A novel bacterium involved in the degradation of 2-methylindole isolated from sediment of Inner Deep Bay of Hong Kong

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Karen Choi-Wan Yip, Ji-Dong Gu


A bacterial strain, designated as MPKc, was isolated from the mudflat sediment of Mai Po Inner Deep Bay of Hong Kong Mai Po Nature Reserve by enrichment culturing with 2-methylindole as the sole source of carbon and energy. The microorganism was a Gram-negative, rod-shaped (0.4–0.6 μm × 1.0–2.2 μm) and aerobic bacterium. Phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain MPKc should be assigned as a novel bacterium, at least, at the species level. The 16S rDNA sequence most similiar to that of strain MPKc was Azoarcus evansii (94%) from available 16S rDNA sequences of the GenBank, indicating that strain MPKc was a member of the β-subclass of the Proteobacteria. Biochemical tests showed that strain MPKc was able to reduce nitrate to nitrogen. Carbon sources utilized by this strain included adipic acid, malate, citrate and phenylacetic acid although it only grew weakly on glucose, arabinose, mannose, mannitol, N-acetyl-glucosamine, maltose and gluconate. Strain MPKc showed no growth on capric acid. Its optimal growth occurred at 30°C, pH 6.5–7.5 and salinity 5–10‰. Strain MPKc was capable of degrading 80 μM 2-methylindole in 7 days under aerobic conditions. The possible chemical pathway for 2-methylindole degradation is through oxidation at 3-position or/and 2-position of the pyrrole ring.


3-methylindole; metabolism; Mai Po Nature Reserve; culturability

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Dailey N S, 1981, Process effluents: quantities and control technologies, in Environmental, Health, and Control Aspects of Coal Conversion: An Information Overview, vol 1. Ann Arbor Science Publishers, Michigan: 11–57.

Grob K and Voellmin J A, 1970, GC-MS analysis of the ‘semi-volatiles’ of cigarette smoke. Journal of Chromatographic Science, vol.8: 218–220. http://dx.doi.org/10.1093/chromsci/8.4.218.

Bergeim O, 1917, The determination of fecal indole. The Journal of Biological Chemistry, vol.32: 17–22.

Anderson G M, 1975, Quantitation of tryptophan metabolities in rat faces by thin-layer chromatography. Journal of Chromatography, vol.105(2): 323–328. http://dx.doi.org/10.1016/S0021-9673(01)82261-5.

Katritzky A R, Rees C W and Scriven E F V, (eds) 1996, Comprehensive Heterocyclic Chemistry II: Review of the Literature 1982–1995: The Structure, Reactions, Synthesis and Uses of Heterocyclic Compounds. Elsevier Science, Oxford: 16–17.

Fetzner S, 1998, Bacterial degradation of pyridine, indole, quinoline, and their derivatives under different redox conditions. Applied Microbiology and Biotechnology, vol.49(3): 237–250. http://dx.doi.org/10.1007/s002530051164.

Gu J-D, Fan Y and Shi H, 2002, Relationship between structures of substituted indolic compounds and their degradation by marine anaerobic microorganisms. Marine Pollution Bulletin, vol.45(1–12): 379–384. http://dx.doi.org/10.1016/S0025-326X(02)00091-7.

Wilkes D J, (eds) 1981, Animals: bioenvironmental effects, in Environmental, Health and Control Aspects of Coal Conversion – An Information Overview, Ann Arbor Science Publishers, Michigan, vol.2: 1–163.

Ochiai M, Wakabayashi K, Sugimura T, et al. 1986, Mutagenicities of indole and 30 derivatives after nitrite treatment. Mutation Research, vol.172(3): 189–197.

Sugimura T, 1982, Mutagens in cooked food, in Genetic Toxicology. Plenum, New York: 243–269.

Gu J-D and Berry D F, 1991, Degradation of substituted indoles by an indole-degrading methanogenic consortium. Applied and Environmental Microbiology, vol.57(9): 2622–2627.

Johansen S S, Licht D, Arvin E, et al. 1997, Metabolic pathways of quinoline, indole and their methylated analogs by Desulfobacterium indolicum (DSM 3383). Applied Microbiology and Biotechnology, vol.47(3): 292–300. http://dx.doi.org/ 10.1007/s002530050929.

Gu J-D and Berry D F, 1992, Metabolism of 3-methy-lindole by a methanogenic consortium. Applied and Environmental Microbiology, vol.58(8): 2667–2669.

Tsim S T and Lock N Y, 2002, Knowing Ramsar Wetland. Cosmos Book Ltd., Hong Kong: 6–12.

Kueh C S W and Chui H K, 1996, Integrated catchment mangement of Deep Bay, Hong Kong. Water Science and Technology, vol.34(12): 1–8. http:/dx.doi.org/10.1016/S0273-1223(96)00847-5.

Zheng G J, Lam M H W, Lam P K S, et al. 2000, Concentrations of persistent organic pollutants in surface sediments of the mudflat and mangroves at Mai Po Marches Nature Reserve, Hong Kong. Marine Pollution Bulletin, vol.40: 1210–1214.

Lau S S S and Chu L M, 1999, Contaminant release from sediments in a coastal wetland. Water Research, vol.33(4): 909–918. http:/dx.doi.org/10.1016/S0043-1354(98)00286-3.

Lai M Y, Shen P P, Zhao Z, et al. 2005, Concentrations of heavy metals in the benthic microgastropods Sermyla riqueti and Stenothyra devalis at Mai Po Inner Deep Bay Ramsar Site of Hong Kong, in Bulletin of Environmental Contamination and Toxicology. http://dx.doi.org/10.1007/s00128-005-0689-9.

Wang Y, 2003, Isolation and characterization of environmental Vibrio species from Mai Po Nature Reserve, thesis, Department of Ecology & Biodiversity, The University of Hong Kong: 29–103, viewed March 31, 2015.

Wang Y, Leung P C, Qian P, et al. 2004, Effects of UV, H2O2 and Fe3+ on the growth of four environmental isolates of Aeromonas and Vibrio species from a mangrove environment. Microbes and the Environments, vol.19(2): 163–171. http://dx.doi.org/10.1264/jsme2.19.163.

Wang Y and Gu J-D, 2005, Influence of temperature, salinity and pH on the growth of environmental Aero-monas and Vibrio species isolated from Mai Po and the Inner Deep Bay Nature Reserve Ramsar Site of Hong Kong. Journal of Basic Microbiology, vol.45(1): 83–93. http://dx.doi.org/10.1002/jobm.200410446.

Wang Y, Leung P C and Gu J-D, 2005, Antibiotic resistance and plasmid profile of environmental isolates of Vibrio species from Mai Po Nature Reserve. Hong Kong. Ecotoxicology, vol.15(4): 371–8. http://dx.doi.org/10.1007/s10646-006-0078-0.

Gu J-D, Wang Y and Li J, (eds) 2004, Degradation of the endocrine-disrupting dimethyl phthalate and dimethyl isophthalate by mangrove microorganisms, in European Symposium on Environmental Biotechnology, ESEB 2004. A.A. Balkema Publishers, London: 557–561.

Li J, Gu J-D and Pan L, 2005, Transformation of dimethyl phthalate, dimethyl isophthalate and dimethyl terephthalate by Rhodococcus rubber Sa and modeling the processes using the modified Gompertz model. International Biodeterioration & Biodegradation, vol.55(3): 223–232. http:/dx.doi.org/10.1016/j.ibiod.2004.12.003.

Li J and Gu J-D, 2005, Biodegradation of dimethyl terephthalate by Pasteurella multocida Sa follows a novel biochemical pathway. Ecotoxicology, vol.15(4): 391–397. http:/dx.doi.org/10.1007/s10646-006-0070-8.

Xu X-R, Li H-B and Gu J-D, 2005, Biodegradation of an endocrine-disrupting chemical din-butyl phthalate ester by Pseudomonas fluorescens B-1. International Biodeterioration & Biodegradation, vol.55(1): 9–15. http://dx.doi.org/10.1016/j.ibiod.2004.05.005.

Benson H J, 1998, Microbiological Applications: Laboratory Manual in General Microbiology, 7th edn, Mc-Graw-Hill Companies, Inc., Boston.

Smibert R M and Krieg N R, 1994, Phenotypic characterization, in Methods for General and Molecular Bacteriology. American Society for Microbiology, Washington, D.C.: 607–654.

Wilson K H, Blitchington R B and Greene R C, 1990, Amplification of bacterial 16S ribosomal DNA with polymerase chain reaction. Journal of Clinical Microbiology, vol.28: 1942–1946.

Sambrook J and Russell D W, 2001, Molecular Cloning: A Laboratory Manual, 3rd edn. Cold Spring Laboratory Press, United States of America.

Saitou N and Nei M, 1987, The neighbour-joining method: a new method for reconstructing phylogenetic trees.

Molecular Biology and Evolution, vol.4(4): 406–425.

Gu J-D, Ford T E and Mitchell R, 1996, Susceptibility of electronic insulating polyimides to microbial degradation. Journal of Applied Polymer Science, vol.62(7): 1029–1034. http://dx.doi.org/10.1002/(SICI)1097-4628(19961114)62:7<1029::AID-APP8>3.0.CO;2-M.

Zwietering M H, Jongenburger I, Rombouts F M, et al. 1990, Modeling of the bacterial growth curve. Applied and Environmental Microbiology, vol.56(6): 1875–1881.

Richards F J, 1959, A flexible growth function for empirical use. Journal of Experimental Botany, vol.10(2): 290–301. http:/dx.doi.org/10.1093/jxb/10.2.290.

Schepers A W, Thibault J and Lacroix C, 2000, Comparison of simple neural networks and nonlinear regression models for descriptive modeling of Lactobacillus helveticus growth in pH-controlled batch cultures. Enzyme and Microbial Technology, vol.26(5–6): 431–445. http:/dx.doi.org/10.1016/S0141-0229(99)00183-0.

Fan Y, Wang Y, Qian P-Y, et al. 2004. Optimization of phthalic acid batch biodegradation and the use of modified Richards model for modelling degradation. International Biodeterioration & Biodegradation, vol.53(1): 57–63. http://dx.doi.org/10.1016/j.ibiod.2003.10.001.

Wackett L P and Hershberger C D, 2001, Biocatalysis and Biodegradation – Microbial Transformation of Organic Compounds, American Society for Microbiology Press, Washington, D.C.

DOI: http://dx.doi.org/10.26789/AEB.2016.01.008


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