• Journal of Life Science
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• v.28 no.3
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• pp.361-368
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• 2018

This study investigated the diversity of communities of intestinal microorganisms, separated from the intestinal organs of Red tilefish (Branchiostegus japonicas), collected on the Jeju Coast. First, in the isolation of 1.5% BHIA, MA, TSA and R2A Agar on the medium, there were most colonies in 1.5% BHIA. The results of aerobic culture and anaerobic culture were $1.7{\times}10^6CFU/g^{-1}$ and $1.1{\times}10^5cfu/g^{-1}$, respectively, on average, and 147 pure colonies were separated in total. In 16S rDNA sequencing, there were 58 genera and 74 species, showing 95-100% similarity with the basic strain. They were divided broadly into 5 phyla, and as the main phyletic group, Proteobacteria phylum comprised 50% with 9 families, 35 genera and 35 species of Moraxellaceae, Rhodobacteraceae, Shewanellae, Halomondaceae, Enterobacteriaceae, Vibrionaceae, Hahellaceae, Pseudomonadaceae, and Erythrobacteraceae, with the highest index of dominance. Actinobacteria phylum comprised 24% with 8 families, 11 genera and 17 species of Microbacteriaceae, Intrasporangiaceae, Dietziaceae, Dermabacteraceae, Dermacoccaceae, Nocardiodaceae, Brevibacteriaceae and Propionobacteriacea; Firmicutes phylum, 16% with 6 families, 8 genera and 17 species of Bacillaceae, Staphylcoccaceae, Planococcaceae, Streptococcaceae, Paenibacillaceae and Clostridiaceae; Bacteroidetes phylum, 6% with 2 families, 3 genera and 4 species of Cyclobacteriaceae and Flavobacteriaceae; and Deinococcus-Thermus phylum, 4% with 1 family, 1 genus and 1 species of Deinococcaceae.

• Journal of Life Science
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• v.25 no.3
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• pp.269-275
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• 2015

Collagen peptides, which are found at high concentrations in the human body, are present in animal bones and the skin of marine organisms, namely, fish scales. Collagen is the most abundant structural protein of various connective tissues in animals. Furthermore, it is widely used in biomedical material, pharmaceutical, cosmetic, food, and leather industries. Peptides extracted from scales of various fish protect against ultraviolet B (UVB)-induced skin damage and photo-aging. However, the protective effects of collagen peptides derived from the scales of Branchiostegus japonicus against UVB exposure are unclear. This study investigated the effects of peptides larger than 1 kDa (high-molecular weight peptides [HMP]) and smaller than 1 kDa (low-molecular weight peptides [LMP]), derived from extracts of B. japonicus scales, against UVB-induced skin damage and photo-aging. These peptides scavenged 1,1-diphenyl-2-picrylhydrazyl radicals in a dose-dependent manner. In UVB-exposed HaCaT human keratinocytes, LMP inhibited 8-isoprostane generation, a marker of cellular lipid peroxidation. The peptides also suppressed the UVB-induced increase in tyrosinase activity and melanin content in B16F10 mouse melanoma cells. In addition, the LMP and HMP treatment suppressed UVB-induced elastase and matrix metalloproteinase-1 activities in the HaCaT cells. These results indicate that peptides derived from B. japonicus scales have antioxidant, antiphoto-aging, and skin-whitening effects.

• Journal of Life Science
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• v.27 no.11
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• pp.1331-1339
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• 2017

DNA barcoding is the identification of a species based on the DNA sequence of a fragment of the cytochrome C oxidase subunit I (COI) gene in the mitochondrial genome. It is widely applied to assist with the sustainable development of fishery-product resources and the protection of fish biodiversity. This study attempted to verify horse-head fish (Branchiostegus japonicus) and fake horse-head fish (Branchiostegus albus) species, which are commonly consumed in Korea. For the validation of the two species, a real-time PCR method was developed based on the species' mitochondrial DNA genome. Inter-species variations in mitochondrial DNA were observed in a bioinformatics analysis of the mitochondrial genomic DNA sequences of the two species. Some highly conserved regions and a few other regions were identified in the mitochondrial COI of the species. In order to test whether variations in the sequences were definitive, primers that targeted the varied regions of COI were designed and applied to amplify the DNA using the real-time PCR system. Threshold-cycle (Ct) range results confirmed that the Ct ranges of the real-time PCR were identical to the expected species of origin. Efficiency, specificity and cross-reactivity assays showed statistically significant differences between the average Ct of B. japonicus DNA ($21.85{\pm}3.599$) and the average Ct of B. albus DNA ($33.49{\pm}1.183$) for confirming B. japonicus. The assays also showed statistically significant differences between the average Ct of B. albus DNA ($22.49{\pm}0.908$) and the average Ct of B. japonicus DNA ($33.93{\pm}0.479$) for confirming B. albus. The methodology was validated by using ten commercial samples. The genomic DNA-based molecular technique that used the real-time PCR was a reliable method for the taxonomic classification of animal tissues.