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Anthony Buaya

Bio: Anthony Buaya is an academic researcher from Goethe University Frankfurt. The author has contributed to research in topics: Oomycete & Genus. The author has an hindex of 6, co-authored 15 publications receiving 101 citations.

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TL;DR: This easyPACId approach (easy Promoter Activated Compound Identification) facilitates NP identification due to low interference from other NPs and allows direct bioactivity testing of supernatants containing secreted NPs, without laborious purification.
Abstract: Natural products (NPs) from microorganisms have been important sources for discovering new therapeutic and chemical entities. While their corresponding biosynthetic gene clusters (BGCs) can be easily identified by gene-sequence-similarity-based bioinformatics strategies, the actual access to these NPs for structure elucidation and bioactivity testing remains difficult. Deletion of the gene encoding the RNA chaperone, Hfq, results in strains losing the production of most NPs. By exchanging the native promoter of a desired BGC against an inducible promoter in Δhfq mutants, almost exclusive production of the corresponding NP from the targeted BGC in Photorhabdus, Xenorhabdus and Pseudomonas was observed including the production of several new NPs derived from previously uncharacterized non-ribosomal peptide synthetases (NRPS). This easyPACId approach (easy Promoter Activated Compound Identification) facilitates NP identification due to low interference from other NPs. Moreover, it allows direct bioactivity testing of supernatants containing secreted NPs, without laborious purification.

32 citations

Journal ArticleDOI
TL;DR: The phylogenetic placement of two oomycete parasitoids one parasitic to Pseudo-nitzschia pungens and the other parasitic to Rhizosolenia imbricata is reported, report the taxonomy of Ectrogella-like organisms and Olpidiopsis is discussed and, as a consequence of morphological differences and phylogenetics, two new species are introduced.
Abstract: Despite their widespread nature and economic impact, little is known regarding the diversity and phylogeny of diatom-infecting oomycetes. While the phylogenetic affinities of Lagenisma, affecting large centric diatoms, has recently been resolved, no member of the widespread genus Ectrogella has, so far, been investigated using molecular phylogenetics. The genus Ectrogella contains about a dozen species, which are all holocarpic. The species in the genus are diverse in terms of morphology and development, and primarily set apart from other holocarpic oomycete genera on the basis of their occurrence in unicellular or colonial algae, predominantly licmophoroid and bacillarioid diatoms. Here, we report the phylogenetic placement of two oomycete parasitoids one parasitic to Pseudo-nitzschia pungens and the other parasitic to Rhizosolenia imbricata. While both parasitoids were placed outside the crown oomycete groups represented by Saprolegniomycetes and Peronosporomycetes, they did not form a monophyletic assemblage. The Rhizosolenia parasitoid was embedded amongst marine Olpidiopsis species, while the Pseudo-nitzschia parasitoid was placed as the sister clade to all remaining oomycetes. The taxonomy of Ectrogella-like organisms and Olpidiopsis is discussed and, as a consequence of morphological differences and phylogenetic placement, two new species, Miracula helgolandica and Olpidiopsis drebesii, are introduced.

28 citations

Journal ArticleDOI
20 Jun 2019
TL;DR: Arctic marine Oomycota are a reservoir of uncharacterized biodiversity, the majority of which are probably parasites of diatoms, while others might cryptically cycle carbon or interface other unknown ecological processes.
Abstract: High-latitude environments are warming, leading to changes in biological diversity patterns of taxa. Oomycota are a group of fungal-like organisms that comprise a major clade of eukaryotic life and are parasites of fish, agricultural crops, and algae. The diversity, functionality, and distribution of these organisms are essentially unknown in the Arctic marine environment. Thus, it was our aim to conduct a first screening, using a functional gene assay and high-throughput sequencing of two gene regions within the 18S rRNA locus to examine the diversity, richness, and phylogeny of marine Oomycota within Arctic sediment, seawater, and sea ice. We detected Oomycota at every site sampled and identified regionally localized taxa, as well as taxa that existed in both Alaska and Svalbard. While the recently described diatom parasite Miracula helgolandica made up about 50% of the oomycete reads found, many lineages were observed that could not be assigned to known species, including several that clustered with another recently described diatom parasite, Olpidiopsis drebesii. Across the Arctic, Oomycota comprised a maximum of 6% of the entire eukaryotic microbial community in Barrow, Alaska May sediment and 10% in sea ice near the Svalbard archipelago. We found Arctic marine Oomycota encode numerous genes involved in parasitism and carbon cycling processes. Ultimately, these data suggest that Arctic marine Oomycota are a reservoir of uncharacterized biodiversity, the majority of which are probably parasites of diatoms, while others might cryptically cycle carbon or interface other unknown ecological processes. As the Arctic continues to warm, lower-latitude Oomycota might migrate into the Arctic Ocean and parasitize non-coevolved hosts, leading to incalculable shifts in the primary producer community.

23 citations

Journal ArticleDOI
10 May 2019
TL;DR: Phylogenetic reconstructions in the current study revealed that O. saprolegniae from Saprolegnia parasitica forms a monophyletic group with a morphologically similar isolate from S. terrestris and all holocarpic parasites in red algae should be considered to be members of the genus Pontisma.
Abstract: Olpidiopsis is a genus of obligate holocarpic endobiotic oomycetes. Most of the species classified in the genus are known only from their morphology and life cycle, and a few have been examined for their ultrastructure or molecular phylogeny. However, the taxonomic placement of all sequenced species is provisional, as no sequence data are available for the type species, O. saprolegniae, to consolidate the taxonomy of species currently placed in the genus. Thus, efforts were undertaken to isolate O. saprolegniae from its type host, Saprolegnia parasitica and to infer its phylogenetic placement based on 18S rDNA sequences. As most species of Olpidiopsis for which sequence data are available are from rhodophyte hosts, we have also isolated the type species of the rhodophyte-parasitic genus Pontisma, P. lagenidioides and obtained partial 18S rDNA sequences. Phylogenetic reconstructions in the current study revealed that O. saprolegniae from Saprolegnia parasitica forms a monophyletic group with a morphologically similar isolate from S. ferax, and a morphologically and phylogenetically more divergent species from S. terrestris. However, they were widely separated from a monophyletic, yet unsupported clade containing P. lagenidioides and red algal parasites previously classified in Olpidiopsis. Consequently, all holocarpic parasites in red algae should be considered to be members of the genus Pontisma as previously suggested by some researchers. In addition, a new species of Olpidiopsis, O. parthenogenetica is introduced to accommodate the pathogen of S. terrestris.

14 citations

Journal ArticleDOI
TL;DR: Successful cultivation of a single spore strain of L. coscinodisci (Isla) is reported, which opens up the opportunity to study the processes and mechanism in plankton/parasitoid interactions under controlled conditions.
Abstract: Diatoms are thought to provide about 40% of total global photosynthesis and diatoms of the genus Coscinodiscus are an important, sometimes dominant, cosmopolitan component of the marine diatom community. The oomycete parasitoid Lagenisma coscinodisci is widespread in the northern hemisphere on its hosts in the genus Coscinodiscus. Because of its potential ecological importance, it would be a suitable pathogen model to investigate plankton/parasite interactions, but the species cannot be cultivated on media without its host, so far. Thus, it was the aim of this study to explore the potential of dual culture of host and pathogen in the laboratory and to optimise cultivation to ensure a long-term cultivation of the pathogen. Here, we report successful cultivation of a single spore strain of L. coscinodisci (Isla), on several Coscinodiscus species and strains, as well as the establishment of a cultivation routine with Coscinodiscus granii (CGS1 and CG36), which enabled us to maintain the single spore strain for more than 3 years in 6 cm Petri dishes and 10 ml tissue culture flasks. This opens up the opportunity to study the processes and mechanism in plankton/parasitoid interactions under controlled conditions.

14 citations


Cited by
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TL;DR: This article provides an outline of the classification of the kingdom Fungi (including fossil fungi), and treats 19 phyla of fungi, including all currently described orders of fungi.
Abstract: This article provides an outline of the classification of the kingdom Fungi (including fossil fungi. i.e. dispersed spores, mycelia, sporophores, mycorrhizas). We treat 19 phyla of fungi. These are Aphelidiomycota, Ascomycota, Basidiobolomycota, Basidiomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomophthoromycota, Entorrhizomycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota and Zoopagomycota. The placement of all fungal genera is provided at the class-, order- and family-level. The described number of species per genus is also given. Notes are provided of taxa for which recent changes or disagreements have been presented. Fungus-like taxa that were traditionally treated as fungi are also incorporated in this outline (i.e. Eumycetozoa, Dictyosteliomycetes, Ceratiomyxomycetes and Myxomycetes). Four new taxa are introduced: Amblyosporida ord. nov. Neopereziida ord. nov. and Ovavesiculida ord. nov. in Rozellomycota, and Protosporangiaceae fam. nov. in Dictyosteliomycetes. Two different classifications (in outline section and in discussion) are provided for Glomeromycota and Leotiomycetes based on recent studies. The phylogenetic reconstruction of a four-gene dataset (18S and 28S rRNA, RPB1, RPB2) of 433 taxa is presented, including all currently described orders of fungi.

381 citations

Journal ArticleDOI
TL;DR: This review covers new information since two previous reviews in 2012, including how and why DA and its isomers are produced, the world distribution of potentially toxigenic Nitzschia species, the prevalence of DA isomers, and molecular markers to discriminate between toxigenics and non-toxigenic species.

202 citations

Journal ArticleDOI
TL;DR: This paper investigated the diversity and novelty of biosynthetic gene clusters in the ocean by integrating around 10,000 microbial genomes from cultivated and single cells with more than 25,000 newly reconstructed draft genomes from more than 1,000 seawater samples.
Abstract: Abstract Natural microbial communities are phylogenetically and metabolically diverse. In addition to underexplored organismal groups 1 , this diversity encompasses a rich discovery potential for ecologically and biotechnologically relevant enzymes and biochemical compounds 2,3 . However, studying this diversity to identify genomic pathways for the synthesis of such compounds 4 and assigning them to their respective hosts remains challenging. The biosynthetic potential of microorganisms in the open ocean remains largely uncharted owing to limitations in the analysis of genome-resolved data at the global scale. Here we investigated the diversity and novelty of biosynthetic gene clusters in the ocean by integrating around 10,000 microbial genomes from cultivated and single cells with more than 25,000 newly reconstructed draft genomes from more than 1,000 seawater samples. These efforts revealed approximately 40,000 putative mostly new biosynthetic gene clusters, several of which were found in previously unsuspected phylogenetic groups. Among these groups, we identified a lineage rich in biosynthetic gene clusters (‘ Candidatus Eudoremicrobiaceae’) that belongs to an uncultivated bacterial phylum and includes some of the most biosynthetically diverse microorganisms in this environment. From these, we characterized the phospeptin and pythonamide pathways, revealing cases of unusual bioactive compound structure and enzymology, respectively. Together, this research demonstrates how microbiomics-driven strategies can enable the investigation of previously undescribed enzymes and natural products in underexplored microbial groups and environments.

72 citations

Journal ArticleDOI
TL;DR: Using single-cell techniques, morphologically and molecularly, intracellular parasitoids infecting four potentially toxin-producing Pseudo-nitzschia and one Melosira species on the North Atlantic coast are characterise and called for investigation of their phenology, evolution, and potential contribution in controlling their host spatial-temporal dynamics.
Abstract: Parasites are key drivers of phytoplankton bloom dynamics and related aquatic ecosystem processes. Yet, the dearth of morphological and molecular information hinders the assessment of their diversity and ecological role. Using single-cell techniques, we characterise morphologically and molecularly, intracellular parasitoids infecting four potentially toxin-producing Pseudo-nitzschia and one Melosira species on the North Atlantic coast. These sequences define two, morphologically indistinguishable clades within the phylum Oomycota, related to the genera of algal parasites Anisolpidium and Olpidiopsis and the diatom parasitoid species Miracula helgolandica. Our morphological data are insufficient to attribute either clade to the still unsequenced genus Ectrogella; hence it is proposed to name the clades OOM_1 and OOM_2. A screening of global databases of the barcode regions V4 and V9 of the 18S rDNA demonstrate the presence of these parasitoids beyond the North Atlantic coastal region. During a biweekly metabarcoding survey (Concarneau Bay, France), reads associated with one sequenced parasitoid coincided with the decline of Cerataulina pelagica bloom, whilst the other parasitoids co-occurred at low abundance with Pseudo-nitzschia. Our data highlight a complex and unexplored diversity of the oomycete parasitoids of diatoms and calls for the investigation of their phenology, evolution, and potential contribution in controlling their host spatial-temporal dynamics.

32 citations

01 Jan 2020
TL;DR: A review of shellfish toxicity in Canadian waters can be found in this paper, where the authors discuss shellfish poisoning in the Canadian waters and changes in nomenclature of Alexandrium catenella species.
Abstract: .................................................................................................................................. ix RÉSUMÉ ........................................................................................................................................ x 1.0 Introduction ............................................................................................................................... 1 1.1 Marine Harmful Algal Blooms (HABs) and Phycotoxins .................................................. 1 1.2 Scope of this review .......................................................................................................... 10 1.3 DFO working groups and workshops on phycotoxins and harmful algae ........................ 12 1.4 Information sources .......................................................................................................... 14 2.0 Saxitoxin Group Toxins (Paralytic Shellfish Poisoning; PSP) ............................................... 16 2.1 Description of saxitoxin group toxins and their biological effects ................................... 16 2.2 Alexandrium species in Canadian waters and changes in nomenclature .......................... 18 2.3 Pacific coast ...................................................................................................................... 19 2.3.1 Contaminated species............................................................................................... 21 2.3.2 Causative species ..................................................................................................... 24 2.4 Atlantic coast .................................................................................................................... 25 2.4.1 Bay of Fundy............................................................................................................ 25 2.4.1.1 Contaminated species ........................................................................................ 26 2.4.1.2 Causative species .............................................................................................. 30 2.4.1.3 Periodicity in shellfish toxicity in the Bay of Fundy ........................................ 33 2.4.2 Nova Scotia – Atlantic coast .................................................................................... 34 2.4.2.1 Contaminated species ........................................................................................ 34 2.4.2.2 Causative species .............................................................................................. 37 2.4.3 Gulf of St. Lawrence ................................................................................................ 37 2.4.3.1 Contaminated species ........................................................................................ 37 2.4.3.2 Causative species .............................................................................................. 40 2.4.3.2.1 Bloom dynamics of Alexandrium catenella ................................................ 41 2.4.3.3 Southern Gulf of St. Lawrence ......................................................................... 43 2.4.4 Newfoundland and Labrador ................................................................................... 45 2.4.5 Canadian Arctic ....................................................................................................... 45 3.0 Domoic Acid Group (Amnesic Shellfish Poisoning; ASP) .................................................... 46 3.1 Description of domoic acid and its biological effects ....................................................... 46 3.2 Atlantic coast .................................................................................................................... 50 3.2.1 Southern Gulf of St. Lawrence ................................................................................ 50 3.2.2 Northern and central Gulf of St. Lawrence .............................................................. 59 3.2.3 Nova Scotia – Atlantic coast .................................................................................... 61 3.2.4 Bay of Fundy............................................................................................................ 62 3.2.5 Newfoundland and Labrador ................................................................................... 64 3.3 Pacific coast ...................................................................................................................... 65 3.4 Canadian Arctic ................................................................................................................ 69 4.0 Okadaic Acid Group Toxins (Diarrhetic Shellfish Poisoning; DSP) ...................................... 71 4.1 Description of okadaic acid group toxins and their biological effects .............................. 71

28 citations