Development of an efficient bacterial consortium for the potential remediation of hydrocarbons from contaminated sites

The intrinsic biodegradability of hydrocarbons and the distribution of proficient degrading microorganisms in the environment are very crucial for the implementation of bioremediation practices. Among others, one of the most favorable methods that can enhance the effectiveness of bioremediation of hydrocarbon-contaminated environment is the application of biosurfactant producing microbes. In the present study, the biodegradation capacities of native bacterial consortia towards total petroleum hydrocarbons (TPH) with special emphasis to poly aromatic hydrocarbons (PAHs) were determined. The purpose of the study was to isolate TPH degrading bacterial strains from various petroleum contaminated soil of Assam, India and develop a robust bacterial consortium for bioremediation of crude oil of this native land. From a total of 23 bacterial isolates obtained from three different hydrocarbons contaminated samples 5 isolates, namely KS2, PG1, PG5, R1 and R2 were selected as efficient crude oil degraders with respect to their growth on crude oil enriched samples. Isolates KS2, PG1 and R2 are biosurfactant producers and PG5, R1 are non-producers. Fourteen different consortia were designed involving both biosurfactant producing and non-producing isolates. Consortium 10, which comprises two Bacillus strains namely, Bacillus pumilus KS2 and Bacillus cereus R2 (identified by 16s rRNA sequencing) has shown the best result in the desired degradation of crude oil. The consortium showed degradation up to 84.15% of total petroleum hydrocarbon (TPH) after five weeks of incubation, as revealed from gravimetric analysis. FTIR (Fourier transform infrared) and GCMS (Gas chromatography-mass spectrometer) analyses were correlated with gravimetric data which reveals that the consortium has removed a wide range of petroleum hydrocarbons in comparison with abiotic control including different aliphatic and aromatic hydrocarbons

<span style="font-size:11.0pt;font-family: "Times New Roman","serif";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language: HI" lang="EN-GB">Degradation of polycyclic aromatic hydrocarbons (PAHs) employing biosurfactant producing <i style="mso-bidi-font-style:normal">Pseudomonas aeruginosa</i> KS3</span>

208-215<span style="font-size:11.0pt;font-family: " times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi"="" lang="EN-GB">An efficient biosurfactant-producing/hydrocarbon-degrading native bacterial strain Pseudomonas aeruginosa KS3 (identified by partial 16S rDNA gene sequencing) was isolated from crude oil contaminated soil collected from the oil field of Lakowa in Sivasagar district of Assam, India. Experiments were conducted in the laboratory to determine the efficiency of strain KS3 to degrade polycyclic aromatic hydrocarbons (PAHs). Further, biosurfactant production was measured based on surface tension (ST) reduction of culture media. The results of the study show that this native biosurfactant producing bacterial strain has great potentiality in the degradation of total petroleum hydrocarbon (TPH) and PAHs, which have great prospects in remediation of hydrocarbon from contaminated sites. It was found that the strain KS3 could degrade 79.16% of TPH in 4 wk of incubation time. The strain also demonstrated efficient degradation of PAHs. Among the 16 major PAHs present in the crude oil sample, strain KS3 could completely degrade 8 of them. Biochemical and FTIR analyses confirmed that the produced biosurfactant was glycolipid in nature.</span

Environment friendly treatment of petroleum hydrocarbon contaminated formation water: Mechanisms and consequences for degradation and adsorption

An innovative approach to remediate oilfield produced water, a major environmental pollutant from the oil and gas industry has been demonstrated in this study. The technique combines: invasive wetland plant (Pistia stratiotes) used in absorbing and metabolizing hydrocarbons present in the oilfield formation water, biosurfactant from indigenous Bacteria making them more accessible for degradation and fertilizer NPK act as biostimulator. The main objectives of this technique are to remediate Total Petroleum Hydrocarbons (TPH) in an environmentally friendly manner to be a potential for the petroleum sector. The success of the technique is supported by the results of GC-MS analysis, which detected no hydrocarbon compounds in treated water. However, after treatment using the proposed combination 90.1% of the TPH was degraded, and the remaining 9.9% was adsorbed by the biomaterials. Thus, this study would present a potential breakthrough in the ongoing battle against pollution caused by the oil and gas industry

Assessment of environmental and carcinogenic health hazards from heavy metal contamination in sediments of wetlands

Sediment contamination jeopardizes wetlands by harming aquatic organisms, disrupting food webs, and reducing biodiversity. Carcinogenic substances like heavy metals bioaccumulate in sediments and expose consumers to a greater risk of cancer. This study reports Pb, Cr, Cu, and Zn levels in sediments from eight wetlands in India. The Pb (51.25 ± 4.46 µg/g) and Cr (266 ± 6.95 µg/g) concentrations were highest in Hirakud, Cu (34.27 ± 2.2 µg/g) in Bhadrak, and Zn (55.45 ± 2.93 µg/g) in Koraput. The mean Pb, Cr, and Cu values in sediments exceeded the toxicity reference value. The contamination factor for Cr was the highest of the four metals studied at Hirakud (CF = 7.60) and Talcher (CF = 6.97). Furthermore, high and moderate positive correlations were observed between Cu and Zn (r = 0.77) and Pb and Cr (r = 0.36), respectively, across all sites. Cancer patients were found to be more concentrated in areas with higher concentrations of Pb and Cr, which are more carcinogenic. The link between heavy metals in wetland sediments and human cancer could be used to make policies that limit people\u27s exposure to heavy metals and protect their health

Assessment of environmental and carcinogenic health hazards from heavy metal contamination in sediments of wetlands

Abstract Sediment contamination jeopardizes wetlands by harming aquatic organisms, disrupting food webs, and reducing biodiversity. Carcinogenic substances like heavy metals bioaccumulate in sediments and expose consumers to a greater risk of cancer. This study reports Pb, Cr, Cu, and Zn levels in sediments from eight wetlands in India. The Pb (51.25 ± 4.46 µg/g) and Cr (266 ± 6.95 µg/g) concentrations were highest in Hirakud, Cu (34.27 ± 2.2 µg/g) in Bhadrak, and Zn (55.45 ± 2.93 µg/g) in Koraput. The mean Pb, Cr, and Cu values in sediments exceeded the toxicity reference value. The contamination factor for Cr was the highest of the four metals studied at Hirakud (CF = 7.60) and Talcher (CF = 6.97). Furthermore, high and moderate positive correlations were observed between Cu and Zn (r = 0.77) and Pb and Cr (r = 0.36), respectively, across all sites. Cancer patients were found to be more concentrated in areas with higher concentrations of Pb and Cr, which are more carcinogenic. The link between heavy metals in wetland sediments and human cancer could be used to make policies that limit people's exposure to heavy metals and protect their health