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        검색결과 3

        1.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Earthworms, especially Eisenia andrei, are cultivated for a variety of purposes including waste disposal and compost production. In this study, bacteria from earthworm gut were cultured and the dominant species identified. Subsequently, we isolated bacteriophages able to lyse the isolated gut bacteria. Two dominant genera of gut bacteria, Aeromonas sp. and Citrobacter sp. were identified by using MALDI-TOF MS analysis and a library was constructed to find lytic phages. Phage EF1 showed lytic activity for C. freundii and two Citrobacter isolates, C. braakii and C. murliniae. These 3 species have similar sensitivities to EF1. Several aspects of the life cycle of EF1 were investigated by using C. freundii under optimal growth conditions. EF1 infects C. freundii with a moderate latent period, approximately 25 min, and a large burst size averaging 5 × 109 per infected cell. Moreover, the antimicrobial activity of EF1 was well maintained under diverse conditions including a broad temperature range of 40°C to 50°C and a wide pH range of 4 to 11. In conclusion, the results indicate that earthworm casting contain a wide range of bacteria species, for which there are various corresponding bacteriophages.
        4,000원
        2.
        2013.04 구독 인증기관·개인회원 무료
        Previously, several levels of phylogenetic relationships in an insect order Odonata have been estimated using morphological and molecular markers. For the molecular phylogeny rRNA sequences were mainly, but other markers were not frequently employed. In this study, we sequenced both two mitochondrial genes (COI and 16S rRNA) and nuclear genes (28S rRNA and elongation factor-1α), composed of ~4,002 bp from 71 species of Odonata, occurring mostly in South Korea. These concatenated sequences were utilized to test the previous phylogenetic hypotheses of Odonata via Bayesian Inference (BI) and Maximum Likelihood (ML) algorithms, along with the data partition option available in BI method. Each families and superfamilies represented by multiple taxa consistently supported monophylies with the highest nodal supports in both Anisoptera and Zygoptera. A close relationship of Anisozygoptera to Anisoptera represented by a single species was obvious. On the other hand, familial relationships within each suborder of Anisoptera and Zygoptera have shown two compelling topologies. The topology obtained by BI method with partitioning of the four genes showed an unresolved relationship among Gomphidae, Aeshnidae, and the suborder Anisozygoptera in Anisoptera clade, presenting the relationships ((((Libellulidae + Corduliidae) + Macromiidae) + (Gomphidae + Aeshnidae + Anisozygoptera)) + (((Coenagrionidae + Platycnemdidae) + Calopterygidae) + Lestidae)). Another topology obtained by both BI and ML methods without partitioning, on the other hand, placed Anisozygoptera the basal lineage of Anisoptera, but Lestidae in Zygoptera was placed as the sister to Anisoptera + Anisozygoptera, presenting the relationships (((((((Libellulidae + Corduliidae) + Macromiidae) + Aeshnidae) + Gomphidae) + Anisozygoptera) + Lestidae) + ((Coenagrionidae + Platycnemdidae) + Calopterygidae)). Topological test to find out better supported tree turned out a slight higher support for the former topology, but the monophyly of Zygoptera with the inclusion of Lestidae was supported only poorly (BPP = 0.68) in the former topology.
        3.
        2011.05 구독 인증기관·개인회원 무료
        The phylogenetic relationships among the Nymphalidae (Lepidoptera: Papilionoidea) have been controversial. The present study sequenced approximately 1,099 bp from cytochrome oxidase subunit I (COI), 1,336 ~ 1,551 bp from 16S ribosomal RNA (16S rRNA), and 1,066 bp from elongation factor-1 alpha (EF-1α) in 80 species belonging to seven subfamilies (Linmenitidinae, Heliconiinae, Nymphalinae, Apaturinae, Libytheinae, Satyrinae, and Danainae) of Nymphalidae, along with those of six lycaenid species as outgroups. The average base compositions for the three genes (COI, 16S rRNA, and EF-1α) are as follows: A (30.6%, 38.8%, and 25.8%), G (14.7, 5.2%, and 23.6%), T (39.8%, 45.2%, and 23.4%), and C (14.9%, 10.8%, and 27.3%). This result shows the A/T bias in the mitochondrial genes, but not for the nuclear EF-1α. Between the two mitochondrial genes, the 16S rRNA gene evidenced a significantly higher A/T content than was detected in the COI gene. These sequences were subjected to phylogenetic reconstruction via Bayesian Inference (BI) and Maximum Likelihood (ML) algorithms. Both analyses concordantly supported the subfamilial relationships of (((((Linmenitidinae + Heliconiinae) + (Nymphalinae + Apaturinae)) + Libytheinae) + Satyrinae) + Danainae), along with highly supported monophyletics of tribes within subfamilies. This result is largely consistent with a previous study performed with a large sequence information and morphological characters, except for the position of Libytheinae, which was suggested to be the basal lineage of Nymphalidae.