Special Issue "Bioactive Compounds from Marine Microorganisms"
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A special issue of Marine Drugs (ISSN 1660-3397).
Deadline for manuscript submissions: closed (31 December 2008)
Special Issue Editor
Guest Editor
Dr. Ipek Kurtboke
Senior Lecturer in Environmental Microbiology, School of Science, Education and Engineering, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore DC, Queensland 4558, Australia
Website: http://www.usc.edu.au/University/AcademicFaculties/Science/Staff/011745.htm
E-Mail: ikurtbok@usc.edu.au
Phone: +61 (07) 5430 2819
Fax: +61 (07) 5430 2881
Interests: microbial diversity; microbial systematics; ecophysiology of microorganisms; functional diversity of microorganisms; microbial ecosystems
Special Issue Information
Guest Editor's Introduction
Bioactive Compounds from Marine Microorganisms
Marine environments are massively complex and contain diverse assemblage of life forms, which occur in environments with extreme variations in pressure, salinity, and temperature. As a result, marine microorganisms have developed unique metabolic and physiological capabilities to be able to survive in such extreme habitats that led them to produce different kind of metabolites, which could not be produced by the terrestrial microorganisms.
It is now becoming evident that marine microorganisms are emerging as a significant chemical resource with novel compounds in clinical trials deriving from these micro-organisms. However, the lack of in-depth knowledge on the physiology and true nutritional requirements of marine microorganisms still hampers the development of effective isolation techniques, which in turn delays the detection of potent therapeutic agents.
This special issue dedicated to “Bioactive Compounds from Marine Microorganisms” aims to place emphasis on the importance of understanding and linking the true ecological and functional roles of these microorganisms in marine environments on the route to biodiscovery.
As the Guest Editor, I invite scientists working with marine bioactive compounds to report recent advances in the field (e.g. marine microbial ecology; detection and selective isolation of bioactive compound producing marine microorganisms; marine microbial physiology; fermentation and identification of bioactive compounds).
I look forward to working with you towards a successful special issue of the journal Marine Drugs dedicated to marine bioactive compounds.
Dr Ipek Kurtböke
University of the Sunshine Coast
Australia
Manuscript submission
Keywords
- marine microorganisms
- biodiscovery
- marine pharmaceuticals
- marine microbial ecology
- novel therapeutic agents
- bioactive compounds
- marine and extreme environments
- natural products
- seawater-derived microorganism
- sediment-derived microorganisms
- marine microbial toxins
Published Papers (9 papers)
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Received: 18 June 2007 / Accepted: 17 July 2007 / Published: 19 July 2007
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Abstract: Many cytotoxic compounds of therapeutic interest have been isolated from marine invertebrates, and some of them have been reported to be of microbial origin. Pyridoacridine alkaloids are the main compounds extracted from the ascidian Cystodytes dellechiajei. Here we describe the in vitro antiproliferative activity against different tumor cell lines of the ascidian extracts and provide some insights on the role of the microbial community associated with the tunicate in the production of these compounds. C. dellechiajei extracts showed remarkably high antiproliferative activity (IC50 ≤5 μg/mL) in human lung carcinoma A-549, colon adenocarcinoma H-116, pancreatic adenocarcinoma PSN-1 and breast carcinoma SKBR3 cell lines. Moreover, we found that the maximum activity was located in the tunic tissue of the colony, which harbours a microbial community. In order to ascertain the involvement of this community in the synthesis of the bioactive compounds different approachs that included culture and culture independent methods were carried out. We undertook a screening for antiproliferative activities of the bacterial isolates from the ascidian, as well as a comprative analysis of the cytotoxic activities and the microbial communities from two color morphs of the ascidian, green and blue. In addition, the changes of the antiproliferative activities and the composition of the microbial communities were studied from ascidians kept in aquaria and treated with antibiotics for one month. Our data obtained from the different experiments did not point out to bacteria as the source of the cytotoxic compounds, suggesting thus an ascidian origin.
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Received: 27 November 2007 / Accepted: 14 December 2007 / Published: 18 December 2007
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Abstract: The genus Pseudoalteromonas is a marine group of bacteria belonging to theclass Gammaproteobacteria that has come to attention in the natural product andmicrobial ecology science fields in the last decade. Pigmented species of the genus havebeen shown to produce an array of low and high molecular weight compounds withantimicrobial, anti-fouling, algicidal and various pharmaceutically-relevant activities.Compounds formed include toxic proteins, polyanionic exopolymers, substitutedphenolic and pyrolle-containing alkaloids, cyclic peptides and a range of bromine-substituted compounds. Ecologically, Pseudoalteromonas appears significant and to datehas been shown to influence biofilm formation in various marine econiches; involved inpredator-like interactions within the microbial loop; influence settlement, germinationand metamorphosis of various invertebrate and algal species; and may also be adopted bymarine flora and fauna as defensive agents. Studies have been so far limited to arelatively small subset of strains compared to the known diversity of the genussuggesting that many more discoveries of novel natural products as well as ecologicalconnections these may have in the marine ecosystem remain to be made.
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Received: 21 November 2007; in revised form: 17 January 2008 / Accepted: 17 January 2008 / Published: 1 February 2008
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Abstract: The marine environment represents a largely untapped source for isolation of new microorganisms with potential to produce biologically active secondary metabolites. Among such microorganisms, Gram-positive actinomycete bacteria are of special interest, since they are known to produce chemically diverse compounds with a wide range of biological activities. We have set out to isolate and characterize actinomycete bacteria from the sediments in one of the largest Norwegian fjords, the Trondheim fjord, with respect to diversity and antibiotic-producing potential. Approximately 3,200 actinomycete bacteria were isolated using four different agar media from the sediment samples collected at different locations and depths (4.5 to 450 m). Grouping of the isolates first according to the morphology followed by characterization of isolates chosen as group representatives by molecular taxonomy revealed that Micromonospora was the dominating actinomycete genus isolated from the sediments. The deep water sediments contained a higher relative amount of Micromonospora compared to the shallow water samples. Nine percent of the isolates clearly required sea water for normal growth, suggesting that these strains represent obligate marine organisms. Extensive screening of the extracts from all collected isolates for antibacterial and antifungal activities revealed strong antibiotic-producing potential among them. The latter implies that actinomycetes from marine sediments in Norwegian fjords can be potential sources for the discovery of novel anti-infective agents.
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Received: 31 March 2008; in revised form: 19 May 2008 / Accepted: 23 May 2008 / Published: 5 June 2008
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Abstract: Screening strategies based on the ecological knowledge of antibiotic producing microorganisms and their roles in the natural environment are being increasingly employed in the search for novel antibiotic agents. Micromonosporae are common inhabitants of aquatic habitats and have proved to be a continuing source of novel bioactive compounds including antibacterial and antitumor agents. The ecological distribution and frequency of bioactive micromonosporae in Sunshine Coast region aquatic habitats were studied through a range of selective isolation procedures designed to negatively select against the isolation of unwanted microbial taxa commonly associated with marine environments. It was revealed that bioactive compound producing species of micromonosporae were present in the aquatic habitats of the Sunshine Coast region in Australia.
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Received: 30 June 2008; in revised form: 9 October 2008 / Accepted: 9 October 2008 / Published: 13 October 2008
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Abstract: Microbial marine biodiscovery is a recent scientific endeavour developing at a time when information and other technologies are also undergoing great technical strides. Global visualisation of datasets is now becoming available to the world through powerful and readily available software such as Worldwind ™, ArcGIS Explorer ™ and Google Earth ™. Overlaying custom information upon these tools is within the hands of every scientist and more and more scientific organisations are making data available that can also be integrated into these global visualisation tools. The integrated global view that these tools enable provides a powerful desktop exploration tool. Here we demonstrate the value of this approach to marine microbial biodiscovery by developing a geobibliography that incorporates citations on tropical and near-tropical marine microbial natural products research with Google Earth ™ and additional ancillary global data sets. The tools and software used are all readily available and the reader is able to use and install the material described in this article.
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Received: 28 October 2008; in revised form: 25 November 2008 / Accepted: 27 November 2008 / Published: 1 December 2008
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Abstract: The water surface microlayer is still poorly explored, although it has been shown to contain a high density of metabolically active bacteria, often called bacterioneuston. Actinomycetes from the surface microlayer in the Trondheim fjord, Norway, have been isolated and characterized. A total of 217 isolates from two separate samples morphologically resembling the genus Streptomyces have been further investigated in this study. Antimicrobial assays showed that about 80% of the isolates exhibited antagonistic activity against nonfilamentous fungus, Gram-negative, and Gram-positive bacteria. Based on the macroscopic analyses and inhibition patterns from the antimicrobial assays, the sub-grouping of isolates was performed. Partial 16S rDNAs from the candidates from each subgroup were sequenced and phylogenetic analysis performed. 7 isolates with identical 16S rDNA sequences were further studied for the presence of PKS type I genes. Sequencing and phylogenetic analysis of the PKS gene fragments revealed that horizontal gene transfer between closely related species might have taken place. Identification of unique PKS genes in these isolates implies that dereplication can not be performed based solely on the 16S rDNA sequences. The results obtained in this study suggest that streptomycetes from the neuston population may be an interesting source for discovery of new antimicrobial agents.
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Received: 5 August 2008; in revised form: 5 January 2009 / Accepted: 19 January 2009 / Published: 10 February 2009
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Abstract: D. salina is one of the recognized natural sources to produce β-carotene, and an useful model for studying the role of inhibitors and enhancers of carotenogenesis. However there is little information in D. salina regarding whether the isoprenoid substrate can be influenced by stress factors (carotenogenic) or selective inhibitors which in turn may further contribute to elucidate the early steps of carotenogenesis and biosynthesis of β-carotene. In this study,Dunaliella salina (BC02) isolated from La Salina BC Mexico, was subjected to the method of isoprenoids-β-carotene interference in order to promote the interruption or accumulation of the programmed biosynthesis of carotenoids. When Carotenogenic and non-carotenogenic cells of D. salina BC02 were grown under photoautotrophicgrowth conditions in the presence of 200 µM fosmidomycin, carotenogenesis and the synthesis of β-carotene were interrupted after two days in cultured D. salina cells. This result is an indirect consequence of the inhibition of the synthesis of isoprenoids and activity of the recombinant DXR enzyme thereby preventing the conversionof 1-deoxy-D-xylulose 5-phosphate (DXP) to 2-C-methyl-D-erythritol (MEP) and consequently interrupts the early steps of carotenogenesis in D. salina. The effect at the level of proteins and RNA was not evident. Mevinolin treated D. salina cells exhibited carotenogenesis and β-carotene levels very similar to those of control cell cultures indicating that mevinolin not pursued any indirect action in the biosynthesis of isoprenoids and had no effect at the level of the HMG-CoA reductase, the key enzyme of the Ac/MVA pathway.
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Received: 6 August 2012; in revised form: 11 September 2012 / Accepted: 18 September 2012 / Published: 28 September 2012
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Abstract: Marine cyanobacteria have been considered a rich source of secondary metabolites with potential biotechnological applications, namely in the pharmacological field. Chemically diverse compounds were found to induce cytoxicity, anti-inflammatory and antibacterial activities. The potential of marine cyanobacteria as anticancer agents has however been the most explored and, besides cytotoxicity in tumor cell lines, several compounds have emerged as templates for the development of new anticancer drugs. The mechanisms implicated in the cytotoxicity of marine cyanobacteria compounds in tumor cell lines are still largely overlooked but several studies point to an implication in apoptosis. This association has been related to several apoptotic indicators such as cell cycle arrest, mitochondrial dysfunctions and oxidative damage, alterations in caspase cascade, alterations in specific proteins levels and alterations in the membrane sodium dynamics. In the present paper a compilation of the described marine cyanobacterial compounds with potential anticancer properties is presented and a review on the implication of apoptosis as the mechanism of cell death is discussed.
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Received: 29 December 2012; in revised form: 29 January 2013 / Accepted: 29 January 2013 / Published: 6 February 2013
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Abstract: Marine microorganisms are of considerable interest as a promising source of enzymes with unsuspected potentials as catalysts for chemical synthesis. We describe here an efficient method for one-pot indolizine synthesis that has been developed using lipase A and lipase B from Candida antarctica as biocatalysts. As showed by HPLC/MS analysis, the yield in indolizines was higher in the presence of the biocatalyst than in absence of enzyme. Lipase A, from Candida antarctica, showed high catalytic activity and selectivity for the cycloaddition reactions. When the reactions were performed under ultrasound irradiation, the Candida antarctica lipase catalyzed reactions yielded pure indolozines, in good yields and in very short time.
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Last update: 10 October 2012
