• Journal of Microbiology
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• 제40권4호
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• pp.335-339
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• 2002

Partial sequences of 16S rRNA gene of five chroococcalian blue-green algal strains, Aphanothece nidulans KCTC AG10041, Aphanothece naegelii KCTC AG10042, Microcystis aeruginosa KCTC AG10159, Microcystis ichthyoblabe KCTC AG10160, and Microcystis viridis KCTC AG10198, which were isolated from water from the Geumgang River, were determined and were inferred their phylogenetic and taxonomic positions among taxa of order Chroococcales. Most taxa of Chroococcales whose partial 16S rRNA gene sequences were aligned in this study, are clustered with other related taxa. Aphanothece nidulans KCTC AG10041 and Aphanothece naegelii KCTC AG10042 made a cluster with other European species of these genera, which supported 100% of the bootstrap trees with a very high sequence similarity (97.4-99.4%) in this study. Three strains, Microcystis aeruginosa KCTC AG10159, M. ichthyoblabe KCTC AG10160, and M. viridis KCTC AG10198, formed a cluster with other Microcystis spp. supported 100 % of the bootstrap trees with a similarity of 97.0-99.9% except for two strains. However, this phylogentic tree made no resolution among the species of Microcystis spp. The topology of the tree reconfirmed the taxonomic status of three species of Microcystis, identified in this study based on the morphology, as three colonial types of Microcystis aeruginosa com. nov. Otsuka et al. (1999c). The genera of chroococcalian cyanophytes are heterogeneously clustered in these sequence analyses. We suggest that more molecular studies on the genera of Chroococcales with reference strains, widely collected from restricted geographic or environmental ranges, get accurate taxonomic or phylogenetic determinations.

• ALGAE
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• 제29권4호
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• pp.289-297
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• 2014

The taxonomic status and the distribution of Rosenvingea species need attention because of the difficulties in morphological identification in the laboratory as well as in the field. We analyzed mitochondrial cox3 and plastid psaA gene sequences from Rosenvingea species from Vietnam, Mexico and Panama in combination with morphological examinations. Our results confirmed the occurrence of R. intricata and R. orientalis in Vietnam. R. intricata formed dense decumbent mats with many flat branches, often inter-adhesive, and was up to 5 cm in diameter. R. orientalis thalli were up to 18 cm long with narrow (less than 2 mm in width) tubular to compressed fronds. Both cox3 and psaA phylogenies revealed the non-monophyly of the genus Rosenvingea, as reported previously for other scytosiphonacean genera.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2005년도 International Meeting of the Microbiological Society of Korea
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• pp.64-66
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• 2005

Photosynthetic microbes possess a wealth of photoactive proteins including chlorophyll-based pigments, phototropin-related blue light receptors, phytochromes, and cryptochromes. Surprisingly, recent genome sequencing projects discovered additional photoactive proteins, retinal-based rhodopsins, in cyanobacterial and algal genera. Most of these newly found rhodopsin genes and retinal synthase have not been expressed and their functions are unknown. Analysis of the Anabaena and Chlamyrhodopsin with retinal synthase revealed that they have sensory functions, which, based on our work with haloarchaeal rhodopsins, may use a variety of signaling mechanisms. Anabaena rhodopsin is believed to be sensory, shown to interact with a soluble transducer and the putative function is either chromatic adaptation or circadian rhythm. Chlamydomonas rhodopsins are involved in phototaxis and photophobic responses based on electrical measurements by RNAi experiment. In order to analyze the protein, we developed a sensory rhodopsin expression system in E. coli. The opsin in E. coil bound endogenous all-trans retinal to form a pigment and can be observed on the plate. Using this system we could identify retinal synthase in Anabaena PCC 7120. We conclude that Anabaena D475 dioxygenase functions as a retinal synthase to the Anabaena rhodopsin in the cell.

• Ocean and Polar Research
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• 제23권3호
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• pp.209-221
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• 2001

Taxonomic composition of marine benthic algal flora was investigated in an Antarctic bay. Specimens of chlorophyte, chrysophyte and phaeophyte were collected and examined over the period from January 1988 to January 1995 from Maxwell Bay, King George Island. A total of 19 genera and 23 species (7 chlorophytes, 1 chrysophyte and 15 phaeophytes) were identified and described. A chlorophyte Lambia antarctica (Skottsberg) Delepine and a phaeophyte Alethocladus corymbosus (Dickie) Sauvageau were recorded in Maxwell Bay for the first time. Taxonomic keys for the chlorophytes and the phaeophytes were also provided.

• ALGAE
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• 제39권2호
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• pp.97-108
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• 2024

The Ralfsiaceae family, part of the Ralfsiales order and consisting of crustose brown algae, includes five genera: Analipus, Endoplura, Fissipedicella, Heteroralfsia, and Ralfsia. In this study, a novel crustose genus named Ramipedicella gen. nov. is introduced within the Ralfsiaceae based on molecular and morphological analyses. Phylogenetic analyses using both concatenated dataset (rbcL + COI-5P genes) and rbcL indicate that the crustose brown algae that we collected from Korea and Russia form a unique grouping within the Ralfsiaceae. This grouping is strongly supported by both bootstrap analysis and Bayesian posterior probabilities. The genetic differences in the rbcL and COI-5P sequences between Ramipedicella and other genera within Ralfsiaceae range from 6.7 to 9.3% for rbcL and from 15.5 to 20.8% for COI-5P. Ramipedicella is characterized by crustose thalli having new crusts growing on top of old ones with a hypothallial basal layer and erect perithallial filaments, long cells with width-to-length ratio of 1 : 1-16, single chloroplast per cell, plurangia with one to several sterile cells, one to several unangia produced from unicellular stalks or from the lateral-basal region to the paraphyses, and unangia arising sequencially in irregularly branched specialized filaments. Ramipedicella, the recently identified genus, comprises two distinct species. Ramipedicella miniloba, the type species, is distinguished by crusts with small lobes, numerous hair tufts, plurangia terminated by 1-4 sterile cells, and large oblong unangia. Ramipedicella longicellularis is identified by generally smooth crusts, absence of phaeophycean hairs, plurangia terminated by 1-2 apical sterile cells, and smaller mostly oblanceolate unangia.

• ALGAE
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• 제20권2호
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• pp.91-97
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• 2005

The brown algal family Chordariaceae sensu lato is a focus of taxonomy because recent studies suggest a broad concept of the family, including genera formerly classified in the Dictyosiphonales. Using morphology, plastid rbcL and nrDNA ITS sequences, we evaluated relationships of the monotyic genus Soranthera (S. ulvoidea), which has been classified in the Punctariaceae. The species occurs in Bering Sea and Aleutian Islands, Alaska to Baja California. Thalli are globose to lobed, hollow, 3-5 cm in diameter, and covered with evenly distributed sori. However, two forms within the species are recognized: f. ulvoidea for globose forms and f. difformis for lobed forms. Plastid rbcL and nuclear ITS region sequences were newly determined in samples of S. ulvoidea from the Pacific coast of the North America. We found little variations in the ITS sequences among samples of S. ulvoidea from five different locations and in the rbcL region from two different locations. These results do not support previous classification of f. ulvoidea and f. difformis within the species. All analyses of our rbcL sequence dataset show that Soranthera was placed in the Chordariaceae s.l., but more related to Botrytella than Punctaria and Asperococcus.

• ALGAE
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• 제29권1호
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• pp.1-13
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• 2014

The genus Erythroglossum is characterized by Phycodrys-type apical organization, Polyneura-type procarp, and the presence of a midrib. We collected an unidentified Delesseriaceaen species from deep water off the southern coast of the Korean Peninsula. This alga resembles Polyneura japonica in terms of having broadly flattened thalli with a cylindrical stipe, the presence of a midrib and alternative lateral veins. To confirm the taxonomic status of this entity, we compared the morphological features and rbcL sequences among other species of Erythroglossum and P. japonica. As a result, we assigned the new species, Erythroglossum hyacinthinum, to the genus Erythroglossum because of the presence of a midrib. This species is characterized by an elliptical to obovate blade with a short cylindrical stipe, a conspicuous midrib and alternate veins, margins with numerous microscopic dentations, di-trichotomously branching, and bulish-violet iridescence. The phylogeny of rbcL sequences indicates that E. hyacinthinum is definitely a separate entity, but the genera in the tribe Phycodryeae have inconsistent phylogenetic relationships. This is the first study comparing the molecular phylogeny within the genus Erythroglossum.

• 한국환경과학회지
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• 제18권1호
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• pp.15-19
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• 2009

Early studies claimed that heterotrophic dinoflagellates Pfiesteria piscicida and related genera may produce a putative water-soluble toxin that causes death of fish and other marine animals. Several methods were tested to visualize plate morphology of Cryptoperidiniopsis brodyi and Pfiesteria piscicida. Cellulose plates of cells were exposed and visualized- by a membrane stripping method using Triton X-100. While calcofluor M2R white stain could readily bind to the thecal plates, details of the plate tabulation were difficult to observe. Fixation with osmium tetroxide $(OsO_4)$ produced well preserved cells with little morphological distortion, but thecal plates could not be visualized. Scanning electron microscopy (SEM) observation using the membrane stripping method showed distinctive plate tabulations between C. brodyi and P. piscicida suggesting that this method is a useful tool for morphological identification of lightly armored dinoflagellates.

• ALGAE
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• 제27권3호
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• pp.155-173
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• 2012

Evidence from molecular data supports the close taxonomic relationship of the two North Pacific species Delesseria decipiens and D. serrulata with Cumathamnion, up to now a monotypic genus known only from northern California, rather than with D. sanguinea, the type of the genus Delesseria and known only from the northeastern North Atlantic. The transfers of D. decipiens and D. serrulata into Cumathamnion are effected. Molecular data also reveal that what has passed as Membranoptera alata in the northwestern North Atlantic is distinct at the species level from northeastern North Atlantic (European) material; M. alata has a type locality in England. Multiple collections of Membranoptera and Pantoneura fabriciana on the North American coast of the North Atlantic prove to be identical for the three markers that have been sequenced, and the name Membranoptera fabriciana (Lyngbye) comb. nov. is proposed for them. Many collections of Membranoptera from the northeastern North Pacific (predominantly British Columbia), although representing the morphologies of several species that have been previously recognized, are genetically assignable to a single group for which the oldest name applicable is M. platyphylla.

• ALGAE
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• 제17권3호
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• pp.135-144
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• 2002

Scytosiphonaceae is an acetocarpalean brown algal family, that is a recent focus of synstematics and marine biodiversity. We describe Petalonia zosterifolia and Scytosiphon gracilis from Korea for the first time. P. zosterifolia occurred on the East coast, and had flat, linear and solid thalli. S. gracilis was found in Jeju, and had cylindircal to flat and hol-low thalli. However, these two species are so similar that it is difficult to identify by morphology alone. In order to determine if the nuclear DNA reveals the distinctness of both species and to know their phylogenies, the ITS region sequences were newly detrmined in 22 samples of P. zosterifolia, Scytosiphon gracilis, and other three members of the genera from Korea. We found 0.12% variation among samples of P. zosterifolia from different locations, and no variation between S. gracilis samples from diferent years, but extensive interspecific divergences (13.62-22.83%) of each species to other members in Petalonia and Scytosiphon . The ITS sequence dta consistently showed a close relationship between P. zosterifolia and S. gracilis. This result is congruent with morphology and with the published data of plastid rbc and partial nrDNA large subunit gene sequences, and suggests that P. zosterifolia and S. gracilis might have diverged from the most recent common ancestor.