As part of the 2024 research initiative, “Investigation and Discovery of Prokaryotes in Freshwater Systems,” samples were collected from diverse freshwater habitats, including both water and soil environments. Approximately 2,000 bacterial strains were isolated as single colonies and identified through 16S rRNA gene sequence analysis. Among these, 38 strains shared ≥98.7% 16S rRNA gene sequence similarities with those of known bacterial species not previously reported in Korea. These strains were thus categorized as newly recorded bacterial species in Korea. These 38 bacterial strains displayed significant phylogenetic diversities, spanning 2 phyla, 4 classes, 15 orders, 24 families, and 34 genera. These unrecorded species were classified into the following classes: Actinomycetia (with genera including Microcella, Conyzicola, Curtobacterium, Leucobacter, Microbacterium, Frigoribacterium, Lysinibacter, Streptomyces, Nonomuraea, Actinocorallia, Ruania, and Actinoplanes), Alphaproteobacteria (Paracoccus, Youngimonas, Loktanella, Corticibacterium, Neorhizobium, Onobrychidicola, Ferranicluibacter, Aureimonas, Asticcacaulis, and Novosphingobium), Betaproteobacteria (Rhodoferax, Rugamonas, and Cupriavidus), and Gammaproteobacteria (Rheinheimera, Shewanella, Kosakonia, Leclercia, Hafnia, Yersinia, Pseudomonas, Lysobacter, and Acinetobacter ). Further characterization included assessment of Gram reaction, colony and cell morphology, biochemical properties, and phylogenetic relationships. This report presents detailed phylogenetic and phenotypic characteristics of these bacterial species.
Background: South Korea has recently faced record-high temperatures, which have adversely affected dairy production. Holstein cows, the primary dairy breed globally, are particularly sensitive to heat stress. In contrast, Jersey cows have shown greater heat tolerance, as demonstrated by phenotypic studies. Methods: We investigated physiological and molecular responses to heat stress in Holstein and Jersey cows by measuring rectal temperature, milk yield, and average daily gain, confirming Holstein cows’ greater vulnerability. To explore molecular mechanisms, we analyzed circulating microRNA profiles from whole blood samples collected under heat stress and normal conditions using microRNA-sequencing. Differential expression patterns were compared between the two breeds to identify biological pathways associated with heat stress. Results: Four microRNAs (bta-miR-20b, bta-miR-1246, bta-miR-2284x, and bta-miR- 2284y) were significantly differentially expressed in both breeds under heat stress (|FC| ≥ 2, p < 0.05). Notably, bta-miR-20b and bta-miR-1246 were linked to corpus luteum function and progesterone biosynthesis, while bta-miR-2284x and bta-miR- 2284y were associated with immune responses. A comparison of 11 potential heat stress-related microRNAs identified in previous studies of Holstein cows revealed consistent expression trends in Jersey cows, albeit with lower fold changes, suggesting their superior heat resilience. Conclusions: Our study highlights the physiological and microRNA-based differences in heat stress responses between Holstein and Jersey cows. Jersey cows exhibited greater resilience, supported by more stable microRNA expression profiles and improved heat stress indicators, making them a promising breed for dairy production in increasingly hot climates.
In today’s rapidly changing business environment, rapid decision making and effective project management are essential for business growth. This study examines how project manager competencies and organizational structures affect business performance. Successful project execution depends on the strategic use of project managers’ skills and organizational resources to maximize performance. An empirical study was conducted with 475 participants from the construction and engineering sectors. The applied analyses included multiple regression analysis and two-way ANOVA to assess how project manager competencies and organizational types affect business performance. The results of the study show that project manager competencies significantly improve business performance, especially when combined with appropriate organizational types. Effective use of organizational frameworks leads to better financial results, increased market competitiveness, and greater innovation. The results of the study are as follows: First, project manager competencies were found to have a significant positive effect on business performance. Second, the use of functional, project, and matrix organizations had a significant positive effect on business performance. This suggests that aligning organizational structures with business objectives is important for achieving optimal performance. Overall, this study provides valuable insights into the academic literature and practical applications of project management and organizational research. In addition, if we can select organizational members based on the learning effects of previous projects when operating new projects in the future, it will help reduce risks. Ultimately, it will improve the project manager’s competency level, promote the individual abilities and knowledge sharing of team members, and provide opportunities for the company to build efficient new systems. This will be evaluated as a valuable study in terms of academic and practical productivity.
Meristem culture (MC) is a technique for producing virus-free garlic plants with high vigor and productivity. We assessed the changes in the agronomic traits of “Namdo” garlic over several generations after the cultivation of MC-induced bulbils. We examined the plant height, leaf sheath length and diameter, leaf number, bulb weight and diameter, clove number, and bulb size distribution. Compared with that of the control, bulb weights of the first-generation bulbils cultivated for three and two years and the second-generation bulbils cultivated for one year increased by 8.7–27.2, 13.9–30.4, and 36.6–46.9%, respectively. In three and two-year cultivation of the firstgeneration bulbils and one-year cultivation of the second-generation bulbils, the proportions of extra-large-sized bulb weight in meristem-cultured plants were 16.2–38.6, 24.0–35.8, and 27.1–51.1%, respectively, whereas that of the control was 7.6%. Thus, the first-generation bulbils can be cultivated for three years to renew the seed bulbs while maintaining productivity.
대표적인 초식곤충인 나방은 기주식물 특이성을 갖고 있어 기주식물 분포에 따른 식생구조나 서식지 유형을 이해하는데 사용이 가능한 분류군이다. 나방은 종 다양성이 높고 분류학적으로 잘 알려져 있어 조사가 많이 이루 어져 풍부한 데이터가 존재하여 이들의 공간적, 시간적 규모의 생물량 변화 추세를 확인할 수 있다. 본 연구에서는 공간적인 유형에 따라 나방의 생물량을 비교하고자 하였다. 생물량을 추정하기 위해 이용된 분류군은 자나방과, 밤나방과, 태극나방과로 이들 분류군의 앞날개 길이를 기준으로 종별로 계산을 하였다. 공간적인 유형은 숲의 위치(연속된 숲, 파편화된 숲)와 숲의 구성(침엽수림, 활엽수림, 혼효림)을 사용하였다. 그 결과 숲의 위치에 따라 생물량은 차이가 존재했지만(F = 16.76, P < 0.001), 숲의 구성(F = 1.54, P = 0.22)과 숲 위치와 구성의 상호작용은(F = 0.34, P = 0.71) 생물량의 차이를 확인하지 못하였다. 숲 구성에 따라 차이가 나타날 것으로 예상하였지만 나타나 지 않은 데에는 추후 분류군을 더 늘려 확인하는 것이 필요하다. 또한 식물 생물량 추정을 통한 곤충과 먹이자원의 가용 관계를 파악하는 연구도 필요할 것으로 예상한다.
본 연구는 식물공장에서 아쿠아포닉스와 수경재배에서 재배된 딸기의 무기양분 흡수율, 생육, 수량을 비 교하고자 수행되었다. 양어는 비단잉어(Cyprinus carpio) 12마리를 수조(W 0.7m × L 1.5m × H 0.45m, 472.5L)에 367.5L 물을 채운 후 입식하였고 5.44kg·m-3 밀도로 사육하였다. 딸기 모종 30개체는 펄라이트를 채운 포트에 정식 하여 아쿠아포닉스 시스템 베드(W 0.7m × L 1.5m × H 0.22m)에 장착하였고, 모종 30개체는 네트포트에 정식한 후 담액수경(DFT)시스템 베드(W 0.7m × L 1.5m × H 0.22m)의 아크릴판(140 cm × 60 cm, Ø80 mm)에 장착하였다. 재 배기간 동안 아쿠아포닉스 수조액의 pH와 EC는 각각 4.3-6.9, 0.32-1.14dS·m-1 수준이었고, 수경재배는 각각 5.1 -7.5, 1.0-1.8dS·m-1이었다. 아쿠아포닉스 수조액의 NO3-N와 NH4-N 농도는 수경재배보다 각각 약 3.6, 2.2 me·L-1 높았다. P, Ca, Mg, S 농도는 수경재배보다 각각 약 0.76, 3.1, 0.8, 0.9me·L-1 높았으며, K와 Fe는 각각 약 0.8me·L-1, 0.5mg·L-1 낮았다. 딸기 잎의 무기이온 함량은 두 재배 처리 간 유의차가 없었으며 엽내 K 함량은 적정 범위를 보였 다. 정식 후 58과 98일 사이에 아쿠아포닉스에서 재배된 딸기의 T-N와 P 흡수율은 수경재배보다 각각 1.5, 1.9배 높 았고 K 흡수율은 유의차가 없었다. 개체당 과실수는 아쿠아포닉스에서 수경재배보다 유의하게 많았으며, 상품과 생체중, 건물중, 과실의 과장과 과폭은 수경재배에서 아쿠아포닉스보다 높았다. 결과를 종합하면, 아쿠아포닉스에 서는 수조액의 물고기 배설물과 먹이 잔여물에 의한 고체 입자의 비료성분을 지속적으로 가용하여 활용한다는 것 을 알 수 있다.
Pasture formation and management are crucial to avoid yield reduction. This experiment aimed to examine the effects of tall fescue-centered mixed-seeding combinations on yield and vegetation changes in perennial pastures in the central region for two years, from September 2020 to October 2022. The treatments were arranged in three replications in a randomized block design: control (C), tall fescue-based mixture-1 (T-1), and tall fescue-based mixture-2 (T-2). The tall fescue (TF), orchard grass (OG), perennial ryegrass (PRG), Kentucky bluegrass (KBG), and white clover (WC) were used. The emergency rate of grasses (70.0 to 73.3%) did not differ among mixed seeding combinations. Overwintering rates (81.7 to 83.3%) were similar among treatments. The plant height of grasses was similar at each harvest date, with the highest height (86.2 cm) recorded in the second harvest of the first year, followed by that (58.4 cm) in the third harvest of the first year; it was least (38.9 cm) in the fourth harvest of the second year. There was no significant difference in the dry matter yield of grasses among the mixed seeding combination treatments in the first, third, or fourth harvests of the first year (p>0.05). For second-year grasses, dry matter yield was not significantly different in harvest date among the treatments (p>0.05). Based on mixed seeding ratio, orchard grass showed the highest yield at 70% in the C treatment, followed by tall fescue at 80% and 60% in the T-1 and T-2 treatments, respectively, in the first harvest after seeding. There was no significant difference in feed value between treatments (p>0.05), but a significant difference was observed between the third and fourth harvest (p<0.05). Therefore, it indicated that it is important to create perennial pastures in the central region through mixed seeding combinations centered on tall fescue.
기후변화와 세계시장 개방에 따른 외래 및 돌발해충의 종류는 다양해지고 밀도는 지속적으로 증가하고 있지 만 발생 실태에 관한 자료는 미흡하다. 본 연구는 경남지역 돌발 및 남방계 해충의 발생과 피해조사를 위해 미국선 녀벌레, 썩덩나무노린재, 담배거세미나방 등 3종을 경남 18시·군에서 조사하였다. 미국선녀벌레는 약충기(6월), 성충기(9월) 조사를 진행하였고, 길이가 50cm 이상되는 가지의 밑동에서 위쪽으로 50cm 내 개체를 육안조사하 였다. 썩덩나무노린재는 콩 개화기(7월), 등숙기(9월) 조사를 진행하였고 지점당 집합페로몬 트랩 1개를 설치하 고 1주 후 채집된 마리 수를 조사하였다. 담배거세미나방은 성페로몬 트랩 1개를 설치한 뒤 1주 후 채집된 마리 수를 조사하였다. 미국선녀벌레는 의령, 함안, 함양 등에서 발생이 많았고, 전년대비 발생이 소폭 감소하였다. 썩덩나무노린재는 합천, 밀양, 함양 등에서 발생이 많았고, 담배거세미나방은 전시군에서 발생이 확인되었으 며, 특히 함양, 산청, 사천, 고성 등에서 밀도가 높았다.
최근 기후변화에 따라 아열대 작물 재배가 증가하면서 경남지역 망고 재배면적도 크게 증가하고 있다. 하지만 망고에 발생하는 병해충 발생 정보가 부족하여 2022년부터 현재까지 경남지역에 있는 망고농장을 조사하였으 며, 그 결과 병해 6종, 해충 8종 발생을 확인하였다. 특히 경남지역 망고 포장에서 꽃노랑총채벌레, 대만총채벌레, 볼록총채벌레 등의 발생을 확인하였고, 통영, 함안, 밀양 등에서 총채벌레류에 의한 피해가 발생하였다. 많은 농가에서 총채벌레류 방제를 위해 화학농약에 의존하고 있으나 총채벌레는 반복적인 약제 노출시 빠른 세대 진전으로 인해 저항성 발달이 쉽기때문에 방제에 어려움을 겪고 있다. 이러한 문제를 해결하고자 색상별 끈끈이 트랩의 총채벌레류 유인효과를 확인하였으며, 꽃노랑총채벌레는 노랑, 주황, 연두, 대만총채벌레는 빨강, 노랑, 파랑, 볼록총채벌레는 파랑, 노랑, 빨강 순으로 유인효과가 높은 것을 확인하였다.
Recently, defects that occurred during the construction of apartment houses have become a social issue. Defects in apartment houses lead to waste of resources and economic loss, causing psychological and physical damage to customers, and a decrease in reliability and financial loss to construction companies. The purpose of this study was to analyze the impact of defect occurrence according to the difference in project management level in the apartment housing construction stage, and to investigate the extent to which the project manager's experience affects the defect occurrence rate. For the empirical analysis of the study, statistical analysis was conducted using data collected from 130 actual projects. The results of the analysis showed that schedule management, cost management, and quality management had a positive effect on reducing the defect occurrence rate in the execution stage of apartment housing construction, while human resource management productivity had a negative effect. This study theoretically demonstrated the importance of project management, and in practice, showed that schedule management, cost management, and quality management should be faithfully performed in the execution stage to reduce the rate of defects after project completion. It was also suggested that hiring an experienced project manager would help reduce project defects.
Marine macroalgae are important in coastal ecosystems and interact with marine microorganisms. In this study, we isolated fungi from seven types of marine macroalgae including Cladophora sp., Gloiopeltis furcate, Gracilariopsis chorda, Hydroclathrus clathratus, Prionitis crispata, Sargassum micracanthum, and Ulva lactuca collected in Korea. Morphological and phylogenetic analyses identified the isolates as four Aspergillus spp. (A. fumigatus, A. sydowii, A. tamarii, and A. terreus), three Penicillium spp. (P. crustosum, P. jejuense, and P. rubens), and Cladosporium tenuissimum. Among them, A. fumigatus TOPU2, A. tamarii SH-Sw5, and A. terreus GJ-Gf2 strains showed the activities of all enzymes examined (amylase, chitinase, lipase, and protease). Based on the enzymatic index (EI) values in solid media, A. terreus GJ-Gf2 and C. tenuissimum UL-Pr1 exhibited the highest amylase and lipase activities, respectively. Chitinolytic activity was only observed in A. terreus GJ-Gf2, A. tamarii SH-Sw5, and A. fumigatus TOP-U2. Penicillium crustosum ULCl2 and C. tenuissimum UL-Pr1 showed the highest protease activities. To the best of our knowledge, this is the first report of lipolytic and proteolytic activities in a marine-derived C. tenuissimum strain. Overall, the fungal strains isolated from the marine macroalgae in this study actively produced industrially important enzymes.