https://repository.kopri.re.kr/handle/201206/9774 2026-04-07T08:33:43Z 2026-04-07T08:33:43Z Kim, Minjae Kim, Jongrae Kim, Sanghee Jin, EonSeon https://repository.kopri.re.kr/handle/201206/12047 2022-03-24T07:15:08Z 2020-11-01T00:00:00Z

Title: Heterologous Gene Expression System Using the Cold-Inducible CnAFP Promoter in Chlamydomonas reinhardtii Authors: Kim, Minjae; Kim, Jongrae; Kim, Sanghee; Jin, EonSeon Abstract: To increase the availability of microalgae as producers of valuable compounds, it is necessary to develop novel systems for gene expression regulation. Among the diverse expression systems available in microalgae, none are designed to induce expression by low temperature. In this study, we explored a cold-inducible system using the antifreeze protein (AFP) promoter from a polar diatom, Chaetoceros neogracile. A vector containing the CnAFP promoter (pCnAFP) was generated to regulate nuclear gene expression, and reporter genes (Gaussia luciferase (GLuc) and mVenus fluorescent protein (mVenus)) were successfully expressed in the model microalga, Chlamydomonas reinhardtii. In particular, under the control of pCnAFP, the expression of these genes was increased at low temperature, unlike pAR1, a promoter that is widely used for gene expression in C. reinhardtii. Promoter truncation assays showed that cold inducibility was still present even when pCnAFP was shortened to 600 bp, indicating the presence of a low-temperature response element between -600 and -477 bp. Our results show the availability of new heterologous gene expression systems with cold-inducible promoters and the possibility to find novel low-temperature response factors in microalgae. Through further improvement, this cold-inducible promoter could be used to develop more efficient expression tools.

2020-11-01T00:00:00Z Kim, Sanghee https://repository.kopri.re.kr/handle/201206/11111 2022-03-24T07:14:36Z 2020-02-28T00:00:00Z

Title: Large-scale production and Clinical evaluation of CPS (Cell-Protecting Substance) from polar microalgae Authors: Kim, Sanghee

2020-02-28T00:00:00Z Kim, Eun Jae Kim, Sanghee Choi, Han-Gu Han, Se Jong https://repository.kopri.re.kr/handle/201206/11007 2022-03-24T07:14:40Z 2020-02-01T00:00:00Z

Title: Co-production of biodiesel and bioethanol using psychrophilic microalga Chlamydomonas sp. KNM0029C isolated from Arctic sea ice Authors: Kim, Eun Jae; Kim, Sanghee; Choi, Han-Gu; Han, Se Jong Abstract: Biofuels, generated using microalgae, as sustainable energy have received a lot of attention. Microalgae can be cultivated at low cost with CO2 and solar energy without competition from edible crops. Psychrophilic microalgae can be a suitable feedstock to produce biofuels without the environmental constraints of low temperatures, because they can grow below 10 °C. However, there is a lack of efficient strategies using psychrophilic microalgae to produce biodiesel and bioethanol. Therefore, the current study aimed to optimize the production of biodiesel and bioethanol from Arctic Chlamydomonas sp. KNM0029C at low temperatures. After incubation in a 20-L photobioreactor, fatty acid methyl ester (FAME) was extracted using modified FAME extraction methods, producing a maximum yield of 0.16 g FAME/g KNM0029C. Residual biomass was pretreated for bioethanol production, and the yields from different methods were compared. The highest bioethanol yield (0.22 g/g residual biomass) was obtained by pretreatment with enzyme (amyloglucosidase) after sonication. Approximately 300 mg biofuel was obtained, including 156 mg FAME biodiesel and 144 mg bioethanol per g dried cells, representing the highest recorded yield from psychrophilic microalgae. This is the first to attempt at utilizing biomass from psychrophilic Arctic microalga Chlamydomonas sp. KNM0029C for the co-production of bioethanol and biodiesel, and it yielded the highest values among reported studies using psychrophilic organisms. These results can be used as a source for the efficient biofuel production using polar microalgae.

2020-02-01T00:00:00Z Min, ByeongSun https://repository.kopri.re.kr/handle/201206/11432 2022-03-24T07:14:25Z 2020-01-31T00:00:00Z

Title: Development for anti-allergic and anti-inflammatory therapeutic compounds from antarctic microalgae Authors: Min, ByeongSun

2020-01-31T00:00:00Z