• Applied Chemistry for Engineering
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• v.33 no.3
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• pp.242-257
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• 2022

Microalgae is becoming a vital component for a circular economy and ultimately for sustainable development. Herein, recent developments in different outcomes of microalgae for wastewater treatment and biorefinery were reviewed. From its primary function as a third-generation resource of biofuel, the usage of microalgae has been diversified as an integral element for the CO₂ sequestration and production of economically valuable products (e.g., pharmaceuticals, animal feeds, biofertilizer, biochar, etc.). Principles and recent challenges for each microalgae application were presented to suggest a motivation for future research and the direction of development. The integration of microalgae within the concept of the circular economy was also discussed with various routes of microalgae-based biorefinery.

• Journal of Ginseng Research
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• v.48 no.2
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• pp.140-148
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• 2024

Synthetic biology approaches offer potential for large-scale and sustainable production of natural products with bioactive potency, including ginsenosides, providing a means to produce novel compounds with enhanced therapeutic properties. Ginseng, known for its non-toxic and potent qualities in traditional medicine, has been used for various medical needs. Ginseng has shown promise for its antioxidant and neuroprotective properties, and it has been used as a potential agent to boost immunity against various infections when used together with other drugs and vaccines. Given the increasing demand for ginsenosides and the challenges associated with traditional extraction methods, synthetic biology holds promise in the development of therapeutics. In this review, we discuss recent developments in microorganism producer engineering and ginsenoside production in microorganisms using synthetic biology approaches.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.4
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• pp.637-649
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• 2011

Soil microorganisms play a major role in improving soil fertility and plant health. Symbiotic arbuscular mycorrhizal fungi (AMF) form a key component of the soil microbial populations. AMF form a mutualistic association with the host plant and exert a positive influence on its growth and nutrient uptake. The establishment of mycorrhizal symbioses with the host plant can positively be influenced by plant growth promoting rhizobacteria through various mechanisms such as increased spore germination and hyphal permeability in plant roots. Though there are evidences that combined interactions between AMF and PGPR can promote the plant growth however mechanisms of these interactions are poorly understood. Better understanding of the interactions between AMF and other microorganisms is necessary for maintaining soil fertility and enhancing crop production. This paper reviews current knowledge concerning the interactions between AMF and PGPR with plants and discusses on enhanced nutrient availability, biocontrol, abiotic stress tolerance and phytoremediation in sustainable agriculture.

• Journal of Hydrogen and New Energy
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• v.20 no.6
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• pp.512-518
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• 2009

Mg 및 Mg합금은 수소 저장량이 7.6wt.%로 비교적 높고 자원도 풍부하여 값이 싼 장점을 가지고 있으나 산화반응성이 높고 활성화 에너지가 크기 때문에 반응온도가 높고 반응시간이 긴 단점을 가지고 있다. 이러한 단점을 극복하기 위해 일반적으로 Mg 및 Mg합금의 표면 개질화, 금속간 화합물 형성, 전이금속 첨가에 대한 연구가 활발히 진행되고 있다. 본 연구에서는 전이금속인 Nb를 촉매제로 사용하여 수소화 특성을 개선하고자 기계적 합금화법(MA;Mechanical Alloying)을 실시하여 복합재료를 합성한 후 수소화 반응을 평가하였다. XRD, SEM, TEM, PSA, TG/DSC 분석을 수행하였으며 Sievert's 형 PCT를 이용하여 온도 및 압력 변화에 따른 특성평가를 하였다. 전이금속인 Nb의 첨가로 수소화 반응개시온도가 낮아지고 수소 저장량이 향상되는 거동을 보였다. 특히, 5mass%Nb가 10mass%Nb 보다 수소 저장량 및 반응속도가 좋은 결과를 보였다.

• Applied Biological Chemistry
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• v.41 no.6
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• pp.451-456
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• 1998

To find out the repeated application effect of chicken and pig manure composts on tomato growth and soil physico-chemical properties, different rates of the composts were applied to greenhouse soils with low fertility for 3 years and tomato was grown annually. As application rate of compost increased, the growth and fruit yield of tomato increased markedly, and there are also a little increase in sugar content in fruit juice and weight per fruit. When only compost was applied, however, physical and chemical properties in soil showed to be unbalanced such as significantly low bulk density and hardness, and high porosity as well as high organic matter and exchangeable K content, and low exchangeable Ca content than those of optimum range for soil diagnosis. Therefore mixed use of compost and chemical fertilizer is more promising way than the only use of compost to make suitable physico-chemical properties for tomato growth.

• Journal of Microbiology and Biotechnology
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• v.31 no.1
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• pp.154-162
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• 2021

L-5-methyltetrahydrofolate (5-MTHF) is one of the biological active forms of folate, which is widely used as a nutraceutical. However, low yield and serious pollution associated with the chemical synthesis of 5-MTHF hampers its sustainable supply. In this study, 5-MTHF production was improved by engineering the 5-MTHF biosynthesis pathway and NADPH supply in Lactococcus lactis for developing a green and sustainable biosynthesis approach. Specifically, overexpressing the key rate-limiting enzyme methylenetetrahydrofolate reductase led to intracellular 5-MTHF accumulation, reaching 18 ㎍/l. Next, 5-MTHF synthesis was further enhanced by combinatorial overexpression of 5-MTHF synthesis pathway enzymes with methylenetetrahydrofolate reductase, resulting in 1.7-fold enhancement. The folate supply pathway was strengthened by expressing folE encoding GTP cyclohydrolase I, which increased 5-MTHF production 2.4-fold to 72 ㎍/l. Furthermore, glucose-6-phosphate dehydrogenase was overexpressed to improve the redox cofactor NADPH supply for 5-MTHF biosynthesis, which led to a 60% increase in intracellular NADPH and a 35% increase in 5-MTHF production (97 ㎍/l). To reduce formation of the by-product 5-formyltetrahydrofolate, overexpression of 5-formyltetrahydrofolate cyclo-ligase converted 5-formyltetrahydrofolate to 5,10-methyltetrahydrofolate, which enhanced the 5-MTHF titer to 132 ㎍/l. Finally, combinatorial addition of folate precursors to the fermentation medium boosted 5-MTHF production, reaching 300 ㎍/l. To the best of our knowledge, this titer is the highest achieved by L. lactis. This study lays the foundation for further engineering of L. lactis for efficient 5-MTHF biosynthesis.

• Korean Journal of Agricultural Science
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• v.50 no.3
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• pp.479-488
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• 2023

As the interest in sustainable and environmentally friendly agriculture continues to grow, there is a corresponding increase in organic fertilizers utilization. However, studies on ammonia (NH₃) emissions, which are primarily generated in the agricultural sector, by organic fertilizers are lacking. Additionally, the reliance on imported ingredients in the production of organic fertilizers hinders the widespread adoption of organic fertilizers. This study aims to evaluate NH₃ volatilization by incorporating rice husk biochar into organic fertilizers. The study also aims to assess whether domestically produced rice husk biochar can serve as a viable substitute for imported ingredients. Here, the dynamic chamber method was used under controlled conditions. Results show that inorganic fertilizers readily undergo hydrolysis, thereby rapidly generating significant amounts of NH₃, particularly in the initial stages. In contrast, organic fertilizers decompose gradually, leading to relatively long-term NH₃ emissions. The incorporation of rice husk biochar into organic fertilizers demonstrated diminished daily NH₃ emissions compared to those from commercial organic fertilizers, resulting in decreased total NH₃ volatilization. These findings show that the combination of rice husk biochar can reduce NH₃ volatilization and serve as an alternative to imported ingredients for organic fertilizers. The results of this study can be utilized as fundamental information for the assessment of biochar as a potential ingredient for organic fertilizers.

• Applied Chemistry for Engineering
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• v.35 no.5
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• pp.473-477
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• 2024

The technology of harvesting energy wasted in daily life is becoming increasingly important for sustainable energy production and climate change. In this study, we investigated an electrochemical energy harvesting system using blue energy generated by the movement of electrodes. We observed that energy could be harvested based on the electrification phenomenon that occurs when an electrode comes into contact with an electrolyte, particularly when the electrode is modified with a self-as-sembled monolayer (SAM) containing the fluorocarbons. The static charges, which are generated by electrification based on the energy level difference between the electrode and the electrolyte, could be transferred to an external circuit. Additionally, we discovered that structural features of SAM molecules are related to the efficiency of energy harvesting, including the number of fluorocarbons. This system successfully powered an LED, proving the practicality of electrochemical harvesting using blue energy. The results suggest the potential for developing more efficient and high-output energy harvesting systems through the application of various SAM molecules.

• Applied Chemistry for Engineering
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• v.3 no.2
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• pp.189-193
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• 1992

The success of 3M's worldwide Pollution Prevention Pays (3P) Program convinced 3M's top management that the program should be expanded into a comprehensive environmental management system called 3P Plus. The emphasize of the 3P Plus program is to continually minimize the environmental impact of 3M processes, products, and operations to include energy management, resource recovery, and other initiatives. 3M's experience with the 3P and 3P Plus programs will be described. 3M's experience can serve as a model for other multi-national companies interested in sustainable development and economic growth with environmental protection.

• Clean Technology
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• v.2 no.2
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• pp.90-99
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• 1996

Being confronted with the 21th century at hand, a paradigm shift has been a common topic for development in many fields. Among these, a concept of sustainable development is the most important one to resolve conflict and nurture mutualism between science/technology(SCI/TEC) and society/environment(SOC/ENV). Looking briefly over the resent stats of the chemical industry in Japan, in this paper, we will introduce a research program named simple chemistry as an example for such a challenge.