| 1. |
- Desale, Prithviraj, et al.
(författare)
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Biosorption of Heavy Metals by Actinomycetes for Treatment of Industrial Effluents
- 2012
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Konferensbidrag (refereegranskat)abstract
- Rapid industrialization usually is the cause of increase in pollutants in the natural river bodies. This pollution is attributed to lack of improper treatment and inadequate disposal mechanisms of the waste generated thereof. The aim of present investigation was to screen actinomycetes for their ability to adsorb heavy metals. Actinomycetes belong to most diverse group of filamentous prokaryotes with ubiquitous presence in different ecological niches. This ubiquity is due to their ability to degrade almost any type of polymer and to use several compounds as carbon sources. Nearly 200 actinomycetes from different niches like fresh water, soda lake, geothermal springs, acid soils, etc from different locations in India were screened for ability to grow in presence of 1 to 5 mM of heavy metals like Cd, Hg, Pb, Ni, Sr, Fe, Mo, Zn and Mn. Most of the strains tolerant to heavy metals belonged to the genus Streptomyces spp. Five strains could grow in presence of 5 mM Cd2+, 4 strains in presence of 0.1 mM Hg2+, 18 strains in presence of 5 mM Pb2+, 21 strains in presence of 5 mM Ni2+, whereas 34 strains grew in presence of 5 mM Fe2+. One of the most promising strain was studied for its ability to absorb cadmium where 2x1011 cells or spores could adsorb 0.32 mM to 0.33 mM of cadmium. Spores and vegetative cells showed nearly similar level of adsorbtion ability. This strain can be very useful in developing a bioreactor for the adsorption of heavy metals from industrial effluents containing cadmium.
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| 2. |
- Desale, Prithviraj, et al.
(författare)
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Biosorption of nickel by Lysinibacillus sp. BA2 native to bauxite mine
- 2014
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Ingår i: Ecotoxicology and Environmental Safety. - : Elsevier. - 0147-6513 .- 1090-2414. ; 107, s. 260-268
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Tidskriftsartikel (refereegranskat)abstract
- The current scenario of environmental pollution urges the need for an effective solution for toxic heavy metal removal from industrial wastewater. Bioremediation is the most cost effective process employed by the use of microbes especially bacteria resistant to toxic metals. In this study, Lysinibacillus sp. BA2, a nickel tolerant strain isolated from bauxite mine was used for the biosorption of Ni(II). Lysinibacillus sp. BA2 biomass had isoelectric point (pI) of 3.3. The maximum negative zeta potential value (−39.45) was obtained at pH 6.0 which was highly favourable for Ni(II) biosorption. 238.04 mg of Ni(II) adsorbed on one gram of dead biomass and 196.32 mg adsorbed on one gram of live biomass. The adsorption of Ni(II) on biomass increased with time and attained saturation after 180 min with rapid biosorption in initial 30 min. The Langmuir and Freundlich isotherms could fit well for biosorption of Ni(II) by dead biomass while Langmuir isotherm provided a better fit for live biomass based on correlation coefficient values. The kinetic studies of Ni(II) removal, using dead and live biomass was well explained by second-order kinetic model. Ni(II) adsorption on live biomass was confirmed by SEM-EDX where cell aggregation and increasing irregularity of cell morphology was observed even though cells were in non-growing state. The FTIR analysis of biomass revealed the presence of carboxyl, hydroxyl and amino groups, which seem responsible for biosorption of Ni(II). The beads made using dead biomass of Lysinibacillus sp. BA2 could efficiently remove Ni(II) from effluent solutions. These microbial cells can substitute expensive methods for treating nickel contaminated industrial wastewaters.
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| 3. |
- Rahman, Aminur, 1984-, et al.
(författare)
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Isolation and characterization of a Lysinibacillus strain B1-CDA showing potential for bioremediation of arsenics from contaminated water
- 2014
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Ingår i: Journal of Environmental Science and Health. Part A. - : Taylor & Francis. - 1093-4529 .- 1532-4117. ; 49:12, s. 1349-1360
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Tidskriftsartikel (refereegranskat)abstract
- The main objective of this study was to identify and isolate arsenic resistant bacteria that can be used for removing arsenic from thecontaminated environment. Here we report a soil borne bacterium, B1-CDA that can serve this purpose. B1-CDA was isolated fromthe soil of a cultivated land in Chuadanga district located in the southwest region of Bangladesh. The morphological, biochemicaland 16S rRNA analysis suggested that the isolate belongs to Lysinibacillus sphaericus. The minimum inhibitory concentration (MIC)value of the isolate is 500 mM (As) as arsenate. TOF-SIMS and ICP-MS analysis confirmed intracellular accumulation and removalof arsenics. Arsenic accumulation in cells amounted to 5.0 mg g¡1 of the cells dry biomass and thus reduced the arsenicconcentration in the contaminated liquid medium by as much as 50%. These results indicate that B1-CDA has the potential forremediation of arsenic from the contaminated water. We believe the benefits of implementing this bacterium to efficiently reducearsenic exposure will not only help to remove one aspect of human arsenic poisoning but will also benefit livestock and native animalspecies. Therefore, the outcome of this research will be highly significant for people in the affected area and also for humanpopulations in other countries that have credible health concerns as a consequence of arsenic-contaminated water.
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