• Biotechnology and Bioprocess Engineering:BBE
• /
• 제7권1호
• /
• pp.10-15
• /
• 2002

Environmental and medium factors were investigated as basic data for optimizing DHA production when using Thraustochytrium aureum. To study the effect of environmental conditions, the rotation speed and culture temperature were changed. Plus the trend of the growth characteristics, lipid content in the biomass, and DHA content in lipids were evaluated according to various initial glucose concentrations. The biomass, lipid, and DHA analyses showed that the physiological characteristics of T. aureum were closely related with the environmental and medium conditions, as in the case of other marine microorganisms. For example, a low rotation speed of 50 rpm lowered the cell growth rate as well as the DHA content in the lipids. A low temperature had a negative effect on the cell growth, yet a positive effect on the lipid content in the biomass. Different initial glucose concentrations had no effect on the lipid content in the biomass or DHA content in the lipids, yet did affect the cell growth. Accordingly, these results show that environmental and medium factors must be synthetically considered in order to optimize DHA production when using T. aureum.

• Journal of Acupuncture Research
• /
• 제23권2호
• /
• pp.113-123
• /
• 2006

Objectives : Deer antler Herbal-Acupuncture (DHA) solution represents one of the most commonly used medicine to treat rheumatoid arthritis. But, mechanisms of its antiarthritic activities are still poorly understood. Identification of common DHA aqua-acupuncture capable of affording protection or modulating the onset and severity of arthritis may have important human health implications. Results : We determined if DHA could prevent the binding of $IL-1{\beta}$ to its cellular receptors. DHA addition to rat chondrocytes treated with $IL-1{\beta}$ or with reactive oxygen species(ROS) prevents the activation of proteoglycan synthesis. After treatment with $IL-1{\beta}$, DHA increased the expression of mRNA encoding the type II $IL-1{\beta}$ receptor. These results emphasize the potential role of two regulating proteins of the $IL-1{\beta}$ signaling pathway that could account for the beneficial effect of DHA in osteRArthritis. The present study also identifies a novel mechanism of DHA-mediated anti-inflammatory activity. Conclusion : It is shown that DHA inhibits both $IL-1{\beta}-$ and $TNF-{\alpha}-induced$ NO production in normal human articular chondrocytes. The observed suppression of IL-1-induced NO production is associated with inhibition of inducible NO synthase(iNOS) mRNA and protein expression. In addition, DHA also suppresses the production of IL-1-induced cyclooxygenase-2 and IL-6. The constitutively expressed cyclooxygenase-1, however, was not affected by the sugar. These results demonstrate that DHA expresses a unique range of activities and identifies a novel mechanism for the inhibition of inflammatory processes.

• Molecules and Cells
• /
• 제42권3호
• /
• pp.252-261
• /
• 2019

The omega-3 fatty acid docosahexaenoic acid (DHA) is known to induce apoptosis and cell cycle arrest via the induction of reactive oxygen species (ROS) production and endoplasmic reticulum (ER) stress in many types of cancers. However, the roles of DHA in drug-resistant cancer cells have not been elucidated. In this study, we investigated the effects of DHA in cisplatin-resistant gastric cancer SNU-601/cis2 cells. DHA was found to induce ROS-dependent apoptosis in these cells. The inositol 1,4,5-triphosphate receptor ($IP_3R$) blocker 2-aminoethyl diphenylboninate (2-APB) reduced DHA-induced ROS production, consequently reducing apoptosis. We also found that G-protein-coupled receptor 120 (GPR120), a receptor of long-chain fatty acids, is expressed in SNU-601/cis2 cells, and the knockdown of GPR120 using specific shRNAs alleviated DHA-mediated ROS production and apoptosis. GPR120 knockdown reduced the expression of ER stress response genes, similar to the case for the pre-treatment of the cells with N-acetyl-L-cysteine (NAC), an ROS scavenger, or 2-APB. Indeed, the knockdown of C/EBP homologous protein (CHOP), a transcription factor that functions under ER stress conditions, markedly reduced DHA-mediated apoptosis, indicating that CHOP plays an essential role in the anti-cancer activity of DHA. These results suggest that GPR120 mediates DHA-induced apoptosis by regulating $IP_3R$, ROS, and ER stress levels in cisplatin-resistant cancer cells, and that GPR120 is an effective chemotherapeutic target for cisplatin resistance.

• ALGAE
• /
• 제32권1호
• /
• pp.67-74
• /
• 2017

The heterotrophic dinoflagellate Oxyrrhis marina is known to produce high levels of docosahexaenoic acid (DHA) when fed on diverse algal prey. However, large-scale culturing of algal prey species is not easy and requires a large amount of budget, and thus more easily cultivable and low-cost prey is required. Dried yeast was selected as a strong candidate for an alternative prey in our preliminary tests. Thus, we explored the fatty acid composition and DHA production of O. marina fed on dried yeast and compared these results to those of O. marina fed on two algal prey species: the phototrophic dinoflagellate Amphidinium carterae and chlorophyte Chlorella sp. powder. O. marina fed on dried yeast, which does not contain DHA, produced the same high level of DHA as those fed on DHA-containing A. carterae. This indicates that O. marina is likely to produce DHA by itself regardless of prey items. Furthermore, the DHA content (and portion of total fatty acid methyl esters) of O. marina satiated with dried yeast, 52.40 pg per cell(and 25.9%), was considerably greater than that of O. marina fed on A. carterae (26.91 pg per cell; 15.7%) or powder of Chlorella sp. powder (21.24 pg per cell; 16.7%). The cost of dried yeast (approximately 10 US dollars for 1 kg dried yeast) was much lower than that of obtaining the algal prey (approximately 160 US dollars for 1 kg A. carterae). Therefore, compared to conventional algal prey, dried yeast is a more easily obtainable and lower-cost prey for use in the production of DHA by O. marina.

• KSBB Journal
• /
• 제20권4호
• /
• pp.271-277
• /
• 2005

본 연구에서는 당의 초기농도는 물론 NaCl과 $MgSO_4{\cdot}7H_2O$의 농도가 T. aureum ATCC 34304 균주의 성장특성, 지질의 생성특성 및 DHA의 생성특성에 미치는 영향을 규명하였다. 당농도 15 g/L까지는 당농도가 증가하면 균체증가량에 대한 지질증가량의 비율인 $Y_{Lipid/X}$간과 지질증가량에 대한 DHA 증가량의 비율인 $Y_{DHA/Lipid}$ 값이 모두 증가하였다. $Y_{lipid/X}$와 $Y_{DHA/Lipid}$의 최대값은 0.18 g/g 과 0.41 g/g을로 모두 당의 초기농도 15 g/L에서 나타났다. 반면 균체수율인 $Y_{x/s}$ 값은 당의 초기농도 변화에 관계없이 0.378 g/g으로 일정하였다. 당의 농도변화에 대한 균체의 비성장속도 역시 당농도 15 g/L까지는 최대 $0.79\;day^{-1}$까지 증가하였으나, 20 g/L에서는 $0.57\;day^{-1}$로 감소하였으며, 그 이상의 당농도에서는 증감현상을 나타내지 아니하였다. 해수배지 조성을 기본으로 하고 NaCl 농도를 0.1 g/L에서 48 g/L까지 변화시켰을 때 NaCl의 농도가 0 g/L인 경우 균체의 성장, 지질의 생성 및 DHA의 생성이 모두 정지되었으며, NaCl 24 g/L에서 균체성장, 지질생성 및 DHA의 생성이 최대값을 나타내었다. 또한 기본해수배지 조성에 $MgSO_4{\cdot}7H_2O$의 농도를 0 g/L에서 24 g/L까지 변화시켰을 때, $MgSO_4{\cdot}7H_2O$ 0 g/L에서는 균체성장, 지질생성 및 DHA 생성이 정지되었으며, $MgSO_4{\cdot}7H_2O$ 18 g/L에서 균체성장, 지질생성 및 DHA의 생성이 최대값을 나타내었다.

• ALGAE
• /
• 제35권3호
• /
• pp.277-292
• /
• 2020

Omega-3 fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are polyunsaturated fatty acids beneficial to human health. A limited number of microalgae have been used for commercial omega-3 production, which necessitates the identification of new microalgae with high omega-3 contents. We explored the fatty acid composition and EPA and DHA contents of the mixotrophic dinoflagellate Gymnodinium smaydae fed with the optimal algal prey species Heterocapsa rotundata. Cells of G. smaydae were found to be rich in omega-3 fatty acids. In particular, the DHA content of G. smaydae was 21 mg g^-1 dry weight, accounting for 43% of the total fatty acid content. The percentage of DHA in the total fatty acid content of G. smaydae was the highest among the reported microalgae except for Crypthecodinium cohnii. Moreover, to determine if the prey supply interval affected the growth rate of G. smaydae and its fatty acid content, three different prey supply intervals (daily, once every 2 d, and once for 4 d) were tested. Daily prey supply yielded the highest total fatty acid and DHA contents in G. smaydae. Furthermore, we successfully produced high-density G. smaydae cultures semi-continuously for 43 d with daily prey supply. During the semi-continuous cultivation period, the highest density of G. smaydae was 57,000 cells mL^-1, with an average growth rate of 0.7 d^-1. Taken together, the percentage of EPA and DHA in the total fatty acid content was maintained in the range of 54.2-56.9%. The results of this study support G. smaydae as a promising microalgal candidate for commercial DHA production and demonstrate that daily supply of prey can efficiently produce high-density G. smaydae cultures for more than a month.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2000년도 춘계학술발표대회
• /
• pp.291-294
• /
• 2000

Thraustochytrium aureum ATCC 34034를 인공 해수 배지에서 $24^{\circ}C$, 200rpm, 초기 pH 6으로 고정하여 빛을 가하면서 3일간 배양을 한 결과, 최대 건조 균체량은 1.34g/L이었으며, 최대 DHA생산량은 41.4mg/L이었다. 모든 실험에서 탄소원으로 glucose를 5g/L로 고정하였다. YM배지와 YPG배지에서는 Thraustochytrium aureum이 DHA를 생산하지 못하였으며, 이 균주가 해양 미생물이라는 점을 고려해보면, 성장과 DHA생산에 있어서 염분이 중요한 영향을 미친다고 생각된다.

• Journal of Nutrition and Health
• /
• 제39권4호
• /
• pp.357-365
• /
• 2006

DHA, one of w-3 fatty acids, modulates cell growth or death though the changes of apoptotic signaling in human endothelial ECV304 cells. We investigated the effects of DHA on the changes of apoptotic signaling in human vascular endothelial ECV304 cells using lipid peroxidation (LPO) metabolites. LPO could be originated by dietary polyunsaturated fatty acids such as linoleic acid(LA), arachidonic acid(AA) and docosahexaenoic acid (DHA). DHA caused cell death of ECV304 cells compared to LA, AA or control as evidenced by changes in cell morphology and MTT assay. LPO levels was significantly elevated by 10 fold in DHA-treated ECV 304 cells and caspase-3 activity was increased by DHA corresponding to increasing incubation times compared to control. One of reasons of the cell death in DHA-treated ECV304 cells could be expected that caspase activity, marker for mitochondrial damages, might be triggered by the increasing LPO levels. Our results strongly indicated that DHA induced LPO production has an important role on apoptotic signaling pathway in ECV304 cells. LPO production in endothelial cells which was metabolized by oxidation of dietary PUFA, might be one of risk factors in the initial progression of atherosclerosis.

• 한국미생물·생명공학회지
• /
• 제33권1호
• /
• pp.51-55
• /
• 2005

교반속도와 배양온도가 T. aureum ATCC 3430의 성장과 지질 및 DHA 생합성에 미치는 영향을 규명하였다. 배양온도 $4^{\circ}C$내지 $39{\circ}C$범위에서 균체성장에 최적인 온도는 $32^{\circ}C$이었으며, DHA와 지질의 생성량이 가장 높은 온도는 $18^{\circ}C$이였다. 배양온도 $39^{\circ}C$ 이상과 $11^{\circ}C$이하에서는 균체의 성장량과 DHA및 지질의 생성량이 대단히 적었으나, 온도가 낮을수록 단위균체당 축적되는 지질과 DHA의 함량은 증가하여 배양온도 $4^{\circ}C$에서는 $Y_{L/X}$의 값이 $32^{\circ}C$가지, $Y_{DHA/X}$의 값은 $15\%$까지 증가하였다. 교반속도 50내지 250rpm사이에서 균체성장이 가장 높은 교반속도는 100rpm이였다. 교반속도 100과 250rpm사이에서는 교반속도가 균체의 성장량과 지질 및 DHA생합 성량에는 영향을 미치지 아니하였으나, 교반속도가 50 rpm으로 감소하면 균체 성장량과 지질 및 DHA생성량이 모두 크게 감소하였다.

• 한국식품과학회지
• /
• 제28권1호
• /
• pp.179-183
• /
• 1996

본 연구는 DHA를 첨가한 마요네즈와 첨가하지 않은 시판 마요네즈의 산화안정성을 비교하고, DHA를 첨가한 마요네즈의 품질을 유지할 수 있는 안정한 조건을 알아보기 위하여 실시하였다. 실온$(25^{\circ}C{\pm}1^{\circ}C)$에서 보관할 경우, DHA가 첨가된 시판 마요네즈는 DHA가 첨가되지 않은 시판 마요네즈보다 더 빨리 산화되는 것으로 나타났으며, DHA가 첨가된 마요네즈의 관능적인 품질은 제조일로부터 5개월 이후부터 현저히 감소되었다. 냉장온도$(4^{\circ}C{\pm}1^{\circ}C)$에서 보관할 경우에도, DHA를 첨가한 시판 마요네즈는 DHA가 첨가되지 않은 시판 마요네즈보다 더 빨리 산화되었다. 그러나, 두가지 마요네즈는 모두가 냉장조건에서 8개월 이내에는 외관상 및 관능상의 문제가 없는 것으로 나타났다. 마요네즈가 상온에서 유통되고 있는 실정을 고려할 때, DHA가 첨가된 시판 마요네즈는 DHA가 첨가되지 않은 시판 마요네즈보다 유통기한을 2내지 3개월 정도 단축하는 것이 바람직한 것으로 나타났다.