Microalgae are efficient fatty acid producers owing to their high photosynthetic activities. They can act as sources of biofuel, feed, and various bioactive compounds. This study aimed to determine optimal culture conditions, including culture medium, temperature, and light intensity, to enhance the biomass and fatty acid content of the indigenous freshwater microalga, Tetradesmus obliquus. Evaluation using a high-throughput photobioreactor revealed that the optimal culture temperature and light intensity were 25°C and 300 μmol m-2 s-1, respectively. Additionally, we optimized components (N, P, and Mg) of the BG-11 medium to enhance the microalgal biomass. Modified BG-11 medium increased the T. obliquus biomass by 37% compared to the standard BG-11 medium. Subsequently, the culture medium was replaced with N- and P-depleted media to determine the abiotic stress factor that could increase the cellular fatty acid content. Notably, fatty acid content was significantly increased from 8.5% up to 14.6% on day 7 of culture in N-deficient (N-P+ and N-P-) media. Sequential optimization effectively increased the biomass by 83% and fatty acid content by >76% in T. obliquus. Our optimization method can be used to enhance the biomass and fatty acid contents of various other microalgae.
아토피 피부염은 만성 염증을 동반한 알레르기성 질환 이며, 일반적으로 Type 2 염증 반응과 관련이 깊다고 알 려져 있다. Corchorus olitorius (C. olitorius)의 아토피 피 부염 치료 효과를 확인하기 위하여 2,4-dinitrochlorbenzene 로 아토피 피부염 모델을 유도한 BALB/c 마우스를 대상 으로 피부 염증 개선도를 육안으로 확인하였으며, 질환 관 련 IgE와 사이토카인(IL-4, IFN-γ and TNF-α)의 수준을 측정 하였다. 7일간의 투여기간동안 양성대조약물인 Dexamethasone 투여군의 체중은 감소하였던 반면에 모든 C. olitorius 투 여군의 체중은 꾸준히 증가하였다. 이와 같은 결과는 C. olitorius이 동물에 위해한 영향이 없었다는 것을 의미한다. C. olitorius 200 mg/kg/day 투여군의 치료 효과가 가장 뛰 어났으며, 모든 C. olitorius 투여군의 염증 관련 면역글로 불린과 사이토카인의 수준은 감소하였다. 따라서, C. olitorius 는 아토피 치료제로 충분히 활용될 수 있다고 판단된다.
Chironomid larvae in drinking water treatment plants (DWTPs) and tap water lead to highlights the urgent need for effective control measures. The use of combined disinfectant treatments is becoming increasingly common to achieve optimal disinfection efficiency while minimizing residual contamination. This study was conducted to study the effect of combined treatment of disinfectants used in DWTPs on the biological control potential of chironomid larvae. In the experiment, Glytotendipes tokunagai larvae reared according to OECD guidelines were exposed to NaOCl, UV, and O3 complex substances, and biological responses were analyzed using survival rate and body color change as key indicators for 24 hours. The survival rate of larvae exposed to combined disinfectants mostly decreased in a time- and concentration-dependent manner, and lightening of body color was observed. The most significant decrease (53%) of the survival rate was observed to a combination of UV and 4 ppm NaOCl disinfectants and body color change also showed a statistically significant difference compared to the control group (P<0.001). The change in body color is suggested to be a physiological change caused by oxidation of hemoglobin due to exposure to disinfectant complexes. The results of this study contribute to determining the biological impact of combined disinfectant treatment on chironomid larvae of DWTPs, and can be used as data to suggest the biological control potential of disinfectants. In addition, it will provide important information for setting standards for combined disinfectant treatment to improve water quality in the future.
Time-series and spatial analysis of collected odor complaints in Seoul megacity during 2014~2021 were conducted for the characterization of odor complaints emitted from the living environment. The ratio of odor complaints in the environmental complaints was 16.7%, and odor complaints increased 3.3 times from 9,053 cases in 2014 to a maximum of 29,425 cases in 2019. In the time-based evaluation (monthly, daily (day of the week), and hourly variations), the highest number of complaints occurred in June, Monday, and 9:00 AM, respectively. While the lowest number of complaints occurred in December, Sunday, and 3:00 AM, respectively. Among 25 provinces in Seoul megacity, the odor complaints that occurred from 2014 to 2021 were concentrated in Eunpyeonggu. The odor complaints of Seodaemun-gu and Nowon-gu occurred at the highest levels in January-February and June, respectively. Based on the characteristics of odor complaint occurrence according to the above time-series and spatial analyses, more effective odor management and control can be implemented by focusing on those hotspot areas and specific time periods.
Tricholoma matsutake, one of the most famous edible mushroom in Asia, has been cultivated in red pine forest. Because of its difficulty in artificial cultivation, T. matsutake cultivation has relied on foraging in the forest. Under certain environmental conditions, T. matsutake form the Shiro, the condensed mycelium, and develop into fruiting bodies. Among the certain environmental conditions, fungal communities play a major role in the mushroom development. Therefore, fungal community investigations for Bonghwa and Yangyang have been conducted on soil with fairy rings in the past, soil with existing fairy rings, and soil with presumptive fairy rings developing in the future. From the six soil samples, total 163 genera of fungi were detected and species diversity and species abundance of each sample were also analyzed. In result, the species diversity and species abundance of the fairy rings in Yangyang were lower than those in Bonghwa. In comparison with the fairy rings in Yangyang and Bonghwa, the dominance of the genus Tricholoma was higher and that of the genus Motilella was lower in Yangyang. Through the continuous study, establishment of optimal environmental conditions to promote the T. matsutake cultivation is highly expected.
Despite their historical use, studies on the genetic functions of mushrooms and varietal improvement via biomolecular techniques are limited compared to other organisms. Recent advancements in CRISPR/Cas9 have enabled precise genetic modifications in mushrooms, with RNP-based systems offering high editing efficiency without foreign gene insertion. In this study, we optimized gene-editing conditions for Ganoderma lucidum (Yongji 2) by utilizing RNP/nanoparticle complexes to enhance efficiency. The optimal conditions included a 0.2 M sorbitol buffer (pH 7.0) and a protoplast-to-complex ratio of 10:1. Among eight gRNAs designed for the catA gene, three were identified with high activity, and PEG-mediated transformation resulted in successful gene edits, primarily involving 1 bp deletions. The editing efficiency reached 7–8%, demonstrating that nanoparticle-supported RNP systems are effective for marker-free gene editing in mushrooms. These findings highlight a promising approach for advancing genetic research and varietal improvement in G. lucidum and other mushroom species.
In order to develop a stable production and delicious unique cultivar of beech mushrooms, we generated hybrids using wild resources collected domestically, and we developed excellent strains by identifying the mycelial cultivability of the hybrid strains. The developed strains were cultivated according to the type of spawn and incubation time, and strains with excellent yield and shape were first selected, and second strains with less bitterness and excellent taste were selected through quantitative descriptive analysis. This was verified in farms, and ‘HM6-6’, which had a good reputation in the field, was directly developed cultivars as ‘Maruking’. In addition, the yield was high overall in the 90-day culture of the growth substrate inoculated with solid spawn, and the ‘Maruking’ cultivar, was also best in the 90-day culture. The yield was high overall in the 75-day culture of the liquid spawn, but ‘Maruking’ showed excellent yield when cultured for 70 days.
The Grifola frondosa cultivar KMCC03118 was used to isolate monokaryotic strains via spore separation, resulting in the successful crossbreeding of strains KMCC03118-11 and KMCC03118-23, which produced F1 hybrids. These F1 hybrids were then further crossed with various monokaryotic strains to generate F2 progeny. In evaluating the effects of different medium compositions on fruit body development, it was found that a substrate consisting of wheat bran and dried sawdust, with a carbon-to-nitrogen (C/N) ratio of 66-68, provided the most favorable conditions for mycelial growth. Among the strains tested, KMCC03137 and GF-18-50 demonstrated superior characteristics, including a larger fruit body diameter, thicker pileus, and greater stipe thickness, with the highest productivity observed at 143.6 ± 13.3 g and 144.7 ± 15.2 g, respectively. Furthermore, the color of the caps (L: 29.7 ± 7.1, a: 2.6 ± 0.7, b: 8.2 ± 1.8) remained consistent, indicating stable high-quality production. Based on these results, the optimal substrate composition for enhancing both the quality and productivity of the fruit bodies was determined to be 42% Quercus sp. sawdust, 42% Quercus sp. fermented sawdust, 6% wheat bran, and 10% dried tofu residue. This study provides a crucial foundation for the commercial cultivation and breeding improvement of Grifola frondosa, offering valuable insights into its genetic enhancement, and providing essential data for future research aimed at increasing the species' genetic diversity and productivity.
This study aims to estimate the trawl net width based on the design drawing and towing condition of sampling trawl used in past surveys to improve the accuracy of estimation for fishery resources. To this end, the trawl gear was modeled as a flexible structure and numerically analyzed, and the analysis results were subjected to multiple regression analysis. As a result, a model was derived to calculate the net width by the towing conditions. When the towing conditions from past surveys were input into this model, it was confirmed that the net width increased in a natural logarithmic manner with the increase in the warp length and that decreased linearly as the water depth increased at the same warp length. For verification of the model, the theoretical formula of other study and this model were compared. As a result, despite the values of the two were slightly different, the tendency of changing net width by increasing warp length was consistent each other. Therefore, it is thought that the derived model can obtain the net width according to various towing conditions and can contribute to improving the accuracy of fishery resources estimation.
본 연구의 목적은 조직구성원의 직장만족도에 따른 잠재프로파일 유형을 분석하고 직장만족도에 영향 을 주는 선행요인과 이직의도를 초래하는 관계를 살펴보는 것이다. 이를 위해 여성관리자 패널데이터를 활용하여 잠재프로파일 분석을 실시하였다. 분석결과, 첫째, 조직구성원의 직장만족도에 따른 잠재프로파 일은 총 5개의 유형이 도출되었다. 둘째, 직장만족도 유형과 개인 및 조직 특성간의 관계에서는 배우자가 있을 경우 직장만족도가 낮은 집단에 속할 확률이 높은 경향을 보였고, 상사지원 및 최고경영자 지원이 높을수록 직장만족도가 높은 집단에 속할 확률이 높게 나타났다. 마지막으로, 직장만족도 유형과 이직의 도와의 차이를 살펴본 결과 직장만족도가 높을수록 이직의도가 낮아지며 집단 간 유의한 차이가 존재하 였다. 이러한 결과를 바탕으로 직장만족도 유형에 따른 이직의도를 낮추기 위한 방안에 대하여 이론적 및 실무적 관점에서 제시하였으며, 본 연구의 한계점과 향구 연구 방향도 논의하였다.
최근 지구온난화로 인해 폭우, 눈 등 이상기후가 발생하면서 노면 동결(블랙아이스)로 인한 사고 및 인명피해가 늘어나고 있 는 것이 문제가 되고 있다. 이를 최소화하기 위해 본 연구에서는 다공성 골재인 팽창점토에 열저장이 가능한 상변화물질(PCM)을 적용 하였다. PCM은 상변화 과정에서 열에너지를 흡수, 저장, 방출할 수 있는 소재로 온도에 따른 결빙을 최소화할 수 있다. 따라서 본 연 구에서는 시멘트 복합재에 적용되는 PCM 함침이 가능한 경량골재에 진공함침을 실시하고 기계적, 열적 성능 검증 연구를 수행하였다. 열적 성능을 향상시키기 위해 다중벽탄소나노튜브(MWCNT)와 실리카흄을 첨가하였다. 본 연구에서는 물체의 열적 성능을 측정할 수 있는 DSC 실험을 통해 PCM 함침 경량골재 및 콘크리트 복합체의 열적 성능을 검증하였다. 콘크리트 복합체 제작 후 압축강도 시험 과 열적 성능시험을 실시하였다. 이때 열적 성능을 검증하기 위해 항온항습 챔버를 이용하여 시험을 진행하였다. 압축강도 실험을 통 해 MWCNT의 분삭액을 혼입한 PCM 함침 팽창점토가 적용된 콘크리트 복합체의 평균 압축강도는 24MPa 이상으로 구조물에 적용이 가능함을 확인하였다. 열적 성능시험을 통해 PCM 함침 팽창점토가 적용된 콘크리트 복합체는 영하의 외기온도에서도 영상의 온도를 유지할 수 있음을 확인하였다. 이와 같은 결과를 통해 주거 및 상업 건물 및 다양한 구조물에 적용이 가능할 것으로 판단된다.
일반적인 택코트용 유화아스팔트는 도로 포장면에 살포되고 양생되는 과정에서 공사차량 및 포설장비 타이어에 쉽게 들 러붙어서 포장면의 코팅막 훼손과 같은 심각한 문제를 일으킬 뿐 아니라, 접착력과 전단강도가 약하여 상하 포장층간 부 착력 저하로 균열, 포트홀, 밀림과 같은 포장도로 조기 파손의 주요 원인이 되고 있다. 본 연구에서는 택코트 시공 후 양생시간을 현저히 단축시키고 공사차량 통행에 의한 접착 처리면 훼손을 최소화하여 아스팔트 포장의 조기 파손을 방지할 뿐 아니라, 포장체의 장기 공용성능을 크게 향상시키는 초속경성 타이어 미부착 택코트 유화아스팔트 개발과 이를 고속도로 현장에서 적용한 사례에 대해 소개하고자 한다. 해당 기술은 택코트 훼손방지 기능 외에도 폴리머가 함유된 아스팔트를 적용하여 부착강도가 매우 우수하며, 배수성 포장, SMA 포장, 교면 포장 등 특수포장의 공용성 증진효과가 큰 것으로 나타났다. 양생시간 또한 크게 단축되어 1액형 택코트의 경우 30분 이내에 양생이 되며, 양생 촉진제를 적용하는 2액형 택코트는 5분 내에 양생을 완료 시킬수 있어서, 시공시간 단축을 통한 조기 교통개방을 가능하게 한다. 해당 기술은 국토교통부 개질 유화아스팔트 품질기준인 RS(C)-PG70T 규격을 만족하였고, 타이어 부착률이 약 1.5% 대로 우수한 것으로 나타났다. 고속도로 현장 적용성 평가 결과, 양생시간이 5분 이내로 확인되었으며, 시공 후 현장 코어 시편 확인 결과, 택코트층이 잘 보전되어 있었으며, 포장층간의 결합력이 우수하게 유지되었다. 따라서 고속도로 뿐만 아니라 서울시와 같은 도심지 및 택코트의 충분한 양생시간을 확보하기 어려운 아스팔트 유지보수 공사에 본 기술을 적용하는 것은 매우 효과적일 것으로 판단된다.