Evaluation of Biotechnological Potential of Novel Mercury Tolerant Strain of Klebsiella Pneumonia (original) (raw)
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Research Journal of Environmental and Earth Sciences, 2014
The most common bacterial mercury resistance mechanism is based on the reduction of Hg 2+ to Hg 0 , which is dependent on the mercuric reductase enzyme (merA) activity. The aims of this research were to isolate and characterize merA gene fragment of mercury resistant bacteria Klebsiella pneumoniae isolate A1.1.1. The gene fragment was amplified by PCR using previously designed primer pairs. Plasmid DNAs were used as template. The result showed that the partial sequence of merA gene has been found on plasmid DNA of mercury resistant bacterium Klebsiella pneumoniae isolates A1.1.1. The nucleotide sequence of the merA gene consists of 285 base pairs (bp) which encodes deduced 94 amino acids of mercury reductase merA protein. The merA protein sequence of isolate A1.1.1 has 99% similarity with some strains of Klebsiella pneumoniae deposited in Gen Bank. There is a gene mutation that causes the deduced amino acid threonine was replaced by serine at position 524 (Thr→Ser) in the merA protein of Klebsiella pneumonia as the accession number: AAR91471.1.
Research Journal of Environmental and Earth Sciences, 2014
The most common bacterial mercury resistance mechanism is based on the reduction of Hg 2+ to Hg 0 , which is dependent on the mercuric reductase enzyme (merA) activity. The aims of this research were to isolate and characterize merA gene fragment of mercury resistant bacteria Klebsiella pneumoniae isolate A1.1.1. The gene fragment was amplified by PCR using previously designed primer pairs. Plasmid DNAs were used as template. The result showed that the partial sequence of merA gene has been found on plasmid DNA of mercury resistant bacterium Klebsiella pneumoniae isolates A1.1.1. The nucleotide sequence of the merA gene consists of 285 base pairs (bp) which encodes deduced 94 amino acids of mercury reductase merA protein. The merA protein sequence of isolate A1.1.1 has 99% similarity with some strains of Klebsiella pneumoniae deposited in Gen Bank. There is a gene mutation that causes the deduced amino acid threonine was replaced by serine at position 524 (Thr→Ser) in the merA protein of Klebsiella pneumonia as the accession number: AAR91471.1.
Procedia Environmental Sciences, 2015
Bioaccumulation of mercury is one of the reclamation methods in ex-gold mining areas. Mercury-resistant bacteria can be used as a mercury bioaccumulation agent. The previous study in Mandor District West Kalimantan has collected four mercuryresistant bacteria from 62 samples with isolates code: HgTA1, HgTL2, HgRL and HgRA. The purpose of this study is to identify and verify the in vitro effectiveness ofthese four mercury-resistant bacteria. Identification of the bacteria is performed using16SrRNAsequencinganalysis, while the in vitro effectiveness test of the bacteria is done by using Canstein's selective media. The results show that the identification of bacterial isolates finds that HgTA1 and HgTL2 are Bacillus subtilis, HgRL is Burkholderia cepacia, and HgRA is Burkholderia cenosepacia. These three species of bacteria belong to the class of bacteria that are resistant to extreme conditions. Thus, these bacteria have anability toaccumulatemercury. Meanwhile, based on the test results of colony growth, detoxification abilities, mercury accumulation and bioaccumulation levels, three out of the four bacterial isolates are proven to be effective and superior to accumulate mercury i.e. HgRA, HgTA1 and HgTL2 isolates. Furthermore, these three isolates can be used as bioacculation agents of mercury-contaminated soil.
Journal of Tropical Life Science, 2018
Mercury pollution is dangerous to health. Previous research was found two potential Gram-negative bacteria for mercury bioremediation, from gold mining in Central Kalimantan, Indonesia. These isolates were identified as Pseudomonas aeruginosa KHY2 and Klebsiella pneumonia KHY3. Mechanisms of mercury bioremediation had not known yet by these isolates. This study purposed to test the role of coenzymes on mercury bioremediation by these isolate and to determine the coenzymes best level of mercury bioremediation. Experimental design was Completely Randomized Design in a laboratory. Treatment factors were coenzymes obtained from vitamins B1, B6, B12, with 6 levels of treatments, included 1 control. All treatments were done in Luria Broth media that contain 12 ppm of mercury. Mercury was measured by AAS Shimadzu AA-6200. The results showed that coenzymes effect was very significant to improve mercury bioremediation by P. aeruginosa KHY2 and K. pneumonia KHY3. Supplementation of vitamin B12 in culture media, more enhance of mercury bioremediation compared with vitamin B1 and B6. These result above, indicated the mechanism of mercury bioremediation in both isolates, were the enzymatic process.
Mercury pollution: an emerging problem and potential bacterial remediation strategies
World Journal of Microbiology & Biotechnology, 2009
Heavy metal toxicity represents an uncommon but clinically significant medical condition, which if unrecognized or inappropriately treated results in significant morbidity and mortality. Mercury is recognized as a potent and widely distributed toxicant in the global environment having ability to accumulate at various levels of food chain besides possessing ability to cross placental and blood–brain barrier. It has been seen that bacteria growing near mercury polluted sites have evolved various means of resistance based on the expression of different genes of mer operon against different forms of mercury. Microbe based remediation/detoxification of mercury is on forefront due to low cost and less health hazardous compared to physicochemical based strategies, which are cost intensive and hazardous to human health. However, strategies based on the modern aspects of biological technologies employing mer operon genes in different combination are needed to be designed for exploitation in the remediation of mercury completely from mercury contaminated environments.