| 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. |
- Nawani, Neelu, et al.
(författare)
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Status of metal pollution in rivers flowing through urban settlements at Pune and its effect on resident microflora
- 2016
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Ingår i: Biologia. - Bratislava : Springer. - 0006-3088 .- 1336-9563. ; 71:5, s. 494-507
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Tidskriftsartikel (refereegranskat)abstract
- This study illustrates the sporadic distribution of metals in fluvial systems flowing from catchments to urban settlements. This is a detailed study prognosticating the deteriorating quality of rivers at specific locations due to metal pollution. Heavy metals like cadmium, lead, nickel and mercury are prominent in industrial sector. Contour plots derived using spatial and temporal data could determine the focal point of metal pollution and its gradation. Metal values recorded were cadmium 157 mg/L, lead 47 mg/L, nickel 61 mg/L and mercury 0.56 mg/L. Prokaryote diversity was less in polluted water and it harboured metal tolerant bacteria, which were isolated from these polluted sites. Actinomycetes like Streptomyces and several other bacteria like Stenotrophomonas and Pseudomonas isolated from the polluted river sites exhibited changes in morphology in presence of heavy metals. This stress response offered remedial measures as Streptomyces were effective in biosorption of cadmium, nickel and lead and Stenotrophomonas and Pseudomonas were effective in the bioaccumulation of lead and cadmium. The amount of 89 mg of lead and 106 mg of nickel could be adsorbed on one gram of Streptomyces biomass-based biosorbent. Such biological remedies can be further explored to remove metals from polluted sites and from metal contaminated industrial or waste waters.
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| 4. |
- Prakash, Divya, et al.
(författare)
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Actinomycetes : A Repertory of Green Catalysts with a Potential Revenue Resource
- 2013
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Ingår i: BioMed Research International. - : Hindawi Publishing Corporation. - 2314-6133 .- 2314-6141.
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Forskningsöversikt (refereegranskat)abstract
- Biocatalysis, one of the oldest technologies, is becoming a favorable alternative to chemical processes and a vital part of green technology. It is an important revenue generating industry due to a global market projected at $7 billion in 2013 with a growth of 6.7% for enzymes alone. Some microbes are important sources of enzymes and are preferred over sources of plant and animal origin. As a result, more than 50% of the industrial enzymes are obtained from bacteria. The constant search for novel enzymes with robust characteristics has led to improvisations in the industrial processes, which is the key for profit growth. Actinomycetes constitute a significant component of the microbial population in most soils and can produce extracellular enzymes which can decompose various materials. Their enzymes are more attractive than enzymes from other sources because of their high stability and unusual substrate specificity. Actinomycetes found in extreme habitats produce novel enzymes with huge commercial potential. This review attempts to highlight the global importance of enzymes and extends to signify actinomycetes as promising harbingers of green technology.
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| 5. |
- Salgaonkar, Neeta A., et al.
(författare)
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Use of N,N-diacetylchitobiose in decreasing toxic effects of indoor air pollution by preventing oxidative DNA damage
- 2016
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Ingår i: Biologia. - Bratislava : Springer. - 0006-3088 .- 1336-9563. ; 71:5, s. 505-515
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Tidskriftsartikel (refereegranskat)abstract
- Indoor air pollution occurs due to hazardous pollutants, such as tobacco smoke, pesticides and carbon oxides, sulphur oxides and nitrogen oxides arising from combustion of biomass fuels. Exposure to these pollutants results in respiratory conditions like asthma, chronic obstructive pulmonary disease, lung cancer, pneumonia and other lower respiratory infections. Several of these infections are a result of inflammation and oxidative stress. Here we demonstrate the ability of N,N-diacetylchitobiose in preventing oxidative DNA damage in peripheral blood mononuclear cells exposed to biomass smoke extracts and cigarette smoke extract. The cytotoxic effect of these pollutants was determined by trypan blue exclusion assay in peripheral blood mononuclear cells, where cytotoxicity in decreasing order was garette > wood > sawdust > cowdung. Cytotoxicity could be due to single- and double-strand breaks in the DNA as a result of oxidative stress. Comet assay measures the extent of DNA damage in the cells exposed to toxic agents. When mononuclear cells were treated with N,N-diacetylchitobiose and later exposed to smoke extracts, the extent of DNA damage decreased by 44.5% and 57.5% as compared to untreated cells. The protection offered by N,N-diacetylchitobiose towards oxidative DNA damage was at par with quercetin, a popular herbal medicine. Glutathione-S-transferase activity was determined in mononuclear cells exposed to smoke extracts, where oxidative stress in cells exposed to cigarette smoke extract was maximum. The present study demonstrates for the first time the ability of N,N -diacetylchitobiose to alleviate the harmful effects of indoor air pollutants.
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