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Isolation of bacteriophages from air using vacuum filtration technique: an improved and novel method
No full textAim: Development of a simple and economical air sampler for isolation and
enrichment of bacteriophages from air samples.
Methods and Results: A vacuum filtration unit with simple modifications was
used for isolation of bacteriophages from air sampled in the lavatory. Air was
sampled at the rate of 62 l min�1 by bubbling into Mcllvaine buffer for
30 min, which was used as bacteriophage solution for enrichment and plaque
assessment against individual hosts. Alternatively, the aforementioned phage
solution was enriched using a host consortium before plaque assessment.
Phages were isolated in the range of 1–12 PFU per ml by the first method,
whereas enrichment with host consortium gave phages around 10- to 1000-
folds higher in number. Combining with established enrichment method, an
improvement of about 10 times in phage isolation efficiency was attained.
Conclusions: The method is very useful for studying the natural
bacteriophages of air, requiring only a basic microbiological laboratory setup
making it simple and economical.
Significance and Impact of the Study: This study brings out a simple,
economical air sampler for assessing air bacteriophages that can be employed
by any microbial laboratory. Although various methods are available for
studying bacteriophages in water and soil, very limited are available for air. To
the best of our knowledge, the method developed in this study is unique in its
design and concept for studying bacteriophages in air. The sampler is
sterilizable by autoclaving and maintains a healthy rate of airflow provided by
conventional vacuum pumps. The use of a nonspecific ‘trapping solution’
allows for the qualitative and quantitative study of air bacteriophages
The genetic influence in fluorosis
No full textFluorosis, caused by ingestion of excess fluoride, is endemic in at least 25 countries across the globe, China and
India being the worst affected among them. Dental, skeletal and non-skeletal are the major types of fluorosis
affecting millions of people in these countries. A number of genetic epidemiological studies carried out by
investigators have shown the evidence for association between genetic polymorphisms in candidate genes and
differences in the susceptibility pattern of different types of fluorosis among individuals living in the same
community and having the same environmental exposure. These studies have pointed out that genetic variants in
some candidate genes like COL1A2 (Collagen type 1 alpha 2), CTR (Calcitonin receptor gene), ESR (Estrogen
receptor), COMT (Catechol-o-methyltransferase), GSTP1 (Glutathione S-transferase pi 1), MMP-2 (Matrix metallopeptidase
2), PRL (Prolactin), VDR (Vitamin D receptor) and MPO (Myeloperoxidase) could increase or
decrease the risk of fluorosis among the exposed individuals in endemic areas. So, it is increasingly becoming
evident that an individual’s genetic background could play a major role in influencing the risk to fluorosis when
other factors like specific environmental exposures including dietary patterns of fluoride intake and other nutrients
remain the same. The current manuscript presents an up-to-date critical review on fluorosis, focusing
mainly on the genetic association studies that have looked at the possible involvement of genetic factors in
fluorosis
How the Atmosphere over Eastern Himalaya, India is Polluted with Carbonyl Compounds? Temporal Variability and Identification of Sources
No full textA study was conducted on atmospheric carbonyl compounds for the first time over a Himalayan atmosphere in India. Samples were collected from a high altitude hill station, Darjeeling (27.01°N, 88.15°E, 2200 masl) during June 2012 to May 2013. Temporal variation, meteorological influence, source apportionment and ozone formation potential etc were studied for acetaldehyde, formaldehyde, acetone, butanaldehyde, propanaldehyde, benzaldehyde, crotonaldehyde, valeraldehyde, isovaleraldehyde, hexanaldehyde, p-tolualdehyde and o-tolualdehyde. High concentration of Acetone (81.6 ± 63.5 µg m–3) was observed which could be due to the higher photochemical production from its precursor volatile organic compounds emitted from tea plants and tea processing units. The concentration of acetaldehyde (20.7 ± 47.6 µg m–3) and formaldehyde (11.6 ± 16.3 µg m–3) were found to be comparable with metro cities of India and world. The average annual concentration of total carbonyl compounds was 174.2 ± 184.6 µg m–3 with maximum during postmonsoon (456.9 ± 199.5 µg m–3) and minimum during winter season (72.2 ± 42.9 µg m–3). Meteorological parameters like temperature and surface reaching solar radiative flux played the major roles for the seasonal variation of the carbonyl concentration over the hill station. The average ratio of formaldehyde to acetaldehyde over Darjeeling was found to be 1.64 ± 1.43 well representing a typical urban atmosphere at this part of Himalaya. Positive matrix factorization model showed that the biogenic emissions from tea plants and vehicular emissions were the major sources of carbonyl compounds over the hill station
Low temperature synthesis of pure anatase carbon doped titanium dioxide: An efficient visible light active photocatalyst
No full textLow temperature pure anatase Carbon Doped Titanium Dioxide (C-TiO2) is successfully synthesized by using
starch as an effective, economical, and nonhazardous carbon source. The synthesized C-TiO2 has been further
characterized by X-Ray Diffraction, SEM, TEM, BET, XPS and UV- DRS techniques, which reveal that the
particles are crystalline with spherical morphology, high surface area and an optical band gap of 2.79 eV for CTiO2
calcined at 400 °C. Furthermore photocatalytic degradation of Rhodamine B dye was carried out using asprepared
C-TiO2 under visible light irradiation. Prepared C-TiO2 calcined at 200 °C and 400 °C show higher
degradation efficiency (85% and 100% in 120 min respectively) as compared to that of undoped TiO2 and
commercial Degussa P-25. Result shows that the C-TiO2 containing lower carbon percentage has higher
photocatalytic activity. Thus enhanced photocatalytic activity of C-TiO2, may be due to synergic effect of carbon doping and [101] facet enhanced synthesis of anatase C-TiO2
Catalytic Control Options for Diesel Particulate Emissions Including that from Locomotive Engines
No full textDiesel engines have gained an edge over other fuel engines in heavy duty transportation sector owing to their high efficiency, high durability and reliability with low operational costs. Also, in the last few decades, diesel engines have chunked out a growing share in the light-duty vehicle market as well
Assessment of Sewage Quality for Implementation of Decentralized Sewage Treatment System for Small Communities in Nagpur
No full textThe present study demonstrates the assessment of sewage quality of two residential areas and two public parks in Nagpur. The sites were chosen considering freshwater demand for non-potable purposes by small communities. Grab samples of raw sewage were collected and analyzed for physicochemical parameters such as pH, alkalinity, Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Dissolved Solids (TDS), Total Suspended Solids (TSS), Total Kjeldahl Nitrogen (TKN), Total Phosphate (TP) and faecal coliforms (FC). The raw sewage of all sites was found to be of moderate strength with an average COD of 250 mg/L, BOD 150 mg/L, TSS 200 mg/L, TKN 25 mg/L and TP 3 mg/L. Baseline data was also generated for groundwater samples of the sites under study. Based on the results, various treatment options were proposed comprising natural treatment by wetlands for removal of organics and nutrients, polishing treatment by granular activated carbon for removal of trace contaminants e.g. Pharmaceuticals and personal care products and finally disinfection of the treated effluent to be reused for non-potable purposes
Process thermoneutral point in dry autothermal reforming for CO2 utilization
No full textDry autothermal reforming is a novel CO2 utilization process. Thermoneutral points are considered to be the best operating points in autothermal reforming reactors. A theoretical study was done to determine the process thermoneutral points for complete dry autothermal reforming process considering the basic preheater, reactor and condenser configuration. The results were compared to the product yields at reactor thermoneutral points for the same input feed and temperature conditions. The process thermoneutral points were found be better for operational reasons than reactor thermoneutral points. Dry autothermal reforming of methane was used as model example in this study. This study can be used for different autothermal processes to calculate the optimum conditions at which the process can be operated in heat integrated loop without the need of any external thermal energ
A mechanical automatic urinal -toilet flusher and its mechanism thereof
Get PDFThis invention relates to a system for facilitating an automatic urinal toilet flushing comprising: a pipe (P) having an intermediate enlarged in- ner diameter area, said pipe comprising: first portion P I having a first diameter d1; second portion P2 having a second diameter d2; a third portion P3 having a third diameter d3; wherein the first, the second and the third portions are se- quential and the diameter d2 is greater than diameter d1 and diameter d3; a tapered forth portion P4 connecting the first portion P I to the second portion P2; and a tapered fifth portion PS connecting the second portion P2 to the third portion P3; a valve mechanism located within the pipe (P), the said valve mechanism comprising an inlet dual valve (I), an outlet dual valve (2) and a connecting rod connecting the inlet dual valve (I) and outlet dual valve (2); and an actuating mechanism that gets automatically actuated and upon actu- ation, operates the valve mechanism to perform a flushing operation
Enhanced expression of catechol 1,2 dioxygenase gene in biofilm forming Pseudomonas mendocina EGD-AQ5 under increasing benzoate stress
No full textIn natural settings, microbes often associate closely with surfaces and interfaces called biofilms and
adhere in an extracellular matrix. The biofilm provide diverse microenvironments and high resistance to
environmental stress on the constituent cells that aid to generate cellular heterogeneity and phenotypic
variability. The work presented here examines for the first time the capability of Pseudomonas mendocina
EGD-AQ5 biofilm-associated cells, compared with that of planktonic cells to utilize toxic intermediate
catechol under benzoate degradation conditions in liquid culture systems. Both planktonic and biofilmassociated
cells utilized benzoate to the same extent but accumulated catechol differently. This differential
catechol accumulation activity of the Pseudomonas mendocina EGD-AQ5 could be accredited to the
cells adapted as a biofilm. Further experiments with transcriptome implicated to increased expression of
genes like pelA (involved in biofilm formation) cat1,2D (ortho pathway) and decreased expression of
cat2,3D (meta pathway) in biofilm harvested cells than free suspended cells. Whole genome sequence
analysis of Pseudomonas mendocina EGD-AQ5 (Genbank Accession No AVQF00000000) deciphered
catechol ortho and meta-pathways for benzoate utilization and pelABCDEFG as involved in biofilm formation.
These results suggest that Pseudomonas mendocina EGD-AQ5 biofilms should facilitate bioaugmentation
to be more resilient and efficient bioremediation technology than free suspended
planktonic cells
Design of cost effective photobioreactor (PBR) for mass production of microalgae: Experiments and CFD simulations
No full textA) Integrated process of CO2 mitigation and wastewater treatment using microalgae on pilot scale to yield biofuels:
Various microalgae strains have been found to produce the suitable feedstock for biofuels production. Although microalgae are having several advantages such as rapid growth, higher lipid productivity, and robustness to various environmental conditions, and sought one of the major promising alternative sources of liquid biofuels, the present cost of microalgae production is very high. One way to lower the cost of production is to use the wastewater instead of freshwater which also satisfies the need of nitrogen and phosphorous, the most required elements for microalgae growth. The production of microalgal biofuels seems to be viable on a large scale with the use of wastewater, industry emitted CO2 and freely available sunlight for cultivation of microalgae. The optimal ways to enhance total lipid content of microalgae under different modes of cultivation (autotrophic as well as mixotrophic mode) is under investigation. The main objective is to see the feasibility of microalgae cultivation in these modes along with maximum possible sequestration of CO2.
B) Design of vertical gas sparged PBR
The cultivation of microalgae is very sensitive to temperature, pH, shear stress, irradiance, and operating conditions of PBR. Suitable strategies are needed to enhance the biomass and lipid productivity in vertical tubular column PBR. The understanding of design parameters is a prerequisite for scale-up of gas sparged vertical column PBRs. The hydrodynamics of gas sparged vertical column PBRs play a very important role in the biomass production and avoiding carbon loss (unabsorbed CO2 out of total supplied). Hence, the hydrodynamic aspects of two and three phase flow in the vertical column PBR are emphasized with respect to its scale-up prospect. The flow regimes and CFD modelling aspects of gas sparged PBRs are key areas to be focused in this study