Characteristics of two new reticuloendotheliosis virus isolates of turkeys.

Reticuloendotheliosis (RE) virus strains MN81 and MN67 isolated from epiornithics of RE in turkeys were partially characterized. Strains MN81 and MN67 replicated in chicken embryo fibroblast,duck embryo fibroblast and turkey embryo-fibroblast cultures and produced syncytial cytopathic effects in duck embryo fibroblast and turkey embryo fibroblast cultures. The virions of MN81 and MN67 measured approximately 100 nm in diameter, resembled RE virus strain T, and could be distinguished from avian leukosis viruses morphologically. The buoyant density of strain MN81 was found to be 1.15 g/cm3 in sucrose gradients. Strains MN81 and MN67 were inactivated by heat, acid pH, ether, and chloroform treatments. These strains were serologically unrelated to avian leukosis virus but were related to RE virus strains T, CS, DIA, and SN.     

Crude Oil-Contaminated Soil Phytoremediation by Using Cyperus brevifolius (Rottb.) Hassk

The degradation of total oil and grease (TOG) in crude oil-contaminated soil in the presence of Cyperus brevifolius (Rottb.) Hassk was investigated in a net house study. C. brevifolius plants were transplanted in to spiked soil containing 8% (w/w) crude oil. The capability of plant for enhancing the biodegradation process was tested in pots containing fertilized and unfertilized soil over a 360-day period. Analysis of the degradation of hydrocarbon contaminants, plant growth, and biomass was conducted at 60-day interval. In the presence of contaminants, plant biomass and height were significantly reduced. The specific root surface area was reduced under the effects of crude oil. Concerning TOG content in soil, C. brevifolius could decrease up to 86.2% in TA (crude oil-contaminated soil with fertilizer) and 61.2% in TC (crude oil-contaminated soil without fertilizer). In the unvegetated pots, the reduction of TOG was 13.7% in TB (crude oil-contaminated soil with fertilizer) and 12.5% in TD (crude oil-contaminated soil without fertilizer). However, biodegradation was significantly more in vegetated pots than in unvegetated pots (p?=?0.05). The addition of fertilizer had positive effect on TOG degradation in the presence of C. brevifolius compared to the unfertilized treatments. Thus, there was evidence of C. brevifolius enhancing the biodegradation of crude oil in soil under the conditions of this experiment.     

Prevalence and antimicrobial resistance of porcine O157 and non-O157 Shiga toxin-producing Escherichia coli from India

The aims of this study were to determine the prevalence of Shiga toxin-producing Escherichia coli (STEC) strains in pigs as a possible STEC reservoir in India as well as to characterize the STEC strains and to determine the antimicrobial resistance pattern of the strains. A total of 782 E. coli isolates from clinically healthy (n?=?473) and diarrhoeic piglets (309) belonging to major pig-producing states of India were screened by the polymerase chain reaction (PCR) assay for the presence of virulence genes characteristic for STEC, that is, Shiga toxin-producing gene(s) (stx1, stx2), intimin (eae), enterohemolysin (hlyA) and STEC autoagglutinating adhesin (Saa). Overall STEC were detected in 113 (14.4 %) piglets, and the prevalence of E. coli O157 and non-O157 STEC were 4 (0.5 %) and 109 (13.9 %), respectively. None of the O157 STEC isolates carried gene encoding for H7 antigen (fliCh7). The various combinations of virulence genes present in the strains studied were stx1 in 4.6 %, stx1 in combination with stx2 gene in 5.1 %, stx1 in combination with stx2 and ehxA in 0.6 %, stx1 in combination with stx2 and eae in 0.2 % and stx2 alone in 3.7 %. All STEC isolates were found negative for STEC autoagglutinating adhesin (Saa). The number of STEC isolates which showed resistance to antimicrobials such as ampicillin, tetracycline, streptomycin, lincomycin, nalidixic acid, sulfadiazine, penicillin, gentamicin, kanamycin and ceftriaxone were 100, 99, 98, 97, 95, 94, 92, 88, 85 and 85, respectively. Ninety-seven isolates showed resistance to more than 2 antimicrobials, and 8 resistance groups (R1 to R8) were observed. This study demonstrates that pigs in India harbour both O157 and non-O157 STEC, and this may pose serious public health problems in future.     

Ontogeny and development of the gastrointestinal system in Indian walking catfish (Clarias magur) during its early development

Fish Physiology and Biochemistry - Ontogeny of the digestive tract and its accessory organs and their further development in the Indian walking catfish (Clarias magur) were examined in larvae,...     

Groundwater quality in Visakhapatnam Basin,India

Visakhapatnam Basin, located on the east coast of India adjoining the Bay of Bengal, is surrounded by hills. Groundwater in the basin is utilized for domestic, irrigational, and industrial purposes. The basin measures about 148 km² in which 35% of the land is utilized for irrigation, and 10% of the land for industries. However there is a rapid industrial development in the basin along with increasing population initiating the necessity to evaluate groundwater resources. The chemical quality of groundwaters available in the basin is discussed in relation to domestic, irrigational, and industrial purposes.     

Combined Effects of Copper and Microalgal (Tetraselmis suecica) Concentrations on the Population Growth of Brachionus plicatilis Müller (Rotifera)

Copper compounds are commonly used to kill algal blooms in fish and shrimp ponds. However, indiscriminate use of copper in the aquaculture ponds may have a negative impact on the production of rotifers, which, in turn, can influence the final yield. In this work we studied the combined effects of chronic toxicity of copper (0, 0.125, 0.25, 0.5 and 1.0 mg L^-1 of copper sulphate) and algal (Tetraselmis suecica) levels (0.05 × 10⁶ and 0.10 × 10⁶ cells ml^-1) on the population growth of the saline water rotifer B. plicatilis at 25 °C, pH 8.5 and salinity 36‰. The population of B. plicatilis increased with increasing levels of T. suecica. Regardless of the food level, rotifers exposed to 1 mg L^-1 of copper did not survive beyond 3 days. Copper of 0.125 mg L^-1 caused a reduction in the population of B. plicatilis but only at low algal food level; at the high (0.2 × 10⁶) food concentration, the growth was comparable to that observed in the control suggesting that higher algal levels had an ameliorating effect on the toxicity of copper to B. plicatilis. The relation between the rotifer density and the egg-ratio was inverse and statistically significant in controls. However, this relation was non-significant in rotifers subjected to the copper concentration. The peak population density of B. plicatilis in controls varied from 36 to 251 ind. ml^-1 depending on the food level. The rate of population increase per day (r) in the controls varied from 0.24–0.63 depending on the food level. In general, an increase in food level resulted in higher peak population abundance and growth rates. The presence of copper resulted in the reduction of both r values and peak population densities of B. plicatilis. The results have been discussed in light of protective role of algae in reducing the toxicity of heavy metals to rotifers.     

Development of an extractive spectrophotometric method for the determination of copper(II) in leafy vegetable and pharmaceutical samples using pyridoxal-4-phenyl-3-thiosemicarbazone (PPT)

A highly sensitive extractive spectrophotometric method has been developed for the determination of copper(II) using pyridoxal-4-phenyl-3-thiosemicarbazone(PPT) as an analytical reagent. The PPT forms reddish brown species of copper(II) at a pH range of 3.0-5.5, and the complex was extracted into n-butanol. The Cu(II)-PPT complex shows maximum absorbance at 440 nm, with molar absorptivity and Sandell's sensitivity being 2.16 x 10(4) L mol(-1) cm(-1) and 2.94 x 10(-3) microg cm(-2), respectively. The system obeys Beer's law in the range of 0.2-5.0 mg/L. The regression coefficient of the Beer's law straight line is 0.338, and the correlation coefficient is 0.96. The detection limit of the method is 0.0065 microg mL(-1). Most of the common metal ions generally found associated with copper do not interfere. The repeatability of the method was checked by finding the relative standard deviation. The developed method has been successfully employed for the determination of copper(II) in leafy vegetable and pharmaceutical samples. The method is evaluated by analyzing samples from the Bureau of Analyzed Samples (BCS 233, 266, 216/1, 207, and 179) and by intercomparison of experimental values using AAS.     

Evaluation of bacterial strains isolated from oil-contaminated soil for production of polyhydroxyalkanoic acids (PHA)

Samples of eight geographically distinct soils contaminated with crude oil were screened for polyhydroxyalkanoic acid (PHA) producing bacterial strains. Twenty three bacterial strains were able to accumulate PHA when sodium gluconate or sodium octanoate was used as the sole carbon source. Biochemical tests and 16S rRNA sequencing identified bacteria of the genera Pseudomonas, Acinetobacter, Sphingobacterium, Brochothrix, Caulobacter, Ralstonia, Burkholderia and Yokenella. Three of the bacterial strains have never been reported to produce PHA. The phylogenetic analysis of the PHA synthase (phaC) gene of these bacteria showed a close homology with the phaC gene of different Pseudomonas species.This study indicates that stressed environments like oil-contaminated sites can be potential sources of medium-chain-length PHA producers.     

Response of a freshwater air-breathing fish, Clarias batrachus to salinity stress: an experimental case for their farming in brackishwater areas in Andaman, India

The study was conducted to assess the effects of salinity on growth and biochemical composition of freshwater catfish, Clarias batrachus. A static nonrenewable acute toxicity bioassay test was conducted and LC₅₀ of salinity for 96-h exposure to the fingerling (14.5 cm) was 12.52 ‰. Based on these results, two sublethal salinity levels, viz. 4 and 8 ‰ were selected to study the long-term effects of salinity on C. batrachus for a period of 90 days. From the study, it was found that growth and survival rate were less in saline water (4 and 8 ‰). Maximum growth and survival were recorded in freshwater (0 ‰ salinity) and subsequently at 4 and 8 ‰. To assess the biochemical alteration, few important biomarkers were estimated. At the end of 90 days rearing period, glucose level in the brain and blood of C. batrachus was found to decrease with salinity. The level of liver and muscle glycogen in the fish reared at 4 ‰ was lower than that of control. Ascorbic acid in all organs under study was found to decrease with increasing salinity, which was attributed to stress mitigation effect of vitamin C. Acetylcholine esterase (AchE) activity recorded a gradual decrease with increasing salinity. Metabolic enzymes, alkaline phosphatase (ALP) activity and adenosine triphosphosphtase (ATPase) activity also reduced both in liver and muscle tissues with increasing salinity. From the present investigation, it can be concluded that exposure to higher salinity significantly (P < 0.01) affects the growth and physiological response of Clarias batrachus.     

Nitrogen Management for Sustainable Soil Organic Carbon Increase in Inceptisols Under Wheat Cultivation

Application of nitrogen (N) fertilizers to increase crop yield is a worldwide practice, which also has a positive influence on the soil organic carbon (SOC) increase. This study was carried out to investigate the dynamics of SOC and its fractions under different levels of N fertilization in wheat grown inceptisols of Northeast India over a period of 2 years. For the purpose of this study, fertilizer treatments with five N levels (40, 60, 72, 80, and 100 kg N ha^?1) were applied in randomized block design. Increased SOC particulate organic carbon (POC), humic acid carbon, and fulvic acid carbon were recorded under application of higher N. Stability of SOC as indicated by E4/E6 ratio and microbial biomass carbon (MBC) was higher on application of 72 kg N ha^?1. Among the SOC fractions, POC and MBC respond rapidly to different N fertilization rates. Available N and phosphatase activity increased while pH and urease activity (UA) decreased as a function of applied N fertilizer levels. Nitrogen fertilization increased wheat yield and biomass with insignificant differences among 100, 80, and 72 kg N ha^?1. Thus, under the present experimental conditions, application of 72 kg N ha^?1 can sustain SOC and soil health without compromising wheat yield in the inceptisols of Northeast India.