Bromoform is the most prominent, relatively long-lived chlorination by-product in condenser effluents from seawater-based power plant cooling systems. There are few reports on the potential toxicity of this trihalomethane to marine phytoplankton. We investigated this using a marine diatom, Chaetoceros lorenzianus as the model organism.
View Article and Find Full Text PDFThe present study was conducted to evaluate the arsenic (As) contamination and possible associated health hazards to exposed population in four villages of two districts (Nadia and North 24 Parganas) of West Bengal, India. The study included two villages each from Nadia (Jaguli and Kugacchi) and North 24 Parganas (Chamta and Byaspur) districts. Groundwater, surface water, soil, rice grains and rice-based food samples were collected from these villages.
View Article and Find Full Text PDFPerna viridis Linnaeus (1758) is a major foulant in the cooling water systems of electric power stations located on the East coast of India. Though chlorination is considered an effective fouling control measure, the strategy may fail in the case of bivalve mussels, due to the ability of the mussels to close their shells and still survive for extended periods of time. In a given power station, continuous low dose (exomotive) chlorination (0.
View Article and Find Full Text PDFToxic effects of continuous low dose application of the antifouling biocide chlorine on marine benthic organisms were monitored using transplanted green mussels (Perna viridis) and a suite of biomarkers. Caged mussels were deployed in chlorinated and non-chlorinated sections of the cooling system of an operating electric power plant. Biomarkers indicative of general stress, oxidative stress (superoxide dismutase and catalase), and DNA integrity, along with expression of stress proteins, were studied to assess the effects.
View Article and Find Full Text PDFAntifouling biocides are commonly used in coastal electric power stations to prevent biofouling in their condenser cooling systems. However, the environmental impact of the chemical biocides is less understood than the thermal stress effects caused by the condenser effluents. In this study, Chaetoceros lorenzianus, a representative marine diatom, was used to analyse the toxicity of two antifouling biocides, chlorine and chlorine dioxide.
View Article and Find Full Text PDFPhytoplankton entrained into cooling water systems of coastal power stations are subjected to acute chemical stress due to biocides (chlorine) used for biofouling control. They are subsequently released into the environment, where they may survive/recover or succumb. Experiments were conducted to evaluate the susceptibility of a centric (Chaetoceros lorenzianus) and pennate (Navicula sp.
View Article and Find Full Text PDFChlorine dioxide (ClO) is seen as an effective alternative to chlorine, which is widely used as an antifouling biocide. However, data on its efficacy against marine macrofoulants is scanty. In this study, acute toxicity of ClO to larval forms of the fouling barnacle Amphibalanus reticulatus was investigated.
View Article and Find Full Text PDFPolysaccharide fouling poses a significant challenge in the widespread application of membrane filtration for water purification. In order to mitigate the problem, a polysaccharide-degrading enzyme alginate lyase (Alg L; EC 4.2.
View Article and Find Full Text PDFMussels are important fouling organisms in the cooling water systems of coastal power plants. Continuous low-dose chlorination (CLDC) is being practiced as an effective method to control mussel biofouling in power plant cooling water systems. CLDC effectively controls mussel fouling by discouraging larval settlement rather than by killing the larvae or adults.
View Article and Find Full Text PDFA 6-L sequencing batch reactor (SBR) was operated for development of granular sludge capable of denitrification of high strength nitrates. Complete and stable denitrification of up to 5420 mg L(-1) nitrate-N (2710 mg L(-1) nitrate-N in reactor) was achieved by feeding simulated nitrate waste at a C/N ratio of 3. Compact and dense denitrifying granular sludge with relatively stable microbial community was developed during reactor operation.
View Article and Find Full Text PDFDibutyl phosphite, an organophosphorous compound, finds applications in different chemical industries and processes. Here, we report an efficient approach of biodegradation to be eventually used in bioremediation of dibutyl phosphite. Aerobic granules capable of dibutyl phosphite biodegradation were cultivated in a sequencing batch reactor (SBR).
View Article and Find Full Text PDFResearch pertaining to microbe-microbe and microbe-plant interactions has been largely limited to small molecules like quorum sensing chemicals. However, a few recent reports have indicated the role of complex molecules like proteins and polysaccharides in microbial communication. Here we demonstrate that exogenous proteins present in culture media can considerably accelerate the growth of Pseudomonas putida KT2440, even when such proteins are not internalized by the cells.
View Article and Find Full Text PDFThe study was aimed at assessing the potential of enzyme-embedded antibiotic-releasing polycaprolactone (PCL)-based electrospun fibres for tunable drug delivery. This was attempted by incorporation of gentamicin sulphate (GS) in the biocompatible polymer (PCL) matrix, with the degradation of the matrix being ensured by co-impregnating a polymer-degrading enzyme (lipase). Single phase solutions were obtained by hydrophobic ion pairing of GS and surfactant coating of lipase with an anionic surfactant, docusate sodium salt Aerosol OT (AOT).
View Article and Find Full Text PDFBackground: Marine epibiotic bacteria produce bioactive compounds effective against microbial biofilms. The study examines antibiofilm ability of a protein obtained from a tropical marine strain of Bacillus licheniformis D1.
Methodology/principal Findings: B.
J Mater Sci Mater Med
December 2012
Chronic wounds are a major cause for both suffering and economical losses. Management of chronic non-healing wounds requires multipronged approach. They are polymicrobial and agonizing for the patient due to associated pain.
View Article and Find Full Text PDFBackground: Yarrowia lipolytica is an ascomycetous dimorphic fungus that exhibits biofilm mode of growth. Earlier work has shown that biosurfactants such as rhamnolipids are efficient dispersants of bacterial biofilms. However, their effectiveness against fungal biofilms (particularly Y.
View Article and Find Full Text PDFMixed microbial consortia in the form of aerobic microbial granules (AMG) capable of xenobiotic degradation can be developed from activated sludge or by adaptation of microbial granules pre-grown on labile carbon sources. Both of these approaches were investigated for the cultivation of AMG capable of p-nitrophenol (PNP) biodegradation. Attempts to cultivate AMG from activated sludge using PNP as the sole carbon source were not successful due to poor microbial growth and washout of the inoculated activated sludge.
View Article and Find Full Text PDFThe aim of the present work was to determine the denitrification potential of aerobic granular sludge for concentrated nitrate wastes. We cultivated mixed microbial granules in a sequencing batch reactor operated at a superficial air velocity of 0.8 cm s(-1).
View Article and Find Full Text PDFCatheters and other indwelling devices placed inside human body are prone to bacterial infection, causing serious risk to patients. Infections associated with implants are difficult to resolve, and hence the prevention of bacterial colonization of such surfaces is quite appropriate. In this context, the development of novel antimicrobial biomaterials is currently gaining momentum.
View Article and Find Full Text PDFColloids Surf B Biointerfaces
November 2010
Removal of detrimental biofilms from surfaces exposed in the marine environment remains a challenge. A strain of Bacillus pumilus was isolated from the surface of titanium coupons immersed in seawater in the vicinity of Madras Atomic Power Station (MAPS) on the East coast of India. The bacterium formed extensive biofilms when compared to species such as Bacillus licheniformis, Pseudomonas aeruginosa PAO1 and Pseudomonas aureofaciens.
View Article and Find Full Text PDFBiotechnol Genet Eng Rev
April 2011
Quorum sensing (QS) has received significant attention in the past few decades. QS describes population density dependent cell to cell communication in bacteria using diffusible signal molecules. These signal molecules produced by bacterial cells, regulate various physiological processes important for social behavior and pathogenesis.
View Article and Find Full Text PDFCompetition between species plays a central role in the activity and structure of communities. Stable co-existence of diverse organisms in communities is thought to be fostered by individual tradeoffs and optimization of competitive strategies along resource gradients. Outside the laboratory, microbes exist as multispecies consortia, continuously interacting with one another and the environment.
View Article and Find Full Text PDFThis paper examines the development of aerobic granular sludge in the presence of a synthetic chelating agent, nitrilotriacetic acid (NTA), in sequencing batch reactors (SBR). The growth of seed sludge at 0.26 mM, 0.
View Article and Find Full Text PDFThis paper describes results of a successful bioaugmentation experiment on aerobic granular sludge using Pseudomonas putida KT2442 cells bearing the TOL (pWWO) plasmid. The methodology was designed to monitor incorporation of the added donor cells into pre-existent microbial granules and the subsequent plasmid transfer to the autochthonous microbial community using shake flask microcosms. Expression of reporter proteins (GFP and DsRed) allowed in situ monitoring of donor cell attachment and plasmid transfer to the recipient cells using confocal laser scanning microscopy.
View Article and Find Full Text PDFIn ecotoxicological studies involving environmental contaminants, rapid and multi-parametric optical detection based methods have definite advantages over traditional growth inhibition assays. In this context, a confocal laser scanning microscopy (CLSM) based method to assess ecotoxicity arising out of biocide insult to marine microalgae is reported. Using this technique, the effect of in-use concentrations of chlorine (an oxidizing biocide) on a marine diatom (Cocconeis scutellum Ehrenb) was determined based on inhibition of chlorophyll autofluorescence and esterase activity (probed by fluorescein diacetate (FDA) staining).
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