• 한국미생물·생명공학회지
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• 제50권3호
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• pp.375-386
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• 2022

In the present study, four distinctly colored bacterial isolates that show intense pigmentation upon brief ultraviolet (UV) light exposure are chosen. The strains are identified as Micrococcus luteus (Milky yellow), Cryseobacterium pallidum (Yellow), Cryseobacterium spp. (Golden yellow), and Kocuria turfanensis (Pink) based on their morphological and 16S rDNA analysis. Moderate salinity (1.25%), 25-37℃ temperature, and pH of 7.2 are found to be the most favorable conditions of growth and pigment production for all the selected isolates. The pigments are extracted using methanol: chloroform (1:1) and the purity of the pigments are confirmed by high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC). Further, Fourier transform infrared (FTIR) and UV-Visible spectroscopy indicate their resemblance with carotenoids and flexirubin family. The antioxidant activities of the pigments are estimated, and, all the pigments have shown significant antioxidant efficacy in 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picryl-hydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) assays. The UV protective property of the pigments is determined by cling-film assay, wherein, at least 25% of UV sensitive Escherichia coli survive with bio-pigments even after 90 seconds of UV exposure compared to control. The pigments also hold a good sun protective factor (SPF) value (1.5-4.9) which is calculated with the Mansur equation. Based on these results, it can be predicted that these bacterial pigments can be further developed into a promising antioxidant and UV-protectant for several biomedical applications.

• Journal of Microbiology and Biotechnology
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• 제28권9호
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• pp.1536-1541
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• 2018

A yellowish, flexirubin-pigment-producing strain $I3-3^T$ was isolated from river water in Iksan, the Republic of Korea. The strain was gram-negative, aerobic, non-motile, showed catalase and oxidase activities, and could grow at a temperature range of $10-35^{\circ}C$, pH 5.0-10 and 0-2.0% (w/v) of NaCl. The major fatty acids were iso-$C_{15:0}$, iso-$C_{17:0}$ 3-OH and summed feature 3 (comprising $C_{16:1}{\omega}7c$ and/or $C_{16:1}{\omega}6c$). The isolate contained phosphatidylethanolamine, one aminolipid, and two unidentified lipids as the major polar lipids. Menaquinone-6 (MK6) was the major respiratory quinone. The G+C content of the genomic DNA of strain $I3-3^T$ was 35.6%. Comparison of the 16S rRNA gene sequence with the sequences of the closely related type strains showed highest sequence similarity of 96.95% and 96.93% to Flavobacterium nitrogenifigens $NXU-44^T$ and Flavobacterium compostarboris $15C3^T$, respectively. Based on phenotypic and phylogenetic distinctiveness, strain $I3-3^T$ is considered as a member of novel species within the genus Flavobacterium, for which Flavobacterium amnigenum sp. nov. is proposed. The type strain is $I3-3^T$ (=KCTC $52884^T$ =NBRC $112871^T$).

• 대한수의학회지
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• 제38권2호
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• pp.371-378
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• 1998

국내의 무지개송어, 금붕어, 은어양식장에서 아가미와 지느러미의 부식과 괴사를 나타내는 물고기로부터 균주를 분리하여 형태학적, 생화학적, 항원적시험 그리고 전기영동을 통하여 분리주와 미국과 일본에서 분리된 표준주(NCMB $2248^T$, EK 28)의 성상을 비교하였다. 즉, 형태학적으로 cytophaga agar에서 강한 점착성, rhizoid 그리고 노랗고 편평한 집락을 나타내었으며 flexirubin type pigment를 산생하고 동종과 이종에 대한 항원적 시험에서도 응집역가는 1024, 512를 나타냈다. 비록 분리주는 각기 다른 어종에서 분리되었음에도 불구하고 형태학적, 생화학적 그리고 혈청학적인 특성에 있어서 미국과 일본에서 분리된 표준주와 유사하였다. SDS-PAGE에 의한 세포외막단백질(outer membrane proteins, OMPs)의 분석에서도 표준주와 gel pattern이 일치하는 형태를 나타내었다. 이상의 결과를 미루어볼 때 국내 무지개송어, 금붕어 및 은어양식장에서 분리된 균주들은 Cytophaga columnaris로 분리 동정할 수 있었다.