Gwang Hoon Kim

Kongju National University | Kongju · Department of Biology

The interplay between calcium signaling and reactive oxygen species (ROS) production is important in many cellular activities, yet its involvement in biological processes in red algae is mostly not studied. Fertilization in red algae is unique, and while it is known that ROS is a necessary signal, its producing and interplay with calcium and calciu...

The genus Aglaothamnion has been separated from Callithamnion based on several characters, most notably the presence of a single nucleus per cell in Aglaothamnion versus multi-nucleate Callithamnion. Few studies have investigated whether these genera are genetically monophyletic. Several species of Aglaothamnion have been reported from Korea, but n...

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http:// creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium , provided the original work is properly cited. Algae 2024, 39(3): 223-224 https://doi.

The escalating threat of ultraviolet radiation (UVR) necessitates the development of sustainable strategies for protection from UVR exposure. Mycosporine-like amino acids (MAAs) provide natural photoprotection by absorbing and dissipating harmful UVR. Here, we present the engineering of Nannochloropsis gaditana, a marine microalga, for enhanced pro...

Mechanical damage to a cell can be fatal, and the cell must reseal its membrane and restore homeostasis to survive. Plant cell repair involves additional steps such as rebuilding vacuoles, rearranging chloroplasts, and remodeling the cell wall. When we pierced a Griffithsia monilis cell with a glass needle, a large amount of intracellular contents...

Seaweeds are important components of marine ecosystems with emerging potential in aquaculture and as sources of biofuel, food products and pharmacological compounds. However, an increasingly recognised threat to natural and industrial seaweed populations is infection with parasitic single‐celled eukaryotes from the relatively understudied oomycete...

Oomycetes are ubiquitous heterotrophs of considerable economic and ecological importance. Lately their diversity in marine environments has been shown to be greatly underappreciated and many lineages of intracellular holocarpic parasites, infecting micro- and macro-algae, remain to be fully described taxonomically. Among them, pathogens of marine r...

Oomycete pathogens are one of the most serious threats to the rapidly growing global algae aquaculture industry but research into how they spread and how algae respond to infection is unresolved, let alone a proper classification of the pathogens. Even the taxonomy of the genera Pythium and Olpidiopsis, which contain the most economically damaging...

Most taxonomic groups of organisms harbor temporarily or permanently multinucleate cells in all or parts of their bodies. Each nucleus in the same cytoplasm responds almost identically to environmental cues, but little is known about the signals that mediate their coordinated division. In this study, we used Griffithsia monilis, a multinucleated gi...

Four species of Erythrotrichia ( E. biseriata , E. reflexa , E. tetraseriata , E. carnea ) have been reported in Korea, but phylogenetic studies have not been conducted on them. We analyzed two newly collected Erythrotrichia isolates using rbc L DNA sequences and determined their species status using four DNA-based species delimitation methods. One...

The oomycete pathogens Pythium porphyrae, causing red rot disease, and Olpidiopsis spp. causing Olpidiopsis-blight, cause serious economic losses to Pyropia sea farms in Korea. During the washing step for Pyropia processing, these pathogens proliferate rapidly, significantly reducing the quality of the final product. To develop non-acidic treatment...

The CRISPR/Cas9 system has been widely applied as a precise gene-editing tool for studying gene functions as well as improving agricultural traits in various crop plants. Here, we optimized a gene-editing system in lettuce (Lactuca sativa L.) using the endogenous U6 promoter and proved that the PHOT2 gene is a versatile target gene. We isolated the...

Increased oceanic temperature due to climatic change is gradually decreasing the production rates of Pyropia yezoensis in South Korea, which accounts for 50 % of the global supply. This study demonstrates the antioxidant property of a newly developed edible marine red algae, heat-resistant P. yezoensis (HrP). The water extract of HrP displayed a no...

The ecology, morphometric diversity and distribution of the whole-leaved kelp species from Kamchatka were studied. These species were previously listed in this region under various names, including Laminaria gurjanovae, Laminaria gurjanovae f. lanciformis, Laminaria lanciformis, Laminaria sp. avgub 1, Saccharina gurjanovae. The molecular-phylogenet...

The trend in naming genera based almost exclusively on molecular data, and not on morphological diagnostic characters, is increasing. In bifurcating phylogenetic trees generic cut-offs are arbitrary, but at the bare minimum nomenclatural changes should be supported by multiple phylogenetic methodologies using appropriate models for all the various...

In many filamentous red algae, cells that die from physical damage are replaced through somatic fusion of repair cells formed from adjacent cells. We visualized ROS generation in repair cells of Giriffthsia monilis using DCFH-DA staining and examined the expression of the genes involved in wound healing using quantitative PCR. Repair cells elongate...

Intercellular nutrient and signal transduction are essential to sustaining multicellular organisms and maximizing thebenefits of multicellularity. It has long been believed that red algal intercellular transport of macromolecules is preventedby the protein-rich pit plug within pit-connections, the only physical connection between cells. Fluorescein...

Liquid-repellent technology is an efficient means of energy-saving and biofouling avoidance. However, liquid-repellent surfaces suffer from inefficient lubricant retention under shear flow and fouling problem in marine environment. Here, the authors demonstrate a fatty acid amide (FAA)-based oleogel for stable and sustainable lubrication in marine...

Highlights 1. This policy brief highlights key challenges that must be addressed for the long-term sustainability of the global seaweed industry, ensuring its role in providing nature-based solutions within the sustainable ocean economy agenda and in contributing to the UN Decade of Ocean Science for Sustainable Development (2021-2030). 2. Seaweed...

Cottier-Cook, E.J., Nagabhatla, N., Asri, A., Beveridge, M., Bianchi, P., Bolton, J., Bondad-Reantaso, M.G., Brodie, J., Buschmann, A., Cabarubias, J., Campbell, I., Chopin, T., Critchley, A., De Lombaerde, P., Doumeizel, V., Gachon, C.M.M., Hayashi, L., Hewitt, C.L., Huang, J., Hurtado, A.Q., Kambey, C., Kim, G.H., Le Masson, V., Lim, P.E., Liu, T...

Reactive oxygen species (ROS) signaling has a multitude of roles in cellular processes throughout biology. We hypothesized that red algal fertilization may offer an interesting model to study ROS-mediated signaling as the stages of fertilization are complex and unique. We microscopically localized ROS production and monitored the expression of thre...

Pyropia yezoensis is the most widely cultivated and economically important marine red alga. However, due to its simple morphology, it is not easy to identify P. yezoensis cultivars by phenotype. In the present study, simple sequence repeats (SSRs) were identified in the scaffold-genome sequence of P. yezoensis cultivar SG104. These SSRs were used t...

The hepatoprotective effect of liposoluble portion of Pyropia yezoensis (PYLP) was investigated against alcohol-induced liver injury in mice. Fatty acids were predominant in PYLP obtained from hexane fraction of 70% EtOH extract after ultrasonication. In particular, polyunsaturated fatty acids such as eicosapentaenoic acid and linoleic acid account...

The Erythropeltidales are a common group of small, mostly epiphytic, marine red algae. However, they are little known in Korea. Many of the described species of Erythropeltidales differ subtly in morphology, and often the morphological differences are due to the substrate or environmental changes. Integration of molecular data with stan- dardized c...

Marine biofouling of ship hulls and ocean structures causes enormous economic losses due to increased frictional drag. Thus, efforts have been exerted worldwide to eliminate biofouling. In addition, a strong demand exists for the development of a cost-effective and eco-friendly anti-biofouling coating technology. Thus, erucamide-polydimethylsiloxan...

Diverse sex determination mechanisms have been reported in eukaryotes, but little is known about the genetic pathways leading to sex determination in red algae. Sex‐specific genes that could be involved in sex determination and sexual differentiation were investigated in the red alga Bostrychia moritziana by analyzing the transcriptomes of various...

Cold weather is one of the biggest challenges in establishing a large-scale microalgae culture facility in temperate regions. In order to develop a strain that is resistant to low temperatures and still maintains high photosynthetic efficiency, transgenic studies have been conducted targeting many genes. Early light-inducible proteins (ELIPs) locat...

Pyropia yezoensis has been used as functional food in East Asia, especially in Korea and Japan, for more than five hun-dred years. This study aims to evaluate the antioxidant effect of polyphenols and proteins-rich extracts from P. yezoensis (PPPs) against 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH)-induced oxidative cell damage. Among si...

The biofouling of marine organisms on a surface induces serious economic damage. One of the conventional anti-biofouling strategies is the use of toxic chemicals. In this study, a new eco-friendly oleamide–PDMS copolymer (OPC) is proposed for sustainable anti-biofouling and effective drag reduction. The anti-biofouling characteristics of the OPC ar...

Marine species of the oomycete genus Olpidiopsis that infect cultivated red macroalgae, most notably Pyropia spp., are one of the main causes of economic loss in the Asian seaweed industry. We recently described novel Olpidiopsis species infecting red algae in Scotland, and thus hypothesized that this genus is more abundant and widespread than prev...

The rapid growth of marine macroalgal cultivation amplifies the potential impacts of seaweed diseases. Here, we combine microscopy and molecular analysis to describe two novel European species, Olpidiopsis palmariae and O. muelleri spp. nov., that infect the commercially important red algae Palmaria and Porphyra, respectively. A Scottish variety of...

Disease outbreaks devastate Pyropia aquaculture farms every year. The three most common and serious diseases are Olpidiopsis‐blight and red‐rot disease caused by oomycete pathogens and green‐spot disease caused by the PyroV1 virus. We hypothesized that a basic genetic profile of molecular defenses will be revealed by comparing and analyzing genetic...

Spirogyra filaments show unique photomovement which differs in response to blue, red and far‐red light. Phototropins involved in the blue‐light movement has been characterized together with downstream signaling components, but the photoreceptors and mechanical effectors of red‐ and far‐red‐light movement is not yet characterized. The filaments of S...

The settlement of zygotes in the right place is the most critical step for the survival of young kelp sporophytes in the marine environment. The eggs of Saccharina species were connected to oogonia with two flagella projected from its basal part, and this connection lasted even after fertilisation and first cell division of the zygote. Transmission...

The settlement of zygotes in the right place is the most critical step for the survival of young kelp sporophytes in the marine environment. The egg of Saccharina species was connected to oogonium with two flagella projected from its distal end, and this connection lasted even after the fertilization and first cell division of the zygote. Transmiss...

Filamentous fungi asymptomatically colonize the inner tissues of macroalgae, yet their ecological roles remain largely underexplored. Here, we tested if metabolites produced by fungal endophytes might protect their host against a phylogenetically broad spectrum of protistan pathogens. Accordingly, the cultivable fungal endophytes of four brown alga...

The present study describes the isolation of a pigment mutant strain of Porphyra lucasii, which was obtained using gamma irradiation. Gametophytic blades of this seaweed were irradiated with gamma rays at doses of 500 and 1000 Gy. After irradiation, red color was observed in the blades exposed to the 500 Gy dose. Single somatic cells from these irr...

Alaria is the second largest genus of the Laminariales, which is distributed far into the northern Pacific and Atlantic oceans. Due to its high morphological plasticity, over 100 specific and sub-specific names have been used in Alaria, this has been tailored down to the present 17 species through morphological revision and molecular phylogenetic a...

Lectins, characterized by their carbohydrate-binding ability, have extensive practical applications. However, their industrial use is limited due to impurity. Thus, quality-controlled production of recombinant lectin is necessary. In this study, the algal lectin BPL3 (Bryopsis plumosa lectin 3) was successfully produced using a bacterial expression...

Synechococcus is an important photosynthetic picoplankton in the temperate to tropical oceans. As a photosynthetic bacterium, Synechococcus has an efficient mechanism to adapt to the changes in salinity and light intensity. The analysis of the distributions and functions of such microorganisms in the ever changing river mouth environment, where fre...

List of Synechococcus genomes. (DOCX)

Bacterial composition of 15 microbiomes. (TIF)

In the present study, we enhanced the phenolic content of 70% ethanol extracts of Spirogyra sp. (SPE, 260.47 ± 5.21 gallic acid equivalent [GAE] mg g⁻¹), 2.97 times to 774.24 ± 2.61 GAE mg g⁻¹ in the ethyl acetate fraction of SPE (SPEE). SPEE was evaluated for its antiradical activity in online high-performance liquid chromatography‒ABTS analysis,...

Lectins, characterized by their carbohydrate-binding ability, have an extensive practical application. However, their industrial use is limited by low yields, and few active recombinant lectins have been reported. In this study, the algal lectin BPL-3 (Bryopsis plumosa lectin 3) was successfully produced using a bacterial expression system, BL21(DE...

A new species of Olpidiopsis, which infects dasyaceaen algae in Korea, is established. This endoparasite was first collected from Heterosiphonia pulchra, thus we named it O. heterosiphoniae. The infection process and asexual life history of O. heterosiphoniae were similar to previously reported Olpidiopsis species except for the cell type-specific...

Plants and freshwater algae devoid of flagella evolved various photomovements to optimize their photosynthetic efficiency. The filaments of Spirogyra varians exhibit complex swaying and undulating movement and form a compact mat which enables them to adjust their light exposure. Photomovement of filament fragments (1-10 cells) was analyzed using va...

Freshwater algae living in shallow waters have evolved various photomovement to stay in the optimum light condition for survival. Previous action-spectra investigations showed that Spirogyra filaments have phototropic movement in blue light. To decipher the genetic control of phototropic movement, two phototropin homologues were isolated from Spiro...

Oomycetes are one of the most serious pathogens that threaten global aquaculture industry, and they cause two out of three most common diseases in Pyropia farms. Recent study showed that Olpidiopsis disease occurring in Pyropia farms in Korea and Japan is caused by different endemic Olpidiopsis species, O. porphyrae in Japan, and O. pyropiae in Kor...

Molecular phylogenetic tools are often useful in distinguishing cryptic species with similar morphologies, but they can also be helpful in identifying morphotypes of a species, which displays completely different shapes. We performed molecular-phylogenetic analysis of supra-tidal green algae in the Kamchatka peninsula that belong to the order Prasi...

Mutations in the NEFH gene encoding the heavy neurofilament protein are usually associated with neuronal damage and susceptibility to amyotrophic lateral sclerosis (ALS). Recently, frameshift variants in NEFH (p.Asp1004Glnfs*58 and p.Pro1008Alafs*56) have been reported to be the underlying cause of axonal Charcot-Marie-Tooth disease type 2CC (CMT2C...

Objective: To evaluate the anti-hyperglycemic potential of sinigrin using in vitro, in silico and in vivo streptozotocin (STZ) induced hyperglycemic zebrafish model. Methods: The in vitro enzyme inhibition assay was carried out to determine the IC50value against α-glucosidase and α-amylase, in silico molecular docking was performed against both...

Morphological, molecular and chromosomal studies were carried out on Tauya basicrassa, an endemic kelp species distributed on the northern continental coast of the Sea of Okhotsk in Russia. The sporophytes of T. basicrassa grow up to 3-6 m long, 1.8-2.2 m wide, and 6.5-7 kg wet weight. The thallus has a blade with very thick narrow basal portion an...

Geographic distributions of pathogens are affected by dynamic processes involving host susceptibility, availability and abundance. An oomycete, Pythium porphyrae, is the causative agent of red rot disease, which plagues Pyropia farms in Korea and Japan almost every year and causes serious economic damage. We isolated an oomycete pathogen infecting...

One of the most devastating diseases in Pyropia sea farms in Korea and Japan is red-rot disease caused by Pythium porphyrae. Outbreaks occur yearly causing losses in millions of dollars. Little is known about the source of the inoculum initiating these epidemics. Outbreaks of red-rot disease usually start in sea farms nearest river mouths. We hypot...