Objectives of this study were to propose an optimal fertilization method of Chlorella and to evaluate its effects on growth of green pepper. Chlorella fusca strain was propagated and used in the experiment. As for treatment, drenching method (DM), foliar fertilization (FF), drench and foliar fertilization combination (DM + FF), and untreated control (CO) were used. Plant height of green pepper was higher in the CO treatment than in chlorella fertilized treatments. Chlorella fertilization inhibited stem growth of green pepper. Chlorophyll contents of green pepper leaves were higher in the DM + FF treatment. Yields were the higher in DM and DM + FF treatments than in other treatments. Vitamin C content was the highest in the DM + FF treatment. These results showed that Chlorella fertilization could increase the growth, yield, and bioactive substance content of green pepper. The Chlorella fertilization method could be applied to other crops. By applying this technology to the farmer, it is possible to increase income and supply healthy and safe high-quality agricultural products to consumers.

Heavy metal pollution has a harmful impact on human health and is regarded as a vital problem. Preparation of a novel, low cost bio-sorbent for heavy metal sorption is the main target of this research. Non-living Chlorella Vulgaris Alga/Date pit activated carbon composite (1:1), (CV/AC), is a novel bio-sorbent prepared by the wet-chemical method for sorption of Pb (II) and Sr (II) from aqueous media. The optimum pH for sorption reaction is 5 and the equilibrium time is achieved within 1 h. The sorption efficiencies are 90.5% for Pb(II) and 95.7% for Sr(II) with initial concentration Co 10 mg L– 1 at 298 K. The monolayer sorption capacities of CV/AC composite at 298 K and pH = 5 were 6.34 ± 0.059, 5.97 ± 0.22 mg g– 1. The saturation capacities were 98.5 and 125 mg g– 1 for Pb (II) and Sr (II), respectively after 10 days. The sorption process is a spontaneous and endothermic reaction. It follows a pseudo-2nd-order mechanism. The results are suggestive of the need to adopt CV/AC composite as a potential bio-sorbent of Pb (II) and Sr (II) for waste water treatment.

본 연구는 클로렐라 엽면시비가 고구마의 생육 및 수확에 미치는 영향을 조사하기 위하여 수행되었다. 클로렐라 엽면시 비구와 무시비구의 생육 비교를 실시한 결과는 다음과 같다. 1. 고구마 1개 식물체에서 수확한 수확량을 조사한 결과, 수확 개수는 클로렐라 무시비구는 60.0개, 클로렐라 시비구는 71.2개로 클로렐라 시비구가 무시비구에 비교하여 19%정도 증가하였다 2. 고구마의 1개의 평균 무게는 무처리구 104.6 g, 클로렐라 시비구 105.7 g으로 클로렐라를 시비하였을 때 다소 높은 경향을 보였으나 큰 차이를 보이지 않았다. 3. 고구마 1.2 m2 구역 내 10개 식물체에서 수확한 고구마의 총 무게는 무처리구 6.3 kg, 클로렐라 시비구 7,5 kg로 20% 정도의 증수 효과를 확인하였다. 4. 농수산물유통공사의 자료에 의거한 소비자 선호 등급인 80-150g 내에 속하는 고구마의 비율은 클로렐라 시비구가 무처리구보다 1.7% 더 높았다. 5. 본 실험의 결과 클로렐라 시비구의 수확량 증가율이 19.9%로 1ha에서 약 5,085,000원 이상의 수익 증가를 기대할 수 있어 클로렐라 시비가 농가의 소득 증대에 크게 도움이 될 것으로 판단된다.

Prediction of the behavior of heavy metals over time is important to evaluate the heavy metal toxicity in algae species. Various modeling studies have been well established, but there is a need for an improved model for predicting the chronic effects of metals on algae species to combine the metal kinetics and biological response of algal cells. In this study, a kinetic dynamics model was developed to predict the copper behavior (5 μg L-1, 10 μg L-1, and 15 μg L-1) for two freshwater algae (Pseudokirchneriella subcapitata and Chlorella vulgaris) in the chronic exposure experiments (8 d and 21 d). In the experimental observations, the rapid change in copper mass between the solutions, extracellular and intracellular sites occurred within initial exposure periods, and then it was slower although the algal density changed with time. Our model showed a good agreement with the measured copper mass in each part for all tested conditions with an elapsed time (R 2 for P. subcapitata: 0.928, R 2 for C. vulgaris: 0.943). This study provides a novel kinetic dynamics model that is compromised between practical simplicity and realistic complexity, and it can be used to investigate the chronic effects of heavy metals on the algal population.

The formation of CaCO3 in microalgal culture is investigated and applied for effective separation of microalgae. The presence of several cationic ions in the culture medium mediates the formation of 3 types of mineral precipitates depending on the concentration of mineral precursors, Ca2+ and CO3 2−, amorphous nano-flakes, rhombohedral calcites, and spherical vaterites. While amorphous phased precipitates are formed for all concentrations of mineral precursor, only calcites are formed for 30 mM solutions of mineral precursor, and mixtures of calcites and vaterites are formed for 50 and 100 mM solutions of mineral precursor. The harvesting efficiency is also dependent on the concentration of the mineral precursor: from 90 % for 10 mM to 99 % for 100 mM after 60 mins’ of gravitational sedimentation. The formation of nano-flakes on the surface of microalgal cells induces the flocculation of microalgae by breaking the stable dispersion. The negatively charged surface of the microalgal cell is compatible not only with nano-flake attachment but also with the growth of calcitic crystals in which microalgal cells are embedded.

This research aims to study the simultaneous extraction and transesterification of Chlorella vulgaris (C. vulgaris) using microwave irradiation with methanol as solvent and potassium hydroxide (KOH) as catalyst. The microwave-assisted insitu transesterification of C. vulgaris is assessed at various ratios of biomass-to-methanol, reaction times, and catalyst concentrations during the centrifugation and evaporation process. Gas chromatography-mass spectrometry (GC-MS) analysis is performed to confirm fatty acid methyl ester (FAME) composition. Biodiesel preparation is carried out by simultaneous extraction and transesterification of microalgae from C. vulgaris. The product is then characterized using Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (1H-NMR); microalgae are observed using scanning electron microscopy (SEM). The highest amount of FAME is obtained at a biomass-to-methanol ratio of 1:12, reaction time of 40 min, and catalyst concentration of 2 wt%. Biodiesel shows conversion to about 77.64% of methyl ester (methyl myristate, methyl palmitoleate, methyl linoleate, methyl oleate, methyl arachidonate, and methyl 5,8,11,14,17-eicosapentanoate).

This study was conducted to evaluate the characteristics of bread and the rheology of flour dough containing chlorella powder(0%, 0.5%, 1.0%, 1.5%, 2.0% and 2.5%). In the farinograph test, the addition of chlorella powder changed water absorption, development time and mixing tolerance index for making bread. As the amount of chlorella powder increased, the water absorption increased, mixing tolerance index and the development time decreased. In the extensograph test, the degree of extension and resistance was decreased with increasing of chlorella powder content. In the amylograph test, the maximum viscosity was slightly decreased with increasing of chlorella powder contents. The colors of L value in bread crumb was significantly decreased as the chlorella powder addition. After fermentation treatment, The dough with 2.5% chlorella powder showed the lowest dough raising power compared to the other doughs. The addition of the chlorella powder had significant effect on bread texture. The bread consisting of 0.5% chlorella powder showed the highest volume of loaf and specific volume. Therefore, high quality of bread can be achieved by adding chlorella powder.

Chlorella gloriosa (Chlorellaceae, Trebouxiophyceae) was isolated from seawater off the coast of the Dokdo Islands in Korea. An axenic culture was established using the streak-plate method on f/2 agar media supplemented with antibiotics, allowing identification of the isolate by morphological, molecular, and physiological analyses. The morphological characteristics observed by light and electron microscopy revealed typical morphologies of C. gloriosa species. The molecular phylogenetic inference drawn from the small-subunit 18S rRNA sequence verified that the microalgal strain belongs to C. gloriosa. Additionally, gas chromatography-mass spectrometry analysis showed that the isolate was rich in nutritionally important omega-3 and -6 polyunsaturated fatty acids and high-performance liquid chromatography analysis revealed that the high-value antioxidants lutein and violaxanthin were biosynthesized as accessory pigments by this microalga, with arabinose, galactose, and glucose as the major monosaccharides. Therefore, in this study, a Korean marine C. gloriosa species was discovered, characterized, and described, and subsequently added to the national culture collection.

Chlorella-derived activated carbon (CDAC) with a high specific surface area and hierarchical pore structure was prepared as a CO2 adsorbent and as a supercapacitor electrode material. During KOH activation of Chlorella-derived carbon, metallic K gas penetrated from the outer walls to the inner cells, and pores formed on the outer frame and the inner surface. Micropores were dominant in CDAC, contributing toward a high specific surface area (> 3500 m2/g) and a hierarchical pore structure owing to the cell walls. Consequently, CDAC exhibited a high CO2 adsorption capacity (13.41 mmol/g at 10 atm and room temperature) and afforded high specific capacitance (142 F/g) and rate capability (retention ratio: 91.5%) in supercapacitors. Compared with woody- and herbaceous-biomass-derived activated carbons, CDAC has a superior specific surface area when the precursors are used without any pretreatment under the same conditions due to their soft components such as lipids and proteins. Furthermore, developing microalgae into high-value-added products is beneficial from both economic and environmental perspectives.

본 연구는 혐기소화액을 클로렐라 배양 배지로 이용하여 클로렐라 처리 농도 및 침종 처리방법에 따른 고추 종자의 발아율에 미치는 영향을 구명하고자 수행하였다. 고추 종자는 증류수(대조구), 클로렐라 배양액의 50% 희석액(50%), 클로렐라 배양원액(100%), 클로렐라 150, 200, 400% 농축액, 클로렐라 배양여액, 대조구를 두었다. 클로렐라 배양액의 무침종 처리구가 86.7~95.6%의 발아율을 나타낸 것과 비교해 볼 때, 침종 처리구의 발아율은 98.3~100%로 5~12% 높은 발아율을 나타내었다. 그러나 클로렐라 배양여액 처리구의 발아율은 73.3%로 클로렐라 배양액 보다 낮았다. 클로렐라 침종처리구의 발아속도는 무침종 처리구보다 1일 빨랐다. 고추 종자의 80% 발아 소요 시간은 클로렐라 배양액 처리구가 대조구보다 1.1~1.2일 빨랐다. 그러나 클로렐라 배양여액 처리구의 발아속도는 클로렐라 배양액 보다 낮았다. 클로렐라 배양액 150% 침종 처리구의 유근길이는 6.23cm로 대조구보다 약 2cm 더 길었다. 상대적 유근신장률은 클로렐라 150% 침종처리구에서 146%로 대조구보다 46% 높게 나타났다. 클로렐라 배양액 처리구의 고추 종자 발아지수(GI)는 130~150%로 무처리구 보다 높았다. 클로렐라 배양액 처리는 고추 종자 발아율이 높았고 발아기간이 단축되고 유근이 길어지는 효과를 나타내었다. 결론적으로 클로렐라 배양액은 고추 종자 발아에 안정성이 높았고 종자의 발아 촉진에 유용하게 적용이 가능하였다.

This experiments were conducted to evaluate the influence of Chlorella culture solution using anaerobic digestate as medium on seed germination of perennial ryegrass seeds. Four treatments were compared: control with distilled water, anaerobic digestate, Chlorella culture solution and Chlorella culture filtrate. The germination percentage of perennial ryegrass seeds was highest in the Chlorella culture solution treatment. Days required for 50, 70% seed germination were faster at 1.7 day in Chlorella culture solution compared to control. Root length of perennial ryegrass seeds was longer by 1~2cm in the Chlorella culture solution compared with control. The relative root length was by 40% longer in the Chlorella culture solution treatment compared to control. The germination index (GI) of perennial ryegrass seeds was higher by 180~202% in the Chlorella culture solution treatment compared to control. The decay rate was low as 50.0% in Chlorella culture solution, but decay rate of perennial ryegrass seeds showed 86.7~83.3% in control plot and in anaerobic digestate, respectively. Chlorella culture solution have shown stimulatory effects in germination and development of root. Overall, Chlorella culture solution could be useful to apply for promotion of germination and root elongation of seeds.

This study aimed to investigate growth rate and nutrient consumption of Chlorella vulgaris according to different light irradiation interval. Applied light irradiation intervals were 12 hr, 4 hr, 1 hr, and 1 min. The light source was flexible LED(Blue:Red=1:1), light intensity was 200 PPFD and Light/Dark cycle was 1:1. As a result, growth rate and nutrient removal efficiencies showed no significant differences depending on the light irradiation interval. Considering the reproduction characteristics of applied microalgae cultures of this study, this is thought to be one of the possible reasons of above results. Because Chlorella vulgaris performs an asexual reproduction and it is known that there is no significant relationship between light irradiation interval and growth rate, including nutrient consumption in case of asexual reproduction.

Anaerobic digestion is a collection of naturally occurring processes that convert organic matter and liquid residue, so-called digestate. The use of digestate biofertilizers is one of the important components of integrated nutrient management, as they are renewable sources of plant nutrients for sustainable agriculture. Seeds of Italian ryegrass (Lolium multiflorum L.) were germinated in different concentration of Chlorella in order to investigate it’s the effect of Chlorella on growth parameters, seed germination and early growth. The experiment using plug tray was conducted at the green house placed in the Sangji University. The experiment consisted of nine treatments including different concentrations of Chlorella sp. culture solution and non-treated control. The germination percentage at the treatment with 25% Chlorella sp. culture solution was greater than that of control. The 50% concentration of Chlorella sp. culture solution was found to promote a better seedling growth in terms of shoot length, fresh weight and dry weight compared to the anaerobic digestate. Results showed that the best concentration of Chlorella culture solution was achieved by the 50% concentration of Chlorella culture solution treatment. As a conclusion, the application of Chlorella culture solution was found to be able to promote the germination and shoots growth of Italian ryegrass