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1.
Sci Total Environ ; 946: 174352, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38969108

RESUMO

Marine plastic debris (MPD) is a potential threat to marine ecosystems, but its function as a vector for the transportation of harmful microalgae and its impact on the habitats of other marine organisms are uncertain. To address this gap in knowledge, we performed month-long experiments in 30 L microcosms that contained plates made of six different plastic polymers (polypropylene [PP], low-density polyethylene [LDPE], high-density polyethylene [HDPE], polyvinyl chloride [PVC], polyethylene terephthalate [PET], and polystyrene [PS]), and examined the time course of changes in planktonic and periphytic microalgae. There were no significant differences in the composition of periphytic microalgae or biomass among the different plastic polymers (p > 0.05). Nutrient depletion decreased the abundance of planktonic microalgae, but increased the biomass of attached periphytic microalgae (p < 0.05). In particular, analysis of the plastic plates showed that the abundance of benthic species that are responsible for harmful algal blooms (HABs), such as Amphidinium operculatum and Coolia monotis, significantly increased over time (days 21-28; p < 0.05). Our findings demonstrated that periphyton species, including benthic microalgae that cause HABs, can easily attach to different types of plastic and potentially spread to different regions and negatively impact these ecosystems. These observations have important implications for understanding the potential role of MPD in the spread of microalgae, including HABs, which pose a significant threat to marine ecosystems.

2.
Sensors (Basel) ; 23(5)2023 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-36904792

RESUMO

Although detecting small objects is critical in various applications, neural network models designed and trained for generic object detection struggle to do so with precision. For example, the popular Single Shot MultiBox Detector (SSD) tends to perform poorly for small objects, and balancing the performance of SSD across different sized objects remains challenging. In this study, we argue that the current IoU-based matching strategy used in SSD reduces the training efficiency for small objects due to improper matches between default boxes and ground truth objects. To address this issue and improve the performance of SSD in detecting small objects, we propose a new matching strategy called aligned matching that considers aspect ratios and center-point distance in addition to IoU. The results of experiments on the TT100K and Pascal VOC datasets show that SSD with aligned matching detected small objects significantly better without sacrificing performance on large objects or requiring extra parameters.

3.
Harmful Algae ; 122: 102371, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36754457

RESUMO

To understand the co-variance between common free-living bacteria and Cochlodinium polykrikoides harmful algal blooms (HABs) and their metabolic functions, we investigated 110 sampling sites in the Southern Sea of South Korea. These sampling sites were divided into three groups based on environmental factors and phytoplankton data with a similarity of 85% using non-metric multidimensional scaling. One group represented high-severity C. polykrikoides blooms, while the other two represented low-severity or no blooms. In high-severity HABs, inorganic phosphorous and dissolved organic carbon concentrations were strongly correlated with C. polykrikoides density (p < 0.01). This may reflect the changes in biochemical cycling due to inorganic and organic substrates released by HAB cells (or by cell destruction). Furthermore, 88 common bacterial operational taxonomic units (OTUs, with mean relative abundance > 1%) were identified. These included Gammaproteobacteria (36 OTUs), Flavobacteriia (24), Alphaproteobacteria (18), and other taxa (11). When C. polykrikoides blooms intensified, the relative abundances of Gammaproteobacteria also increased. OTU #030 (Flavicella sp., Flavobacteria, 96%) was positively correlated with C. polykrikoides abundance (r = 0.77, p < 0.001). Functional analysis based on the dominant bacterial OTUs revealed that chemoheterotrophy-related functions were more common in high-severity sites of HABs than in other groups. Therefore, the occurrence of HABs highlighted their interactions with bacteria and affected the bacterial community structure and metabolic functions.


Assuntos
Dinoflagellida , Proliferação Nociva de Algas , Bactérias , Fitoplâncton , República da Coreia
4.
Adv Healthc Mater ; 11(21): e2201586, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36047642

RESUMO

Patient-specific cancer therapies can evolve by vitalizing the mother tissue-like cancer niche, cellular profile, genetic signature, and drug responsiveness. This evolution has enabled the elucidation of a key mechanism along with development of the mechanism-driven therapy. After surgical treatment, glioblastoma (GBM) patients require prompt therapy within 14 days in a patient-specific manner. Hence, this study approaches direct culture of GBM patient tissue (1 mm diameter) in a microchannel network chip. Cancer vasculature-mimetic perfusion can support the preservation of the mother tissue-like characteristic signatures and microenvironment. When temozolomide and radiation are administered within 1 day, the responsiveness of the tissue in the chip reflected the clinical outcomes, thereby overcoming the time-consuming process of cell and organoid culture. When the tissue chip culture is continued, the intact GBM signature gets lost, and the outward migration of stem cells from the tissue origin increases, indicating a leaving-home effect on the family dismantle. Nanovesicle production using GBM stem cells enables self-chasing of the cells that escape the temozolomide effect owing to quiescence. The anti-PTPRZ1 peptide display and temozolomide loading to nanovesicles awakes cancer stem cells from the quiescent stage to death. This study suggests a GBM clinic-driven avatar platform and mechanism-learned nanotherapy for translation.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Nanomedicina , Humanos , Neoplasias Encefálicas/terapia , Linhagem Celular Tumoral , Glioblastoma/terapia , Células-Tronco Neoplásicas , Temozolomida/farmacologia , Microambiente Tumoral
5.
Bioact Mater ; 18: 433-445, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35415304

RESUMO

All-in-one treatments represent a paradigm shift in future medicine. For example, inflammatory bowel disease (IBD) is mainly diagnosed by endoscopy, which could be applied for not only on-site monitoring but also the intestinal lesion-targeted spray of injectable hydrogels. Furthermore, molecular conjugation to the hydrogels would program both lesion-specific adhesion and drug-free therapy. This study validated this concept of all-in-one treatment by first utilizing a well-known injectable hydrogel that underwent efficient solution-to-gel transition and nanomicelle formation as a translatable component. These properties enabled spraying of the hydrogel onto the intestinal walls during endoscopy. Next, peptide conjugation to the hydrogel guided endoscopic monitoring of IBD progress upon adhesive gelation with subsequent moisturization of inflammatory lesions, specifically by nanomicelles. The peptide was designed to mimic the major component that mediates intestinal interaction with Bacillus subtilis flagellin during IBD initiation. Hence, the peptide-guided efficient adhesion of the hydrogel nanomicelles onto Toll-like receptor 5 (TLR5) as the main target of flagellin binding and Notch-1. The peptide binding potently suppressed inflammatory signaling without drug loading, where TLR5 and Notch-1 operated collaboratively through downstream actions of tumor necrosis factor-alpha. The results were produced using a human colorectal cell line, clinical IBD patient cells, gut-on-a-chip, a mouse IBD model, and pig experiments to validate the translational utility.

6.
Harmful Algae ; 109: 102107, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34815020

RESUMO

To clarify an unspecified toxic Gambierdiscus-like species isolated from seawaters off Jeju Island, Korea, its morphology and molecular phylogeny based on the small subunit (SSU) and partial large subunit (LSU) rRNA gene sequences were examined. Cells were narrow in ventral view and broad in lateral view with a smooth surface. The round thecal pores were evenly distributed, with an average diameter of 0.41 µm. Cell depth, width and height were 51.7 ± 4.5 µm, 43.0 ± 4.2 µm and 55.0 ± 4.7 µm, respectively, and depth-to-width (D/W) and height-to-width (H/W) ratios were 1.1 ± 0.2 µm and 1.3 ± 0.02 µm, respectively. The nucleus was located in the hypotheca. Scanning electron microscope observations revealed that the cells displayed a plate formula of Po, 4', 6'', 6c, 6s, 5''' and 2''', and transmission electron microscope observation demonstrated that the cells contained crystal-like particles. Morphological features indicated that the unspecified Korean isolate belonged to the genus Fukuyoa, and based on the H/W and D/W ratios, the apical pore H/W ratio and thecal pore size, it could be differentiated from other Fukuyoa species. The phylogenetic analyses based on the SSU and LSU rRNA sequences revealed that the Korean isolate was nested within the genus Fukuyoa with high support, and it grouped with F. cf. yasumotoi isolated from Japan. Based on the morpho-molecular data, a new species, Fukuyoa koreansis sp. nov. is proposed. The maximum growth rate (0.254 d-1) of F. koreansis was observed at 25°C and a salinity of 25. The required levels of temperature and salinity for growth distinguished Fukuyoa koreansis from Gambierdiscus species.


Assuntos
Dinoflagellida , Filogenia , Salinidade , Água do Mar , Temperatura
7.
Mar Pollut Bull ; 172: 112895, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34455348

RESUMO

To determine how bacterial communities succeed after the initial attachment of the bacterial biofilm adhesion using 16S rDNA meta-barcoding in plates coated with copper-based anti-fouling (AF) and non-AF (control) coatings as well as ambient seawater, coated plates were submerged in a marine environment in situ. Alteromonas genovensis (Gammaproteobacteria) in AF coating and Pacificibacter sp. (Alphaproteobacteria) in the control plate were initially abundant. In the AF coating, the abundance of A. genovensis decreased rapidly, whereas that of genus Phaeobacter (Alphaproteobacteria), Serratia (Gammaproteobacteria) and Cupriavidus (Betaproteobacteria) increased. Bacterial community in the control plate had a strong connection to pathogenic Vibrio spp. associated with the growth of invertebrates. Therefore, in the in situ AF coating experiment, A. genovensis accumulation was initially and intensively increased, and the bacteria responded to chemical antagonism, induced the proliferation of specific biofilm bacteria and influenced the interactions and recruitment of additional bacterial communities.


Assuntos
Incrustação Biológica , Alteromonas , Bactérias , Biofilmes , Incrustação Biológica/prevenção & controle , Pintura
8.
Front Pharmacol ; 12: 683575, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34054558

RESUMO

Prostate cancer is the second most commonly diagnosed cancer, and prostate cancer is the second most common cause of cancer death in United States men after lung cancer. Many therapies are used to treat prostate cancer, and chemotherapy is one of the most relevant treatments. However, chemotherapy has many side effects, and repeated administration of chemotherapeutic agents leads to acquired resistance. Thus, new drugs with few side effects are needed. We investigated the molecular mechanism of action of JI017 in human prostate cancer cells. We identified an endoplasmic reticulum (ER) stress pathway that depended on the reactive oxygen species (ROS) pathway and played a crucial role in JI017-induced apoptosis. We measured cell viability by the MTS assay to determine the effect of JI017. Analysis of apoptosis, mitochondrial dysfunction, and cell cycle features was performed by flow cytometry. We used western blot and RT-PCR to measure the levels of the proteins of the unfolded protein response (UPR) pathway and apoptosis markers. Immunoprecipitation assay and transfection were used to determine the expression levels of proteins interacting with the pathways influenced by JI017 in prostate cancer cells. The anticancer effects induced by JI017 were evaluated. JI017 induced cell death that regulated apoptotic molecules and caused cell cycle arrest that inhibited the proliferation of cancer cells. Moreover, JI017 generated ROS. Accumulation of ROS caused ER stress through the PERK-eIF2α-CHOP and IRE1α-CHOP pathways. Furthermore, persistent activation of the UPR pathway induced by JI017 treatment triggered mitochondrial dysfunction, including dissipation of mitochondrial membrane potential, which activated intrinsic apoptotic pathway in human prostate cancer cells. The data indicated that N-acetyl-L-cysteine diminished apoptosis. We demonstrated that JI017 induced ER stress and cell death. Anticancer properties of JI017 in prostate cancer cells and in a human prostate cancer model involved ROS-mediated ER stress. Thus, JI017 treatment provides a new strategy for chemotherapy of prostate cancer.

9.
Sci Rep ; 11(1): 6983, 2021 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-33772091

RESUMO

We investigated the dynamics of the bacterial composition and metabolic function within Akashiwo sanguinea bloom using a 100-L indoor microcosm and metagenomic next-generation sequencing. We found that the bacterial community was classified into three groups at 54% similarity. Group I was associated with "during the A. sanguinea bloom stage" and mainly consisted of Alphaproteobacteria, Flavobacteriia and Gammaproteobacteria. Meanwhile, groups II and III were associated with the "late bloom/decline stage to post-bloom stage" with decreased Flavobacteriia and Gammaproteobacteria in these stages. Upon the termination of the A. sanguinea bloom, the concentrations of inorganic nutrients (particularly PO43-, NH4+ and dissolved organic carbon) increased rapidly and then decreased. From the network analysis, we found that the A. sanguinea node is associated with certain bacteria. After the bloom, the specific increases in NH4+ and PO43- nodes are associated with other bacterial taxa. The changes in the functional groups of the bacterial community from chemoheterotrophy to nitrogen association metabolisms were consistent with the environmental impacts during and after A. sanguinea bloom. Consequently, certain bacterial communities and the environments dynamically changed during and after harmful algal blooms and a rapid turnover within the bacterial community and their function can respond to ecological interactions.


Assuntos
Alphaproteobacteria/isolamento & purificação , Dinoflagellida/crescimento & desenvolvimento , Flavobacteriaceae/isolamento & purificação , Gammaproteobacteria/isolamento & purificação , Proliferação Nociva de Algas , Metagenoma , Água do Mar/microbiologia , Alphaproteobacteria/genética , Alphaproteobacteria/crescimento & desenvolvimento , Carbono/análise , Dinoflagellida/microbiologia , Flavobacteriaceae/genética , Flavobacteriaceae/crescimento & desenvolvimento , Gammaproteobacteria/genética , Gammaproteobacteria/crescimento & desenvolvimento , Sequenciamento de Nucleotídeos em Larga Escala , Nitrogênio/análise , Fósforo/análise
10.
Mar Pollut Bull ; 163: 111937, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33341583

RESUMO

To understand how the marine copepod Tigriopus japonicus responds to the toxic marine dinoflagellate Gymnodinium catenatum, we assessed acute toxicity and investigated swimming behavior parameters (e.g., swimming speed, swimming path trajectory, and swimming distance) in response to G. catenatum exposure. In addition, the mRNA expression levels of detoxification-related genes (e.g., phase I cytochrome P450 [CYP] and phase II glutathione-S transferase [GST]) were measured in G. catenatum-exposed copepods. No significant change in survival was observed in response to G. catenatum, but swimming speed was significantly decreased (P < 0.05) at a high concentration of G. catenatum (600 cells/mL). Furthermore, the swimming distance was significantly decreased (P < 0.05) compared to that of the control at 600 cells/mL G. catenatum, while no significant change in swimming path trajectory was observed, suggesting that G. catenatum potentially has adverse effects on the swimming behavior of T. japonicus. In addition, the transcriptional regulation of T. japonicus CYPs and -GSTs were significantly upregulated and downregulated (P < 0.05), respectively, in response to G. catenatum. In particular, certain genes (e.g., CYPs [CYP307E1, CYP3041A1, and CYP3024A2] and GSTs [GST-kappa, GST-mu5, and GST-omega]) were significantly induced (P < 0.05) by G. catenatum, suggesting that these genes likely play a critical role in detoxification mechanisms and might be useful as potential molecular biomarkers in response to G. catenatum exposure. Overall, these results elucidate the potential impacts of the dinoflagellate G. catenatum on the swimming behavior and detoxification system of the marine copepod T. japonicus.


Assuntos
Copépodes , Dinoflagellida , Intoxicação por Frutos do Mar , Animais , Copépodes/metabolismo , Dinoflagellida/metabolismo , Inativação Metabólica , Saxitoxina
11.
Mol Ecol ; 30(1): 207-221, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33113287

RESUMO

Characterizing ecological relationships between viruses, bacteria and phytoplankton in the ocean is critical to understanding the ecosystem; however, these relationships are infrequently investigated together. To understand the dynamics of microbial communities and environmental factors in harmful algal blooms (HABs), we examined the environmental factors and microbial communities during Akashiwo sanguinea HABs in the Jangmok coastal waters of South Korea by metagenomics. Specific bacterial species showed complex synergistic and antagonistic relationships with the A. sanguinea bloom. The endoparasitic dinoflagellate Amoebophrya sp. 1 controlled the bloom dynamics and correlated with HAB decline. Among nucleocytoplasmic large DNA viruses (NCLDVs), two Pandoraviruses and six Phycodnaviruses were strongly and positively correlated with the HABs. Operational taxonomic units of microbial communities and environmental factors associated with A. sanguinea were visualized by network analysis: A. sanguinea-Amoebophrya sp. 1 (r = .59, time lag: 2 days) and A. sanguinea-Ectocarpus siliculosus virus 1 in Phycodnaviridae (0.50, 4 days) relationships showed close associations. The relationship between A. sanguinea and dissolved inorganic phosphorus relationship also showed a very close correlation (0.74, 0 day). Microbial communities and the environment changed dynamically during the A. sanguinea bloom, and the rapid turnover of microorganisms responded to ecological interactions. A. sanguinea bloom dramatically changes the environments by exuding dissolved carbohydrates via autotrophic processes, followed by changes in microbial communities involving host-specific viruses, bacteria and parasitoids. Thus, the microbial communities in HAB are composed of various organisms that interact in a complex manner.


Assuntos
Dinoflagellida , Microbiota , Dinoflagellida/genética , Proliferação Nociva de Algas , Microbiota/genética , Fitoplâncton/genética , República da Coreia
12.
Sci Rep ; 8(1): 7011, 2018 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-29725114

RESUMO

The total dinoflagellate cyst community and the cysts of Cochlodinium polykrikoides in the surface sediments of South Sea (Tongyeong coast), South Korea, were analysed using next-generation sequencing (NGS) and morphological approaches. Dinoflagellate cysts can be highly abundant (111-4,087 cysts g-1 dry weight) and have diverse species composition. A total of 35 taxa of dinoflagellate cysts representing 16 genera, 21 species (including four unconfirmed species), and 14 complex species were identified by NGS analysis. Cysts of Scrippsiella spp (mostly Scrippsiella trochoidea) were the most dominant and Polykrikos schwartzii, Pentapharsodinium dalei, Ensiculifera carinata, and Alexandrium catenella/tamarense were common. Thus, a combination of NGS and morphological analysis is effective for studying the cyst communities present in a given environment. Although C. polykrikoides developed massive blooms during 2013-2014, microscopy revealed low density of their cysts, whereas no cysts were detected by NGS. However, the vegetative C. polykrikoides not appeared during 2015-2017 in spite of the observation of C. polykrikoides cysts. This suggests that the C. polykrikoides blooms were not due to development of their cysts but to other factors such as currents transporting them to a marine environment suitable for their growth.


Assuntos
Biodiversidade , Dinoflagellida/classificação , Dinoflagellida/isolamento & purificação , Sedimentos Geológicos/parasitologia , Animais , Dinoflagellida/citologia , Dinoflagellida/genética , Sequenciamento de Nucleotídeos em Larga Escala , República da Coreia
13.
Ann Rehabil Med ; 41(4): 582-588, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28971042

RESUMO

OBJECTIVE: To compare the effectiveness of extracorporeal shock wave therapy (ESWT) and trigger point injection (TPI) for the treatment of myofascial pain syndrome in the quadratus lumborum. METHODS: In a retrospective study at our institute, 30 patients with myofascial pain syndrome in the quadratus lumborum were assigned to ESWT or TPI groups. We assessed ESWT and TPI treatment according to their affects on pain relief and disability improvement. The outcome measures for the pain assessment were a visual analogue scale score and pain pressure threshold. The outcome measures for the disability assessment were Oswestry Disability Index, Roles and Maudsley, and Quebec Back Pain Disability Scale scores. RESULTS: Both groups demonstrated statistically significant improvements in pain and disability measures after treatment. However, in comparing the treatments, we found ESWT to be more effective than TPI for pain relief. There were no statistically significant differences between the groups with respect to disability. CONCLUSION: Compared to TPI, ESWT showed superior results for pain relief. Thus, we consider ESWT as an effective treatment for myofascial pain syndrome in the quadratus lumborum.

14.
PLoS One ; 12(9): e0181980, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28873451

RESUMO

The marine diatoms Thalassiosira proschkinae and T. spinulata are relatively small in size; their taxonomic identities have been debated owing to the diverse morphological variations. In the present study, we isolated both morphotypes from Korean coastal waters and examined their fine structures and conducted molecular sequence comparisons. The morphological and molecular analyses showed that T. proschkinae and T. spinulata were certainly distinct, and phenotypic plasticity of valve structure was not noted. Based on the morphological similarity and phylogenetic relationship, we transferred T. proschkinae and T. spinulata to another genus Minidiscus within Thalassiosirales that includes small-sized species and proposed new combination names, Minidiscus proschkinae (Makarova) Park & Lee comb. nov. and Minidiscus spinulatus (Takano) Park & Lee comb. nov., respectively. The genus description of Minidiscus was emended.


Assuntos
Diatomáceas/classificação , Diatomáceas/genética , Diatomáceas/citologia , Geografia , Funções Verossimilhança , Filogenia , Filogeografia , República da Coreia , Homologia de Sequência do Ácido Nucleico , Especificidade da Espécie , Transformação Genética
15.
Ann Rehabil Med ; 41(3): 483-487, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28758087

RESUMO

This case report describes a severe nerve injury to the right ulnar nerve, caused by bee venom acupuncture. A 52-year-old right-handed man received bee venom acupuncture on the medial side of his right elbow and forearm, at a Traditional Korean Medicine (TKM) clinic. Immediately after acupuncture, the patient experienced pain and swelling on the right elbow. There was further development of weakness of the right little finger, and sensory changes on the ulnar dermatome of the right hand. The patient visited our clinic 7 days after acupuncture. Electrodiagnostic studies 2 weeks after the acupuncture showed ulnar nerve damage. The patient underwent steroid pulse and rehabilitation treatments. However, his condition did not improve completely, even 4 months after acupuncture.

16.
Ann Rehabil Med ; 38(6): 791-8, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25566478

RESUMO

OBJECTIVE: We used lumbar magnetic resonance image (MRI) findings to determine possible outcome predictors of a caudal epidural steroid injection (CESI) for radicular pain caused by a herniated lumbar disc (HLD). METHODS: Ninety-one patients with radicular pain whose MRI indicated a HLD were enrolled between September 2010 and July 2013. The CESIs were performed using ultrasound (US). A responder was defined as having complete relief or at least a 50% reduction of pain as assessed by the visual analog scale (VAS) and functional status on the Roland Morris Disability Questionnaire (RMDQ); responder (VAS n=61, RMDQ n=51), and non-responder (VAS n=30, RMDQ n=40). MRI findings were analyzed and compared between the two groups with regard to HLD level, HLD type (protrusion or exclusion), HLD zone (central, subarticular, foraminal, and extraforaminal), HLD volume (mild, moderate, or severe), relationship between HLD and nerve root (no contact, contact, displaced, or compressed), disc height loss (none, less than half, or more than half ), and disc degeneration grade (homogeneous disc structure or inhomogeneous disc structure-clear nucleus and height of intervertebral disc). RESULTS: A centrally located herniated disc was more common in the responder group than that in the non-responder group. Treatment of centrally located herniated discs showed satisfactory results. (VAS p=0.025, RMDQ p=0.040). Other factors, such as HLD level, HLD type, HLD volume, relationship to nerve root, disc height loss, and disc degeneration grade, were not critical. CONCLUSION: The HLD zone was significant for pain reduction after CESI. A centrally located herniated disc was a predictor of a good clinical outcome.

17.
J Microbiol ; 48(5): 594-600, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21046336

RESUMO

To assess the effects of crude oil spills on marine microbial communities, 10 L outdoor microcosms were manipulated over an exposure period of 8 days. The responses of microbial organisms exposed to five crude oil concentrations in 10 to 10,000 ppm (v/v) were monitored in the microcosms. The abundance of microalgae and copepods decreased rapidly upon the addition of crude oil at concentrations over 1,000 ppm, whereas the total density of heterotrophic bacteria increased dramatically at the higher concentrations. Bacterial diversity, determined by denaturing gradient gel electrophoresis, was increased at higher concentrations. In particular, the intensity of the bands representing Jannaschia sp. and Sulfitobacter brevis increased with the addition of oil. These results indicate that crude oil spills with concentrations over 1,000 ppm seriously affected the structure of the microbial communities.


Assuntos
Biodiversidade , Metagenoma , Petróleo/metabolismo , Água do Mar/microbiologia , Água do Mar/parasitologia , Poluentes Químicos da Água/metabolismo , Animais , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Copépodes/efeitos dos fármacos , Copépodes/crescimento & desenvolvimento , Impressões Digitais de DNA , Eletroforese em Gel de Poliacrilamida , Microalgas/efeitos dos fármacos , Microalgas/crescimento & desenvolvimento , Dados de Sequência Molecular , Desnaturação de Ácido Nucleico , Análise de Sequência de DNA
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