Water pollution and fish mortality in Ennore estuary, Madras

Pollution problems are encountered in Ennore estuary as it receives industrial effluents and domestic sewage mostly in untreated condition. These affect water quality and living organisms. It has been estimated that about 449,000 litres/day of industrial effluents carrying heavy metals are let out into this estuary by these industrial establishments. Based on the present investigation, it may be stated that the presence of some metallic elements, with their synergistic effects would have poisoned the water resulting in the mass mortality of fishes and prawns and dislocation of the most bottom fauna from their habitat in this estuary

On two juvenile whale sharks Rhincodon typus Smith caught at Madras

The present report provides details regarding two juvenile whale sharks Rhincodon typus Smith, caught at Mullikuppam (Thiruvanmiyur) and Royapuram, Madras

Groupers and snappers of India: biology and exploitation

The fishes of the families Serranidae (groupers) and Lutjanidae (snappers) are an important resource along the Indian coast. They are represented by 79 species in the Indian seas, reach up to 2 m and are abundant in and around rocky outgrowths and coral ridges at depths extending to about 360 m. Their exploitation presently yields an average annual landing of 8 000 t or about 3% of total Indian marine fish landings. This paper summarizes present knnowledge on distribution, exploitation, culture and biology of groupers and snappers in India

Small Molecule Inhibitors of the BfrB-Bfd Interaction Decrease Pseudomonas aeruginosa Fitness and Potentiate Fluoroquinolone Activity

© 2019 American Chemical Society. All rights reserved. The iron storage protein bacterioferritin (BfrB) is central to bacterial iron homeostasis. The mobilization of iron from BfrB, which requires binding by a cognate ferredoxin (Bfd), is essential to the regulation of cytosolic iron levels in P. aeruginosa. This paper describes the structure-guided development of small molecule inhibitors of the BfrB-Bfd protein-protein interaction. The process was initiated by screening a fragment library and followed by obtaining the structure of a fragment hit bound to BfrB. The structural insights were used to develop a series of 4-(benzylamino)- A nd 4-((3-phenylpropyl)amino)-isoindoline-1,3-dione analogs that selectively bind BfrB at the Bfd binding site. Challenging P. aeruginosa cells with the 4-substituted isoindoline analogs revealed a dose-dependent growth phenotype. Further investigation determined that the analogs elicit a pyoverdin hyperproduction phenotype that is consistent with blockade of the BfrB-Bfd interaction and ensuing irreversible accumulation of iron in BfrB, with concomitant depletion of iron in the cytosol. The irreversible accumulation of iron in BfrB prompted by the 4-substituted isoindoline analogs was confirmed by visualization of BfrB-iron in P. aeruginosa cell lysates separated on native PAGE gels and stained for iron with Ferene S. Challenging P. aeruginosa cultures with a combination of commercial fluoroquinolone and our isoindoline analogs results in significantly lower cell survival relative to treatment with either antibiotic or analog alone. Collectively, these findings furnish proof of concept for the usefulness of small molecule probes designed to dysregulate bacterial iron homeostasis by targeting a protein-protein interaction pivotal for iron storage in the bacterial cell

Stranding of Pseudorca crassidens at Calicut, Kerala

During the last few years a number of strandings of whales, dolphins, and porpoises have been detected and same have been reported along our coasts. The accidental capture of dolphins and the dugong in fishing operations have also been reported. These marine mammals are protected under the Indian Wild Life (Protection) Act 1972, and trade in many of the marine mammals is also banned or controlled under the Convention of International Trade in Endangered Species of Fauna and Flora (CITES). The present studies were documenting a few strandings of lesser cetaceans (the false killer whale Pseudorca crassidens) from along our coast

Survey of Valinokkam Bay and adjoining area to assess its suitability for integrated sea farming — A report

The Valinokkam Bay and the adjoining area, east of the Bay surveyed, lie between Lat. 9°9' N and 9° 12' N and Long. 78°30'E and 78°42'E . The available information indicates that the bay and the adjoining grounds in the sea are highly productive and suitable for sea farming activities

Brucella suis urease encoded by ure1 but not ure2 is necessary for intestinal infection of BALB/c mice

BACKGROUND: In prokaryotes, the ureases are multi-subunit, nickel-containing enzymes that catalyze the hydrolysis of urea to carbon dioxide and ammonia. The Brucella genomes contain two urease operons designated as ure1 and ure2. We investigated the role of the two Brucella suis urease operons on the infection, intracellular persistence, growth, and resistance to low-pH killing. RESULTS: The deduced amino acid sequence of urease-α subunits of operons-1 and -2 exhibited substantial identity with the structural ureases of alpha- and beta-proteobacteria, Gram-positive and Gram-negative bacteria, fungi, and higher plants. Four ure deficient strains were generated by deleting one or more of the genes encoding urease subunits of B. suis strain 1330 by allelic exchange: strain 1330Δure1K (generated by deleting ureD and ureA in ure1 operon), strain 1330Δure2K (ureB and ureC in ure2 operon), strain 1330Δure2C (ureA, ureB, and ureC in ure2 operon), and strain 1330Δure1KΔure2C (ureD and ureA in ure1 operon and ureA, ureB, and ureC in ure2 operon). When grown in urease test broth, strains 1330, 1330Δure2K and 1330Δure2C displayed maximal urease enzyme activity within 24 hours, whereas, strains 1330Δure1K and 1330Δure1KΔure2C exhibited zero urease activity even 96 h after inoculation. Strains 1330Δure1K and 1330Δure1KΔure2C exhibited slower growth rates in tryptic soy broth relative to the wild type strain 1330. When the BALB/c mice were infected intraperitoneally with the strains, six weeks after inoculation, the splenic recovery of the ure deficient strains did not differ from the wild type. In contrast, when the mice were inoculated by gavage, one week after inoculation, strain 1330Δure1KΔure2C was cleared from livers and spleens while the wild type strain 1330 was still present. All B. suis strains were killed when they were incubated in-vitro at pH 2.0. When the strains were incubated at pH 2.0 supplemented with 10 mM urea, strain 1330Δure1K was completely killed, strain 1330Δure2C was partially killed, but strains 1330 and 1330Δure2K were not killed. CONCLUSION: These findings suggest that the ure1 operon is necessary for optimal growth in culture, urease activity, resistance against low-pH killing, and in vivo persistence of B. suis when inoculated by gavage. The ure2 operon apparently enhances the resistance to low-pH killing in-vitro