department of Energy, National Energy Technology Laboratory, USAWolin, E.A., Wolin, M.J., Wolfe, R.S., Formation of methane by bacterial extracts (1963) Journal of Biological Chemistry, 238, pp. 2882-2886Yang, C., Wang, Z., Li, Y., Niu, Y., Du, M., He, X., Ma, C., Xu, P., Metabolic versatility of halotolerant and alkaliphilic strains of Halomonas isolated from alkaline black liquor (2010) Bioresource Technology, 101, pp. 6778-6784Zhao, B., Wang, H., Mao, X., Li, R., Biodegradation of phenanthrene by a halophilic bacterial consortium under aerobic conditions (2009) Current Microbiology, 58 (3), pp. 205-210Zhuang, X., Han, Z., Bai, Z., Zhuang, G., Shim, H., Progress in decontamination by halophilic microorganisms in saline wastewater and soil (2010) Environmental Pollution, 158, pp. 1119-211

Phenol degradation by halophilic bacteria isolated from hypersaline environments

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Phenol is a toxic aromatic compound used or produced in many industries and as a result a common component of industrial wastewaters. Phenol containing waste streams are frequently hypersaline and therefore require halophilic microorganisms for efficient biotreatment without dilution. In this study three halophilic bacteria isolated from different saline environments and identified as Halomonas organivorans, Arhodomonas aquaeolei and Modicisalibacter tunisiensis were shown to be able to grow on phenol in hypersaline media containing 100 g/L of total salts at a concentration of 3 mM (280 mg/L), well above the concentration found in most waste streams. Genes encoding the aromatic dioxygenase enzymes catechol 1,2 dioxygenase and protocatechuate 3,4-dioxygenase were present in all strains as determined by PCR amplification using primers specific for highly conserved regions of the genes. The gene for protocatechuate 3,4-dioxygenase was cloned from the isolated H. organivorans and the translated protein was evaluated by comparative protein sequence analysis with protocatechuate 3,4-dioxygenase proteins from other microorganisms. Although the analysis revealed a wide range of sequence divergence among the protocatechuate 3,4-dioxygenase family, all of the conserved domain amino acid structures identified for this enzyme family are identical or conservatively substituted in the H. organivorans enzyme.245699709Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Analysis and characterization of cultivable extremophilic hydrolytic bacterial community in heavy-metal-contaminated soils from the Atacama Desert and their biotechnological potentials

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Aims To isolate and characterize the cultivable community of hydrolase producers (amylase, protease, lipase, DNase, xylanase and pullulanase) inhabiting heavy-metal-contaminated soils in extreme conditions from the Atacama Desert. Methods and Results A total of 25 bacterial strains showing hydrolytic activities have been selected including halotolerants, extremely halotolerants and moderate halophiles. Most hydrolase producers were assigned to the family B acillaceae, belonging to the genera Bacillus (nine strains), Halobacillus (seven strains) and Thalassobacillus (five strains) and four isolates were related to members of the families Pseudomonadaceae, Halomonadaceae and Staphylococcaceae. The selected strains were then characterized for their tolerance pattern to six heavy metals, measured as minimal inhibitory concentrations (MICs). Conclusions The diversity found in the cultivable bacterial community analysed is more limited than that detected in other ecological studies owing to the restrictive conditions used in the screening. The dominant bacteria were Firmicutes and particularly, species related to the genus Bacillus. Significance and Impact of the Study This study is focused on the characterization of extremophilic hydrolytic bacteria, providing candidates as a source of novel enzymes with biotechnological applications.1133550559Spanish Ministry of Science and Education [CTM 2006-03310]Junta de Andalucia [P08-RMN-3515]University of SevillaCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Spanish Ministry of Science and Education [CTM 2006-03310]Junta de Andalucia [P08-RMN-3515

Analysis And Characterization Of Cultivable Extremophilic Hydrolytic Bacterial Community In Heavy-metal-contaminated Soils From The Atacama Desert And Their Biotechnological Potentials

Aims: To isolate and characterize the cultivable community of hydrolase producers (amylase, protease, lipase, DNase, xylanase and pullulanase) inhabiting heavy-metal-contaminated soils in extreme conditions from the Atacama Desert. Methods and Results: A total of 25 bacterial strains showing hydrolytic activities have been selected including halotolerants, extremely halotolerants and moderate halophiles. Most hydrolase producers were assigned to the family B acillaceae, belonging to the genera Bacillus (nine strains), Halobacillus (seven strains) and Thalassobacillus (five strains) and four isolates were related to members of the families Pseudomonadaceae, Halomonadaceae and Staphylococcaceae. The selected strains were then characterized for their tolerance pattern to six heavy metals, measured as minimal inhibitory concentrations (MICs). Conclusions: The diversity found in the cultivable bacterial community analysed is more limited than that detected in other ecological studies owing to the restrictive conditions used in the screening. The dominant bacteria were Firmicutes and particularly, species related to the genus Bacillus. Significance and Impact of the Study: This study is focused on the characterization of extremophilic hydrolytic bacteria, providing candidates as a source of novel enzymes with biotechnological applications. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.1133550559Amoozegar, M.A., Hamedi, J., Dadashipour, M., Shariatpanahi, S., Effect of salinity on the tolerance to toxic metals and oxyanions in native moderately halophilic spore-forming bacilli (2005) World J Microbiol Biotechnol, 21, pp. 1237-1243Baati, H., Amdouni, R., Gharsallah, N., Sghir, A., Ammar, E., Isolation and characterization of moderately halophilic bacteria from tunisian solar saltern (2010) Curr Microbiol, 60, pp. 157-161Chong, G., Die Salare in Nordchile - Geologie, Struktur und geochimie (1984) Goetektonische Forschung, 67, pp. 1-146Cohn, F., Untersuchungen über Bakterien (1872) Beitr Biol Pflanz Heft, 21, pp. 127-224Connon, S.A., Lester, E.D., Shafaat, H.S., Obenhuber, D.C., Ponce, A., Bacterial diversity in hyperarid Atacama Desert soils (2007) J Geophys Res, 112, pp. G04S17Cowan, S.T., Steel, K.J., (1982) Manual para la Identificación de Bacterias de Importancia Médica, , 2nd edn. Mexico DF: CECSADe los Ríos, A., Valea, S., Ascaso, C., Davila, A., Kastovsky, J., McKay, C.P., Gómez-Silva, B., Wierzchos, J., Comparative analysis of the microbial communities inhabiting halite evaporites of the Atacama Desert (2010) Int Microbiol, 13, pp. 79-89Demergasso, C., Casamayor, E., Chong, G., Galleguillos, P., Escudero, L., Pedrós-Alió, C., Distribution of prokaryotic genetic diversity in athalassohaline lakes of the Atacama desert Northern Chile (2004) FEMS Microbiol Ecol, 48, pp. 57-69Duxbury, T., Microbes and heavy metals: an ecological overview (1986) Microbiol Sci, 8, pp. 336-339El-meleigy, M.A., El-kasaby, A.M., Osman, N.H., Microorganisms as a tool in biotechnology of sea water treatment (2010) Aust J Basic Appl Sci, 4, pp. 1083-1099Gaballa, A., Amer, R., Hussein, H., Moawad, H., Sabry, S., Heavy metals resistance pattern of moderately halophytic bacteria (2003) Arab J Biotechnol, 6, pp. 267-278García, M.T., Mellado, E., Ostos, J.C., Ventosa, A., Halomonas organivorans sp. nov., a moderate halophile able to degrade aromatic compounds (2004) Int J Syst Evol Microbiol, 54, pp. 1723-1728García, M.T., Gallego, V., Ventosa, A., Mellado, E., Thalassobacillus devorans gen. nov., sp. nov., a moderately halophilic, phenol-degrading, Gram-positive bacterium (2005) Int J Syst Evol Microbiol, 55, pp. 1789-1795Hartley, A.J., Chong, G., Houston, J., Mather, A.E., 150 million years of climatic stability: evidence from the Atacama Desert, northern Chile (2005) J Geol Soc, 162, pp. 421-424Jeffries, C.D., Holtman, D.F., Guse, D.G., Rapid method for determining the activity of microorganisms on nucleic acids (1957) J Bacteriol, 73, pp. 590-591Kulkarni, N., Shendye, A., Rao, M., Molecular and biotechnological aspects of xylanases (1999) FEMS Microbiol Rev, 23, pp. 11-456Kushner, D.J., Kamekura, M., Physiology of halophilic bacteria (1988) Halophilic Bacteria, pp. 109-138. , Ed. Rodríguez-Valera, F. Boca Raton, FL: CRC PressLane, D.J., 16S/23S rRNA sequencing (1991) Nucleic Acid Techniques in Bacterial Systematics, pp. 115-148. , ed. Stackebrandt, E. and Goodfellow, M. Chichester, UK: WileyLester, E.D., Satomi, M., Ponce, A., Microflora of extreme arid Atacama Desert soils (2007) Soil Biol Biochem, 39, pp. 704-708Ludwig, W., Strunk, O., (1996), http://www.mikro.biologie.tu-muenchen.de, Arb: a software environment for sequence dataLudwig, W., Strunk, O., Klugbauer, S., Klugbauer, N., Weizenernegger, M., Neumaier, J., Bachleitner, M., Schleifer, K.-H., Bacterial phylogeny based on comparative sequence analysis (1998) Electrophoresis, 19, pp. 554-568Massadeh, A.M., Al-Momani, F.A., Haddad, H.I., Removal of lead and cadmium by halophilic bacteria isolated from the Dead Sea shore, Jordan (2005) Biol Trace Elem Res, 108, pp. 259-269McKay, C.P., Friedmann, E.I., Gómez-Silva, B., Cáceres-Villanueva, L., Andersen, D.T., Landheim, R., Temperature and moisture conditions in the extreme arid regions of the Atacama Desert: four years of observations including the El Niño of 1997-1998 (2003) Astrobiology, 3, pp. 393-406Mishra, R.R., Dangar, T.K., Rath, B., Thatoi, H.N., Characterization and evaluation of stress and heavy metal tolerance of some predominant Gram negative halotolerant bacteria from mangrove soils of Bhitarkanika, Orissa, India (2009) Afr J Biotechnol, 8, pp. 2224-2231Moreno, M.L., Garcia, M.T., Ventosa, A., Mellado, E., Characterization of Salicola sp. IC10, a lipase- and protease producing extreme halophile (2009) FEMS Microbiol Ecol, 68, pp. 59-71Mourey, A., Kilbertus, G., Simple media containing stabilized tributyrin for demonstrating lipolytic bacteria in foods and soils (1976) J Appl Bacteriol, 40, pp. 47-51Navarro-González, R., Rainey, F.A., Molina, P., Bagaley, D.R., Hollen, B.J., de la Rosa, J., Small, A.M., Quinn, R.C., Mars-like soils in the atacama, chile, and the dry limit of microbial life (2003) Science, 302, pp. 1018-1021Niehaus, F., Bertoldo, C., Kahler, M., Antranikian, G., Extremophiles as a source of novel enzymes for industrial application (1999) Appl Microbiol Biotechnol, 51, pp. 711-729Nies, D.H., Microbial heavy metal resistance (1999) Appl Microbiol Biotechnol, 51, pp. 730-750Nieto, J.J., Fernandez-Castillo, R., Marquez, M.C., Ventosa, A., Quesada, E., Ruiz-Berraquero, F., Survey of metal tolerance in moderately halophilic eubacteria (1989) Appl Environ Microbiol, 55, pp. 2385-2390Oren, A., Diversity of halophilic microorganisms: environments, phylogeny, physiology, and applications (2002) J Ind Microbiol Biotechnol, 28, pp. 56-63Oren, A., Biotechnological Applications and Potentials of Halophilic Microorganisms (2002) Halophilic Microorganisms and their Environments, pp. 357-388. , Ed. Oren, A. the Netherlands: SpringerOsman, O., Tanguichi, H., Ikeda, K., Park, P., Tanabe-Hosoi, S., Nagata, S., Copper-resistant halophilic bacterium isolated from the polluted Maruit Lake, Egypt (2010) J Appl Microbiol, 108, pp. 1459-1470Rao, M.B., Tanksale, A.M., Ghatge, M.S., Deshpande, V.V., Molecular and Biotechnological aspects of microbial proteases (1998) Microbiol Mol Biol Rev, 62, pp. 597-635Rohban, R., Amoozegar, M.A., Ventosa, A., Screening and isolation of halophilic bacteria producing extracellular hydrolyses from Howz Soltan Lake, Iran (2009) J Ind Microbiol Biotechnol, 36, pp. 333-340Salamanca, M.A., Camaño, A., Jara, B., Rodríguez, T., Cu, Pb and Zn distribution in nearshore water en San Jorge Bay, Northern Chile (2000) Gayana (Concepción), 64, pp. 195-204Sánchez-Porro, C., Martín, S., Mellado, E., Ventosa, A., Diversity of moderately halophilic bacteria producing extracellular hydrolytic enzymes (2003) J Appl Microbiol, 94, pp. 295-300Schallmey, M., Singh, A., Ward, O.P., Developments in the use of Bacillus species for industrial production (2004) Can J Microbiol, 50, pp. 1-17Setati, M.E., Diversity and industrial potential of hydrolase producing halophilic/halotolerant eubacteria (2010) Afr J Biotechnol, 9, pp. 1555-1560Sorokin, D.Y., Tourova, T.P., Galinski, E.A., Belloch, C., Tindall, B.J., Extremely halophilic denitrifying bacteria from hypersaline inland lakes, Halovibrio denitrificans sp. nov. and Halospina denitrificans gen. nov., sp. nov., and evidence that the genus name Halovibrio Fendrich 1989 with the type species Halovibrio variabilis should be associated with DSM 3050 (2006) Int J Syst Evol Microbiol, 56, pp. 379-388Spring, S., Ludwig, W., Marquez, M.C., Ventosa, A., Schleifer, K.-H., Halobacillus gen. nov., with description of Halobacillus litoralis sp. nov. and Halobacillus trueperi sp. nov., and transfer of Sporosarcina halophila to Halobacillus halophilus comb. nov (1996) Int J Syst Bacteriol, 46, pp. 492-496Ventosa, A., Marquez, M.C., Ruiz-Berraquero, F., Kocur, M., Salinicoccus roseus gen. nov., a new moderately halophilic Gram-positive coccus (1990) Syst Appl Microbiol, 13, pp. 29-33Walkley, A., Black, I.A., An examination of the Degtjareff method for determining soil organic matter and a proposed modification of the chromic acid titration method (1934) Soil Sci, 37, pp. 29-38Warren-Rhodes, K.A., Rhodes, K.L., Pointing, S.B., Ewing, S.A., Lacap, D.C., Gómez-Silva, B., Amundson, R., Friedmann, E.I., Hypolithic cyanobacteria, dry limit of photosynthesis, and microbial ecology in the hyperarid Atacama Desert (2006) Microb Ecol, 52, pp. 389-398Wierzchos, J., Ascaso, C., McKay, C.P., Endolithic cyanobacteria in halite rocks from the hyperarid core of the Atacama Desert (2006) Astrobiology, 6, pp. 415-422Wilson, K., Preparation of genomic DNA from bacteria (1987) Current Protocols in Molecular Biology, pp. 241-242. , ed. Ausubel, F.M., Brent, R., Kingston, R.E., Moore, D.D., Seidman, J.G., Smith, J.A. and Struhl, K. New York: John Wiley & SonsZhuang, X., Han, Z., Bai, Z., Zhuang, G., Shim, H., Progress in decontamination by halophilic microorganisms in saline wastewater and soil (2010) Environ Pollut, 158, pp. 1119-112

Cloning, Characterization and Analysis of cat and ben Genes from the Phenol Degrading Halophilic Bacterium Halomonas organivorans

Background: Extensive use of phenolic compounds in industry has resulted in the generation of saline wastewaters that produce significant environmental contamination; however, little information is available on the degradation of phenolic compounds in saline conditions. Halomonas organivorans G-16.1 (CECT 5995(T)) is a moderately halophilic bacterium that we isolated in a previous work from saline environments of South Spain by enrichment for growth in different pollutants, including phenolic compounds. PCR amplification with degenerate primers revealed the presence of genes encoding ring-cleaving enzymes of the beta-ketoadipate pathway for aromatic catabolism in H. organivorans. Findings: The gene cluster catRBCA, involved in catechol degradation, was isolated from H. organivorans. The genes catA, catB, catC and the divergently transcribed catR code for catechol 1,2-dioxygenase (1,2-CTD), cis, cis-muconate cycloisomerase, muconolactone delta-isomerase and a LysR-type transcriptional regulator, respectively. The benzoate catabolic genes (benA and benB) are located flanking the cat genes. The expression of cat and ben genes by phenol and benzoic acid was shown by RT-PCR analysis. The induction of catA gene by phenol and benzoic acid was also probed by the measurement of 1,2-CTD activity in H. organivorans growth in presence of these inducers. 16S rRNA and catA gene-based phylogenies were established among different degrading bacteria showing no phylogenetic correlation between both genes. Conclusions/Significance: In this work, we isolated and determined the sequence of a gene cluster from a moderately halophilic bacterium encoding ortho-pathway genes involved in the catabolic metabolism of phenol and analyzed the gene organization, constituting the first report characterizing catabolic genes involved in the degradation of phenol in moderate halophiles, providing an ideal model system to investigate the potential use of this group of extremophiles in the decontamination of saline environments.66Spanish Ministry of Science and Education [CTM2006-03310, BIO2006-06927]Junta de Andalucia [P08-RNM-3515]Spanish Ministry of Science and Education [CTM2006-03310, BIO2006-06927]Junta de Andalucia [P08-RNM-3515

New Findings on Aromatic Compounds’ Degradation and Their Metabolic Pathways, the Biosurfactant Production and Motility of the Halophilic Bacterium Halomonas sp. KHS3

The study of the aromatic compounds’ degrading ability by halophilic bacteria became an interesting research topic, because of the increasing use of halophiles in bioremediation of saline habitats and effluents. In this work, we focused on the study of aromatic compounds’ degradation potential of Halomonas sp. KHS3, a moderately halophilic bacterium isolated from hydrocarbon-contaminated seawater of the Mar del Plata harbour. We demonstrated that H. sp. KHS3 is able to grow using different monoaromatic (salicylic acid, benzoic acid, 4-hydroxybenzoic acid, phthalate) and polyaromatic (naphthalene, fluorene, and phenanthrene) substrates. The ability to degrade benzoic acid and 4-hydroxybenzoic acid was analytically corroborated, and Monod kinetic parameters and yield coefficients for degradation were estimated. Strategies that may enhance substrate bioavailability such as surfactant production and chemotactic responses toward aromatic compounds were confirmed. Genomic sequence analysis of this strain allowed us to identify several genes putatively related to the metabolism of aromatic compounds, being the catechol and protocatechuate branches of β-ketoadipate pathway completely represented. These features suggest that the broad-spectrum xenobiotic degrader H. sp. KHS3 could be employed as a useful biotechnological tool for the cleanup of aromatic compounds-polluted saline habitats or effluents.Fil: Corti Monzón, Georgina de la Paz. Universidad Nacional de Mar del Plata; Argentina. Instituto de Ciencia y Tecnología de Alimentos y Ambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Nisenbaum, Melina. Universidad Nacional de Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Herrera Seitz, Karina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Murialdo, Silvia Elena. Universidad Nacional de Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentin