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Arulazhagan P.,King Abdulaziz University | Yeom I.T.,University of Suwon | Sivaraman C.,Applied and Environmental Biotechnology Laboratory | Srikanth M.,Applied and Environmental Biotechnology Laboratory | Rajesh Banu J.,Anna University
Advances in Environmental Biology

The cyclic ether 1,4 dioxane is a carcinogenic, emerging micropollutant present in water and wastewater. The treatment methods are ineffective due to its high solubility (low Henrys law constant 5 x 10-6 atm m3/ mol) and also its heterocyclic structure (with two linear ethers). The present study was focused on biodegradation of 1,4 dioxane by a bacterial consortium enriched from 1,4 dioxane contaminated industrial sludge. The Bacterial consortium degraded 74% of 1,4 dioxane in 72 h. To enhance the biodegradation process, additional carbon substrates such as glucose, yeast extract and tetrahydrofuran (THF) were used. Among those carbon substrate, THF acts as a best substrate in accelerating the biodegradation process for complete degradation of 1,4 dioxane and also reducing the time taken for biodegradation. Yeast extract as additional substrate showed 92% of 1,4 dioxane degradation in 72 h whereas glucose showed 59% degradation in 72 h and also extended the time taken for complete degradation of 1,4 dioxane which was at 168 h. Further, the bacterial strains present in the consortium were identified as: bacterium enrichment culture clone strain AYS1 (JQ419749), Runella sp. AYS2 (JQ419750), Achromobacter sp. AYS3 (JQ419751), Marinobacter sp. AYS4 (JQ419752) and Rhodanobacter sp. AYS5 (JQ419753) using molecular techniques. Source

Pasumarthi R.,Applied and Environmental Biotechnology Laboratory | Chandrasekaran S.,Applied and Environmental Biotechnology Laboratory | Chandrasekaran S.,King Abdulaziz University | Mutnuri S.,Applied and Environmental Biotechnology Laboratory
Marine Pollution Bulletin

Petroleum hydrocarbons are major pollutants of the marine environment. Bioremediation is a promising approach for treating such contaminated environments. The present study aims at isolating naturally occurring bacteria from the coast of Goa, India and to study their hydrocarbonoclastic capacity. Pseudomonas aeruginosa and Escherichia fergusonii were isolated from a crude oil-contaminated sediment sample using diesel oil as the sole carbon source. The capability of the enriched culture to degrade crude oil was estimated using microcosm studies under saline conditions. Based on GC-MS analysis, the culture was found to degrade n-alkanes at a higher rate compared to polyaromatic hydrocarbons. It was also found that the culture degraded alkylated polyaromatic hydrocarbons much less than unalkylated ones. Alkanes ranging from C12 to C33 were highly degraded compared to n-C34. This study shows bioremediation of crude oil in saline (3% NaCl) conditions by naturally existing bacteria isolated from the marine environment. © 2013 Elsevier Ltd. Source

Pasumarthi R.,Applied and Environmental Biotechnology Laboratory | Kumar V.,BITS Pilani | Chandrasekharan S.,Applied and Environmental Biotechnology Laboratory | Chandrasekharan S.,King Abdulaziz University | And 3 more authors.
Marine Pollution Bulletin

Aliphatic hydrocarbons are one of the major environmental pollutants with reduced bioavailability. The present study focuses on the effect of hydroxy cucurbit[6]uril on the bioavailability of hydrocarbons. A bacterial consortium was used for biodegradation studies under saline and non-saline conditions. Based on denaturing gradient gel electrophoresis results it was found that the consortium under saline conditions had two different strains. The experiment was conducted in microcosms with tetradecane, hexadecane, octadecane and mixture of the mentioned hydrocarbons as the sole carbon source. The residual hydrocarbon was quantified using gas chromatography every 24. h. It was found that biodegradation of tetradecane and hexadecane, as individual carbon source increased in the presence of hydroxy CB[6], probably due to the increase in their bioavailability. In case of octadecane this did not happen. Bioavailability of all three aliphatic hydrocarbons was increased when provided as a mixture to the consortium under saline conditions. © 2014 Elsevier Ltd. Source

Prabhu M.S.,Applied and Environmental Biotechnology Laboratory | Walawalkar Y.D.,Applied and Environmental Biotechnology Laboratory | Furtado I.,Goa University
World Journal of Microbiology and Biotechnology

Pseudomonas aeruginosa—an opportunistic pathogen, perhaps best known for chronic lung infections, produces wide range of pigments that possess specific activities which either assist the organism’s survival or bring about changes within host. A similar blue-green diffusible pigment producing P. aeruginosa was isolated from dug-well water, so as to extract 1-hydroxyphenazine from its crude pigment. The compound was purified from the crude pigment using column chromatography followed by a preparative thin layer chromatography that showed a single yellow spot. Further molecular characterisation of the purified component was carried out using UV–Vis spectrophotometer, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy and mass spectroscopy which showed respective peaks corresponding to 1-hydroxyphenazine. Biological characterisation using in vitro assays revealed that 1-hydroxyphenazine showed anti-bacterial activity only against Bacillus sp. and a concentration of 30 µg/ml induced noticeable morphological alteration in A549 human lung adenocarcinoma cells followed by cell death after 48 h. Thus, such active components within bacterial pigments can be characterized and used as possible anti-bacterial or anti-cancer agents. © 2014, Springer Science+Business Media Dordrecht. Source

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