https://repository.kopri.re.kr/handle/201206/11557 2026-04-06T01:00:50Z 2026-04-06T01:00:50Z Kim, Jun-Tae Choi, Yun-Jeong Barghi, Mandana Kim, Jeong-Hoon Jung, Jin-Woo Kim, Kitae Kang, Jung-Ho Lammel, Gerhard Chang, Yoon-Seok https://repository.kopri.re.kr/handle/201206/13002 2022-03-24T07:15:12Z 2021-03-05T00:00:00Z

Title: Occurrence, distribution, and bioaccumulation of new and legacy persistent organic pollutants in an ecosystem on King George Island, maritime Antarctica Authors: Kim, Jun-Tae; Choi, Yun-Jeong; Barghi, Mandana; Kim, Jeong-Hoon; Jung, Jin-Woo; Kim, Kitae; Kang, Jung-Ho; Lammel, Gerhard; Chang, Yoon-Seok Abstract: The occurrence and bioaccumulation of new and legacy persistent organic pollutants (POPs), organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), hexabromocyclododecanes (HBCDs), and Dechlorane Plus (DPs) and their related compounds (Dechloranes) in an ecosystem on King George Island, Antarctica are investigated. The new and legacy POPs were widely detected in the animal samples collected from Antarctica, which included Limpet, Antarctic cod, Amphipods, Antarctic icefish, Gentoo and Chinstrap penguins, Kelp gull, and South polar skua. The trophic magnification factors indicated that the levels of PCNs and HBCDs, as well as the legacy POPs, were magnified through the food web, whereas DPs might be diluted through the trophic levels contradicting the classification of Dechloranes as POPs. This is one of the first extensive surveys on PCNs, HBCDs, and Dechloranes, which provides unique information on the distribution and trophic biomagnification potential of the new and legacy POPs in the Antarctic region.

2021-03-05T00:00:00Z Noh, Hyun-Ju Park, Yerin Hong, Soon Gyu Lee, Yung Mi https://repository.kopri.re.kr/handle/201206/13579 2022-07-07T02:29:56Z 2021-03-01T00:00:00Z

Title: Diversity and Physiological Characteristics of Antarctic Lichens-Associated Bacteria Authors: Noh, Hyun-Ju; Park, Yerin; Hong, Soon Gyu; Lee, Yung Mi Abstract: The diversity of lichen-associated bacteria from lichen taxa Cetraria, Cladonia, Megaspora, Pseudephebe, Psoroma, and Sphaerophorus was investigated by sequencing of 16S rRNA gene amplicons. Physiological characteristics of the cultured bacterial isolates were investigated to understand possible roles in the lichen ecosystem. Proteobacteria (with a relative abundance of 69.7-96.7%) were mostly represented by the order Rhodospirillales. The 117 retrieved isolates were grouped into 35 phylotypes of the phyla Actinobacteria (27), Bacteroidetes (6), Deinococcus-Thermus (1), and Proteobacteria (Alphaproteobacteria (53), Betaproteobacteria (18), and Gammaproteobacteria (12)). Hydrolysis of macromolecules such as skim milk, polymer, and (hypo)xanthine, solubilization of inorganic phosphate, production of phytohormone indole-3-acetic acid, and fixation of atmospheric nitrogen were observed in different taxa. The potential phototrophy of the strains of the genus Polymorphobacter which were cultivated from a lichen for the first time was revealed by the presence of genes involved in photosynthesis. Altogether, the physiological characteristics of diverse bacterial taxa from Antarctic lichens are considered to imply significant roles of lichen-associated bacteria to allow lichens to be tolerant or competitive in the harsh Antarctic environment.

2021-03-01T00:00:00Z Byun, Mi Young Kim, Dockyu Youn, Ui Joung Lee, Seulah Lee, Hyoungseok https://repository.kopri.re.kr/handle/201206/11792 2022-03-24T07:14:07Z 2021-02-01T00:00:00Z

Title: Improvement of moss photosynthesis by humic acids from Antarctic tundra soil Authors: Byun, Mi Young; Kim, Dockyu; Youn, Ui Joung; Lee, Seulah; Lee, Hyoungseok Abstract: There have been several published reports regarding the growth promoting effect of humic acids (HA) on vascular plants; however, the effect of HA on bryophytes is still unknown. Due to the ecological importance of mosses, which dominate the Antarctic flora, we assessed the effectiveness of HA as a biostimulant using three moss species: Antarctic Ceratodon purpureus KMA5038, Arctic Bryum sp. KMR5045, and Physcomitrella patens which inhabits temperate regions. Natural HA (KS1-3_HA) were extracted through acidic precipitaion of alkaline extracts from Antarctic tundra soil. Spectroscopic structural properties of KS1-3_HA were characterized and determined to possess several functional groups such as hydroxyl (R-OH) and carboxyl (R-COOH), implying they could have a growth-related biological function. For two polar mosses, increasing HA concentrations correlated with increased growth and photosynthesis. The efficiency for temperate moss increased at lower concentrations tested, but rather began to reduce at the highest HA concentration, indicating that effective concentrations of HA vary depending on the moss species and habitat. Based on these results, Antarctic HA may have ecological role in enhancing the growth and photosynthesis of Antarctic mosses. We believe this is the first study to establish a positive physiological effect of HA on mosses and hope it may serve as a basis for studying the role of HA in preserving the terrestrial ecosystem of Antarctica.

2021-02-01T00:00:00Z Park, Ha Ju Lee, Yung Mi Do, Hackwon Lee, Jun Hyuck Kim, Eungbin Lee, Hyoungseok Kim, Dockyu https://repository.kopri.re.kr/handle/201206/13583 2022-07-07T04:46:59Z 2021-01-01T00:00:00Z

Title: Involvement of laccase-like enzymes in humic substance degradation by diverse polar soil bacteria Authors: Park, Ha Ju; Lee, Yung Mi; Do, Hackwon; Lee, Jun Hyuck; Kim, Eungbin; Lee, Hyoungseok; Kim, Dockyu Abstract: Humic substances (HS) in soil are widely distributed in cold environments and account for a significant fraction of soil's organic carbon. Bacterial strains (n = 281) were isolated at 15 degrees C using medium containing humic acids (HA), a principal component of HS, from a variety of polar soil samples: 217 from the Antarctic and 64 from the Arctic. We identified 73 potential HA-degrading bacteria based on 16S rRNA sequence similarity, and these sequences were affiliated with phyla Proteobacteria (73.9%), Actinobacteria (20.5%), and Bacteroidetes (5.5%). HA-degrading strains were further classified into the genera Pseudomonas (51 strains), Rhodococcus (10 strains), or others (12 strains). Most strains degraded HA between 10 and 25 degrees C, but not above 30 degrees C, indicating cold-adapted degradation. Thirty unique laccase-like multicopper oxidase (LMCO) gene fragments were PCR-amplified from 71% of the 73 HA-degrading bacterial strains, all of which included conserved copper-binding regions (CBR) I and II, both essential for laccase activity. Bacterial LMCO sequences differed from known fungal laccases; for example, a cysteine residue between CBR I and CBR II in fungal laccases was not detected in bacterial LMCOs. This suggests a bacterial biomarker role for LMCO to predict changes in HS-degradation rates in tundra regions as global climate changes. Computer-aided molecular modeling showed these LMCOs contain a highly-conserved copper-dependent active site formed by three histidine residues between CBR I and CBR II. Phylogenetic- and modeling-based methods confirmed the wide occurrence of LMCO genes in HA-degrading polar soil bacteria and linked their putative gene functions with initial HS-degradation processes.

2021-01-01T00:00:00Z