Identification of an antimicrobial entity from the cyanobacterium Fischerella sp. isolated from bark of Azadirachta indica (Neem) tree

Asthana, Ravi Kumar; Srivastava, Amit Kumar; Singh, Apekshita; DEEPALI, .; Singh, Satnam; Nath, Gopal; Srivastava, Ranjana; Srivastava, Bhavana

doi:10.1007/s10811-005-9011-9

Cited by 65 publications

(40 citation statements)

References 22 publications

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“…In different studies, the an- Results are the means of values±standard deviation, ND-not detected 2-11 -Dilution range 512 μg/ml to 1 μg/ml 2-512 μg/ml, 3-256 μg/ml, 4-218 μg/ml 5-64 μg/ml, 6-32 μg/ml, 7-16 μg/ml, 8-8 μg/ml 9-4 μg/ml, 10-2 μg/ml, 11-1μg/ml. 12-Positive control (MHB+Culture) timicrobial effect of Fischerella sp [11] Oscillatoria anguistisima and Calothrix parietina [12], Anabaena, Oscillatoria, Pseudoanabaena, Synechocystis [1], Nostoc [13], Phormedium [14] and Fischerella ambigua [15] extracts on some pathogenic microorganisms have been reported. They have also reported that the extracts extracted in different solvents were effective against both Gram-positive and Gram-negative organisms.…”

Section: Resultsmentioning

confidence: 99%

In vitro antibacterial activity of laboratory grown culture of Spirulina platensis

Kaushik

Chauhan

2008

Indian J Microbiol

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The hexane, ethyl acetate, dichloromethane, methanol extracts and spent media (extracellular substances) were tested in vitro for their antibacterial activity for which one Gram-positive bacterium (Staphylococcus aureus) and four Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, and Klebsiella pneumoniae) were used as test organisms. The methanol extract showed more potent activity than other organic extracts, spent medium of the culture exhibited little activity against E. coli only. No inhibitory effect was found against Klebsiella pneumoniae .The broth microdilution assay gave minimum inhibitory concentrations (MIC) values ranging from 1 to 512 μg/ml. The MIC of methanol extract against S. aureus and E. coli were 128 μg/ml and 256 μg/ml, respectively.

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Section: Resultsmentioning

confidence: 99%

In vitro antibacterial activity of laboratory grown culture of Spirulina platensis

Kaushik

Chauhan

2008

Indian J Microbiol

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“…Amongst other compounds, antimicrobial or cytotoxic metabolites are of particular interest because such compounds represent a promising source of new potential pharmaceuticals, while also leading to enhancement of knowledge about the nature and metabolism of cyanobacteria. Most of the relevant studies in this area have focussed on metabolites accumulated in the cyanobacterial biomass (Asthana et al 2006;Blom et al 2006;Falch et al 1995;Flores and Wolk 1986;Ördög et al 2004;Piccardi et al 2000;Schlegel et al 1998); others have focussed on compounds excreted by cyanobacteria during growth (Hirata et al 1996(Hirata et al , 2003Jaki et al 1999Jaki et al , 2000Jaki et al , 2001. In our own previous studies aimed at discovering cyanobacterial exometabolites with antimicrobial activity, the toxic (anticyanobacterial, antibacterial, antifungal and cytotoxic) compounds 4,4′-dihydroxybiphenyl and 9H-pyrido(3,4-b)indole (norharmane), and the non-toxic compound N,N′-(4,5-dimethyl-1,2-phenylene)-bis-acetamide were identified as predominating metabolites in culture media of the cyanobacterium Nostoc insulare (Volk 2005;Volk and Furkert 2006;Volk and Mundt 2006).…”

Section: Introductionmentioning

confidence: 99%

Studies on culture age versus exometabolite production in batch cultures of the cyanobacterium Nostoc insulare

Volk

2007

J Appl Phycol

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Changes in the content of exometabolites excreted by the cyanobacterium Nostoc insulare during batch cultivation were determined. During linear growth, only the non-toxic compound N,N′-(4,5-dimethyl-1,2-phenylene) bis-acetamide was detectable in appreciable quantities in the medium, whereas during stationary growth the antimicrobial and cytotoxic exometabolites 4,4′-dihydroxybiphenyl and 9H-pyrido(3,4-b)indole (norharmane) were also present to an increasing degree. Hence it is proposed that biosynthesis of N,N′-(4,5-dimethyl-1,2-phenylene)bisacetamide in N. insulare is associated with cell proliferation and primary metabolism of this organism. 4,4′-Dihydroxybiphenyl and norharmane, however, are proposed to be products of secondary metabolism that are excreted by N. insulare primarily under nutrient-restricted conditions and under increased pressure of competition with other organisms.Key words antimicrobial activity . 4,4′-dihydroxybiphenyl . N,N′-(4,5-dimethyl-1,2-phenylene)bis-acetamide . fermenter batch cultivation . microalgal culture medium extracts . norharmane (9H-pyrido(3,4-b)indole)

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“…In the present study, we have used Hap-T, a broad spectrum antibacterial biomolecule (Asthana et al, 2006) against a model bacterium E. coli DH5α and addressed the evolution of drug resistance. Computer modeling of the target molecule and its inslico interaction with Hap-T revealed involvement of fimbrial biogenesis outer membrane usher protein in resistance of the model bacterium.…”

Section: Discussionmentioning

confidence: 99%

“…Hap-T (C 21 H 23 N 2 ClSO, Mr 386, melting point 179-182°C) isolated from the biomass of Fischerella sp. a cyanobacterium colonizing Neem tree (an Indian medicinal plant) bark (Asthana et al, 2006) was used in the present investigation. …”

Section: Bacteria Media and Hapalindole-t: Escherichia Colimentioning

confidence: 99%

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Use of Enterobacterial Repetitive Intergenic Consensus PCR in Detecting Target(s) of Hapalindole-T, From a Cyanobacterium, in <i>Escherichia Coli</i>: <i>In Silico</i> Validation

Xia¹

2012

American Journal of Bioinformatics

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Problem statement: Identification of newer biomolecule as well as targets are a rising concern because of increasing drug resistance in bacteria. We have isolated a broad spectrum antibiotic biomolecule Hapalindole-T from a cyanobacterium, Fisherella sp. growing on local Azadirachta indica tree bark. A model bacterium E. coli was screened spontaneously for Hap-T resistance. These resistant strains of E. coli were used to identify Hap-T target(s). Approach: These strains were subjected to Enterobacterial Repetitive Intergenic Consensus (ERIC) PCR analysis and compared with the sensitive one. We have used different bioinformatic tools like Clustalw, NJ Plot and Docking server. The Swiss-model server was used for homology modelling. Predicted 3D structure was refined by energy minimization and quality was assessed by Procheck. The model protein hailed from fimbrial biogenesis outer membrane usher protein (ADK89122.1). The interaction between the predicted structure of Model-1 protein and Hap-T biomolecule was analysed in silico using Autodock and Mopac parameters. Results: An additional band of DNA fragment (~500 base pairs) was found on agarose gel run after amplified genome of resistant strain. The results indicated that certain residues (Tyr-28), (Phe-54), (Leu-36) and (Val-52) were highly conserved and present in active sites. Conclusion/Recommendations: Thus understanding of microbial adhesion can act as an alternative approach in development of broad spectrum antibiotics.

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Identification of an antimicrobial entity from the cyanobacterium Fischerella sp. isolated from bark of Azadirachta indica (Neem) tree

Cited by 65 publications

References 22 publications

In vitro antibacterial activity of laboratory grown culture of Spirulina platensis

In vitro antibacterial activity of laboratory grown culture of Spirulina platensis

Studies on culture age versus exometabolite production in batch cultures of the cyanobacterium Nostoc insulare

Use of Enterobacterial Repetitive Intergenic Consensus PCR in Detecting Target(s) of Hapalindole-T, From a Cyanobacterium, in <i>Escherichia Coli</i>: <i>In Silico</i> Validation

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