Anginosus group streptococci (AGS) were classified based on the nucleotide sequences of the 16S rRNA gene (16S rDNA) and comprised Streptococcus anginosus, Streptococcus intermedius, and Streptococcus constellatus. It is known that AGS is a causative factor of oral and systematic diseases. The purpose of this study was to discriminate the 56 clinical strains of AGS isolated from Korean oral cavities using phylogenetic analysis of 16S rDNA and species‐specific PCR at the species-level. The 16S rDNA of clinical strains of AGS was sequenced using the dideoxy chain termination method and analyzed using MEGA version 5 software. PCR was performed to identify the clinical strains using species‐specific primers described in previous studies and S. intermedius‐specific PCR primers eveloped in our laboratory. The resulting phylogenetic data showed that the 16S rDNA sequences can delineate the S. anginosus, S. intermedius, and S. constellatus strains even though the 16S rDNA sequence similarity between S. intermedius and S. constellatus is above 98%. The PCR data showed that each speciesspecific PCR primer pair could iscriminate between clinical strains at the species‐level through phylogenetic analysis of 16S rDNA nucleotide sequences. These results suggest that phylogenetic analysis of 16S rDNA and PCR are useful tools for discriminating between AGS strains at the species-level.

Copepod nauplii plays an important role as a linker between the microbial food web and classical food chain in marine ecosystem and is an essential food source for early stage of many larval fishes. Study on the influencing factors on the growth of copepo

Noctiluca scintillans의 시간적 변동과 생태학적 특성을 파악하기 위해 N. scintillans의 현존량과 수리-생물학적 요인에 대한 조사가 1999년 1월부터 2000년 12월까지 인천 연안에서 수행되었다. N. scintillans는 수온 10.3~21.5℃ 범위를 보인 춘계 및 추계에 출현 개체수가 높았으며 동계 및 하계에 낮았다. 동계에는 4.5℃이하 수온에서 출현이 제한되는 것으로 보