Eun-Young Min

Growth performance and immunological and antioxidant status of Chinese shrimp, Fennerpenaeus chinensis reared in bio-floc culture system using probiotics

Chinese shrimp Fennerpenaeus chinensis (mean length 1.86 ± 0.15 cm, and weight 137.4 ± 12.7 mg) were reared in the different concentrations of bio-floc (control, 60, 80, 100, 120, and 140%) for 90 days. The growth rate was significantly increased over 100% bio-floc concentrations. In the immunological parameters, the gene expression of proPO and lysozyme was considerably increased over 120% bio-floc concentrations. The gene expression of SP was notably elevated at 140% bio-floc concentration. In the antioxidant enzymes, the activity of SOD was considerably decreased over 80% bio-floc concentrations. A notable decline in the activity of CAT was observed over 120% bio-floc concentrations. The results indicate that rearing of Chinese shrimp in bio-floc system can induce the increase of growth performance, enhancement of immune responses, and reduction of oxidative stress.

The effects of fucodian on senescence are controlled by the p16INK4a-pRb and p14Arf-p53 pathways in hepatocellular carcinoma and hepatic cell lines

Fucoidan is known to have various pharmacological effects, including antitumor activity. Although it has potential as a therapeutic agent for cancer cells, the anti-senescence effects and detailed mechanism of action remain poorly understood in normal hepatic cells. We investigated the anticancer functions of fucoidan using HepG2 cells as well as the mechanisms mediating the anti-senescent actions in Chang liver cells. Fucoidan effectively inhibited HepG2 cell viability and induced apoptosis. Also, fucoidan-induced G1 phase arrest was caused by the activity of the p16INK4a-Rb and p14Arf-p53 pathways. Furthermore, upregulation of p16INK4a was critical to the antitumor activity of HepG2 cells treated with fucoidan and was correlated with inhibition of Cdk4 and pRb and upregulation of p21 expression. Our results suggest that fucoidan upregulates INK4a locus genes to induce apoptosis through p38 MAPK in HepG2 cells. Moreover, it prevents cellular senescence of Chang-L cells, by decreasing p14Arf expression as cells enter quiescence, with the reduction of p16INK4a. Fucoidan treatment also downregulated the expression of α2M. In conclusion, fucoidan can be considered a potential therapeutic agent against liver cancer that does not cause senescence in normal hepatic cells. Thus, it may be possible to use fucoidan therapeutically in both tumor suppression and aging.

Effects on the antioxidant and immunological parameters in two species of the abalone, Haliotis discus discus and Haliotis gigantea during thermal stress

A study was conducted to evaluate the effects of elevated water temperature on antioxidant and immunological response in the abalones, Haliotis discus discus and Haliotis gigantea. The abalones were exposed to various water temperature; 20, 21, 22, 24, 26 and 28℃ for 96 hours. After thermal stress for 96 hours, in the control, superoxide dismutase (SOD) activities in hepatopancreas of H. gigantea were higher (1.3 times) than the values in H. discus discus. Although SOD activities showed no significant differences in H. discus discus, the values in H. gigantea were significantly increased in 24℃ or higher compared to the control after 24 hours exposure. Catalase (CAT) activities in hepatopancreas of H. discus discus were higher (1.4 times) than the values of H. gigantea in the control. After thermal stress (≥ 26℃), CAT activities significantly increased in both species compared to the control. The phenoloxidase (PO) activity of hemolymph was decreased in both species exposed to high temperature (≥ 26℃) compared to the control (P < 0.05). The values of lysozyme were significantly decreased in H. discus discus exposed to 28℃, and in H. gigantea to 26℃. In conclusion, in both species, there was a significant increase on antioxidant abilities (CAT) and a decrease on immunological parameters (PO and lysozyme) after thermal stress of 26℃ or higher. Also, antioxidant enzymes, SOD activities significantly increased in H. gigantea, but there was no significance in H. discus discus after thermal stress. These results suggested that H. gigantea is considered to be more sensitive than H. discus discus on thermal stress even though the similar warm current type.

Effects of Bio-floc System on Growth and Environmental Improvement in the Chinese White Shrimp Fenneropenaeus chinensis

우리나라 새우양식은 축제식 양식장에서 반집약적인 방법으 로 이루어지고 있으며, 지난 20년간 서해안을 중심으로 빠르 게 증가하였으나, 2002년 이후부터는 생산량이 해마다 크게 감 소하였다(Jang et al., 2007; Kim, 2010). 그 이유는 여러 요인 이 있지만 바이러스성 질병, 특히 흰반점바이러스(white spot syndrome virus)에 의한 대량폐사로 때문인 것으로 알려져 있 다(Chou et al., 1995; Jang, 2009). 또한, 새우 양식장에서 배출 되는 사료 찌꺼기, 대사산물 및 배설물 등에서 유래된 많은 양 의 질산, 아질산 및 암모니아와 같은 질소성분은 사육수의 부영 양화와 이에 따른 수질악화를 초래하기 때문에 질병과 함께 가 장 문제시되고 있는 점이다(Liu et al., 2004). 이러한 문제에 대 한 대안으로 최근에는 물리 또는 화학적 방법보다는 친환경적 이며 안정성이 확보된 Bio-floc technology (BFT) 또는 바이오 플락 시스템(bio-floc system) 양식이 주목을 받고 있다(Bashan and Bashan, 2010). 바이오플락 시스템(bio-floc system)은 생산성 향상을 위하여 물을 순환시키지 않기 때문에 바이러스 및 세균이 침입하지 못 하며, 다른 한편으론 양식 생물에 해롭지 않은 유용 미생물 또 는 타가 영양 미생물을 이용하기 때문에 수중의 유기질소와 암 모니아 등이 효과적으로 제거되어 사육수의 교환 없이도 수질 을 정화할 수 있는 장점이 있다(Emerenciano et al., 2013). 또 한 사육수 내 질소 성분에서 전환된 미생물이 양식 생물의 추가 단백질원 즉 양식 생물의 먹이가 되기 때문에 전체 양식 비용의 50% 이상을 차지하는 사료 비용의 절감을 가져오는 장점도 있 바이오플락(Bio-floc) 시스템이 사육 환경개선 및 대하(Fenneropenaeus chinensis)의 성장에 미치는 영향 김민수·민은영·구자근·강주찬*

Thermal Effects on Bioaccumulation and Antioxidant Enzyme Response in the Liver and Gills of Tilapia Oreochromis niloticus Exposed to Arsenic

The effects of waterborne arsenic (As) exposure on bioaccumulation and antioxidant defenses were examined in the liver and gills of tilapia, Oreochromis niloticus, under thermal stress. Tilapia were exposed to different As concentrations (0, 200, and 400 μg L -1 ) at three water temperatures (20, 25, and 30°C) for 20 days. After As exposure, higher levels of As accumulation were observed in the gills compared with the liver in elevated water temperatures. In terms of the antioxidant response, glutathione (GSH) levels and the activities of glutathione reductase (GR), glutathione peroxidase (GPx), and glutathione S-transferase (GST) significantly decreased in the liver and gills of tilapia exposed to As for 20 days, regardless of the As concentration (200 and 400 μg L -1 ) or water temperature. These enzyme activities exhibited greater fluctuations in the liver and gills of tilapia after As exposure in water warmer than 20°C. The present findings suggest that the simultaneous stress of temperature change and As exposure can accelerate As accumulation and alter the antioxidant enzymes activities of tilapia.