• ALGAE
• /
• 제29권4호
• /
• pp.311-319
• /
• 2014

The biocide sodium hypochlorite (NaOCl) is widely used for controlling algal growth, and this application can be extended to marine environments as well. This study evaluates the biocidal efficiency and cellular toxicity of NaOCl on the harmful dinoflagellate Cochlodinium polykrikoides, with emphasis on pigment production and antioxidant enzyme activity. The test organism showed dose-dependent decrease in growth rate on exposure to NaOCl, and the 72 h $EC_{50}$ was measured to be $0.584mg\;L^{-1}$. NaOCl significantly decreased pigment levels and chlorophyll autofluorescence intensity, indicating possible detrimental effects on the photosystem of C. polykrikoides. Moreover, it significantly increased the activities of antioxidant enzymes, suggesting the production of reactive oxygen species in the cells. These data indicate that NaOCl exerted deleterious effects on the photosynthetic machinery and induced oxidative damage in the dinoflagellate and this biocide could be effectively used for the control of algal blooms.

• 미생물학회지
• /
• 제30권2호
• /
• pp.129-133
• /
• 1992

소양호에서 여름에 출현하는 동물 플랑크톤의 포식 작용을 형광 현미경으로 관찰하였다. 형광 bead 와 형광 염색한 세균을 bacterivore 로 보았으며 장내에서 엽록소의 autofluorescence 가 발견되는 것은 algavore 로 보았다. Copepoda 의 유츙과, Thermocyclops, Pleosoma 등은 algavore 였으며, Daphnia, Bosmina, Keratella, Hexathra 등은 bacteriovore 였다. 개체수로는 65.7% 가 algavore 였으며, 34.4% 가 bacteriovore 였다. Bacteriovore 인 동물 플랑크톤은 직경이 0.5 $\mu$m 이상인 입자를 선호하였으며, 형광 bead 와 형광 엽색 세균은 섭취율에 큰차이가 없었다.

• 환경생물
• /
• 제38권3호
• /
• pp.424-432
• /
• 2020

The present study aimed to analyze the metaproteome of the microbial community comprising harmful algal bloom (HAB) in the Daechung reservoir, Korea. HAB samples located at GPS coordinates of 36°29'N latitude and 127°28'E longitude were harvested in October 2013. Microscopic observation of the HAB samples revealed red signals that were presumably caused by the autofluorescence of chlorophyll and phycocyanin in viable cyanobacteria. Metaproteomic analysis was performed by a gelbased shotgun proteomic method. Protein identification was conducted through a two-step analysis including a forward search strategy (FSS) (random search with the National Center for Biotechnology Information (NCBI), Cyanobase, and Phytozome), and a subsequent reverse search strategy (RSS) (additional Cyanobase search with a decoy database). The total number of proteins identified by the two-step analysis (FSS and RSS) was 1.8-fold higher than that by one-step analysis (FSS only). A total of 194 proteins were assigned to 12 cyanobacterial species (99 mol%) and one green algae species (1 mol%). Among the species identified, the toxic microcystin-producing Microcystis aeruginosa NIES-843 (62.3%) species was the most dominant. The largest functional category was proteins belonging to the energy category (39%), followed by metabolism (15%), and translation (12%). This study will be a good reference for monitoring ecological variations at the meta-protein level of aquatic microalgae for understanding HAB.