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
Cyanobacteria can produce cyanotoxins such as microcystin-LR(MC),saxitoxin(STX),and anatoxin-a(ANTX-a)which are harmful to humans and other animals.Individual removal efficiencies of STX and ANTX-a by powdered activat...Cyanobacteria can produce cyanotoxins such as microcystin-LR(MC),saxitoxin(STX),and anatoxin-a(ANTX-a)which are harmful to humans and other animals.Individual removal efficiencies of STX and ANTX-a by powdered activated carbon(PAC)was investigated,aswell as when MC-LR and cyanobacteriawere present.Experimentswere conductedwith distilled water and then source water,using the PAC dosages,rapid mix/flocculation mixing intensities and contact times of two drinking water treatment plants in northeast Ohio.At pH 8 and 9,STX removal was 47%-81%in distilled water and 46%-79%in source water,whereas it was 0-28%for pH 6 in distilled water and 31%-52%in source water.When 1.6μg/L or 20μg/L MC-LR was present with STX,STX removal was increased with PAC simultaneously removing 45%-65%of the 1.6μg/L MC-LR and 25%-95%of the 20μg/L MC-LR depending on the pH.ANTX-a removal at pH 6 was 29%-37%for distilled water and 80%for source water,whereas it was 10%-26%for pH 8 in distilled water and 28%for pH 9 in source water.The presence of cyanobacteria cells decreased ANTX-a removal by at least 18%.When 20μg/L MC-LR was present with ANTX-a in source water,59%-73%ANTX-a and 48%-77%of MCLR was removed at pH 9 depending on the PAC dose.In general,a higher PAC dose led to higher cyanotoxin removals.This study also documented that multiple cyanotoxins can be effectively removed by PAC for water at pH’s between 6 and 9.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This work was supported by the Ohio Department of Higher Education Harmful Algal Bloom Research Initiative(No.60075961).Funding was solely for support of conducting the research.The authorswould like to thank Jessica Glowczewski fromCity of Akron and Amy Elliot fromCity of Alliance for providing water treatment details and permission for source water collection as well as Dr.Xiaozhen Mou and Madison Summers from Kent State University for assistance in conducting the toxin measurements.
文摘Cyanobacteria can produce cyanotoxins such as microcystin-LR(MC),saxitoxin(STX),and anatoxin-a(ANTX-a)which are harmful to humans and other animals.Individual removal efficiencies of STX and ANTX-a by powdered activated carbon(PAC)was investigated,aswell as when MC-LR and cyanobacteriawere present.Experimentswere conductedwith distilled water and then source water,using the PAC dosages,rapid mix/flocculation mixing intensities and contact times of two drinking water treatment plants in northeast Ohio.At pH 8 and 9,STX removal was 47%-81%in distilled water and 46%-79%in source water,whereas it was 0-28%for pH 6 in distilled water and 31%-52%in source water.When 1.6μg/L or 20μg/L MC-LR was present with STX,STX removal was increased with PAC simultaneously removing 45%-65%of the 1.6μg/L MC-LR and 25%-95%of the 20μg/L MC-LR depending on the pH.ANTX-a removal at pH 6 was 29%-37%for distilled water and 80%for source water,whereas it was 10%-26%for pH 8 in distilled water and 28%for pH 9 in source water.The presence of cyanobacteria cells decreased ANTX-a removal by at least 18%.When 20μg/L MC-LR was present with ANTX-a in source water,59%-73%ANTX-a and 48%-77%of MCLR was removed at pH 9 depending on the PAC dose.In general,a higher PAC dose led to higher cyanotoxin removals.This study also documented that multiple cyanotoxins can be effectively removed by PAC for water at pH’s between 6 and 9.
