Siderophores, the secondary metabolite of various microorganisms are ferric ion specific chelators secreted under iron stressed condition. These non-ribosomal peptides have been classified as catecholate, hydroxamate, carboxylate and mixed types. Recent studies focus on discovery of possible mammalian siderophores. The biosynthesis pathway including non-ribosomal dependent as well as non-ribosomal independent pathways are of great interest now a days. Many significant roles of siderophores such as virulence in pathogens, oxidative stress tolerance, classification of organisms etc. are being discovered. Studies on siderophore utilization in bioremediation and other heavy metal chelation have increased in past decade. The iron chelation ability of siderophores is being recently studied with regards to malignant cancerous cells. Not only this, it has been found that they possess antimicrobial properties which can be utilized against number of microbes. This review covers all recent aspects of siderophore and its applications.

This study presents a phenol and lysozyme free protocol for genomic DNA isolation of cyanobacteria from culture, mats and soil. For an efficient and pure DNA isolation from cyanobacteria having tough cell wall, extra steps of glass beading and Sepharose 4B purification were added. The modified method gave a higher yield of DNA than the phenol: chloroform extraction method. Four parameters selected for purity testing of the isolated DNA were: (i) restriction digestion with Hind III, (ii) randomly amplified polymorphic DNA-PCR of axenic culture of cyanobacteria to assess phylogenetic relatedness, (iii) denaturing gradient gel electrophoretic (DGGE) analysis of cyanobacterial mat and soil to ascertain the applicability of the isolated DNA for community analysis, and (iv) sequencing of partial 16S rDNA of Hapalosiphon intricatus BHULCR1, Anabaena doliolum LCR1, Anabaena oryzae LCR2, Aulosira fertilissima LCR4, and Tolypothrix tenuis LCR7 and BLAST analysis to confirm their cyanobacterial identity. Data generated from above analyses lead us to conclude that the modified method in question is rapid, cost effective, health and time conscious and promising for genetic fingerprinting and community analysis of cyanobacteria from diverse habitats.

HighlightsIn middle Gangetic plains, high arsenic concentration is present in water, which causes a significant health risk.Two bacterial isolates, AK1 (KY569423) and AK9 (KY569424) were isolated and characterised for Arsenic detoxification.aoxR, aoxB and aoxC genes were also observed in the isolated starin which help in arsenic detoxification by oxidation method.

Background:There is a high risk of suicidal attempt in patients with depression. This risk varies according to the sociodemographic status and clinical presentation.Aim:To assess the prevalence of suicidal ideation and attempt in patients with major depressive disorder, and to find the correlation between the two.Methods:Sixty patients with major depressive disorder having suicidal ideation were recruited in the study. Of these, 10 had a history of suicidal attempt made in the past or current episode. Sociodemographic details were evaluated and the Hamilton Rating Scale for Depression (HAM-D) was administered.Results:Analysis of the data showed that the incidence of suicidal attempt was 16.6% in patients with suicidal ideation. Statistically, a higher risk of suicidal attempt was found in individuals <30 years of age. Single men, married women and students were more likely to attempt suicide; higher education was also a vulnerability factor. Attempters scored significantly higher in severity of suicidal ideation, agitation and paranoid symptoms whereas among non-attempters, hypochondriasis and general somatic symptoms were more often present.Conclusion:All patients expressing suicidal ideation do not attempt suicide. Young patients with depression, especially unmarried men, married women and students, having severe suicidal ideation with agitation or paranoid symptoms are more likely to attempt suicide.

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