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Se Chang Park - One of the best experts on this subject based on the ideXlab platform.

  • effect of the Algicide thiazolidinedione 49 on immune responses of bay scallop argopecten irradians
    Molecules, 2019
    Co-Authors: Cheng Chi, Sib Sankar Giri, Jeong Woo Kang, Hyoun Joong Kim, Saekil Yun, Sang Wha Kim, Se Chang Park
    Abstract:

    The thiazolidinedione 49 (TD49) is an effective algaecide against harmful algae; however, its potential effects on the immune function of the edible bay scallop are unclear. Therefore, the present work studied the effects of TD49 on the immune response in bay scallop by evaluating activities of acid phosphatase (ACP), alkaline phosphatase (ALP), and superoxide dismutase (SOD), as well as nitric oxide (NO) levels, total protein content, and expression of immune genes (CTL-6, PGRP, PrxV, MT, and Cu/Zn-SOD) at 3–48 h post-exposure (hpe) to TD49. The activities of ACP and ALP significantly increased in TD49-treated groups at 3–24 hpe, whereas NO levels decreased significantly in 0.58 and 0.68 μM of TD49 at 6–24 hpe, after which the level was similar to that in the untreated control. Moreover, SOD activity significantly increased in all three concentration groups at 3–6 hpe, while it decreased at 12 hpe in the 0.68 μM TD49 treatment group. Notably, total protein content increased with TD49 treatment at each time interval. The results revealed that variable effects on the expression of immune-related genes were observed after treatment with TD49. The findings demonstrate that exposure of scallops to TD49 changes immune responses and expression of immune-related genes. We hypothesize that TD49 may disrupt immune system in bay scallop. The current investigation highlights the potential negative effects of using TD49 as an algaecide on marine economic bivalves to control harmful algal blooms in marine environments.

  • detoxification apoptosis and immune transcriptomic responses of the gill tissue of bay scallop following exposure to the Algicide thiazolidinedione 49
    Biomolecules, 2019
    Co-Authors: Cheng Chi, Sib Sankar Giri, Jeong Woo Kang, Jin Woo Jun, Hyoun Joong Kim, Saekil Yun, Sang Wha Kim, Se Chang Park
    Abstract:

    Thiazolidinedione 49 (TD49), a newly synthesized Algicide, shows strong toxicity at low concentrations of 0.1-2.0 μM. However, its potential effects on non-target species at the transcript level were not investigated. Differentially expressed genes (DEGs) in the gills of the bay scallop, Argopecten irradians, were accessed after treatment with 0.68 μM TD49 for up to 48 h. Following exposure, it was observed that 5214 genes were upregulated and 3497 were downregulated. Functional enrichment analysis revealed that the apoptosis pathway was activated. The extrinsic apoptosis pathway was activated and the survival factors related pathway was suppressed. Furthermore, gene expressions related to ATP-binding cassette, nuclear factor erythroid 2-related factor, B cell lymphoma-2 family protein, glutathione reductase, glutathione peroxidase, catalase, NADPH2:quinone reductase, and superoxide dismutase were decreased. Conversely, gene expressions related to FAS-associated death domain protein, glutathione S-transferase, caspase 6, 8, cytochrome P450 1A1, and 2C8 were increased. These results comprehensively demonstrated the toxicity of the novel Algicide TD49, and should draw the attention of researchers to the importance of analyzing the potential impact of chemical compounds as Algicides to control the proliferation of harmful algae, due to the secondary pollution caused by their application.

  • detoxification and immune transcriptomic response of the gill tissue of bay scallop argopecten irradians following exposure to the Algicide palmitoleic acid
    Biomolecules, 2018
    Co-Authors: Sib Sankar Giri, Jeong Woo Kang, Se Chang Park
    Abstract:

    Palmitoleic acid (PA) is an effective Algicide against Alexandrium tamarense. However, the toxicological mechanism of PA exposure is unclear. The transcript abundance and differentially expressed genes (DEGs) in gills of bay scallop were investigated following 80 mg/L PA exposure up to 48 h using the Illumina HiSeq 4000 deep-sequencing platform with the recommended read length of 100 bp. De novo assembly of paired-end reads yielded 62,099 unigenes; 5414 genes were identified as being significantly increased, and 4452 were decreased. Based on gene ontology classification and enrichment analysis, the ‘cellular process’, ‘metabolic process’, ‘response to stimulus’, and ‘catalytic process’ with particularly high functional enrichment were revealed. The DEGs, which are related to detoxification and immune responses, revealed that acid phosphatase, fibrinogen C domain-containing protein, cyclic AMP-responsive element-binding protein, glutathione reductase, ATP-binding cassette, nuclear factor erythroid 2-related factor, NADPH2:quinone reductase, and cytochrome P450 4F22, 4B1, and 2C8-related gene expression decreased. In contrast, some genes related to glutathione S-transferase, C-type lectin, superoxide dismutase, toll-like receptors, and cytochrome P450 2C14, 2U1, 3A24 and 4A2 increased. The results of current research will be a valuable resource for the investigation of gene expression stimulated by PA, and will help understanding of the molecular mechanisms underlying the scallops’ response to PA exposure.

  • immune response of the bay scallop argopecten irradians after exposure to the Algicide palmitoleic acid
    Fish & Shellfish Immunology, 2016
    Co-Authors: Sib Sankar Giri, Se Chang Park
    Abstract:

    Abstract Palmitoleic acid (PA) is an effective Algicide against the toxin-producing dinoflagellate Alexandrium tamarense ; however, its effects on the immune system of the edible bay scallop Argopecten irradians are unclear. Therefore, we investigated the effects of PA on the immune response in A. irradians by assessing total haemocyte counts (THC), alkaline phosphatase activity (ALP), nitrite oxide (NO), glutathione (GSH), and lactate dehydrogenase (LDH) levels, as well as the expression of immune-related genes ( FREP , PGRP , HSP90 , MnSOD , and Cu/ZnSOD ) at various hours post-exposure (hpe) to the compound. THC decreased in PA-treated groups, whereas ALP increased significantly in all of the PA treatment groups at 3 hpe, after which it significantly decreased. The LDH and NO levels were significantly enhanced in the high and medium concentration group. Notably, the GSH level increased in all PA treatment groups at each time interval. Our study revealed that after treatment with different concentrations of PA, variable effects on the expression of genes involved in the immune system response were observed. The results of our study demonstrate that immersing scallops in PA at effective concentrations could result in differential effects on immune system responses and expression of immune-related genes. Specifically, PA may disrupt the endocrine system or affect signal transduction pathways in the scallops. Therefore, the present study highlights the potential risk of using the PA as an Algicide to control algal bloom outbreaks in the marine environment.

Seung Ho Baek - One of the best experts on this subject based on the ideXlab platform.

  • can Algicide the thiazolidinedione derivative td49 truly contribute to the restoration of microbial communities
    Environmental Research, 2019
    Co-Authors: Seung Ho Baek, Bum Soo Park, Moonho Son, Youngok Kim, Hoon Cho, Ik Kyo Chung
    Abstract:

    Harmful algal blooms (HABs) are becoming a more serious ecological threat to marine environments; they not only produce toxins, resulting in the death of marine organisms, but they also adversely affect biodiversity, which is an indicator of the health of an ecosystem. Thus, to mitigate HABs, numerous studies have been conducted to develop an effective Algicide, but few studies have elucidated the effect of Algicides on marine environmental health. In this study, thiazolidinedione derivative 49 (TD49), which has been developed as an Algicide for the dinoflagellate Heterocapsa circularisquama, was used, and we investigated changes in phytoplankton biomass (abundance, chlorophyll a, and carbon biomass) and biodiversity (diversity, evenness, and richness) following the application of TD49. To gain deeper understanding, a large-scale mesocosm (1300 L) experiment containing control and treatment with four different concentrations (0.2, 0.4, 0.6 and 1 μM) was conducted for 10 days. Based on a previous study, TD49 shows algicidal activity against H. circularisquama depending on its concentration. The phytoplankton biomass in the TD49 treatments was generally lower than that in the control due to the algicidal effect of TD49 on H. circularisquama. The biodiversity indices (e.g., the Shannon-Weaver index) in the treatments were consistently higher than those in the control before depletion of nitrite + nitrate. Interestingly, the 0.6 μM TD49 treatment had higher biodiversity indices than the high-concentration treatment (1 μM), which appeared to show a better algicidal effect. These findings suggest that mitigation of H. circularisquama blooms with TD49 treatment may enhance phytoplankton biodiversity, but treatment with excessively high concentrations can lead to harmful effects. During the study period, regardless of the control and TD49 treatments, the total biomass of phytoplankton gradually decreased from the midpoint of the experiment to the end of the experiment. This was more likely caused by the depletion of nutrients than by the toxicity of TD49.

  • response of chattonella marina raphidophyceae and marine plankton to yellow clay and thiazolidinedione derivative td49 in a mesocosm enclosure
    Journal of Applied Phycology, 2017
    Co-Authors: Seung Ho Baek, Moonho Son, Youngok Kim, Hoon Cho, Minji Lee, Si Wouk Kim
    Abstract:

    We examined the effects of the Algicide thiazolidinedione (TD49) and yellow clay on Chattonella marina and assessed their ecological risk for the entire planktonic community. Mesocosm (1000 L) exposure experiments were employed to investigate time-course responses over 9 days. The growth of C. marina was controlled at ≥0.4 μM TD49 but not inhibited in yellow clay treatments. Although the algicidal activity of the 0.4-μM TD49 + 0.4 kg t−1 yellow clay treatment for C. marina was high (72.5 % at 24 h), target alga regrowth occurred. In all treatments, inorganic nutrients such as nitrate + nitrite and phosphate decreased following commencement of the experiment but were >1 μM (limitation concentration) at days 5 and 6, even though consumption pattern of those nutrients was influenced by the TD49 concentration. Depletion of silicate in initial stages played an important role in controlling the shift from diatoms including Chaetoceros and Skeletonema spp. to cryptophytes. Zooplankton were not affected by even the highest the yellow clay treatments and TD concentration of <0.8 μM, but their abundance significantly reduced after day 1 at 0.8 μM TD49. Zooplankton nauplii gradually increased to the end of the experimental period, implying that TD49 may have a limited effect on zooplankton communities. The initial dosing concentration of each substance and the fate of nutrients following Algicide application were critical in determining the timing of shifts in the phytoplankton and zooplankton species composition, as well as the algicidal effect on the target alga.

  • the difference of photosynthetic efficiency and electron transport rate by control of the red tide organism using algicidal substance and yellow clay
    The Korea Academia-Industrial cooperation Society, 2015
    Co-Authors: Moonho Son, Seung Ho Baek
    Abstract:

    The development of worldwide harmful algal blooms(HAB) is a serious problem for public health and fisheries industries. To evaluate the algicidal impact on the HAB species, Algicide thiazolidinedione derivative (TD49) and yellow clay were examined, which is focus on assess the algicidal effects and inhibition to photosynthesis of HAB species. To obtain the detailed information, we analyzed the viability of target species related to activity Chl. a, photosynthetic efficiency(), and electron transport rate(ETR). Culture experiment was conducted to evaluate the algicidal effects of three harmful species(raphidophyceae Heterosigma akashiwo, Chattonella marina, and dinophyceae Heterocapsa circularisquama) and one non-harmful species (cryptophyceae Rhodomonas salina). Our experiments revealed that three HAB species were easily destroyed of the cell walls after TD49 dosing. Also, they had significantly reducing values of active Chl. a, , and ETR, due to the damage of photosystem II by inter-cellular disturbance. As a result, the algicidal effect(%) for the three HABs were as follows, in the order of greatest to the least: H. circularisquama> C. marina> H. akashiwo. However, the algicidal effect for yellow clay remained to be 0.01), implying that it may not have damaged the photosystem II. On the other hand, non-HAB R. salina was promoted at both TD49 and yellow clay treatments. Our results demonstrated that the TD49 is a good agent for the control of HABs H. akashiwo, C. marina, and H. circularisquama, whereas the yellow clay would not be suitable for the field application based on our experimental results.

  • effects of the Algicide thiazolidinedione derivative td49 on microbial communities in a mesocosm experiment
    Environmental Monitoring and Assessment, 2015
    Co-Authors: Seung Ho Baek, Moonho Son, Hoon Cho, Si Wouk Kim, Kyoungsoon Shin, Keunhyung Choi, Jaewon Ryu, Seung Won Jung, Ik Kyo Chung
    Abstract:

    We investigated the effects of the Algicide thiazolidinedione derivative TD49 on microbial community in mesocosm experiments. The TD49 concentration exponentially decreased over time, with half-life of 3.5 h, following addition in the seawater (R 2 = 0.98, P < 0.001). Among microbial communities, heterotrophic bacteria and heterotrophic nanoflagellates (HNFs) grew well in all treatments following the addition of TD49. The abundance of HNFs lagged behind the increase in heterotrophic bacteria by 24 h in the 0.2 and 0.4 μM TD49 concentrations (R 2 = 0.28, P < 0.05), and by 48 h in the 0.6 and 1.0 μM TD49 concentrations (R 2 = 0.30, P < 0.05). This implies a strong concentration-dependent top-down effect of TD49 on microbial communities, with indications that the degradation of planktonic organisms, including the target alga, led to high heterotrophic bacteria concentrations, which in turn stimulated the population growth of predatory HNF. However, total ciliate numbers remained relatively low in the TD49 treatments relative to the control and blank groups, suggesting limited carbon flow from bacteria to these grazers even though the abundance of aloricate ciliates gradually increased toward the end of the experimental period, particularly at the high TD49 concentrations. TD49 appears to provide an environmentally safe approach to the control of harmful algal blooms (HABs) in aquatic ecosystems.

  • algicidal effects on heterosigma akashiwo and chattonella marina raphidophyceae and toxic effects on natural plankton assemblages by a thiazolidinedione derivative td49 in a microcosm
    Journal of Applied Phycology, 2013
    Co-Authors: Seung Ho Baek, Moonho Son, Hoon Cho, Minchul Jang, Si Wouk Kim, Youngok Kim
    Abstract:

    The algicidal effects of the thiazolidinedione derivative TD49 on Heterosigma akashiwo and Chattonella marina (Raphidophyceae) were assessed, and the response of the planktonic community and environment to the Algicide was evaluated in a microcosm, quantifying 12 L. The abundance of over 80 % of H. akashiwo and C. marina declined in a day significantly in microcosms to which TD49 was added (final concentration 2 μM), and this was correlated with an abrupt decline in the culture pH. The number of protists (i.e., ciliates) other than H. akashiwo and C. marina gradually increased with time in the TD49 treatments, implying that the decline in numbers of H. akashiwo and C. marina cells resulting from TD49 treatment was a major factor in the growth of the other organisms. However, TD49 may be toxic to aquatic zooplankton communities, even though it is a highly selective Algicide for harmful algae bloom species. The study indicates that TD49 is an effective agent for the control for H. akashiwo and C. marina blooms in enclosed and eutrophic water bodies.

Moonho Son - One of the best experts on this subject based on the ideXlab platform.

  • can Algicide the thiazolidinedione derivative td49 truly contribute to the restoration of microbial communities
    Environmental Research, 2019
    Co-Authors: Seung Ho Baek, Bum Soo Park, Moonho Son, Youngok Kim, Hoon Cho, Ik Kyo Chung
    Abstract:

    Harmful algal blooms (HABs) are becoming a more serious ecological threat to marine environments; they not only produce toxins, resulting in the death of marine organisms, but they also adversely affect biodiversity, which is an indicator of the health of an ecosystem. Thus, to mitigate HABs, numerous studies have been conducted to develop an effective Algicide, but few studies have elucidated the effect of Algicides on marine environmental health. In this study, thiazolidinedione derivative 49 (TD49), which has been developed as an Algicide for the dinoflagellate Heterocapsa circularisquama, was used, and we investigated changes in phytoplankton biomass (abundance, chlorophyll a, and carbon biomass) and biodiversity (diversity, evenness, and richness) following the application of TD49. To gain deeper understanding, a large-scale mesocosm (1300 L) experiment containing control and treatment with four different concentrations (0.2, 0.4, 0.6 and 1 μM) was conducted for 10 days. Based on a previous study, TD49 shows algicidal activity against H. circularisquama depending on its concentration. The phytoplankton biomass in the TD49 treatments was generally lower than that in the control due to the algicidal effect of TD49 on H. circularisquama. The biodiversity indices (e.g., the Shannon-Weaver index) in the treatments were consistently higher than those in the control before depletion of nitrite + nitrate. Interestingly, the 0.6 μM TD49 treatment had higher biodiversity indices than the high-concentration treatment (1 μM), which appeared to show a better algicidal effect. These findings suggest that mitigation of H. circularisquama blooms with TD49 treatment may enhance phytoplankton biodiversity, but treatment with excessively high concentrations can lead to harmful effects. During the study period, regardless of the control and TD49 treatments, the total biomass of phytoplankton gradually decreased from the midpoint of the experiment to the end of the experiment. This was more likely caused by the depletion of nutrients than by the toxicity of TD49.

  • response of chattonella marina raphidophyceae and marine plankton to yellow clay and thiazolidinedione derivative td49 in a mesocosm enclosure
    Journal of Applied Phycology, 2017
    Co-Authors: Seung Ho Baek, Moonho Son, Youngok Kim, Hoon Cho, Minji Lee, Si Wouk Kim
    Abstract:

    We examined the effects of the Algicide thiazolidinedione (TD49) and yellow clay on Chattonella marina and assessed their ecological risk for the entire planktonic community. Mesocosm (1000 L) exposure experiments were employed to investigate time-course responses over 9 days. The growth of C. marina was controlled at ≥0.4 μM TD49 but not inhibited in yellow clay treatments. Although the algicidal activity of the 0.4-μM TD49 + 0.4 kg t−1 yellow clay treatment for C. marina was high (72.5 % at 24 h), target alga regrowth occurred. In all treatments, inorganic nutrients such as nitrate + nitrite and phosphate decreased following commencement of the experiment but were >1 μM (limitation concentration) at days 5 and 6, even though consumption pattern of those nutrients was influenced by the TD49 concentration. Depletion of silicate in initial stages played an important role in controlling the shift from diatoms including Chaetoceros and Skeletonema spp. to cryptophytes. Zooplankton were not affected by even the highest the yellow clay treatments and TD concentration of <0.8 μM, but their abundance significantly reduced after day 1 at 0.8 μM TD49. Zooplankton nauplii gradually increased to the end of the experimental period, implying that TD49 may have a limited effect on zooplankton communities. The initial dosing concentration of each substance and the fate of nutrients following Algicide application were critical in determining the timing of shifts in the phytoplankton and zooplankton species composition, as well as the algicidal effect on the target alga.

  • the difference of photosynthetic efficiency and electron transport rate by control of the red tide organism using algicidal substance and yellow clay
    The Korea Academia-Industrial cooperation Society, 2015
    Co-Authors: Moonho Son, Seung Ho Baek
    Abstract:

    The development of worldwide harmful algal blooms(HAB) is a serious problem for public health and fisheries industries. To evaluate the algicidal impact on the HAB species, Algicide thiazolidinedione derivative (TD49) and yellow clay were examined, which is focus on assess the algicidal effects and inhibition to photosynthesis of HAB species. To obtain the detailed information, we analyzed the viability of target species related to activity Chl. a, photosynthetic efficiency(), and electron transport rate(ETR). Culture experiment was conducted to evaluate the algicidal effects of three harmful species(raphidophyceae Heterosigma akashiwo, Chattonella marina, and dinophyceae Heterocapsa circularisquama) and one non-harmful species (cryptophyceae Rhodomonas salina). Our experiments revealed that three HAB species were easily destroyed of the cell walls after TD49 dosing. Also, they had significantly reducing values of active Chl. a, , and ETR, due to the damage of photosystem II by inter-cellular disturbance. As a result, the algicidal effect(%) for the three HABs were as follows, in the order of greatest to the least: H. circularisquama> C. marina> H. akashiwo. However, the algicidal effect for yellow clay remained to be 0.01), implying that it may not have damaged the photosystem II. On the other hand, non-HAB R. salina was promoted at both TD49 and yellow clay treatments. Our results demonstrated that the TD49 is a good agent for the control of HABs H. akashiwo, C. marina, and H. circularisquama, whereas the yellow clay would not be suitable for the field application based on our experimental results.

  • effects of the Algicide thiazolidinedione derivative td49 on microbial communities in a mesocosm experiment
    Environmental Monitoring and Assessment, 2015
    Co-Authors: Seung Ho Baek, Moonho Son, Hoon Cho, Si Wouk Kim, Kyoungsoon Shin, Keunhyung Choi, Jaewon Ryu, Seung Won Jung, Ik Kyo Chung
    Abstract:

    We investigated the effects of the Algicide thiazolidinedione derivative TD49 on microbial community in mesocosm experiments. The TD49 concentration exponentially decreased over time, with half-life of 3.5 h, following addition in the seawater (R 2 = 0.98, P < 0.001). Among microbial communities, heterotrophic bacteria and heterotrophic nanoflagellates (HNFs) grew well in all treatments following the addition of TD49. The abundance of HNFs lagged behind the increase in heterotrophic bacteria by 24 h in the 0.2 and 0.4 μM TD49 concentrations (R 2 = 0.28, P < 0.05), and by 48 h in the 0.6 and 1.0 μM TD49 concentrations (R 2 = 0.30, P < 0.05). This implies a strong concentration-dependent top-down effect of TD49 on microbial communities, with indications that the degradation of planktonic organisms, including the target alga, led to high heterotrophic bacteria concentrations, which in turn stimulated the population growth of predatory HNF. However, total ciliate numbers remained relatively low in the TD49 treatments relative to the control and blank groups, suggesting limited carbon flow from bacteria to these grazers even though the abundance of aloricate ciliates gradually increased toward the end of the experimental period, particularly at the high TD49 concentrations. TD49 appears to provide an environmentally safe approach to the control of harmful algal blooms (HABs) in aquatic ecosystems.

  • algicidal effects on heterosigma akashiwo and chattonella marina raphidophyceae and toxic effects on natural plankton assemblages by a thiazolidinedione derivative td49 in a microcosm
    Journal of Applied Phycology, 2013
    Co-Authors: Seung Ho Baek, Moonho Son, Hoon Cho, Minchul Jang, Si Wouk Kim, Youngok Kim
    Abstract:

    The algicidal effects of the thiazolidinedione derivative TD49 on Heterosigma akashiwo and Chattonella marina (Raphidophyceae) were assessed, and the response of the planktonic community and environment to the Algicide was evaluated in a microcosm, quantifying 12 L. The abundance of over 80 % of H. akashiwo and C. marina declined in a day significantly in microcosms to which TD49 was added (final concentration 2 μM), and this was correlated with an abrupt decline in the culture pH. The number of protists (i.e., ciliates) other than H. akashiwo and C. marina gradually increased with time in the TD49 treatments, implying that the decline in numbers of H. akashiwo and C. marina cells resulting from TD49 treatment was a major factor in the growth of the other organisms. However, TD49 may be toxic to aquatic zooplankton communities, even though it is a highly selective Algicide for harmful algae bloom species. The study indicates that TD49 is an effective agent for the control for H. akashiwo and C. marina blooms in enclosed and eutrophic water bodies.

Tianling Zheng - One of the best experts on this subject based on the ideXlab platform.

  • Toxic Effects of Prodigiosin Secreted by Hahella sp. KA22 on Harmful Alga Phaeocystis globosa
    Frontiers in microbiology, 2017
    Co-Authors: Huajun Zhang, Hui Wang, Wei Zheng, Zhiyuan Yao, Yun Peng, Su Zhang, Zhen Tao, Tianling Zheng
    Abstract:

    Application of algicidal compounds secreted by bacteria is a promising and environmentally friendly strategy to control harmful algal blooms (HABs). Years ago prodigiosin was described as an efficient algicidal compound, but the details about the effect of prodigiosin on algal cells are still elusive. Prodigiosin shows high algicidal activity on Phaeocystis globosa, making it a potential Algicide in HAB control. When P. globosa were treated with prodigiosin at 5 μg/mL, algae cells showed cytoplasmic hypervacuolization, chloroplast and nucleus rupture, flagella missing, and cell fracture, when observed by scanning electron microscope and transmission electron microscopy. Prodigiosin induced a reactive oxygen species (ROS) burst in P. globosa at 2 h, which could result in severe oxidative damage to algal cells. Chlorophyll a (Chl a) fluorescence decreased significantly after prodigiosin treatment; about 45.3 and 90.0% of algal cells lost Chl a fluorescence at 24 and 48 h. The Fv/Fm value, reflecting the status of the photosystem II electron flow also decreased after prodigiosin treatment. Quantitative polymerase chain reaction (PCR) analysis psbA and rbcS expression indicated that photosynthesis process was remarkably inhibited by prodigiosin. The results indicated that the inhibition of photosynthesis may produce excessive ROS causing cell necrosis. This study is the first report about algal lysis mechanism of prodigiosin on harmful algae. Our results could increase our knowledge on the interaction between algicidal compounds and harmful algae, which could lead to further studies in the microcosm.

  • discovery of an algicidal compound from brevibacterium sp bs01 and its effect on a harmful algal bloom causing species alexandrium tamarense
    Frontiers in Microbiology, 2015
    Co-Authors: Huajun Zhang, Wei Zheng, Bangzhou Zhang, Lijun Fu, Xinli An, Yi Li, Zhiming Yu, Tianling Zheng
    Abstract:

    Blooms of the dinoflagellate Alexandrium tamarense have become worldwide phenomena and have detrimental impacts on aquatic ecosystems and human health. In this study, a culture supernatant of the marine actinomycete BS01 exerted a strong algicidal effect on A. tamarense (ATGD98-006). The target Algicide from BS01 was separated by adsorption chromatography and identified by MALDI-TOF-MS and NMR analysis. The results suggested that the purified algicidal component corresponded to a hydrophobic compound (2-isobutoxyphenyl)amine (C10H15NO) with a molecular weight of 165 Da, which exhibited a significant algicidal effect (64.5%) on A. tamarense. After incubation in 5 μg/mL of (2-isobutoxyphenyl)amine for 24 h, the algae lost mobility and sank to the bottom of the flasks, and 56.5% of the algae cells lost vitality at a concentration of 20 μg/mL (p < 0.01) despite having intact cell profiles. Morphological analysis revealed that the cell structure of A. tamarense was altered by (2-isobutoxyphenyl)amine resulting in cytoplasm degradation and the loss of organelle integrity. The images following propidium iodide staining suggested that the algal nucleus was also severely damaged and eventually degraded due to exposure to the algicidal compound. All of the results indicate that (2-isobutoxyphenyl)amine from the actinomycete might be a candidate for the control of bloom-forming A. tamarense.

  • the first evidence of deinoxanthin from deinococcus sp y35 with strong algicidal effect on the toxic dinoflagellate alexandrium tamarense
    Journal of Hazardous Materials, 2015
    Co-Authors: Yi Li, Huajun Zhang, Wei Zheng, Yun Tian, Zhangran Chen, Chengwei Guan, Hong Xu, Zhiming Yu, Tianling Zheng
    Abstract:

    Harmful algal blooms (HABs) could be deemed hazardous materials in aquatic environment. Alexandrium tamarense is a toxic HAB causing alga, which causes serious economic losses and health problems. In this study, the bacterium Deinococcus xianganeasis Y35 produced a new Algicide, showing a high algicidal effect on A. tamarense. The algicidal compound was identified as deinoxanthin, a red pigment, based on high resolution mass spectrometry and NMR after the active compound was isolated and purified. Deinoxanthin exhibited an obvious inhibitory effect on algal growth, and showed algicidal activity against A. tamarense with an EC50 of 5.636 mu g/mL with 12 h treatment time. Based on the unique structure and characteristics of deinoxanthin, the content of reactive oxygen species (ROS) increased after 0.5 h exposure, the structure of organelles including chloroplasts and mitochondria were seriously damaged. All these results firstly confirmed that deinoxanthin as the efficient and eco-environmental algicidal compound has potential to be used for controlling harmful algal blooms through overproduction of ROS. (C) 2015 Elsevier B.V. All rights reserved.

  • a novel Algicide evidence of the effect of a fatty acid compound from the marine bacterium vibrio sp bs02 on the harmful dinoflagellate alexandrium tamarense
    PLOS ONE, 2014
    Co-Authors: Dong Li, Huajun Zhang, Wei Zheng, Bangzhou Zhang, Zhangran Chen, Lijun Fu, Xinli An, Yi Li, Lin Yi, Tianling Zheng
    Abstract:

    Alexandrium tamarense is a notorious bloom-forming dinoflagellate, which adversely impacts water quality and human health. In this study we present a new Algicide against A. tamarense, which was isolated from the marine bacterium Vibrio sp. BS02. MALDI-TOF-MS, NMR and algicidal activity analysis reveal that this compound corresponds to palmitoleic acid, which shows algicidal activity against A. tamarense with an EC50 of 40 μg/mL. The effects of palmitoleic acid on the growth of other algal species were also studied. The results indicate that palmitoleic acid has potential for selective control of the Harmful algal blooms (HABs). Over extended periods of contact, transmission electron microscopy shows severe ultrastructural damage to the algae at 40 μg/mL concentrations of palmitoleic acid. All of these results indicate potential for controlling HABs by using the special algicidal bacterium and its active agent.

Si Wouk Kim - One of the best experts on this subject based on the ideXlab platform.

  • response of chattonella marina raphidophyceae and marine plankton to yellow clay and thiazolidinedione derivative td49 in a mesocosm enclosure
    Journal of Applied Phycology, 2017
    Co-Authors: Seung Ho Baek, Moonho Son, Youngok Kim, Hoon Cho, Minji Lee, Si Wouk Kim
    Abstract:

    We examined the effects of the Algicide thiazolidinedione (TD49) and yellow clay on Chattonella marina and assessed their ecological risk for the entire planktonic community. Mesocosm (1000 L) exposure experiments were employed to investigate time-course responses over 9 days. The growth of C. marina was controlled at ≥0.4 μM TD49 but not inhibited in yellow clay treatments. Although the algicidal activity of the 0.4-μM TD49 + 0.4 kg t−1 yellow clay treatment for C. marina was high (72.5 % at 24 h), target alga regrowth occurred. In all treatments, inorganic nutrients such as nitrate + nitrite and phosphate decreased following commencement of the experiment but were >1 μM (limitation concentration) at days 5 and 6, even though consumption pattern of those nutrients was influenced by the TD49 concentration. Depletion of silicate in initial stages played an important role in controlling the shift from diatoms including Chaetoceros and Skeletonema spp. to cryptophytes. Zooplankton were not affected by even the highest the yellow clay treatments and TD concentration of <0.8 μM, but their abundance significantly reduced after day 1 at 0.8 μM TD49. Zooplankton nauplii gradually increased to the end of the experimental period, implying that TD49 may have a limited effect on zooplankton communities. The initial dosing concentration of each substance and the fate of nutrients following Algicide application were critical in determining the timing of shifts in the phytoplankton and zooplankton species composition, as well as the algicidal effect on the target alga.

  • effects of the Algicide thiazolidinedione derivative td49 on microbial communities in a mesocosm experiment
    Environmental Monitoring and Assessment, 2015
    Co-Authors: Seung Ho Baek, Moonho Son, Hoon Cho, Si Wouk Kim, Kyoungsoon Shin, Keunhyung Choi, Jaewon Ryu, Seung Won Jung, Ik Kyo Chung
    Abstract:

    We investigated the effects of the Algicide thiazolidinedione derivative TD49 on microbial community in mesocosm experiments. The TD49 concentration exponentially decreased over time, with half-life of 3.5 h, following addition in the seawater (R 2 = 0.98, P < 0.001). Among microbial communities, heterotrophic bacteria and heterotrophic nanoflagellates (HNFs) grew well in all treatments following the addition of TD49. The abundance of HNFs lagged behind the increase in heterotrophic bacteria by 24 h in the 0.2 and 0.4 μM TD49 concentrations (R 2 = 0.28, P < 0.05), and by 48 h in the 0.6 and 1.0 μM TD49 concentrations (R 2 = 0.30, P < 0.05). This implies a strong concentration-dependent top-down effect of TD49 on microbial communities, with indications that the degradation of planktonic organisms, including the target alga, led to high heterotrophic bacteria concentrations, which in turn stimulated the population growth of predatory HNF. However, total ciliate numbers remained relatively low in the TD49 treatments relative to the control and blank groups, suggesting limited carbon flow from bacteria to these grazers even though the abundance of aloricate ciliates gradually increased toward the end of the experimental period, particularly at the high TD49 concentrations. TD49 appears to provide an environmentally safe approach to the control of harmful algal blooms (HABs) in aquatic ecosystems.

  • algicidal effects on heterosigma akashiwo and chattonella marina raphidophyceae and toxic effects on natural plankton assemblages by a thiazolidinedione derivative td49 in a microcosm
    Journal of Applied Phycology, 2013
    Co-Authors: Seung Ho Baek, Moonho Son, Hoon Cho, Minchul Jang, Si Wouk Kim, Youngok Kim
    Abstract:

    The algicidal effects of the thiazolidinedione derivative TD49 on Heterosigma akashiwo and Chattonella marina (Raphidophyceae) were assessed, and the response of the planktonic community and environment to the Algicide was evaluated in a microcosm, quantifying 12 L. The abundance of over 80 % of H. akashiwo and C. marina declined in a day significantly in microcosms to which TD49 was added (final concentration 2 μM), and this was correlated with an abrupt decline in the culture pH. The number of protists (i.e., ciliates) other than H. akashiwo and C. marina gradually increased with time in the TD49 treatments, implying that the decline in numbers of H. akashiwo and C. marina cells resulting from TD49 treatment was a major factor in the growth of the other organisms. However, TD49 may be toxic to aquatic zooplankton communities, even though it is a highly selective Algicide for harmful algae bloom species. The study indicates that TD49 is an effective agent for the control for H. akashiwo and C. marina blooms in enclosed and eutrophic water bodies.

  • acute toxicity assessment of new Algicide thiazolidinedione derivative td53 to marine ecosystem
    KSBB Journal, 2011
    Co-Authors: Eunchae Yim, Hoon Cho, Si Wouk Kim, Junjae Shin, Intaek Park, Hyokyung Han, Seongjun Kim
    Abstract:

    A thiazolidinedione derivative, TD49 with the highly selective Algicide to red tide was newly synthesized and its acute toxicity was examined in order to evaluate the effect on aquatic ecosystems of coast. Major three species having important role in the food chain of marine ecosystem, such as Skeletonema costatum of microalgae, Daphnia magna of crustacea, Paralichthys olivaceus of flatfish fingerling were employed for the acute toxicity assessment. EC 50 or LC 50 as the assessment criterion was investigated to each specie, and NOEC (No Observed Effect Concentration) and PNEC (Predicted No Effect Concentration) from most sensitive specie to toxicity of TD49 were further calculated. EC 50 of S. costatum in 96-hour, EC 50 of D. magna in 48-hour, and LC 50 of P. olivaceus in 72-hour for TD49 were 0.34 μM, 0.68 μM, and 0.58 μM, respectively. NOEC from the results of S. costatum was estimated to be 0.20 μM and PNEC was estimated as 3.40 nM by applying factor value of 100 to EC50 0.34 μM of S. costatum. In addition, it was revealed that Solutol used as the dispersing agent of TD49 had very little toxic influence under the concentration range of 0~0.4 μM used in TD49 toxicity experiment. Although the estimated concentration of TD49 that will be sprayed onto the coastal field for the Algicide is higher than NOEC value, it is considered that the spraying concentration would not be a considerable problem due to a dilution effect by tide at the opened coast.

  • thiazolidinediones as a novel class of Algicides against red tide harmful algal species
    Applied Biochemistry and Biotechnology, 2010
    Co-Authors: Yeonmi Kim, Si Wouk Kim, Thi Uyen Duong, Gajanan Ghodake, Eonseon Jin, Hoon Cho
    Abstract:

    This paper reports the synthesis of 28 thiazolidinedione derivatives along with their algicidal activity against microalgae causing harmful algal blooming. Among the 28 compounds tested, most showed effective algicidal activity against Heterosigma akashiwo, Chattonella marina, and Cochlodinium polykrikoides, while non-harmful algae were relatively tolerant to these thiazolidinedione derivatives. Compounds 6, 13, and 22 were the most potent against C. polykrikoides with IC50 values <0.5 µM. Among the thiazolidinedione derivatives tested, compounds 7, 13, 27, and 28 were extremely competent and selective to C. polykrikoides with IC50 values ranging from 0.1 to 2 µM, while C. marina and H. akashiwo showed an IC50 value ranging from 30 to 130 µM. These results show that some thiazolidinedione derivatives can act as potent Algicides against harmful algal blooms.