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Sergey B Zotchev - One of the best experts on this subject based on the ideXlab platform.
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Actinomycetes from sediments in the trondheim fjord norway diversity and biological activity
Marine Drugs, 2008Co-Authors: Harald Bredholt, Espen Fjaervik, Geir Johnsen, Sergey B ZotchevAbstract: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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rare actinomycete bacteria from the shallow water sediments of the trondheim fjord norway isolation diversity and biological activity
Environmental Microbiology, 2007Co-Authors: Harald Bredholdt, Olga A Galatenko, Kerstin Engelhardt, Espen Fjaervik, Larissa P Terekhova, Sergey B ZotchevAbstract:Actinomycete bacteria produce a wide variety of secondary metabolites with diverse biological activities, some of which have been developed for human medicine. Rare Actinomycetes are promising sources in search for new drugs, and their potential for producing biologically active molecules is poorly studied. In this work, we have investigated the diversity of Actinomycetes in the shallow water sediments of the Trondheim fjord (Norway). Due to the use of different selective isolation methods, an unexpected variety of actinomycete genera was isolated. Although the predominant genera were clearly Streptomyces and Micromonospora, representatives of Actinocorallia, Actinomadura, Knoellia, Glycomyces, Nocardia, Nocardiopsis, Nonomuraea, Pseudonocardia, Rhodococcus and Streptosporangium genera were isolated as well. To our knowledge, this is the first report describing isolation of Knoellia and Glycomyces species from the marine environment. 35 selected actinomycete isolates were characterized by 16S rDNA sequencing, and were shown to represent strains from 11 different genera. In addition, these isolates were tested for antimicrobial activity and the presence of polyketide synthase and non-ribosomal peptide synthetase genes. This study confirms the significant biodiversity of actinobacteria in the Norwegian marine habitats, and their potential for producing biologically active compounds.
William Fenical - One of the best experts on this subject based on the ideXlab platform.
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hybrid isoprenoid secondary metabolite production in terrestrial and marine Actinomycetes
Current Opinion in Biotechnology, 2010Co-Authors: Kelley A Gallagher, William Fenical, Paul R. JensenAbstract:Terpenoids are among the most ubiquitous and diverse secondary metabolites observed in nature. Although actinomycete bacteria are one of the primary sources of microbially derived secondary metabolites, they rarely produce compounds in this biosynthetic class. The terpenoid secondary metabolites that have been discovered from Actinomycetes are often in the form of biosynthetic hybrids called hybrid isoprenoids (HIs). HIs include significant structural diversity and biological activity and thus are important targets for natural product discovery. Recent screening of marine Actinomycetes has led to the discovery of a new lineage that is enriched in the production of biologically active HI secondary metabolites. These strains represent a promising resource for natural product discovery and provide unique opportunities to study the evolutionary history and ecological functions of an unusual group of secondary metabolites.
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culturable marine actinomycete diversity from tropical pacific ocean sediments
Environmental Microbiology, 2005Co-Authors: Paul R. Jensen, Tracy J Mincer, Erin A Gontang, Chrisy Mafnas, William FenicalAbstract:Author(s): Jensen, Paul R; Gontang, Erin; Mafnas, Chrisy; Mincer, Tracy J; Fenical, William | Abstract: Actinomycetes were cultivated using a variety of media and selective isolation techniques from 275 marine samples collected around the island of Guam. In total, 6425 actinomycete colonies were observed and 983 (15%) of these, representing the range of morphological diversity observed from each sample, were obtained in pure culture. The majority of the strains isolated (58%) required seawater for growth indicating a high degree of marine adaptation. The dominant actinomycete recovered (568 strains) belonged to the seawater-requiring marine taxon 'Salinospora', a new genus within the family Micromonosporaceae. A formal description of this taxon has been accepted for publication (Maldonado et al., 2005) and includes a revision of the generic epithet to Salinispora gen. nov. Members of two major new clades related to Streptomyces spp., tentatively called MAR2 and MAR3, were cultivated and appear to represent new genera within the Streptomycetaceae. In total, five new marine phylotypes, including two within the Thermomonosporaceae that appear to represent new taxa, were obtained in culture. These results support the existence of taxonomically diverse populations of phylogenetically distinct Actinomycetes residing in the marine environment. These bacteria can be readily cultured using low nutrient media and represent an unexplored resource for pharmaceutical drug discovery.
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culturable marine actinomycete diversity from tropical pacific ocean sediments
Environmental Microbiology, 2005Co-Authors: Paul R. Jensen, Tracy J Mincer, Erin A Gontang, Chrisy Mafnas, William FenicalAbstract:Actinomycetes were cultivated using a variety of media and selective isolation techniques from 275 marine samples collected around the island of Guam. In total, 6425 actinomycete colonies were observed and 983 (15%) of these, representing the range of morphological diversity observed from each sample, were obtained in pure culture. The majority of the strains isolated (58%) required seawater for growth indicating a high degree of marine adaptation. The dominant actinomycete recovered (568 strains) belonged to the seawater-requiring marine taxon 'Salinospora', a new genus within the family Micromonosporaceae. A formal description of this taxon has been accepted for publication (Maldonado et al., 2005) and includes a revision of the generic epithet to Salinispora gen. nov. Members of two major new clades related to Streptomyces spp., tentatively called MAR2 and MAR3, were cultivated and appear to represent new genera within the Streptomycetaceae. In total, five new marine phylotypes, including two within the Thermomonosporaceae that appear to represent new taxa, were obtained in culture. These results support the existence of taxonomically diverse populations of phylogenetically distinct Actinomycetes residing in the marine environment. These bacteria can be readily cultured using low nutrient media and represent an unexplored resource for pharmaceutical drug discovery.
Paul R. Jensen - One of the best experts on this subject based on the ideXlab platform.
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hybrid isoprenoid secondary metabolite production in terrestrial and marine Actinomycetes
Current Opinion in Biotechnology, 2010Co-Authors: Kelley A Gallagher, William Fenical, Paul R. JensenAbstract:Terpenoids are among the most ubiquitous and diverse secondary metabolites observed in nature. Although actinomycete bacteria are one of the primary sources of microbially derived secondary metabolites, they rarely produce compounds in this biosynthetic class. The terpenoid secondary metabolites that have been discovered from Actinomycetes are often in the form of biosynthetic hybrids called hybrid isoprenoids (HIs). HIs include significant structural diversity and biological activity and thus are important targets for natural product discovery. Recent screening of marine Actinomycetes has led to the discovery of a new lineage that is enriched in the production of biologically active HI secondary metabolites. These strains represent a promising resource for natural product discovery and provide unique opportunities to study the evolutionary history and ecological functions of an unusual group of secondary metabolites.
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culturable marine actinomycete diversity from tropical pacific ocean sediments
Environmental Microbiology, 2005Co-Authors: Paul R. Jensen, Tracy J Mincer, Erin A Gontang, Chrisy Mafnas, William FenicalAbstract:Author(s): Jensen, Paul R; Gontang, Erin; Mafnas, Chrisy; Mincer, Tracy J; Fenical, William | Abstract: Actinomycetes were cultivated using a variety of media and selective isolation techniques from 275 marine samples collected around the island of Guam. In total, 6425 actinomycete colonies were observed and 983 (15%) of these, representing the range of morphological diversity observed from each sample, were obtained in pure culture. The majority of the strains isolated (58%) required seawater for growth indicating a high degree of marine adaptation. The dominant actinomycete recovered (568 strains) belonged to the seawater-requiring marine taxon 'Salinospora', a new genus within the family Micromonosporaceae. A formal description of this taxon has been accepted for publication (Maldonado et al., 2005) and includes a revision of the generic epithet to Salinispora gen. nov. Members of two major new clades related to Streptomyces spp., tentatively called MAR2 and MAR3, were cultivated and appear to represent new genera within the Streptomycetaceae. In total, five new marine phylotypes, including two within the Thermomonosporaceae that appear to represent new taxa, were obtained in culture. These results support the existence of taxonomically diverse populations of phylogenetically distinct Actinomycetes residing in the marine environment. These bacteria can be readily cultured using low nutrient media and represent an unexplored resource for pharmaceutical drug discovery.
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culturable marine actinomycete diversity from tropical pacific ocean sediments
Environmental Microbiology, 2005Co-Authors: Paul R. Jensen, Tracy J Mincer, Erin A Gontang, Chrisy Mafnas, William FenicalAbstract:Actinomycetes were cultivated using a variety of media and selective isolation techniques from 275 marine samples collected around the island of Guam. In total, 6425 actinomycete colonies were observed and 983 (15%) of these, representing the range of morphological diversity observed from each sample, were obtained in pure culture. The majority of the strains isolated (58%) required seawater for growth indicating a high degree of marine adaptation. The dominant actinomycete recovered (568 strains) belonged to the seawater-requiring marine taxon 'Salinospora', a new genus within the family Micromonosporaceae. A formal description of this taxon has been accepted for publication (Maldonado et al., 2005) and includes a revision of the generic epithet to Salinispora gen. nov. Members of two major new clades related to Streptomyces spp., tentatively called MAR2 and MAR3, were cultivated and appear to represent new genera within the Streptomycetaceae. In total, five new marine phylotypes, including two within the Thermomonosporaceae that appear to represent new taxa, were obtained in culture. These results support the existence of taxonomically diverse populations of phylogenetically distinct Actinomycetes residing in the marine environment. These bacteria can be readily cultured using low nutrient media and represent an unexplored resource for pharmaceutical drug discovery.
Ute Hentschel - One of the best experts on this subject based on the ideXlab platform.
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Actinomycetes from red sea sponges sources for chemical and phylogenetic diversity
Marine Drugs, 2014Co-Authors: Usama Ramadan Abdelmohsen, Chen Yang, Hannes Horn, Dina Hajjar, Timothy Ravasi, Ute HentschelAbstract:The diversity of Actinomycetes associated with marine sponges collected off Fsar Reef (Saudi Arabia) was investigated in the present study. Forty-seven Actinomycetes were cultivated and phylogenetically identified based on 16S rRNA gene sequencing and were assigned to 10 different actinomycete genera. Eight putatively novel species belonging to genera Kocuria, Mycobacterium, Nocardia, and Rhodococcus were identified based on sequence similarity values below 98.2% to other 16S rRNA gene sequences available in the NCBI database. PCR-based screening for biosynthetic genes including type I and type II polyketide synthases (PKS-I, PKS-II) as well as nonribosomal peptide synthetases (NRPS) showed that 20 actinomycete isolates encoded each at least one type of biosynthetic gene. The organic extracts of nine isolates displayed bioactivity against at least one of the test pathogens, which were Gram-positive and Gram-negative bacteria, fungi, human parasites, as well as in a West Nile Virus protease enzymatic assay. These results emphasize that marine sponges are a prolific resource for novel bioactive Actinomycetes with potential for drug discovery.
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diversity abundance and natural products of marine sponge associated Actinomycetes
Natural Product Reports, 2014Co-Authors: Usama Ramadan Abdelmohsen, Kristina Bayer, Ute HentschelAbstract:Covering: up to December 2012 Actinomycetes are known for their unprecedented ability to produce novel lead compounds of clinical and pharmaceutical importance. This review focuses on the diversity, abundance and methodological approaches targeting marine sponge-associated Actinomycetes. Additionally, novel qPCR data on actinomycete abundances in different sponge species and other environmental sources are presented. The natural products literature is covered, and we are here reporting on their chemical structures, their biological activities, as well as the source organisms from which they were isolated.
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isolation phylogenetic analysis and anti infective activity screening of marine sponge associated Actinomycetes
Marine Drugs, 2010Co-Authors: Usama Ramadan Abdelmohsen, Sheila Marie Pimentelelardo, Amro Hanora, Mona Radwan, Soad H Abouelela, Safwat A Ahmed, Ute HentschelAbstract:Terrestrial Actinomycetes are noteworthy producers of a multitude of antibiotics, however the marine representatives are much less studied in this regard. In this study, 90 Actinomycetes were isolated from 11 different species of marine sponges that had been collected from offshore Ras Mohamed (Egypt) and from Rovinj (Croatia). Phylogenetic characterization of the isolates based on 16S rRNA gene sequencing supported their assignment to 18 different actinomycete genera representing seven different suborders. Fourteen putatively novel species were identified based on sequence similarity values below 98.2% to other strains in the NCBI database. A putative new genus related to Rubrobacter was isolated on M1 agar that had been amended with sponge extract, thus highlighting the need for innovative cultivation protocols. Testing for anti-infective activities was performed against clinically relevant, Gram-positive (Enterococcus faecalis, Staphylococcus aureus) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria, fungi (Candida albicans) and human parasites (Leishmania major, Trypanosoma brucei). Bioactivities against these pathogens were documented for 10 actinomycete isolates. These results show a high diversity of Actinomycetes associated with marine sponges as well as highlight their potential to produce anti-infective agents.
Usama Ramadan Abdelmohsen - One of the best experts on this subject based on the ideXlab platform.
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Actinomycetes from red sea sponges sources for chemical and phylogenetic diversity
Marine Drugs, 2014Co-Authors: Usama Ramadan Abdelmohsen, Chen Yang, Hannes Horn, Dina Hajjar, Timothy Ravasi, Ute HentschelAbstract:The diversity of Actinomycetes associated with marine sponges collected off Fsar Reef (Saudi Arabia) was investigated in the present study. Forty-seven Actinomycetes were cultivated and phylogenetically identified based on 16S rRNA gene sequencing and were assigned to 10 different actinomycete genera. Eight putatively novel species belonging to genera Kocuria, Mycobacterium, Nocardia, and Rhodococcus were identified based on sequence similarity values below 98.2% to other 16S rRNA gene sequences available in the NCBI database. PCR-based screening for biosynthetic genes including type I and type II polyketide synthases (PKS-I, PKS-II) as well as nonribosomal peptide synthetases (NRPS) showed that 20 actinomycete isolates encoded each at least one type of biosynthetic gene. The organic extracts of nine isolates displayed bioactivity against at least one of the test pathogens, which were Gram-positive and Gram-negative bacteria, fungi, human parasites, as well as in a West Nile Virus protease enzymatic assay. These results emphasize that marine sponges are a prolific resource for novel bioactive Actinomycetes with potential for drug discovery.
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diversity abundance and natural products of marine sponge associated Actinomycetes
Natural Product Reports, 2014Co-Authors: Usama Ramadan Abdelmohsen, Kristina Bayer, Ute HentschelAbstract:Covering: up to December 2012 Actinomycetes are known for their unprecedented ability to produce novel lead compounds of clinical and pharmaceutical importance. This review focuses on the diversity, abundance and methodological approaches targeting marine sponge-associated Actinomycetes. Additionally, novel qPCR data on actinomycete abundances in different sponge species and other environmental sources are presented. The natural products literature is covered, and we are here reporting on their chemical structures, their biological activities, as well as the source organisms from which they were isolated.
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isolation phylogenetic analysis and anti infective activity screening of marine sponge associated Actinomycetes
Marine Drugs, 2010Co-Authors: Usama Ramadan Abdelmohsen, Sheila Marie Pimentelelardo, Amro Hanora, Mona Radwan, Soad H Abouelela, Safwat A Ahmed, Ute HentschelAbstract:Terrestrial Actinomycetes are noteworthy producers of a multitude of antibiotics, however the marine representatives are much less studied in this regard. In this study, 90 Actinomycetes were isolated from 11 different species of marine sponges that had been collected from offshore Ras Mohamed (Egypt) and from Rovinj (Croatia). Phylogenetic characterization of the isolates based on 16S rRNA gene sequencing supported their assignment to 18 different actinomycete genera representing seven different suborders. Fourteen putatively novel species were identified based on sequence similarity values below 98.2% to other strains in the NCBI database. A putative new genus related to Rubrobacter was isolated on M1 agar that had been amended with sponge extract, thus highlighting the need for innovative cultivation protocols. Testing for anti-infective activities was performed against clinically relevant, Gram-positive (Enterococcus faecalis, Staphylococcus aureus) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria, fungi (Candida albicans) and human parasites (Leishmania major, Trypanosoma brucei). Bioactivities against these pathogens were documented for 10 actinomycete isolates. These results show a high diversity of Actinomycetes associated with marine sponges as well as highlight their potential to produce anti-infective agents.
