Changes in growth and pigment content in Sweet potato by triadimefon and hexaconazole

            Triadimefon and hexaconazole are triazole group of fungicides have plant growth regulating properties. The present investigation aimed to study the growth regulating effect of these compounds on sweet potato (Ipomoea batatas L.). Each plant was treated with one litre of aqueous solutions containing 15mg L-1 triadimefon and 10mg L-1 hexaconazole on 40 and 70 days after planting (DAP) by soil drenching. The growth parameters of the plants were estimated on 45, 60, 75, 90 and 105 DAP.  Among the triazole, hexaconazole inhibited the number of leaves, total leaf area, stem length, internodal length, leaf and stem dry weight, relative shoot growth rate significantly when compared to triadimefon.  Triazole (chiefly available and plant control and yield production) treatments increase the root length, root and tuber dry weight, relative tuber growth rate, net assimilation rate root/shoot ratio, leaf dry weight per unit area, chlorophyll and carotenoid content

Biosorption of mercury by <em>Bacillus thuringiensis</em> (CASKS3) isolated from mangrove sediments of southeast coast India

143-150Present study highlights the fact that the bacterium B. thuringiensis CASKS3, isolated from mangrove sediments is an efficient strain for biosorption of mercury. Metal-tolerant bacterial strain CASKS3 was identified as Bacillus thuringiensis following 16S rRNA gene sequence analysis. Initially, the strain was tested at a minimal inhibitory concentration (MIC) of mercury and its antibiotic resistance was observed. Bacterium was exposed to different concentrations of mercury ranging from 200 to 800 mg-l.  Adsorption ability was observed to be 38–62 at 800 mg-l to 200ppm

Screening and fractional purification of antimicrobial compound of Streptomyces sp. MAB 18 isolated from coastal sediment of Nagapattinam, south-east coast of India

662-669A total of 42 strains of actinobacteria were isolated from five different stations. Out of these 42 isolates, the suspected 10 actinobacterial strains were screened and inoculated for purification, and based on the preliminary screening results, MAB18 was taken to investigate the extraction evaluation of its antimicrobial property. Then it was tested against bacterial and fungal pathogens. The highest zone of inhibition was observed against E. coli (8.2±0.8mm), P. aeroginosa (10.4±0.6 mm), Vibrio harveyi (7.2±0.8mm), S. typhi (10.6±-0.4 mm) for bacteria and A. niger (11.2±0.8 mm), and A. flavus (9.8±0.2 mm) C. albicans (10.4±0.6mm), and Penicillium sp. (7.2±0.8mm), for fungi, whereas it was 21.4±0.6 and 20.4±0.6 mm for the standard ampicillin and nystatin. The antibiotic producing actinomycetes may be tapped as one of the India’s potential source of novel antibiotics to be used against both bacterial and fungal pathogenic organisms

Antibiotic and antioxidant activities biogenic silver nanoparticles synthesized using Escherichia coli (VM1) bacterium

Synthesis of silver nanoparticles (AgNPs) using microorganisms has gained considerable attention as an efficient alternative for conventional chemical synthesis. Earlier, we have demonstrated biosynthesis of silver nanoparticles using marine Escherichia coli VM1. Here, we investigated antibacterial, antifungal and antioxidant efficacy of the synthesized silver nanoparticles using standard techniques. The results have shown that the AgNPs synthesized using the marine Escherichia coli have potential antibacterial activity against both Gram positive (Staphylococcus aureus) and Gram negative (E. coli, Klebsiella pneumoniae, S. paratyphi, Vibrio parahaemolyticus, V. cholerae and Proteus mirabilis) pathogenic bacteria and moderate antifungal activity was observed against Aspergillus niger, Penicillium sp., Trichothecium roseum and Trichophyton rubrum . Further, in vitro antioxidant study was examined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. We observed significant effect on scavenging of free radicals suggesting that the AgNPs biosynthesized using E. coli could be an efficient and eco-friendly material for biomedical applications

Antibiotic and antioxidant activities biogenic silver nanoparticles synthesized using <i>Escherichia coli</i> (VM1) bacterium

523-529Synthesis of silver nanoparticles (AgNPs) using microorganisms has gained considerable attention as an efficient alternative for conventional chemical synthesis. Earlier, we have demonstrated biosynthesis of silver nanoparticles using marine Escherichia coli VM1. Here, we investigated antibacterial, antifungal and antioxidant efficacy of the synthesized silver nanoparticles using standard techniques. The results have shown that the AgNPs synthesized using the marine Escherichia coli have potential antibacterial activity against both Gram positive (Staphylococcus aureus) and Gram negative (E. coli, Klebsiella pneumoniae, S. paratyphi, Vibrio parahaemolyticus, V. cholerae and Proteus mirabilis) pathogenic bacteria and moderate antifungal activity was observed against Aspergillus niger, Penicillium sp., Trichothecium roseum and Trichophyton rubrum . Further, in vitro antioxidant study was examined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. We observed significant effect on scavenging of free radicals suggesting that the AgNPs biosynthesized using E. coli could be an efficient and eco-friendly material for biomedical applications

Total organic carbon profile in water and sediment in coral reef ecosystem of Agatti Island, Lakshadweep Sea

936-942Total organic carbon profile in sea water (depth-wise) and sediment has been investigated on seasonal basis in the coral reef ecosystem of Agatti island, Lakshadweep sea. The TOC values of sea water and sediment were converted into percentage to understand its level of distribution. The level of TOC in the surface sea water ranged from 0.40 to 1.02 ppm and the level of TOC at the ~5 m depth ranged from 0.18 to 1.86 ppm. The pH did not show any variation depth-wise (7.65 to 8.49). Sedimentary organic carbon (SOC) was found in the range of 0.21 to 2.35 mg C/g. Significant seasonal variation was not found for water TOC and SOC levels. The pH for sediment was recorded from 7.79 to 8.62. Water pH showed significant positive correlation with sediment pH (R2=0.959). The sand fraction was found more in the texture followed by silt and clay. Clay was found to have positive correlation with SOC (P >0.01). The TOC profile in the Lakshadweep sea was found in the order: Surface water TOC < water TOC at ~5 m depth < SOC. The percentage composition of SOC showed more than 1000 times as compared to water TOC. However, the levels recorded in this study are found within the limit prescribed by EPA and its influence on coral reef ecosystem is discussed

Source of plastic contamination of the rivers ending to the Gorgan Bay, southeast of the Caspian Sea, Iran

The widespread presence of microplastics (MPs) in freshwater systems as an emerging environmental pollutant has caused a global environmental problem. The present study investigates the distribution and abundance of source pathway and abundance of microplastics in surface sediment samples from rivers discharging into the Gorgan Bay, southeast of the Caspian Sea. A total of 57 surface sediment samples were taken from 19 stations to investigate the potential hot spots of pollution in the four rivers leading to the Gorgan Bay. The average level of microplastics was 333 ± 268 particles/kg. The highest amount is in the estuary of the Qarasu River (1080 ± 380 particles/kg) due to the accumulation of fishing, boating and tourism activities and the lowest amount in the forest area (80 ± 19 particles/kg) in the Klak River. The most common type of microplastic was fiber (68%). Microplastic pollution in the studied rivers is mostly black and gray (75.39%), and about 53% of them were sized less than 1000 μm. Spectroscopic analysis (Fourier Transform Infrared (FT-IR) of the MP showed that 37% were polyethylene, polyethylene (37%) and polypropylene (27%) were the dominating groups. The sediments’ size was significantly correlated (p&gt;0.05) with the presence of microplastics. Sediments with a coarse grain (sand) demonstrated a great potential to store microplastics. The results of this study can be used for the management and protection policies of Gorgan Bay

Further records of rare brachyuran crab Eucrate indica (Crustacea: Decapoda: Brachyura Euryplacidae) along the Chennai coast, Tamil Nadu, India

This study reports further occurrence of the crab Eucrate indica (Crustacea: Decapoda: Brachyura: Euryplacidae) along the Chennai coast, Tamil Nadu, India. The crabs were obtained from a depth of 40-60 m in the trawl by-catch. The morphological features, color and distribution of these crabs are given

Further records of rare brachyuran crab Eucrate indica (Crustacea: Decapoda: Brachyura Euryplacidae) along the Chennai coast, Tamil Nadu, India

This study reports further occurrence of the crab Eucrate indica (Crustacea: Decapoda: Brachyura: Euryplacidae) along the Chennai coast, Tamil Nadu, India. The crabs were obtained from a depth of 40-60 m in the trawl by-catch. The morphological features, color and distribution of these crabs are given

First record of the silver-cheeked toad fish Lagocephalus scleratus (Gmelin, 1789) (Actinopterygii: Tetraodontidae) from Chennai coastal waters, Southeast India

The silver-cheeked toad fish, Lagocephalus scleratus, was recorded for the first time on 25 September 2014. Two specimens of this fish species were collected from the by-catch landed by a commercial deep-sea trawler at Kasimedu Fishing Harbour, Chennai coast, Southeast India. The morphometric and meristic characters of the recorded specimens are described and discussed. The specimen was compared with earlier reports