Screening of seaweed extracts against antibiotic resistant post operative infectious pathogens

Fifty five seaweed extracts belonging to 11 species of seaweeds were tested against post operative infectious drug resistant bacteria viz., E. coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Streptococcus pyogens, Staphylococcus aureus. Among the seaweed extracts, the acetone extracts of Caulerpa cupressoides shows maximum inhibtory activity against E. coli and propanol extracts of Gracilaria edulis shows maximum inhibitory effect against K. pneumoniae. Acetone extracts of Padina tetrastromatica and Laurencia cruciata show maximum inhibitory activity against P. aeruginosa, butanol extracts of Hypnea musciformis, Caulerpa cupressoides and Chaetomorpha linoides show maximum inhibitory effect against S. aureus

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Not AvailableCholine dehydrogenase catalyzes the oxidation of choline to glycine betaine via betaine aldehyde as intermediate. Biotechnological applications of glycine betaine in transgenic plant improvement have been shown to have enhanced tolerance towards hypersalinity and freezing. It can also restore and maintain osmotic balance of living cells under stress. In this study, choline dehydrogenase gene from E. coli was cloned and homologously expressed in E. coli M15. The recombinant enzyme was purified by column chromatography using DEAE Sepharose. The purified enzyme showed a fourfold increase in the activity of choline dehydrogenase enzyme with choline as substrate and phenazine methosulfate as electron acceptor, compared to the control strain. The betA gene sequence reported in this study contains several base substitutions with that of reported sequences in GenBank, resulting in the altered amino acid sequences of the translated proteins.Not Availabl

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Not AvailableAbstract White spot syndrome virus (WSSV) is the causative agent of a disease that causes severe mortalities in cultured shrimp worldwide. The sequence of five structural genes of an Indian isolate of WSSV was compared with sequences from other WSSV isolates deposited in GenBank. Among the structural genes analyzed, the sequences of vp28 and vp19 had maximum divergence with nucleotide changes at ten different positions from twenty eight submissions for vp28 and six changes from seventeen submissions for vp19. The vp68, vp26, and vp281 genes were found to be highly conserved between isolates.Not Availabl

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Not AvailableViral pathogens appear to exert the most significant constraints on the growth and survival of crustaceans under culture conditions. The prevalence of viral pathogens White Spot Syndrome Virus (WSSV), Hepatopancreatic Parvo Virus (HPV), Monodon Baculo Virus (MBV) and Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV) in Penaeus monodon post-larvae was studied. Samples collected from different hatcheries and also samples submitted by farmers from Kerala were analyzed. Out of 104 samples collected, WSSV was detected in 12.5% of the postlarvae samples. Prevalence of concurrent infections by HPV, MBV and WSSV (either dual or triple infection) was present in 60.6% of the total post-larvae tested. Out of the 51 double positives, 98% showed either HPV or IHHNV infection. HPV or IHHNV was detected in 11 post-larval samples showing triple viral infection. This is the first report of IHHNV from India. Result of this study reveals the lack of efficient screening strategies to eradicate viruses in hatchery reared post-larvae.Not Availabl

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Not AvailableThe genes involved in the biosynthetic pathway of ectoine (2-methyl-1,4,5,6-tetrahydropyrimidine-4-carboxylic acid) from Bacillus halodurans were cloned as an operon and expressed in E. coli. Analysis of the deduced ectoine biosynthesis cluster amino acid sequence revealed that the ectoine operon contain 2,389 bp, encoded by three genes; ectA, ectB and ectC that encode proteins of 189, 427 and 129 amino acids with deduced molecular masses of 21,048, 47,120 and 14,797 Da respectively. Extracts of induced cells showed two bands at 41 kDa and 17 kDa, possibly corresponding to the products of the later two genes. However the expression of ectA gene could not be ascertained by SDS-PAGE. The activity of the ectA protein was confirmed by an acylation assay. The transgenic E. coli accumulated upto 4.6 mg ectoine/l culture. This is the first report of an engineered E. coli strain carrying the ectoine genes of the alkaliphilic bacterium, B. halodurans.Not Availabl

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Not AvailableEctoine, a cyclic tetrahydropyrimidine (2-methyl-1,4,5,6-tetrahydropyrimidine-4-carboxylic acid), is a natural compound, which serves as a protective substance in many bacterial cells. In this study, the putative ectABC gene cluster from Bacillus halodurans was heterologously expressed in E. coli and the production of ectoine was confirmed by HPLC analysis. The activity of the enzymes coded by the ectA, B and C genes were found to be higher in induced transgenic cells compared to the uninduced cells. Phylogenetic analysis revealed sequence identities ranging from 36–73% for ectA gene, 55–81% for ectB gene and 55–80% for ectC gene indicating that the enzymes are evolutionarily well conserved.Not Availabl

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Not AvailableAn open reading frame encoding the surfactin synthetase gene (srfA) was cloned from the Bacillus licheniformis NIOT-06 genome. An expression plasmid containing the srfA operon was introduced into Escherichia coli M15 cells and the recombinant biosurfactant was purified and quantified. Purified recombinant surfactin revealed excellent emulsification activity. HPLC fraction of the purified recombinant surfactin revealed significant surface tension reducing property. Secondary structure of the surfactin synthetase enzyme was predicted to have alpha-helical structure. Three dimensional structure model of surfactin synthase was found to be 0.243 Å units.Not Availabl

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Not AvailableSurfactin is a lipopeptide, composed of one b-hydroxy fatty acid, a long fatty acid moiety, and seven amino acids. In this study, the biosurfactant biosynthesis genes; 40-pantetheinyl transferase (sfp), phosphopantetheinyl transferase (sfpO), and surfactin synthetase (srfA) have been characterized from the marine sponge-associated Bacillus licheniformis NIOT-06 from the Andaman and Nicobar Islands. The purified recombinant biosurfactant revealed excellent emulsification activity with crude oil and kerosene. Reverse-phase high-performance liquid chromatography resolved the purified recombinant biosurfactant into several fractions and one of which had significant surface tension reducing property. Fourier transform infrared spectroscopy spectrum also revealed the presence of C–N–N, alkenes, and N–H as the functional groups, and a similar overlapping pattern was observed with that of standard lipopeptide surfactin. The diversity and phylogeny of sfp, sfpO, and srfA gene sequences were compared with other eubacteria. The sfp, sfpO, and srfA gene sequences obtained from Bacillus licheniformis NIOT-06 were diverse and appeared to be partially conserved when compared with the GenBank reported sequences of several eubacteria.Not Availabl

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Not AvailableSurfactin is a lipopeptide, composed of one β-hydroxy fatty acid, a long fatty acid moiety, and seven amino acids. In this study, the biosurfactant biosynthesis genes; 4′-pantetheinyl transferase (sfp), phosphopantetheinyl transferase (sfpO), and surfactin synthetase (srfA) have been characterized from the marine sponge-associated Bacillus licheniformis NIOT-06 from the Andaman and Nicobar Islands. The purified recombinant biosurfactant revealed excellent emulsification activity with crude oil and kerosene. Reverse-phase high-performance liquid chromatography resolved the purified recombinant biosurfactant into several fractions and one of which had significant surface tension reducing property. Fourier transform infrared spectroscopy spectrum also revealed the presence of C–N–N, alkenes, and N–H as the functional groups, and a similar overlapping pattern was observed with that of standard lipopeptide surfactin. The diversity and phylogeny of sfp, sfpO, and srfA gene sequences were compared with other eubacteria. The sfp, sfpO, and srfA gene sequences obtained from Bacillus licheniformis NIOT-06 were diverse and appeared to be partially conserved when compared with the GenBank reported sequences of several eubacteria.Not Availabl