We have verified the use of a serial filtration method to isolate picocyanobacteria for analysis. We used eDNA metabarcoding to confirm the picocyanobacteria as members of the Order Synechococcales, Genus Cyanobium, s...We have verified the use of a serial filtration method to isolate picocyanobacteria for analysis. We used eDNA metabarcoding to confirm the picocyanobacteria as members of the Order Synechococcales, Genus Cyanobium, specifically Cyanobium 6307. Fluorometric analysis using accessory pigments phycocyanin and phycoerythrin described periods of excess biomass, where the net growth rate model confirmed these conditions. The total anatoxin-a concentrations in the picocyanobacterial sample ranged from 0.0074 - 6.41 μg·L<sup>-1</sup> representing a 40-fold difference over the entire sampling season. Sampling frequency of every three days appeared to be an important factor in capturing these changes in anatoxin-a concentration. During a period of excess biomass, we were able to establish a linear correlation between cyanobacterial biomass and Anatoxin-a concentrations.展开更多
We have used serial filtration to isolate picocyanobacteria from brackish and marine microhabitats for analysis. We used 16s metabarcoding to confirm the picocyanobacteria as members of the Order Synechococcales, Genu...We have used serial filtration to isolate picocyanobacteria from brackish and marine microhabitats for analysis. We used 16s metabarcoding to confirm the picocyanobacteria as members of the Order Synechococcales, Genus Cyanobium 6307 (Upper Chilmark Pond) and differing abundances of Cyanobium 6307 and Synechococcus 9902 (Chilmark Pond, Edgartown Great Pond, Tisbury Great Pond and Tashmoo Pond). The proportion and composition of (pico)cyanobacteria in water samples were influenced by the salinity concentrations at various sites, as evidenced by fluorometry and 16s metabarcoding analysis. The cyanobacterial neurotoxin anatoxin-a was present in the picocyanobacterial samples from all studied sites. Additional analyses using fluorometry and 16s metabarcoding described members of the Order Nostocales, including a halotolerant population of Dolichospermum sp., Sphaerospermopsis spp. and Nodularia spp. in Upper Chilmark Pond. We were able to establish a positive linear correlation between cyanobacterial biomass (phycocyanin) and anatoxin-a concentrations using samples taken from Upper Chilmark Pond.展开更多
Variations of picoplankton groups were investigated over a one-month period in Daya Bay and Sanya Bay,in the northern South China Sea.The two coastal regions exhibited different variation patterns in physicochemical p...Variations of picoplankton groups were investigated over a one-month period in Daya Bay and Sanya Bay,in the northern South China Sea.The two coastal regions exhibited different variation patterns in physicochemical parameters.Moreover,the diel variations of picoplankton groups were different between the two bays.The abundance of the picoplankton in Sanya Bay displayed a pronounced diel variation,while it was not significant in Daya Bay.In addition,some similar patterns of picoplankton abundance were discovered.In the two bays,virioplankton exhibited the smallest fluctuation range,whereas picocyanobacteria fluctuated most markedly.The fluctuation range of picoplankton groups was larger in spring tide than in neap tide,especially in Sanya Bay.Random forest model analysis demonstrated that the variation of picoplankton groups was attributed to physical and chemical factors in Sanya Bay and Daya Bay,respectively.Therefore,our findings suggest that virioplankton abundance can persist more stably in response to changing environmental conditions compared to bacterioplankton and picophytoplankton.展开更多
文摘We have verified the use of a serial filtration method to isolate picocyanobacteria for analysis. We used eDNA metabarcoding to confirm the picocyanobacteria as members of the Order Synechococcales, Genus Cyanobium, specifically Cyanobium 6307. Fluorometric analysis using accessory pigments phycocyanin and phycoerythrin described periods of excess biomass, where the net growth rate model confirmed these conditions. The total anatoxin-a concentrations in the picocyanobacterial sample ranged from 0.0074 - 6.41 μg·L<sup>-1</sup> representing a 40-fold difference over the entire sampling season. Sampling frequency of every three days appeared to be an important factor in capturing these changes in anatoxin-a concentration. During a period of excess biomass, we were able to establish a linear correlation between cyanobacterial biomass and Anatoxin-a concentrations.
文摘We have used serial filtration to isolate picocyanobacteria from brackish and marine microhabitats for analysis. We used 16s metabarcoding to confirm the picocyanobacteria as members of the Order Synechococcales, Genus Cyanobium 6307 (Upper Chilmark Pond) and differing abundances of Cyanobium 6307 and Synechococcus 9902 (Chilmark Pond, Edgartown Great Pond, Tisbury Great Pond and Tashmoo Pond). The proportion and composition of (pico)cyanobacteria in water samples were influenced by the salinity concentrations at various sites, as evidenced by fluorometry and 16s metabarcoding analysis. The cyanobacterial neurotoxin anatoxin-a was present in the picocyanobacterial samples from all studied sites. Additional analyses using fluorometry and 16s metabarcoding described members of the Order Nostocales, including a halotolerant population of Dolichospermum sp., Sphaerospermopsis spp. and Nodularia spp. in Upper Chilmark Pond. We were able to establish a positive linear correlation between cyanobacterial biomass (phycocyanin) and anatoxin-a concentrations using samples taken from Upper Chilmark Pond.
基金Supported by the National Natural Science Foundation of China(Nos.42176116,41576126,41890851,U21A6001)the Natural Science Foundation of Guangdong Province(No.2017A030306020)+4 种基金the Guangdong Major Project of Basic and Applied Basic Research(No.2019B030302004)the Rising Star Foundation of the South China Sea Institute of Oceanology(No.NHXX2019ST0101)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2018377)the Science and Technology Planning Project of Guangdong Province of China(No.2021B1212050023)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA19060503)。
文摘Variations of picoplankton groups were investigated over a one-month period in Daya Bay and Sanya Bay,in the northern South China Sea.The two coastal regions exhibited different variation patterns in physicochemical parameters.Moreover,the diel variations of picoplankton groups were different between the two bays.The abundance of the picoplankton in Sanya Bay displayed a pronounced diel variation,while it was not significant in Daya Bay.In addition,some similar patterns of picoplankton abundance were discovered.In the two bays,virioplankton exhibited the smallest fluctuation range,whereas picocyanobacteria fluctuated most markedly.The fluctuation range of picoplankton groups was larger in spring tide than in neap tide,especially in Sanya Bay.Random forest model analysis demonstrated that the variation of picoplankton groups was attributed to physical and chemical factors in Sanya Bay and Daya Bay,respectively.Therefore,our findings suggest that virioplankton abundance can persist more stably in response to changing environmental conditions compared to bacterioplankton and picophytoplankton.
