Production, optimization and characterization of partially purified anti-mycotic compound from marine soil derived streptomycetes originating at unexplored region of Bay of Bengal, India.

Sixty-eight morphologically distinct isolates of marine actinomycetes were derived from seashore, mangrove, and saltpan ecosystems located between the Palk Strait and Gulf of Mannar region, Bay of Bengal, Tamilnadu. Twenty-five (36.8%) isolates exhibited anti-mycotic activity against Candida albicans and Cryptococcus neoformans in preliminary screening, and 4 isolates with prominent activity were identified and designated at the genus level as Streptomyces sp. VPTS3-I, Streptomyces sp. VPTS3-2, Streptomyces sp. VPTSA1-4 and Streptomyces sp. VPTSA1-8. All the potential antagonistic isolates were further characterized with phenotypic and genotypic properties including 16S rRNA gene sequencing and identified species level as Streptomyces afghaniensis VPTS3-1, S. matensis VPTS3-2, S. tuirus VPTSA1-4 and S. griseus VPTSA1-8. In addition, the active fractions from the potential antagonistic streptomycetes were extracted with organic solvents by shake flask culture method and the anti-mycotic efficacies were evaluated. The optimization parameters for the production of the anti-mycotic compound were found to be pH between 7 and 8, the temperature at 30ᵒC, the salinity of 2%, incubation of 9 days, and starch and KNO3 as the suitable carbon and nitrogen sources respectively in starch casein medium.

Bacterial diversity of geochemically distinct hot springs located in Maharashtra, India.

Bacterial diversity of four thermally different hot springs of Ratnagiri district, Maharashtra, India, was investigated using culture-dependent and culture-independent approaches. A total of 144 bacterial cultures were isolated and identified using MALDI-TOF MS (matrix-assisted laser desorption ionization-time of flight mass spectrometry) and 16S rRNA gene sequencing. Culture-independent analysis by Ion Torrent sequencing targeting the V3 region of the 16S rRNA gene revealed the predominance of Firmicutes across all the hot springs, followed by Chloroflexi, Bacteroidetes, Cyanobacteria, Proteobacteria, Armatimonadetes, Actinobacteria, Nitrospirae, Acidobacteria, and Deinococcus-Thermus, with subtle differences in their abundance. At the lower taxonomic rank of genus, we noted the prevalence of Acinetobacter followed by Clostridium, Planomicrobium, Bacillus, Streptomyces, and Leptolyngbya. Metagenomics imputation using in silico approach revealed divergence in the metabolic capabilities of bacterial communities along the thermal gradient of host springs, with site TS (63 °C) featuring the abundant functional gene families.

Novel wastewater surveillance strategy for early detection of coronavirus disease 2019 hotspots.

The novel coronavirus disease 2019, a pandemic of global concern, caused by the novel severe acute respiratory syndrome coronavirus 2 has severely revealed the need for public monitoring and efficient screening techniques. Despite the various advancements made in the medical and research field, containment of this virus has proven to be difficult on several levels. As such, it is a necessary requirement to identify possible hotspots in the early stages of any disease. Based on previous studies carried out on coronaviruses, there is a high likelihood that severe acute respiratory syndrome coronavirus 2 may also survive in wastewater. Hence, we propose the use of nanofiber filters as a wastewater pretreatment routine and upgradation of existing wastewater evaluation and treatment systems to serve as a beneficial surveillance tool.

Climate and Soil Properties Influence Species Diversity of Soil Bacillus Community in India.

Bacillus is an important genus as it is a source for antibiotics, enzymes, and probiotics. Therefore, several studies are targeted on this genus in order to understand its diversity abundance in different soil environments. In present study, we investigated the diversity of Bacillus at species level using culturable approach in soils collected at different climatic zones of India and identified 20 prominent members of genus Bacillus species that are able to grow in different media types under same culture conditions. Results also showed that the species diversity of Bacillus changes according to the soil microenvironment under the influence of different climatic conditions. As a pilot study using culturable approach, we made an attempt to investigate the shift in Bacillus species diversity present in the Indian soils experiencing a climatic gradient over a large geographic area.

Heterogeneity of coarse particles in an urban area.

The variation in composition and concentration of coarse particles in Rochester, a medium-sized city in western New York, was studied using UNC passive samplers and computer-controlled scanning electron microscopy (CCSEM). The samplers were deployed in a 5 × 5 grid (2 km × 2 km per grid cell) for 2-3 week periods in two seasons (September 2008 and May 2009) at 25 different sites across Rochester. CCSEM analysis yielded size and elemental composition for individual particles and analyzed more than 800 coarse particles per sample. Based on the composition as reflected in the fluoresced X-ray spectrum, the particles were grouped into classes with similar chemical compositions using an adaptive resonance theory (ART) network. The mass fractions of particles in the identified classes were then used to assess the homogeneity of composition and concentration across the measurement domain. These results illustrate how particle sampling using the UNC passive sampler coupled with CCSEM/ART can be used to determine the concentration and source of the coarse particulate matter at multiple sites. The particle compositions were dominated by elements suggesting that the major particle sources are road dust and biological particles. Considerable heterogeneity in both composition and concentration were observed between adjacent sites as indicated by cofficient of divergence analyses.

Resuspension of indoor aeroallergens and relationship to lung inflammation in asthmatic children.

Studies have shown links between the concentration of allergens found in homes and asthma. Inhalation of allergens present in settled residential dust can occur when the dust is resuspended via human activity or air currents. Although previous studies have measured allergen concentrations in homes, the focus has been on the presence of the allergens in settled dust samples. However, the actual inhalation exposure is to airborne allergens. The relationship between the settled dust composition and suspended allergens and endotoxin and the effect of exposure of these aeroallergens to asthmatics are not well understood for species typically present indoors. In this study, settled dust and airborne particulate matter samples were collected in the homes and school classrooms of asthmatic children of ages 9 to 16 and analyzed for endotoxin and allergens including dust mite and cockroach allergen, and dog and cat dander (Der p1, Der f1, Bla g1, Can f1, and Fel d1, respectively). Concentrations of cockroach allergen were below detection limit for all samples. Measurements of the settled dust samples show higher dust mite allergen in bedroom samples than in living room samples. Concentrations of airborne endotoxin and indoor allergens were generally higher in the homes than those measured at school. Within the homes, higher concentrations of airborne allergens and endotoxin were observed in the living rooms compared to the bedrooms. Resuspension rates for endotoxin, dust mite allergen, and, cat and dog dander were estimated in this study. Calculated resuspension rates for cat dander (8.1x10(-7)+/-3.5x10(-7)min(-1)) and dust mite allergen (2.1x10(-6)+/-7.6x10(-7)min(-1)and 1.4x10(-5)+/-4.6x10(-6)min(-1) for Der p 1 and Der f 1, respectively) were found to be higher than those for dog dander (3.1x10(-7)+/-1.3x10(-7)min(-1)) and endotoxin (3.6x10(-7)+/-1.6x10(-7)min(-1)). Markers of asthma inflammation including nitrate in exhaled breath condensate (EBC) and exhaled nitric oxide (eNO), were correlated with the concentrations of dust mite allergen (Der p 1) (Spearman r=0.598; p-value=0.068 for EBC and Spearman r=0.819; p-value=0.007 for eNO) and cat dander (Fel d 1) (Spearman r=0.917; p-value=0.0002 for EBC and Spearman r=0.697; p-value=0.054 for eNO) present in PM(10) samples.

Deposition of reactive nitrogen during the Rocky Mountain Airborne Nitrogen and Sulfur (RoMANS) study.

Increases in reactive nitrogen deposition are a growing concern in the U.S. Rocky Mountain west. The Rocky Mountain Airborne Nitrogen and Sulfur (RoMANS) study was designed to improve understanding of the species and pathways that contribute to nitrogen deposition in Rocky Mountain National Park (RMNP). During two 5-week field campaigns in spring and summer of 2006, the largest contributor to reactive nitrogen deposition in RMNP was found to be wet deposition of ammonium (34% spring and summer), followed by wet deposition of nitrate (24% spring, 28% summer). The third and fourth most important reactive nitrogen deposition pathways were found to be wet deposition of organic nitrogen (17%, 12%) and dry deposition of ammonia (14%, 16%), neither of which is routinely measured by air quality/deposition networks operating in the region. Total reactive nitrogen deposition during the spring campaign was determined to be 0.45 kg ha(-1) and more than doubled to 0.95 kg ha(-1) during the summer campaign.

Using high time resolution aerosol and number size distribution measurements to estimate atmospheric extinction.

Rocky Mountain National Park is experiencing reduced visibility and changes in ecosystem function due to increasing levels of oxidized and reduced nitrogen. The Rocky Mountain Atmospheric Nitrogen and Sulfur (RoMANS) study was initiated to better understand the origins of sulfur and nitrogen species as well as the complex chemistry occurring during transport from source to receptor. As part of the study, a monitoring program was initiated for two 1-month time periods--one during the spring and the other during late summer/fall. The monitoring program included intensive high time resolution concentration measurements of aerosol number size distribution, inorganic anions, and cations, and 24-hr time resolution of PM2.5 and PM10 mass, sulfate, nitrate, carbon, and soil-related elements concentrations. These data are combined to estimate high time resolution concentrations of PM2.5 and PM10 aerosol mass and fine mass species estimates of ammoniated sulfate, nitrate, and organic and elemental carbon. Hour-by-hour extinction budgets are calculated by using these species concentration estimates and measurements of size distribution and assuming internal and external particle mixtures. Summer extinction was on average about 3 times higher than spring extinction. During spring months, sulfates, nitrates, carbon mass, and PM10 - PM2.5 mass contributed approximately equal amounts of extinction, whereas during the summer months, carbonaceous material extinction was 2-3 times higher than other species.

Typing of Aeromonas hydrophila of fish and human diarrhoeal origin by outer membrane proteins and lipopolysaccharides.

A study was undertaken to discriminate the strains of Aeromonas hydrophila isolated from fish and diarrhoeal samples by SDS-PAGE analysis of outer membrane proteins (OMPs) and lipopolysaccharides (LPSs). Common bands at 47 kDa positions for OMPs and at 31-38 kDa for LPSs were observed. No strain of A. hydrophila from clinical or fish samples was found identical in either OMPs or LPSs profile.

Heterogeneous oxidation by ozone of naphthalene adsorbed at the air-water interface of micron-size water droplets.

The mass transfer of naphthalene vapor to water droplets in air was studied in the presence of ozone (O3) in the gas phase. A falling droplet reactor with water droplets of diameters 55, 91, and 182 microm was used for the study. O3 reacted with naphthalene at the air-water interface, thereby decreasing the mass transfer resistance and increasing the rate of uptake of naphthalene into the droplet. A Langmuir-Hinshelwood reaction mechanism at the air-water interface satisfactorily described the surface reaction. The first-order surface reaction rate constant, ks, increased with decreasing droplet size. Three organic intermediates were identified in the aqueous phase as a result of ozonation of naphthalene at the surface of the droplet indicating both peroxidic and nonperoxidic routes for ozonation. The presence of an organic carbon surrogate (fulvic acid) increased both the partition constant of naphthalene and the surface reaction rate of O3. The heterogeneous oxidation of naphthalene by O3 on the droplet was 15 times faster than the homogeneous oxidation by O3 in the bulk air phase, whereas it was only 0.08 times the homogeneous gas-phase oxidation by hydroxyl radicals under atmospheric conditions.

Human leptospirosis in Erode, South India: serology, isolation, and characterization of the isolates by randomly amplified polymorphic DNA (RAPD) fingerprinting.

The study describes the first attempt to record leptospirosis in Erode by isolation and serological tests such as the microscopic agglutination test and IgM-based enzyme-linked immunosorbent assay. Twenty-nine clinically suspected cases showing fever, headache, body ache associated with jaundice, decreased urine output, and conjunctival suffusion were included. The age of the patients ranged between 10-71 years and most of them were agricultural workers. Paired sera were possible among 12 cases. All the patients had fever and headache and other more common symptoms were myalgia and icterus. Leptospiral culture was positive in 7 (24.1%) patients. Out of 29 patients, 26 (89.7%) were diagnosed as having current leptospiral infection based on serology and isolation. The leptospiral isolates KSR 1-6 were further characterized by using randomly amplified polymorphic DNA fingerprinting shown genetic similarities with Leptospira interrogans spp. This study shows the presence of leptospirosis among the hospital cases of Erode and that this disease is a potential health hazard of agricultural workers in Cauvery basin.

Adsorption and transport of gas-phase naphthalene on micron-size fog droplets in air.

Aromatic hydrocarbon vapors adsorb to the air/water interface and are transported by wet deposition processes via fog, mist, and rain. A falling droplet apparatus was used to study the adsorption and uptake of naphthalene vapor on water droplets with diameters ranging from 14 to 200 microm. Uptake of naphthalene vapor greater than that predicted by bulk (air-water) phase equilibrium was noted for diameters less than 50 microm and was attributed to surface adsorption. The experimental values of the droplet-vapor partition constants were used to obtain the mass accommodation coefficient for naphthalene at the interface. The effect of temperature on the mass accommodation coefficientwas measured. The effects of a synthetic surfactant and a natural organic carbon surrogate (Suwanee Fulvic acid) on the uptake of naphthalene vapors on water droplets were also examined. Small droplet diameter, decreased temperature, and the presence of dissolved surface-active material in water enhanced the uptake of naphthalene into fog droplets.

Uptake of aromatic hydrocarbon vapors (benzene and phenanthrene) at the air-water interface of micron-size water droplets.

Uptake of aromatic hydrocarbon vapors (benzene and phenanthrene) by typical micrometer-sized fog-water droplets was studied using a falling droplet reactor at temperatures between 296 and 316 K. Uptake of phenanthrene vapor greater than that predicted by bulk (air-water)-phase equilibrium was observed for diameters less than 200 microm, and this was attributed to surface adsorption. The experimental values of the droplet-vapor partition constant were used to obtain the overall mass transfer coefficient and the mass accommodation coefficient for both benzene and phenanthrene. Mass transfer of phenanthrene was dependent only on gas-phase diffusion and mass accommodation at the interface. However, for benzene, the mass transfer was limited by liquid-phase diffusion and mass accommodation. A large value of the mass accommodation coefficient, alpha = (1.4 +/- 0.4) x 10(-2) was observed for the highly surface-active (hydrophobic) phenanthrene, whereas a small alpha = (9.7 +/- 1.8) x 10(-5) was observed for the less hydrophobic benzene. Critical cluster numbers ranging from 2 for benzene to 5.7 for phenanthrene were deduced using the critical cluster nucleation theory for mass accommodation. The enthalpy of mass accommodation was more negative for phenanthrene than it was for benzene. Consequently, the temperature effect was more pronounced for phenanthrene. A linear correlation was observed for the enthalpy of accommodation with the excess enthalpy of solution. A natural organic carbon surrogate (Suwannee Fulvic acid) in the water droplet increased the uptake for phenanthrene and benzene, the effect being more marked for phenanthrene. A characteristic time constant analysis showed that uptake and droplet scavenging would compete for the fog deposition of phenanthrene, whereas deposition would be unimpeded by the uptake rate for benzene vapor. For both compounds, the characteristic atmospheric reaction times were much larger and would not impact fog deposition.