• Title/Summary/Keyword: environmental biotechnology

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Transgenic poplar expressing AtNDPK2 exhibits enhanced biomass in the LMO field

  • An, Chul-Han;Kim, Yun-Hee;Park, Sung-Chul;Jeong, Jae-Cheol;Lee, Haeng-Soon;Choi, Yong-Im;Noh, Eun-Woon;Yun, Dae-Jin;Kim, Se-Bin;Kwak, Sang-Soo
    • Journal of Plant Biotechnology
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    • v.38 no.3
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    • pp.228-233
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    • 2011
  • Nucleoside diphosphate kinase 2 (NDPK2) is known to regulate the expression of antioxidant genes and auxin-responsive genes in plants. Previously, it was noted that the overexpression of Arabidopsis NDPK2 (AtNDPK2) under the control of an oxidative stress-inducible SWPA2 promoter in transgenic poplar (Populus alba ${\times}$ P. tremular var. glandulosa) plants (referred to as SN plants) enhanced tolerance to oxidative stress and improved growth (Plant Biotechnol J 9: 34-347, 2011). In this study, growth of transgenic poplar was assessed under living modified organism (LMO) field conditions in terms of biomass in the next year. The growth of transgenic poplar plants increased in comparison with non-transgenic plants. The SN3 and SN4 transgenic lines had 1.6 and 1.2 times higher dry weight in stems than non-transgenic plants at 6 months after planting, respectively. Transgenic poplar also exhibited increased transcript levels of auxin-response genes such as IAA1, IAA2, IAA5 and IAA6. These results suggest that enhanced AtNDPK2 expression increases plant biomass in transgenic poplar through the regulation of auxin-response genes.

Investigation of Filamentous Fungi Producing Safe, Functional Water-Soluble Pigments

  • Heo, Young Mok;Kim, Kyeongwon;Kwon, Sun Lul;Na, Joorim;Lee, Hanbyul;Jang, Seokyoon;Kim, Chul Hwan;Jung, Jinho;Kim, Jae-Jin
    • Mycobiology
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    • v.46 no.3
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    • pp.269-277
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    • 2018
  • The production of water-soluble pigments by fungal strains indigenous to South Korea was investigated to find those that are highly productive in submerged culture. Among 113 candidates, 34 strains that colored the inoculated potato dextrose agar medium were selected. They were cultured in potato dextrose broth and extracted with ethanol. The productivity, functionality (radical-scavenging activities), and color information (CIELAB values) of the pigment extracts were measured. Five species produced intense yellowish pigments, and two produced intense reddish pigments that ranked the highest in terms of absorbance units produced per day. The pigment extracts of Penicillium miczynskii, Sanghuangporus baumii, Trichoderma sp. 1, and Trichoderma afroharzianum exhibited high radical-scavenging activity. However, the S. baumii extract showed moderate toxicity in the acute toxicity test, which limits the industrial application of this pigment. In conclusion, P. miczynskii KUC1721, Trichoderma sp. 1 KUC1716, and T. afroharzianum KUC21213 were the best fungal candidates to be industrial producers of safe, functional water-soluble pigments.

Comparison of Ammonia-Oxidizing Bacterial Community Structure in Membrane-Assisted Bioreactors Using PCR-DGGE and FISH

  • Ziembinska, A.;Ciesielski, S.;Gnida, A.;Zabczynski, S.;Surmacz-Gorska, J.;Miksch, K.
    • Journal of Microbiology and Biotechnology
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    • v.22 no.8
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    • pp.1035-1043
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    • 2012
  • The ammonia-oxidizing bacterial (AOB) communities in three membrane bioreactors (MBRs) were monitored for 2 months after an acclimation period in order to investigate the influence of sludge age and medium type on AOB changeability and its connection with nitrification effectiveness. One MBR with a sludge age of 4 days was fed with a synthetic medium, whereas the other two with sludge ages of 8 and 32 days were fed with landfill leachate. The research revealed that landfill leachate can be effectively treated in an MBR with a higher sludge age for longer periods of time and that this improvement in performance was correlated with an increase in AOB biodiversity. Interestingly, the medium type has a stronger influence on AOB biocenosis formation than the sludge age.

p-Terphenyls from Fungus Paxillus curtisii Chelate Irons: A Proposed Role of p-Terphenyls in Fungus

  • Lee, In-Kyoung;Ki, Dae-Won;Kim, Seong-Eun;Lee, Myeong-Seok;Song, Ja-Gyeong;Yun, Bong-Sik
    • Journal of Microbiology and Biotechnology
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    • v.23 no.5
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    • pp.652-655
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    • 2013
  • Diverse p-terphenyl compounds, named curtisians, have been isolated from the fungus Paxillus curtisii, and degradation of wood by this fungus is thought to be progressed by iron chelation of p-terphenyl curtisians. In this study, the iron chelation ability of p-terphenyls has been proved by chrome azurol S (CAS) assay, reducing power, and UV-visible spectroscopic analyses. The catechol moiety of p-terphenyl is an essential factor for the potent iron chelation ability, and thus deacylated curtisian with a tetrahydroxyl moiety in the central ring of p-terphenyl is more effective than acylated curtisians.

A Lipopeptide Biosurfactant Produced by Bacillus subtilis C9 Selected through the Oil Film-collapsing Assay

  • Kim, Hee-Sik;Lee, Chang-Ho;Suh, Hyun-Hyo;Ahn, Keug-Hyun;Oh, Hee-Mock;Kwon, Gi-Seok;Yang, Ji-Won;Yoon, Byung-Dae
    • Journal of Microbiology and Biotechnology
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    • v.7 no.3
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    • pp.180-188
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    • 1997
  • Bacillus subtilis C9 was selected by measuring the oil film-collapsing activity and produced biosurfactant in a medium containing glucose as a sole carbon source. The biosurfactant emulsified hydrocarbons, vegetable oils and crude oil, and lowered the surface tension of culture broth to 28 dyne/cm. A biosurfactant, C9-BS produced by B. subtilis C9 was purified by ultrafiltration, extraction with chloroform and methanol, adsorption chromatography, and preparative reversed phase HPLC. Structural analyses, IR spectroscopy, FAB mass spectroscopy, amino acid composition, and NMR analyses, demonstrated that C9-BS was a lipopeptide comprising a fatty acid tail and peptide moiety. The lipophilic part consisting of $C_{14}\;or\;C_{15}$ hydroxy fatty acid was linked to the hydrophilic peptide part, which contained seven amino acids (Glu-Leu-Leu-Val-Asp-Leu-Leu) with a lactone linkage.

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