• Fisheries and Aquatic Sciences
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• v.9 no.4
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• pp.175-178
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• 2006

An acidic ent-cyclic peroxide was isolated from a sponge, Plakotis sp., and showed activity against leishmaniasis and pathogenic fungi. To improve the activity of this compound, we coupled the acidic ent-cyclic at the C1 position of ircinol A. Compound 3 exhibited significant activity against Leishmania mexican a and fungi with $IC_{50}$ values of 0.7 and $0.3-34{\mu}g/mL$, respectively. The yield of compound 3 was 98%.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.2
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• pp.219-221
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• 2017

In 2015, white cottony tufts were observed on gametophytes of the kelp Saccharina japonica. Wet mount and histopathology examination revealed numerous fungal hyphae and mycelium around the gametophytes. The gametophytes surrounded by fungal hyphae were generally round and empty. A specific 610-bp fragment of the internal transcribed spacer (ITS)-5.8S rDNA-ITS gene of fungi was amplified by polymerase chain reaction and the nucleotide sequence showed 100% identity with those of Acremonium sclerotigenum, Acremonium sp. and Ascomycota sp. When fungus-infected gametophytes were mixed with healthy gametophytes, a high transmission rate (100%) resulted. This is the first report of mycosis of gametophytes in Korea.

• Mycobiology
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• v.49 no.6
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• pp.559-581
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• 2021

The coastal marine ecosystems of Vietnam are one of the global biodiversity hotspots, but the biodiversity of marine fungi is not well known. To fill this major gap of knowledge, we assessed the genetic diversity (ITS sequence) of 75 fungal strains isolated from 11 surface coastal marine and deeper waters in Nha Trang Bay and Van Phong Bay using a culture-dependent approach and 5 OTUs (Operational Taxonomic Units) of fungi in three representative sampling sites using next-generation sequencing. The results from both approaches shared similar fungal taxonomy to the most abundant phylum (Ascomycota), genera (Candida and Aspergillus) and species (Candida blankii) but were different at less common taxa. Culturable fungal strains in this study belong to 3 phyla, 5 subdivisions, 7 classes, 12 orders, 17 families, 22 genera and at least 40 species, of which 29 species have been identified and several species are likely novel. Among identified species, 12 and 28 are new records in global and Vietnamese marine areas, respectively. The analysis of enzyme activity and the checklist of trophic mode and guild assignment provided valuable additional biological information and suggested the ecological function of planktonic fungi in the marine food web. This is the largest dataset of marine fungal biodiversity on morphology, phylogeny and enzyme activity in the tropical coastal ecosystems of Vietnam and Southeast Asia. Biogeographic aspects, ecological factors and human impact may structure mycoplankton communities in such aquatic habitats.

• Journal of fish pathology
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• v.34 no.1
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• pp.117-121
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• 2021

An ayu (Plecoglossus altivelis) farm in Korea recently experienced an epidemic of vertebral column deformities where about 90% of fry displayed a vertebral column that was grossly opaque along either the cranial part of the column or its entire length. Abnormal fish were lordotic, scoliotic and/or kyphotic about midway down the spine. Examination of serial sections of whole fish showed only histological lesions in the vertebral column and suggested some disturbance in the early development of the vertebral centrum. Such abnormalities included a frayed spinal or notochord sheaths with irregular thickening and compression, mal-absorbed notochord cells, thickening of around cell layer and hypercellularity on both facets of the notochord sheath. No parasites, fungi, or bacteria were detected. While this lesion has only been reported once in the past, this is the first report of histopathological findings.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.1
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• pp.15-22
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• 2024

This study assessed microbial contamination in seven fried fish pastes sold in Southeast Asian traditional markets during summer. It measured viable cell count, coliforms, Escherichia coli, fungi, and Staphylococcus spp. It also qualitatively analyzed Vibrio parahaemolyticus, Salmonella spp., Bacillus cereus, Listeria monocytogenes, and Clostridium perfringens. The average viable cell count, coliforms and fungi were detected as 6.34 (3.84-8.13), 2.16 (1.00-3.55), and 3.92 (1.85-7.74) log₁₀ CFU/g, respectively. Staphylococcus spp. was detected at 4.59 (2.10-7.63) log₁₀ CFU/g. Some samples had high contamination levels: viable cell count (8.13 log₁₀ CFU/g), fungi (7.74 log₁₀ CFU/g) and S. aureus (7.63 log₁₀ CFU/g). However, E. coli was not detected in any samples (ND, <1 log₁₀ CFU/g). V. parahaemolyticus, Salmonella spp., B. cereus, L. monocytogenes, and Cl. perfringens were also not detected in the samples. The microbial contamination data provide insight into managing microbial contamination and ensuring the safety of fried fish pastes in traditional summer markets.

• The Korean Journal of Mycology
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• v.47 no.2
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• pp.165-172
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• 2019

To investigate the diversity of aquatic fungi, we collected deposits of soil, plants, and plant litter from ponds and streams. NNIBRFG1552 was isolated from soil deposits and NNIBRFG3013 from plant deposits in Namsaengi-mot in Jeju, Korea in 2016; NNIBRFG5472 was isolated from plant litter in Bocheong-cheon, Boeun, Korea in 2018. Based on morphological characteristics and phylogenetic analysis using rDNA sequences of the internal transcribed spacer (ITS), NNIBRFG1552, NNIBRFG3013, and NNIBRFG5472 were identified as Filoporella exilis (100% similarity with KC834046), F. fistucella (99.8% with KC834047), and F. cf. annelidica (100% with KC834044), respectively. Furthermore, cultural and morphological characteristics were analyzed to confirm the molecular identification. No species of the genus Filosporella has yet been reported in Korea.

• The Korean Journal of Mycology
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• v.18 no.4
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• pp.181-190
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• 1990

The growth and biochemical activities of Chlorella fusca were studied in the presence of different concentrations of either filtrates or mycelial mats of Saprolegnia ferax and Pythium graminicola. Low concentrations of both fungal filtrates exerted increase in total count, dry weight and in the biosynthesis of photosynthetic pigments, carbohydrates and nitrogen content. High concentrations showed inhibitory effect on both growth and biochemical activities of Chlorella fusca. Supplementation with different concentrations of dry mycelial mats of either fungi the culture of Chlorella showed elevation in biomass, dry weight, and biosynthesis of carbohydrates and nitrogen content especially at low concentrations. The contents of photosynthetic pigment were inhibited only at low concentrations. Neither the culture filtrate of Pythium nor Saprolegnia had cellulolytic activity, although polygalacturonase enzymes were detected, whereas chloroform-extract of both fungal filtrates showed blue spots under long wave light (366 nm).

• Fisheries and Aquatic Sciences
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• v.5 no.2
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• pp.97-102
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• 2002

Pyricularia oryzae (P. oryzae), the cause of rice blast, is one of the most important fungal pathogens of rice. Seventy strains of marine fungi were isolated from marine algae, and it was measured antifungal activity against P. oryzae. Metabolites of marine fungus A-248 which isolated from marine algae showed strong antifungal activity against P. oryzae. The antifungal substance from the metabolites of marine fungus A-248 was extracted with ethylacetate, and then purified by preparative TLC and reverse-phase HPLC. The minimum inhibitory concentration (MIC) value was $0.18\mu g/mL$ for the antifungal activity of the substance purified from A-248 metabolites. The purified substance was similar to antifungal activity of rhizoxin, which is a commercial antifungal agent.

• Fisheries and Aquatic Sciences
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• v.8 no.1
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• pp.6-9
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• 2005

Two new cyclic peroxides were isolated from an undescribed sponge of the genus Plakortis sp. collected at Discovery Bay, Jamaica. The molecular structures were elucidated by interpreting ID and 2D NMR and HRMS data. The cyclic peroxides, Compound 1 and 2, exhibited significant antimicrobial activity against pathogenic bacteria and fungi with IC$_${50} values of 0.9-5.0$\mug/mL and 0.7-8.0$\mug/mL, respectively.

• Fisheries and Aquatic Sciences
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• v.18 no.4
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• pp.341-347
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• 2015

We evaluated the biological activities of five water extracts of tissue of the mottled anemone Urticina crassicornis. Most extracts exhibited broad-spectrum antimicrobial activity as determined by ultrasensitive radial diffusion assay (URDA) against gram-positive and -negative bacteria, including a fish pathogen, Aeromonas hydrophila, but no activity against fungi. The activity of the extracts was abolished by tryptic digestion, indicating that protein compounds were responsible for the antimicrobial activity. Furthermore, in a 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging activity assay, only the visceral tissue extract showed activity. However, no extract had hemolytic activity against human red blood cells. Consequently, this study suggests the water-soluble extract of mottled anemone to be a promising source of proteinaceous antimicrobial compounds that can be utilized for development of novel antibiotics.