• 한국수산과학회지
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• 제44권4호
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• pp.332-338
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• 2011

Two feeding trials were conducted to determine the effects of dietary supplementation with Hizikia fusiformis or Ecklonia cava on the non-specific immune responses of parrot fish Oplegnathus fasciatus. Fish were fed experimental diets to which H. fusiformis or E. cava powder were added to final concentrations of 0, 2, 4 and 6%, respectively. After feeding for two weeks, phagocytic activity was significantly higher in fish fed diets containing H. fusiformis, but not E. cava, than in fish fed the basal diet. Lysozyme activity was significantly increased in the fish fed diets containing 6% H. fusiformis and E. cava. Myeloperoxidase activity was also significantly higher in fish fed diets containing 2 and 4% H. fusiformis, as compared to the basal diet, but not in those fish fed E. cava. These two studies indicate that dietary supplementation with H. fusiformis or E. cava could enhance the innate immune responses of parrot fish during their growth stage.

• Journal of Microbiology and Biotechnology
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• 제19권9호
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• pp.932-945
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• 2009

Several species of Gram-positive bacteria have cell wall peptidoglycan (syn. murein) in which not all of the sugar moieties are N-acetylated. This has recently been shown to be a secondary effect, caused by the action of a peptidoglycan N-acetylglucosamine deacetylase. We have found that the opportunistic pathogen Listeria monocytogenes is unusual in having three enzymes with such activity, two of which remain in the cytoplasm. Here, we examine the enzyme (PgdA) that crosses the cytoplasmic membrane and is localized in the cell wall. We purified a hexa-His-tagged form of PgdA to study its activity and constructed a mutant devoid of functional Lmo0415 (PgdA) protein. L. monocytogenes PgdA protein exhibited peptidoglycan N-acetylglucosamine deacetylase activity with natural substrates (peptidoglycan) from both L. monocytogenes and Escherichia coli as well as the peptidoglycan sugar chain component N-acetylglucosamine, but not with N-acetylmuramic acid. As was reported recently [6], inactivation of the structural gene was not lethal for L. monocytogenes nor did it affect growth rate or morphology of the cells. However, the pgdA mutant was more prone to autolysis induced by such agents as Triton X-100 and EDTA, and is more susceptible to the cationic antimicrobial peptides (CAMP) lysozyme and mutanolysin, using either peptidoglycan muramidases or autolysis-inducing agents. The pgdA mutant was also slightly more susceptible than the wild-type strain to the action of certain beta-lactam antibiotics. Our results indicate that protein PgdA plays a protective physiological role for listerial cells.

• Journal of Microbiology
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• 제35권2호
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• pp.109-116
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• 1997

An extracellular proteinase of Candida albicans was purified by a combination of 0~75% ammonium sulfate precipitation, DEAE Sepharose Fast Flow ion exchange chromatography, and Sephacryl S-200 HR molecular sieve chromatography. Its mlecular weight was approximately 41 kDa on SDS-PAGE and isoelectric point was 4.4. The enzyme was inhibited by pepstain A. Optimum enzyme activity ranged from pH 2.0 to 3.5 with its maximum at pH 2.5 and a temperature of 45$^{\circ}C$. The addition of divalent cations, $Ca^{2+}$, Zn$^{2+}$ and $Mg^{2+}$, resulted in no significant inhibition of enzymatic activity. However, some inhibitory effects were observed by Fe$^{2+}$, Ag$^{2+}$ and Cu$^{2+}$. With BSA as substrate, an apparent $K_m$ was determined to be 7$\times$10$^{-7}$ M and $K_i$, using pepstatin A as an inhibitor, was 8.05$\times$10$^{-8}$ M. N-terminal amino acid sequence was QAVPVTLXNEQ. Degradation of BSA and fibronectin was shown but not collagen, hemoglobin, immunoglobulin G, or lysozyme. The enzyme preferred peptides with Glu and Leu at the P$_1$ position, but the enzyme activity was highly reduced when the P$_2$ position was phe or pro. This enzyme showed antigenicity against sera of patients with candidiasis.

• Animal cells and systems
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• 제15권3호
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• pp.219-225
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• 2011

We studied oxidative stress in cinnamon clownfish exposed to hypoosmotic (35 psu ${\rightarrow}$ 17.5 psu and 17.5 psu with prolactin (PRL)) and low temperature ($28^{\circ}C{\rightarrow}24^{\circ}C$ and $20^{\circ}C$) conditions by measuring the expression and activity of Cu/Zn-superoxide dismutase (Cu/Zn-SOD), catalase (CAT), and glutathione peroxidase (GPX). The expression and activity of the antioxidant enzymes were significantly higher after the fish were exposed to $24^{\circ}C$, $20^{\circ}C$, and 17.5 psu, and expression was repressed by PRL treatment. Furthermore, we measured $H_2O_2$ and lipid peroxidation levels and found that they were significantly higher after exposure to the hypoosmotic and low-temperature environments. Additionally, we investigated changes in plasma AST and ALT levels after exposure to low temperature and hypoosmotic stress. These levels increased upon exposure of the clownfish to $24^{\circ}C$, $20^{\circ}C$, and 17.5 psu, but the levels of these parameters decreased in the 17.5 psu with PRL treatment during a salinity change. The results indicate that hypoosmotic and low-temperature conditions induce oxidative stress in cinnamon clownfish and that the parameters tested in this study may be indices of oxidative stress in the cinnamon clownfish.

• Fisheries and Aquatic Sciences
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• 제24권4호
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• pp.153-162
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• 2021

In this study, a fish metabolic accelerator (a combination of butaphosphan and cyanocobalamin [BPC]) was injected into the muscle of the olive flounder, Paralichthys olivaceus, to investigate its effect on immunity and stress in fish maintained at low temperatures. A single dose of BPC was injected (100 mg/kg body weight) into the olive flounder, and its immunity and stress were observed after one and two weeks. Immunity tests revealed the presence of lysozyme (LZM), nitroblue tetrazolium (NBT), myeloperoxidase (MPO), anti-protease (AP), glutathione peroxidase (GPx), and total immunoglobulin (TIg). BPC injection was found to increase immunity activity compared to the control group. In particular, there was significantly high GPx activity. There was similarly high activity for MPO and GPx in the first week following the injection, followed by significant differences between the BPC-injected and control groups in the second week. There was a reduced low water-temperature stress response in the BPC-injected fish, as evidenced by the cortisol and glucose levels of the control and BPC groups. Lower levels were also observed in the BPC group than the control group during the second week. Cortisol levels were significantly lower in the BPC group than the control group. Histological examinations were conducted in the first and second weeks after the intramuscular injection of the recommended BPC dose to confirm the safety of BPC in aquaculture. There were no abnormalities observed in any tissue samples. This study confirms that the injection of BPC is safe even when used in a culture situation. BPC helps relieve stress and improves non-specific immune responses (innate immunity) in the olive flounder.

• 미생물학회지
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• 제49권2호
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• pp.172-178
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• 2013

본 연구는 양식 넙치 Paralichthys olivaceus 사료 내 생균제 첨가가 넙치의 성장, 면역반응 및 병저항성에 미치는 영향을 평가하였다. 실험사료는 넙치용 배합사료(조단백질 52%, 조지방 11%, 조섬유 3%, 조회분 14%, 인 2.7%, 칼슘 1.5%, Suhyup Co., Korea)에 Bacillus sp. IS-2를 첨가하여 $10^3$, $10^5$, $10^7$ CFU/kg의 실험사료를 제작하였다. 2주간의 예비사육 후, 평균무게 $210{\pm}13g$인 실험어를 1,000 L 원형수조에 실험구 당 70마리씩 무작위로 배치하여 실험사료를 1일 2회 어체 중의 2%씩 12주 동안 공급하였다. 성장도 조사 결과 모든 실험구에서는 일반사료를 투여한 대조구에 비해 높은 성장률을 나타내었으며 $10^5$ CFU/kg 실험구에서는 대조구에 비해 약 13% 정도 높은 성장률을 나타내었다. 혈액분석 결과에는 glucose를 제외한 GOT, GPT, 단백질, 총콜레스테롤 등에서 실험구간 유의적인 차이를 나타내지 않아 생균제로 인한 간독성이나 어체 내 문제가 발생하지 않은 것으로 사료된다. Glucose인 경우 실험 종료 시점에서 증가되는 변화를 확인 할 수 있었는데 이는 수온, 수질에 의한 일시적인 현상이라 사료된다. Respiratory burst activity (NBT assay)에 있어서는 실험사료를 공급한 실험구가 대조구에 비해 높은 값을 확인할 수 있었으며 특히 $10^5$ CFU/kg 실험구와 $10^7$ CFU/kg 실험구에서 유의적으로 높은 값을 확인하였다. 혈청의 lysozyme 및 백혈구 활성에 있어서도 실험사료를 투여한 실험구에서 대조구에 비해 높은 활성을 확인 하였다. 공격실험 결과, Streptococcus inae를 접종한지 5일째부터 폐사가 시작되어 7일째 일반사료를 투여한 대조구에서는 100% 폐사율을 보인 반면, $10^3$ CFU/kg 실험구에서는 73%의 폐사율을 $10^5$ CFU/kg 실험구에서는 53%의 폐사율을 나타냈으며, $10^7$ CFU/kg 실험구에서는 45%의 폐사율을 보여 대조구에 비해 많게는 55% 이상의 높은 생존율을 나타내었다. 사료 내 첨가한 Bacillus sp. IS-2의 장내 생존 확인을 위해 실험이 종료 된 후 모든 실험구와 대조구 실험어의 장을 분리하여 배양 된 균체를 DNA를 분리 한 후에 제작 된 ditection primer를 이용한 PCR 결과 일반사료를 투여한 대조구를 제외한 모든 실험구에서 1,465 bp의 PCR product를 확인 할 수 있었다. 상기 결과를 토대로 양식넙치 사료 내 Bacillus sp. IS-2의 첨가는 양식넙치의 성장 및 면역증강, S. iniae에 대한 병정항성에 좋은 효과를 나타내어 사료첨가제로써의 이용 가능성이 클 것이라 사료된다.

• 한국어병학회지
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• 제24권3호
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• pp.307-313
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• 2011

To examine the effects of Euglena rubra (E. rubra) feeding on Nile tiapia, Oreochromis niloticus were fed diets containing dried powder of E. rubra at 0.5 or 2% for 4 weeks. Growth, selected hematological and non-specific immune parameters were assessed at 2 and 4 weeks. There were no significant changes in body weigh gain and erythrocyte levels. However a significant and diet E. rubra level-related decrease in leukocyte level was noted. Significant increases were observed in respiratory burst activity (nitroblue tetrazolium reduction) and lysozyme activities following E. rubra feeding. These results indicate that E. rubra could be beneficial to fish, but excess feeding could toxic.

• 한국수산과학회지
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• 제47권5호
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• pp.567-576
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• 2014

This study investigated the physiological effects of a diet containing calcium oxide (CaO) on the olive flounder, Paralichthys olivaceus. The results indicate that the amount of calcium in the blood was higher in the calcium group compared with the controls. The aspartate amino transferase (AST) and alanine amino transferase (ALT) levels were lower in the calcium group, while lysozyme activity was higher in the calcium group. Histologically, fish in the calcium group had more hepatocytes in the liver and more intact scales. In addition, an attack experiment using Vibrio anguillarum (KCTC-2711) and Edwardsiella tarda (KCTC-3657) showed that the survival was higher in the calcium group compared with the controls. These results suggest that feeding fish CaO when they require it, such as during periods of gonadal maturation and rapid growth, will increase their immunity and resistance to pathogens.

• 동아시아식생활학회지
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• 제5권1호
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• pp.93-99
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• 1995

For the improvement of the L-lysine productivity of Brevibacterium flavum and Corynebacterium glutamicum, fusants were induced by interspecific protoplast fusion of Bacillus subtilis with C. glutamicum and B. flavum. The following results were obtained through protoplast formation of strains condition of protoplast fusion, characteristics of the fusants, and the productivity of lysine form starch. B. flavum BF-5 and C. glutamicum protoplasts were made by the treatment of 0.3unit/$m\ell$ of penicillin G at the early stationary growth phase for 2 hours followed by incubation with 10mg/$m\ell$ of lysozyme at 37$^{\circ}C$ for 120 min. When a mixture of the protoplast was treated with 30% PEG(M.W.6,000) solution containing 50mM CaCl2 at optimal conditions, the intergeneric fusion frequency between protoplasts of C. glutamicum CG-2 and B. subtilis BD 224 was 7.1${\times}$105. The genetic properties on the L-lysine producing fusants were compared with those of parental strains. As a results, the intergeneric fusants were completed in each auxotrophic requirement, resistances for S-(2-amino-ethyl)-L-cysteine and kanamycine were confirmed. And one of fusants selected, FBB-41 were found to be genetically stable fusants. The aspartokinase activity of FBB-41 strain increased than that of the parent strain.

• BMB Reports
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• 제34권4호
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• pp.310-315
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• 2001

The uneven distribution of acidic and basic chitinases in different parts of rice seed, and also the characterization of hull-specific chitinases, are reported here. After extraction of chitinases from polished rice, bran, and rice hulls, the chitinases were separated into acidic and basic fractions, according to their behavior on an anion exchanger column. Both fractions from different parts of rice seed showed characteristic activity bands on SDS-PAGE that contained 0.01% glycol chitin. The basic chitinases from rice hulls were further purified using chitin affinity chromatography. The chitinase, specific to rice hulls (RHBC), was 88-fold purified with a 1.3% yield. RHBC has an apparent molecular weight of 22.2 kDa on SDS-PAGE. The optimal pH and temperature were 4.0 and $35^{\circ}C$, respectively. With [$^3H$]chitin as a substrate, RHBC has $V_{max}$ of 13.51 mg/mg protein/hr and $K_m$ of 1.36 mg/ml. This enzyme was an endochitinase devoid of ${\beta}$-1,3-glucanase, lysozyme, and chitosanase activities.