A new species of the cave-dwelling springtail Lethemurus coreanus Chang and Bae, sp. n. is described from Korea. Lethemurus coreanus can be distinguished from congeners by the spinelike setae on the tibiotarsus, numbers of dental spines, number of setae on the trochanteral organ, and body macrochaetae chaetotaxy. A key to the species of Lethemurus is provided.
본 연구에서는 수수 등겨에 함유되어 있는 타닌의 새로운 천연 색소자원으로서의 활용 가능성을 알아보기 위해서 추출된 색소의 성분을 조사하였으며, Fe와의 킬레이트 반응 조건과 킬레이트화 색소에 대한 여러 가지 특성이 조사되었다.
수수 등겨로부터 추출된 수용액의 흡수 스펙트럼에서는 자외선 영역인 281 nm에서 타닌에 의한 최대 흡수 peak을 보여주고 있다. pH 조건에 따른 킬레이트화 반응에서는 pH 7.5의 반응 조건이 가장 효과적이었다. Fe 농도 2 mg/L 까지는 킬레이트화 반응이 급격히 증가하나, 그 이상의 농도에서는 더 이상의 추가적인 킬레이트화는 없는 것으로 나타났다
킬레이트화 된 타닌 색소의 입자 크기는 4.5~17 μm, 20~42 μm, 45~80 μm, 83~160 μm 범위의 네 그룹으로 나누어지는 것을 확인 할 수 있었다. DSC 분석에서는 타닌의 킬레이트화에 따라 열분해에 기인한 흡열 peak가 크게 증가(318oC→415oC)한다는 것을 확인 할 수 있었으며, TGA 분석에서도 열분해 시작 온도가 253oC에서 382oC까지 상승하는 것을 알 수 있어, 킬레이트화는 열 안정성을 향상시킨다는 것을 확인하였다.
In this study, silk sericin solutions and films were prepared with different solvents: formic acid and water. Also, silk sericin film from aqueous solution was prepared at different casting temperature. Regardless of solvent type, silk sericin solutions showed a shear thinning implying highly molecular entangled state of silk sericin. Silk sericin aqueous solution showed a higher turbidity than that of formic acid solution. Silk sericin aqueous solution showed shorter gelation time than formic acid. FTIR results showed β-sheet crystallization of silk sericin was affected by casting solvent and temperature. Silk sericin film from aqueous solution showed more β-sheet conformation as the casting temperature was decreased. Silk sericin film from formic acid showed higher crystallinity index than silk sericin films cast from aqueous solution. XRD diffraction measurement showed similar results to those of FTIR. In case of mechanical properties, tensile strength of sericin film from formic acid was higher than sericin films from aqueous solution.
Cave-dwelling springtail studies in Korea initiated during 1960s by the Japanese Collembola researcher, R. Yosii, and comprehensive taxonomic studies on Korean Collembola were conducted by B. H. Lee during 1970-1990s wherein the new family Gulgastruridae was established using the type species Gulgastrura reticulosa from the Gossidonggul cave in Gangwon-do, South Korea. Eight families of cave-dwelling Collembola are known in Korea, and the family Tomoceridae is the most abundant and diverse group of cave-dwelling Collembola with 11 known species belonging to 4 genera in Korea. In this study, 12 species of Korean Tomoceridae are reviewed, and 1 new species from the genus Plutomurus and 2 new species from the genus Tomocerus are described.