Biosorption of cadmium and nickel by pretreated Aspergillus spp. biomass

460-464Industrial effluents contaminated with the heavy metals pose threat to the environment and its habitants. Biosorption is an effective and eco-friendly method for sequestration of heavy metals from such effluents. Fungi, with their remarkable metabolism-independent metal uptake systems, are efficient natural biosorbents of heavy metals. Therefore, we explored fungal biomass (Aspergillus spp.) pretreated with formaldehyde (solvent) and sodium hydroxide (alkali) for sequestration of metals cadmium (Cd) and nickel (Ni) from the aqueous solutions contaminated with heavy metals. The results have shown significant increase in the sequestration of Cd and Ni by the Aspergillus spp. biomass pretreated with formaldehyde and sodium hydroxide and thereby demonstrated its potential in cleaning the environment polluted with heavy metals

Liquid based formulations of bacteriophages for the management of waterborne bacterial pathogens in water microcosms

1038-1045Water resources are contaminated by life-threatening multidrug resistant pathogenic bacteria. Unfortunately, these pathogenic bacteria do not respond to the traditional water purification methods. Therefore, there is a need of environmentally friendly strategies to overcome the problems associated with the antimicrobial resistant bacterial pathogens. In the present study, highly potent lytic phages against multidrug-resistant Salmonella enterica serovar Paratyphi B, Pseudomonas aeruginosa and Klebsiella pneumoniae were isolated from the Pavana river water. They belonged to the Podoviridae and<i style="mso-bidi-font-style: normal"> Siphoviridae families. These phages were purified and enriched in the laboratory. Monovalent formulations of φSPB, BVPaP-3 and KPP phages were prepared in three different liquids viz., phage broth, saline and distilled water. The phages were stable for almost 8-10 months in the phage broth at 4 °C. The stability of the phages in saline and distilled water was 5-6 months at 4 °C. All of the phages were stable only for 4-6 months in the phage broth at 30 °C. The monovalent phage formulation of φSPB was applied at MOI Salmonella enterica serovar Paratyphi B in various water microcosms. The results indicated that there was almost 80 % reduction in the log phase cells of Salmonella serovar Paratyphi B in 24 h. In stationary phase cells, the reduction was comparatively less within same period. At the same time, there was concomitant increase in the phage population by 80% in all the microcosms indicating that φSPB phage is highly potent in killing pathogen in water. Results strongly support that the formulation of φSPB in the phage broth in monovalent form could be used as an effective biological disinfectant for preventing transmission of water- borne bacterial pathogens, including antimicrobial resistant ones. </span

Biosynthesis of colloidal gold nanoparticles by <i style="mso-bidi-font-style:normal">Streptomyces</i> sp. NK52 and its anti-lipid peroxidation activity

969-972Gold nanoparticles (Au-NPs) were synthesized from chloroauric acid using cell free supernatant of <i style="mso-bidi-font-style: normal">Streptomyces sp. NK52 grown in nutrient broth. These nanoparticles were synthesized by varying pH and temperature of the reaction mixture and chloroauric acid concentration. The nanoparticles were characterized by spectrometry, X-ray diffraction, Scanning electron microscopy and energy dispersive spectrometry. Au-NP ranged from 10-100 nm in size and exhibited a polydispersive nature with various shapes like rods, hexagons, triangles, spheres. The diffraction peaks at 2θ = 38.1◦ and 44.5◦ could be assigned to the (1 1 1) and (2 0 0) planes of a faced centre cubic (fcc) lattice of gold. Au-NP showed 47% inhibition of lipid peroxidation in vitro. To the best of our knowledge, this is the first report on the rapid biosynthesis of Au-NP using cell free supernatant of Streptomyces sp. and its evaluation for anti-lipid peroxidation

Status of metal pollution in rivers flowing through urban settlements at Pune and its effect on resident microflora

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.Bioremediation of toxic metals and other pollutants for protecting human health and the ecosyste

Actinomycetes: A Repertory of Green Catalysts with a Potential Revenue Resource

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

Use of N,N-diacetylchitobiose in decreasing toxic effects of indoor air pollution by preventing oxidative DNA damage

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 &gt; wood &gt; sawdust &gt; 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.COPD-project funded by SID