Synthesis and Characterization of Some New Transition Metal Complexes of the Schiff Base Derived from Quinoxaline-2-Carboxaldehyde and 2- Aminophenol

Some new transition metal complexes of the Schiff base quinoxaline-2-car boxalidene-2-aminophenol (HQAP) have been synthesized and characterized by elemental analyses, conductance and magnetic measurements and IR and UV-Visible spectral studies. The complexes have the following empirical formulae: [Mn(QAP121, [Fe(QAPl2C1I, [Co(QAPl21, [Ni(QAP121 and [Cu(QAP121. A tetrahedral structure has been assigned for the manganese(=), cobalt(II1, nickel(II1 and copper(II1 complexes. For the iron(IIIl complex an octahedral dimeric structure has been suggested

Antibiotic resistance of Aeromonas hydrophila isolated from marketed fish and prawn of South India

A total of 319 strains of Aeromonas hydrophila were isolated from 536 fish and 278 prawns for a 2-year period. All the strains were tested for resistance to 15 antibiotics and 100% of the strains was resistant to methicillin and rifampicin followed by bacitracin and novobiocin (99%). Only 3% of the strains exhibited resistance against chloramphenicol. The multiple antibiotic resistance (MAR) indexing of A. hydrophila strains showed that all of them originated from high-risk sources

Anti-lipopolysaccharide factor and crustin-III, the anti-white spot virus peptides in Penaeus monodon: Control of viral infection by up-regulation

White Spot Syndrome Virus (WSSV) is the most devastating disease affecting shrimp culture around the world. Though, considerable progress has been made in the detection and molecular characterization of WSSV in recent years, information pertaining to immune gene expression in shrimps with respect to WSSV infection remains limited. In this context, the present study was undertaken to understand the differential expression of antimicrobial peptide (AMP) genes in the haemocytes of Penaeus monodon in response to WSSV infection on a time-course basis employing semi-quantitative RT-PCR. The present work analyzes the expression profile of six AMP genes (ALF, crustin-1, crustin-2, crustin-3, penaeidin-3 and penaeidin-5), eight WSSV genes (DNA polymerase, endonuclease, immediate early gene, latency related gene, protein kinase, ribonucleotide reductase, thymidine kinase and VP28) and three control genes (18S rRNA, β-actin and ELF) in P. monodon in response to WSSV challenge. Penaeidins were found to be up-regulated during early hours of infection and crustin-3 during late period of infection. However, ALF was found to be up-regulated early to late period of WSSV infection. The present study suggests that AMPs viz. ALF and crustin-3 play an important role in antiviral defense in shrimps. WSSV gene transcripts were detected post-challenge day 1 itself and increased considerably day 5 onwards. Evaluation of the control genes confirmed ELF as the most reliable control gene followed by 18S rRNA and β-actin for gene expression studies in shrimps. This study indicated the role of AMPs in the protection of shrimps against viral infection and their possible control through the up-regulation of AMPs

Molecular characterization and phylogenetic analysis of a penaeidin-like antimicrobial peptide, Fi-penaeidin from Fenneropenaeus indicus

Antimicrobial peptides (AMPs) play a major role in innate immunity. Penaeidins are a family of AMPs that appear to be expressed in all penaeid shrimps. Penaeidins are composed of an N-terminal proline-rich domain, followed by a C-terminal domain containing six cysteine residues organized in two doublets. This study reports the first penaeidin AMP sequence, Fi-penaeidin (GenBank accession number HM243617) from the Indian white shrimp, Fenneropenaeus indicus. The full length cDNA consists of 186 base pairs encoding 61 amino acidswith an ORF of 42 amino acids and contains a putative signal peptide of 19 amino acids. Comparison of F. indicus penaeidin (Fi-penaeidin) with other known penaeidins showed that it shared maximum similarity with penaeidins of Farfantepenaeus paulensis and Farfantepenaeus subtilis (96% each). Fi-penaeidin has a predicted molecular weight (MW) of 4.478 kDa and theoretical isoelectric point (pI) of 5.3

Fractionation and bioavailability of phosphorus in a tropical estuary, Southwest India

Phosphorus fractionation was employed to find the bioavailability of phosphorus and its seasonal variations in the Panangad region of Cochin estuary, the largest estuarine system in the southwest coast of India. Sequential extraction of the surficial sediments using chelating agents was taken as a tool for this. Phosphate in the water column showed seasonal variations, with high values during the monsoon months, suggesting external runoff. Sediment texture was found to be the main factor influencing the spatial distribution of the geochemical parameters in the study region. Similarly, total phosphorus also showed granulometric dependence and it ranged between 319.54 and 2,938.83 μg/g. Calcium-bound fraction was the main phosphorus pool in the estuary. Significant spatial variations were observed for all bioavailable fractions; iron-bound inorganic phosphorus (5.04–474.24 μg/g), calcium-bound inorganic phosphorus (11.16–826.09 μg/g), and acidsoluble organic phosphorus (22.22–365.86 μg/g). Among the non-bioavailable phosphorus, alkalisoluble organic fraction was the major one (51.92– 1,002.45 μg/g). Residual organic phosphorus was K. R. Renjith (B) · N. Chandramohanakumar · M. M. Joseph Department of Chemical Oceanography, School of Marine Sciences, Cochin University of Science and Technology, Kochi 682016, Kerala, India e-mail: renjithaqua@gmail.com comparatively smaller fraction (3.25–14.64% of total). The sandy and muddy stations showed distinct fractional composition and the speciation study could endorse the overall geochemical character. There could be buffering of phosphorus, suggested by the increase in the percentage of bioavailable fractions during the lean premonsoon period, counteracting the decreases in the external loads. Principal component analysis was employed to find the possible processes influencing the speciation of phosphorus in the study region