Earticle

부영양화로 인한 녹･적조류가 과잉 번식하여 다양한 환경문제를 야기해왔으나, 최근 조류를 에너지원으로 활용할 수 있는 바이오 디젤 연구가 활발하게 진행되고 있다. 특히 하수처리장의 산소공급을 위한 송풍에너지 절약을 위해 미세 조류의 광합성 작용으로 발생하는 산소를 하수처리장에 적용시키는 연구도 다양하게 이루어지고 있다. 본 연구에서는 조류광합성 산소를 질산화에 필요한 산소로 활용하고자 실험실 규모의 조류-질산화 반응조를 운영하였으며, 운전구간 은 크게 3구간으로 운전하였다. MLSS(Mixed Liquer Suspended Solid) 농도에 변화를 준 구간에서 24~38 %, Micro-algae 농도에 변화를 준 구간에서는 38~50%, 그리고 HRT(Hydraulic Retention Time)에 변화를 준 구간에서 61~80%의 암모니아성 질소 제거율이 나타났다. 연구결과 MLSS 가 감소함에 따라, Algae Biomass가 증가함에 따라 암모니아성 질소 제거율이 증가하는 경향을 보였으나, MLSS에 의한 영향보다 Algae biomass 에 의한 영향이 더 큰 것으로 나타났다.

Water-bloom and red tide due to eutrophication have been overgrown and have caused various environmental problems. Recently, however, research on bid-diesel that can utilize algae as an energy source has been actively carried out. In particular, many studies variously have been conducted to utilize algal photosynthesis oxygen as a supply method for reducing the energy by an air blower in MWTP. In this study, a lab scale algae-nitrification reactor was operated to replace the oxygen required for nitrogen removal and the operation period was largely divided into three sections. In the first section, ammonia nitrogen removal efficiency was 24 ~ 38% according to the MLSS (Mixed Liquer Suspended Solid) concentration. In the second section, ammonia nitrogen removal efficiency was 38 ~ 50% according to the micro-algae concentration and in the last section ammonia nitrogen removal efficiency was 61 ~ 80% according to HRT (Hydraulic Retention Time). As a result, as the MLSS decreased and algae biomass increased, the ammonia nitrogen removal efficiency tended to increase, but the effect of Algae biomass was greater than that of MLSS.

본 연구에서는 재생에너지로서 바이오 디젤유 제조와 고도 폐수처리 에서 생흡착제로 활발히 연구되고 있는 Chlorella vulgaris 바 이오매스가 TOC(Total Organic Carbon)의 농도변화 관찰을 목적으로 하여 인공으로 제작된 하천수 연속흐름 체계(CRWFS, continuous river water flow system)에서 조류생산력(AGP, algal growthl potential)을 어떻게 나타나는 가를 조사하여 보았다. 연구결 과 다음의 결론을 얻을 수 있었다. 즉, Type 1 실험에서 BOD5: T-N: T-P의 비가 84 : 3 : 1로서 활성슬럿지 공정에서의 적정 비 BOD5: TN: T-P = 100 : 5 : 1에 근접하여 있었음에도 불구하고 Type 1의 glucose 농도(1,335 mg/L)는 DOC의 감소를 자져오지 못하고 있다. 이는 이 시스템에서 우선적으로 인공폐수의 연속적 주입에 문제가 있 음을 의미한다. 폐수처리 관점에서는 본 시스템에서 TOC의 감 소가 없으므로 Chlorella vulgaris의 생장력을 Monod 식으로 산출할 수 없는 한계가 있다. 지난 1981년에 발표한 Kuo 식에 의하면 Chlorella vulgaris의 생장력이 Type 1 : 0.65/day, Type 2 : 0.58/day로 나타나는데 이는 매일의 조류 성장력을 일일 정산으로 나타낼 경우에 Type 1이 Type 2보다 약 1.12배 정도됨을 의미한다. 본 시스템 의 실험결과를 Pond에서의 BOD, Algae, Bacteria, 산소 변수 의 정량화학적 분석 결과와 비교하여 보면 Chlorella vulgaris의 산소생 산만으로는 Escherichia coli w3110의 생물학적 분해작용을 가 능하게 하지 못한다. 그러므로 본 시스템의 성공적인 실험을 위해서는 별도의 폭기장치가 필요하다.

In this study, Chlorella vulgaris biomass, studied actively for manufacture of renewable energy, biodiesel oil, and of biosorbent in advanced wastewater treatment, was studied how their growth potential represents using continuous river water flow system (CRWFS). As a result, the followings were obtained : In type 1 experimentation, although the ratio of BOD5: TN : T-P (84 : 3 : 1) was similar to optimum ratio (100 : 5 : 1) of activated sludge process, glucose concentration (1,335 mg/ L) could not get the decrease of DOC. This means that the system keeps preferably the problem of continuous feeding of artificial wastewater. Seeing the scope of wastewater treatment, there is a limit which Monod formula can not be used because of not existence of TOC decrease in this system. In accordance of Kuo formula of 1981 year, The growth potential of Chlorella vulgaris is represented Type 1 : 0.65/day, Type 2 : 0.58/day. This means that one of Type 1 is 1.12 times more than one of Type 2. Comparing the experimentation results with stoichimetric analysis results for BOD, Algae, Bacteria, O2 parameters in pond system, Only oxygen production by Chlorella vulgaris can not support the biological degradation activity by Escherichia coli w3110. Therefore the seperated aeration apparatus must be installed for successful experimentation.

Cultivate of marine microalgae in the ocean for bioenergy seems to have bulky benefit in many aspects over conventional biofuel production. Any successful biofuel production must only depend on the eventual energy source of the world, the sun light. Ocean can provision larger area with less effects on the circumstances, free energy for blending such as wind and tidal flow, relatively small change in temperature and unlimited amount of water and eutrophic compounds for microalgae. However, since there would be no effective method to control light intensity, which is the most important parameter for algal growth, a beware-designed floating photobioreactor will be in need of pursuance of utilize the sun energy efficiently without photoinhibition. A variety of types of floating bag closed photobioreactors were designed and erected for culturing Dunaliella tertiolecta in the coastal area near Young-Heung Island. Various photobioreactors with different light transmission (ranging from 87% to 45%) were introduced. The maximum productivity of each type of photobioreactor was in the range between 0.07 g/L/day and 0.12 g/L/day. When an extra UV cutoff film is overlaid on high-transmitting bag, the growth of the cells inside the PBRs was greaten especially when the cell concentration was low. Relatively low-transmitting films would partially block the transmission of UV, resulting in no upbeat effect on cell growth when an extra UV cutoff film was overlaid. The results distinctly showed the well-known truth that the light is the most important parameter for algal culture even on near shore area and the PBRs for ocean culture must designed carefully to utilize the maximum potential of the natural sunlight.

Having been exposed into the ocean, heavy metals were accumulated within organism. In the food chain, the higher rank of predator takes the more amount of heavy metals into its own body. Once accumulated, heavy metals were hardly decomposed or excreted. So heavy metals in the ocean could take place heavy metal poisoning and ecocide. As a result, this study were purposed to develop ocean heavy metal bio-sorption process using micro algae. Through the screening, some micro algae having an ability to remove heavy metals, Chlamydomonas reinhardtii, Chlorella sorokiniana, Chlorococcum littorale and Ettlia oleoabundans were selected. Then bio-sorption ability of the heavy metal containing As, Cd, Co, Cr and Zn was measured by ICP-OES. These four kinds of micro algae were immobilized in the beads to perform the continuous heavy metal sorption process.

Biofuels are one of those renewable fuel sources developed to fuel the transportation sector to replace conventional petroleum based fuels. Due to widespread research and development programs from last two decades, significant progress has been made in the field of biofuels. The first and second generation biofuels are produced from various food crops and plant seed oils. Algae has been identified as a the potential source to produce biofuels, which can replace transportation fuels derived from fossil energy sources due to various advantages than the previous two generation feed stocks. The ability to produce high amounts of oil, efficiency in harvesting solar energy, adaptability to different climatic conditions and capability to produce valuable byproducts makes algae as a potential source for renewable energy source. In the present work the key concentration is directed towards producing renewable biofuels from algal biomass by transesterfication process. Its Characterization study reveals that algal based biodiesel is an alternative source of diesel.

Fifty seven taxa of Cyanobacteria and 15 taxa of Chlorophyta were recorded from the exterior of buildings and rock surfaces of monuments in different regions in India. Four cyanobacteria, e.g. Chroococcidiopsis kashayi, Pseudophormidium indicum, Plectonema puteale and Scytonema geitleri, and the green alga Trentepholia abietina var. tenue occur on the sub-aerial habitats throughout the year. In addition, five other green algae: Chlorococcum infusionum, Scenedesmus arcuatus, Trentepholia aurea, Gloeocystis polydermatica and Printzina effusa, and 18 other cyanobacteria taxa of the genera Chroococcus (5), Asterocapsa (1), Cyanosarcina (2), Gloeocapsa (7), Gloeothece (2) and Scytonema (1) occur on the sub-aerial surfaces enduring extreme temperature and desiccation during summer months of the tropics. During the rainy season, the warm and humid climatic regime coupled with availability of moisture supported an additional ten green algae and 29 cyanobacteria in eight and 17 genera, respectively. The green algal genera Klebsormidium, Stichococcus and Trebouxia, which are dominant in temperate regions, did not occur on the sub-aerial habitats in India, however, species of Gloeocapsa, Chroococcus, Chroococcidiopsis, Phormidium, Leptolyngbya, Nostoc, Scytonema, Chlorella and Trentepholia showed global occurrence in similar habitats.

본 연구에서는 해양미세조류 A. carterae의 기능성 평가를 위해 에탄올 추출을 하였고, 기존의 건강기능성식품인 클로렐라를 에탄올 추출하여 기능성을 비교하였다. 클로렐라 에탄올 추출물(CE)과 A. carterae 에탄올 추출물(AE)의 총페놀성 화합물은 각각 47.39 mg/g과 8.88 mg/g 으로 CE가 5.33배 높았으나, DPPH 라디컬소거능은 22.42%와 20.16%로 비슷한 수준이었다. 반면에 CE와 AE의 ABTS 라디컬 소거능은 각각 28.58%와 17.69%로 CE가 높아 CE의 항산화능은 페놀성 화합물의 효과로 판단된다. AE(10 mg/mL)의 항균활성은 그람음성균 6종과 그람양성균 10종에서 확인하였다. 그리고 CE(10 mg/mL)의 항균활성은 그람음성균 3종과 그람양성균 3종에서 확인되었다. ${\alpha}$-glucosidase의 억제활성은 AE($500{\mu}g/mL$)에서 82.07%이었고, CE는 효소활성을 촉진하는 것으로 나타났다. 암세포 생장억제활성은 $125{\mu}g/mL$ 농도의 AE를 첨가했을 때, HepG2와 HT-29의 생존율이 각각 38%와 11.27%이었다. $31.25-125{\mu}g/mL$의 농도범위에서 CE 첨가가 HepG2와 HT-29의 생장을 촉진하는 것으로 확인되었다. 이와 같은 결과를 종합하면, A. carterae 에탄올 추출물은 페놀성 화합물 이외의 항산화 물질을 보유하고, 항균활성, 항당뇨효과와 암세포 억제활성이 우수한 기능성 물질을 함유하고 있는 것으로 판단되어 기능성 소재로써의 활용가치가 높을 것으로 판단된다.

In this study, the antimicrobial, antioxidant activities and ${\alpha}$-glucosidase inhibitory activities of Amphidinium carterae ethanol extract (AE) was evaluated for using as a functional food ingredient. Chlorella ethanol extract (CE) was used to the comparison as a control. Anticancer activities of the AE and CE were analyzed by HepG2 and HT-29 human cancer cell. The AE showed antimicrobial activities for all tested bacterial strains. Whereas, CE showed antimicrobial activities for several tested bacterial strains only. The CE showed higher total phenolics contents, DPPH and ABTS radical-scavenging activities (47.36 mg/g, 22.42% and 28.58%, respectively) than those of AE (8.88 mg/g, 20.16% and 17.69%, respectively). AE showed anti-diabetic effect on ${\alpha}$-glucosidase inhibitory activity with dose-dependantly manner. The cell viability of AE ($125{\mu}g/mL$) on HepG2 and HT-29 human cancer cells were 38.12% and 11.27%, respectively. It was demonstrated that ethanol was efficient solvent for extracting functional components from A. carterae. These results indicated that AE can be described as a good candidate for using as a functional food ingredient.

Mixed A, Chlorella vulgaris, Nannochloropsis oculata, Chaetoceros calcitrans 등 4종류의 미세조류로부터 99.9% 에탄올로 추출한 성분의 항균활성을 검증하기 위해 그람음성세균 2종(E. coli, S. Typhimurium)과 그람양성세균 2종(S. aureus, B. cereus)에 대하여 paper disk diffusion assay, MIC, MBC를 측정하였다. 4종류의 미세조류 추출물은 공시균주에 대하여 0.62-1.66 mg/mL의 MIC를 나타내었으며, C. vulgaris 추출물이 4종의 공시균주에 대한 MIC가 0.62 mg/mL로 가장 강한 항균활성을 나타내었으며, MBC 또한 C. vulgaris 에탄올 추출물이 E. coli에 대해 2.50 mg/mL, S. aureus, B. cereus와 S. Typhimurium에 대해서는 4.16-5.00 mg/mL로 가장 강한 항균활성을 나타내었다. 항균활성이 가장 강한 C. vulgaris 에탄올 추출물의 성분을 분석한 결과, 함량이 가장 많은 성분은 9,12-octadecadienoic acid (linoelaidic acid, peak 5, 7)로 38.8%이었으며, 그 다음이 2-Hexadecen-1-o1, 3,7,11,15-tetramethyl (phytol, peak 2,6)로 30.0%이었다. Octadecadienoic acid는 일명 linoelaidic acid로 탄소수 18개의 고도불포화지방산이며, 두 번째로 함량이 많은 Phytol은 클로로필을 구성하는 불포화 제1급 알코올의 일종으로서(엽록소의 구성 성분) 병원성 대장균 및 황색포도상구균에 항균활성을 나타낸다는 보고로 볼 때, 이 2가지 성분이 항균활성의 주성분인 것으로 사료된다.

The antibacterial activity of ethanol (99.9%) extracts from marine micro-algae, namely, Mixed A (Pavlova sp., Thalassiosira weissflogii, Tetraselmis suecica and Isochrysis galbana were mixed with 1:1:1:1 ratio), Chlorella vulgaris, Nannochloropsis oculata and Chaetoceros calcitrans were estimated against food-borne bacteria, namely, Escherichia coli, Salmonella Typhimurium, Staphylococcus aureus and Bacillus cereus. The extracts from these marine micro-algae showed potent antibacterial activity against all tested bacteria by the paper disk method. The extracts from C. vulgaris showed the strongest antibacterial activity against E. coli with minimum inhibitory concentration (MIC) of 0.62 mg/mL, and minimum bactericidal concentration (MBC) of 2.50 mg/mL. The extract from C. vulgaris contained 2 active compounds, 38.8% linoelaidic acid and 30.0% phytol. These results indicated that the ethanol extract from C. vulgaris may be a putative natural antibacterial agent against food-borne bacteria.