The Role of Coenzymes on Mercury (Hg2+) Bioremediation by Isolates Pseudomonas aeruginosa KHY2 and Klebsiella pneumonia KHY3 (original) (raw)
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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.
A Study on Mercury-Resistant Bacteria Isolated from a Gold Mine in Pongkor Village, Bogor, Indonesia
HAYATI Journal of Biosciences, 2012
Mercury is one of the major pollutant in the environment which is highly toxic. Bioremediation strategies using bacteria have been proposed as an attractive alternative because this is effective, less expensive and more efficient to remove mercury. Brevundimonas sp. HgP1 and Brevundimonas sp. HgP2 were two highly mercury resistant bacteria isolated from a gold mine in Pongkor village with MIC of 575 ppm. The purposes of the research were to study the effect of mercury on bacterial growth and morphological changes of bacterial colony and to measure the ability of bacterial isolates to accumulate Hg 2+. The growth was monitored by measuring optical density at 600 nm, whereas accumulation of Hg 2+ was measured by mercury vaporation unit. This present studies revealed that the addition of 50 and 100 ppm HgCl 2 in Brevundimonas sp. HgP1 resulted in the decreasing of growth rate and the elongation of lag phase in 8 and 16 hours, respectively. The addition of HgCl 2 also affected morphological appearance of the bacterial colony to black. Brevundimonas sp. HgP1 accumulated Hg 2+ up to 1.09 and 2.7 mg/g dry weight of cells and removed 64.38 and 57.10% Hg 2+ from the medium containing 50 and 100 ppm HgCl 2 , respectively.
Mechanisms of mercury bioremediation
2002
Mercury is one of the most toxic heavy metals, and has significant industrial and agricultural uses. These uses have led to severe localized mercury pollution. Mercury volatilization after its reduction to the metallic form by mercury-resistant bacteria has been reported as a mechanism for mercury bioremediation [Brunke, Deckwer, Frischmuth, Horn, Lunsdorf, Rhode, Rohricht, Timmis and Weppen (1993) FEMS Microbiol. Rev. 11, 145-152; von Canstein, Timmis, Deckwer and Wagner-Dobler (1999) Appl. En-viron. Microbiol. 65, 5279-5284]. The reduction\ volatilization system requires to be studied further, in order to eliminate the escape of the metallic mercury into the environment. Recently we have demonstrated three different mechanisms for mercury detoxification in one organism, Kleb-siella pneumoniae M426, which may increase the capture efficiency of mercury.
Potential of Soil Bacteria as Mercury Bioremediation Agent in Traditional Gold Mining
Biosaintifika: Journal of Biology & Biology Education
Mandor Village has developed as a tradisional gold mining area since years ago. It involved activities that have led to extreme land condition and the release of mining residues, i.e., mercury, to the soils. The study examined the potential of soil bacteria as mercury bioremediation agent based on their population and activity in former mines with different ages. The bacterial population was measured by isolating soil bacteria on solid media using the pour plate method, and the colonies were enumerated during the incubation. The Nutrient Agar (NA) medium was used to obtain the total population, whereas the Salt Base Solution (SBS) was to determine the presence of mercury-tolerant bacteria. The addition of HgCl2 affected the number of the colonies. The colony only grew until the concentration of HgCl2 reached 5 mg/l, and the total colony was larger in older mines. The observation of bacterial activity showed that biotransformation performance was lower when the concentration of mercu...
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.
2016
A mercury resistant Pseudomonas spp. was isolated from industrial effluent that was able to tolerate 200 µM HgCl 2 . The Hg 2+ -resistant Pseudomonas spp. exhibited elevated stress-regulatory mechanisms as indicated by its high and inducible mercury reductase activity, high intrinsic catalase activity and enhanced resistance to Hg 2+ -induced release of protein-bound iron. An enhanced resistance of the bacterium to Hg 2+ -induced lipid peroxidation was observed as indicated by 40% lower conjugated diene and 60% lower lipid hydroperoxide content compared to a non-mercury resistant strain Pseudomonas aeruginosa (ATCC 27853). Phospholipid (PL) analysis of both the species reveled intrinsic differences in their PL composition. We observed 80% PE, 15% PG and 5% of an unidentified PL (U) in MRP compared to 65% PE, 20% PG and 17% CL in Pseudomonas aeruginosa (ATCC 27853). Mercury toxicity led to significant reorganization of PL in Pseudomonas aeruginosa (ATCC 27853) compared to MRP. While ...
2012
Active resistance to the mercuric ion is widely distributed in environmental microbes and results from the action of mercuric reductase. Five mercury resistant bacteria: Escherichia coli Z1, E. coli Z3, Pseudomonas putida Z2, Serratia marcescens Z4 and Xanthomonas sp. Z5 were isolated and identified from sludge sample. The presence of mercury resistance determinants was screened by polymerase chain reaction (PCR) using merA-specific primers. Based on the analysis of merA amplicons, high similarity was recorded between the merA region of the strains P. putida Z2 and Xanthomonas sp. Z5 with those of Tn5053; while the merA of E. coli Z1 was analogous to those of Tn21. In case of the bacterial strains E. coli Z3 and S. marcescens Z4 a great matching was obtained between their merA and those of Tn5036. The effect of mercury stress upon the structure of mercury reducing biofilm at the species level and the type of mercury resistance determinants was studied in a continuous bioreactor. Community analysis suggested that the bacterial strain E. coli Z3 containing Tn5036-like determinant is well adapted strain that tolerated elevated levels of mercury whereas the other strains showed a less fitness under these extreme conditions.
2016
Mercury resistant bacteria isolated from gold mining soil in Kabupaten Sijunjung, West Sumatera, Indonesia. Our prior study found 5 bacteria isolates with highest resistant capability. The present study is to evaluate all five isolates abilities in Nutrient Broth medium with three variant additional of mercury (HgCl 2): 150 ppm, 200 ppm, and 250 ppm. The result shows all five isolates grow well in the media indicated by the increase of optical density value observed once in three days for twelve days. The highest OD value achieved by MRB 5, which is 1.2. Mercury reduce analyzed on day 12. Mercury reduce (HgCl 2) by all five isolate reach the highest value, within range 70.69-85.44%, with highest mercury reduce percentage achieved by isolate MRB5 and the lowest one by isolate MRB2. This research may become the basic concern in bioremediation of mercury contaminated environment, particularly in West Sumatera, Indonesia.
Journal of Ecological Engineering, 2018
In certain small-gold mining activities in West Lombok, Indonesia, the tailings containing mercury are discharged to agricultural lands, reducing their productivity. One of the efforts to restore the land is by bioremediation of mercury, using mercury-resistant microbes. This study was aimed to isolate the mercury-resistant bacteria from smallscale gold mine tailings containing mercury, and to test their capability in accumulating mercury. Bacterial isolation and identification were conducted from nutrient broth supplemented with 5 ppm HgCl 2. The isolated bacteria were tested for mercury accumulation in the nutrient broth containing 10, 20 and 30 ppm Hg for 24 hours, and in small-scale gold mine tailing containing 41.37 ppm Hg for 2 weeks. The results showed that there were four pure isolates of mercury-resistant bacteria which were identified as Brevundimonas vesicularis, Nitrococcus mobilis, Fusobacterium aquatile and Fusobacterium necrogenes. The highest Hg accumulation from nutrient broth liquid media containing 10, 20 and 30 ppm Hg was observed for Brevundimonas vesicularis. The mercury accumulation efficiency of the four bacteria applied to small-scale gold mine tailing containing mercury was in the order of Fusobacterium aquatile (76.1%) > Brevundimonas vesicularis (75.6%) > Fusobacterium necrogenes (74.4%) > Nitrococcus mobilis (74.2%). On the basis of the Hg accumulation efficiency of more than 75%, Fusobacterium aquatile and Brevundimonas vesicularis are prospective for bioremediation of mercury-contaminated soils.