Analysis of Microcystis aeruginosa physiology by spectral flow cytometry: Impact of chemical and light exposure. new technique to observe photosynthesis to monitor the health or cyanobacteria and their reaction to hydrogen peroxide. This dataset is not publicly accessible because: The public would require specialized software in order to view and interpret files. It can be accessed through the following means: Email zucker.robert@epa.gov. Format: The data in the paper is acquired in proprietary format from the manufacturer of the equipment. This data presented in the paper can be read only by using the software from the manufacturer which is quite costly and not feasible to purchase unless the scientist owns the equipment. This dataset is associated with the following publication: Brentjens, E., E. Beall, and R. Zucker. Analysis of Microcystis aeruginosa physiology by spectral flow cytometry: Impact of chemical and light exposure. PLOS Water. Public Library of Science, San Francisco, CA, USA, 2(10): e0000177, (2023).

Data includes quantification of microcystin by ELISA and quantification of gene copy number for Microcystis aeruginosa. In addition the genomic sequences associated with glucose addition to lake water are shown. This dataset is not publicly accessible because: public link too long. It can be accessed through the following means: https://gcc02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fsra%2FPRJNA786865&data=04%7C01%7CLinz.David%40epa.gov%7Cf41cc9e7fe7449eb4b1308d9bbc99a0f%7C88b378b367484867acf976aacbeca6a7%7C0%7C0%7C637747296829394696%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=F%2FUVwqnPj4pzWRiccZKHXh2jcxZ9bWxx1MD1Ux%2B1TBM%3D&reserved=0. Format: https://gcc02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fsra%2FPRJNA786865&data=04%7C01%7CLinz.David%40epa.gov%7Cf41cc9e7fe7449eb4b1308d9bbc99a0f%7C88b378b367484867acf976aacbeca6a7%7C0%7C0%7C637747296829394696%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=F%2FUVwqnPj4pzWRiccZKHXh2jcxZ9bWxx1MD1Ux%2B1TBM%3D&reserved=0. This dataset is associated with the following publication: Vesper, S., N. Sienkiewicz, I. Struewing, D. Linz, and J. Lu. Prophylactic Addition of Glucose Suppresses Cyanobacterial Abundance in Lake Water. Life. MDPI AG, Basel, SWITZERLAND, 12(3): 385, (2022).

The dataset including qPCR and microcystin is used for assessment of treatment. This dataset is associated with the following publication: Struewing, I., N. Sienkiewicz, C. Zhang, N. Dugan, and J. Lu. Effective Early Treatment of Microcystis Exponential Growth and Microcystin Production with Hydrogen Peroxide and Hydroxyapatite. Toxins. MDPI, Basel, SWITZERLAND, 15(1): 3, (2023).

From 2017-2019, the Upper Midwest Environmental Sciences Center (UMESC) analyzed microcystin concentrations in samples collected from three different studies. The first study was on the movement and distribution of invasive carp (Bighead Carp, Silver Carp, Grass Carp) in the upper Mississippi River between lock and dam 16 and lock and dam 19. Samples were collected from May through October of 2017 and 2018 from backwaters, impounded areas and main channel areas in this reach of the Mississippi River. The second study was a nutrient and metal amendment study performed on natural phytoplankton communities from Lake Erie and Lake Michigan. This was a laboratory study where natural phytoplankton communities were incubated for 72 hours with amendments of ammonium, phosphate and metals (iron, zinc, molybdenum, nickel and manganese). After 72 hours, communities were sampled for microcystin concentration (among other metrics not reported here). The third study was a nutrient diffusing substrate study, where periphyton were grown on suspended substrates that leached nutrients or metals. After two weeks of deployment periphyton was collected from the substrates, diluted in purified water and then analyzed for microcystin concentration. Microcystin concentrations for all experiments were estimated using enzyme-linked immunosorbent assay (ELISA) test kits. We used a Bayesian method to calibrate the absorbance data from the kit and report here on both the microcystin concentrations of the samples analyzed, but also report the raw absorbance data from both samples and calibration standards so that others could recreate the microcystin analysis using other methods if they so choose.

The data include sequences, qPCR, RT-qPCR, water nutrients and cyanotoxins.

(1) qPCR and RT-qPCR for cyanotoxin producing genes, and (2) some water quality parameters. This dataset is associated with the following publication: Duan, X., C. Zhang, I. Struewing, X. Li, H. Allen, and J. Lu. Cyanotoxin-encoding genes as powerful predictors of cyanotoxin production during harmful cyanobacterial blooms in an inland freshwater lake: Evaluating a novel early-warning system. SCIENCE OF THE TOTAL ENVIRONMENT. Elsevier BV, AMSTERDAM, NETHERLANDS, 830: 154568, (2022).

This dataset shows the effects of imazapic (detected in the Great Barrier Reef catchments) on the growth rate (from cell density data) on the cyanobacteria Microcystis aeruginosa over a 72 hour exposure period during laboratory experiments conducted in 2019. The aims of this project were to develop and apply standard ecotoxicology protocols to determine the effects of Photosystem II (PSII) and alternative herbicides on the growth of the cyanobacteria Microcystis aeruginosa. Growth bioassays were performed over 3-day exposures using imazapic which has been detected in the Great Barrier Reef catchment area (O’Brien et al. 2016). This toxicity data will enable improved assessment of the risks posed by the herbicide imazapic to cyanobacteria for both regulatory purposes and for comparison with other taxa. Methods: The cyanobacteria Microcystis aeruginosa (Kutzing) Kutzing 1846 (Cyanophyceae) (CS338/01) was purchased from the Australian National Algae Supply Service, Hobart (CSIRO). Cultures of M. aeruginosa were established in MLA medium (Bolch and Blackburn 1996). Cultures were maintained in sterile 250 mL Erlenmeyer flasks as batch cultures in exponential growth phase with weekly transfers of 1 - 3 mL of a 7 day-old M. aeruginosa suspension to 100 mL MLA medium under sterile conditions. Clean culture solutions were maintained at 26 ± 2°C, and under a 12:12 h light:dark cycle (91 ± 12 µmol photons m–2 s–1). Imazapic stock solution was prepared using PESTANAL (Sigma-Aldrich) analytical grade (HPLC greater than or equal to 98%) imazapic (CAS 104098-48-8). The selection of imazapic was based on application rates and detection in coastal waters of the GBR (Grant et al. 2017, O’Brien et al. 2016). Imazapic stock solution was prepared in 1 L volumetric flasks using milli-Q water. Imazapic was dissolved using analytical grade methanol (final concentration < 0.01% (v/v) in exposures). Cultures of M. aeruginosa were exposed to a range of herbicide concentrations over a period of 72 h. The inoculum was taken from cultures in the exponential growth phase (4 - 7-day-old cultures). A M. aeruginosa working suspension was prepared in a 100 mL volumetric flask. A 1:10 and 1:100 dilution was prepared and counted using a haemocytometer under a compound microscope to determine appropriate dilution volumes. The pre-determined inoculum was added to 50 mL of each test and control treatment replicates to the required dilution (3.1 x 104 cells / mL). A control (no herbicide) and solvent control treatment was added to support the validity of the test protocols and to monitor continued performance of the assays. All treatment concentrations were prepared in 0.5x strength MLA medium. Replicates were incubated at 26.6 ± 0.5 °C under a 12:12 h light:dark cycle (59 ± 9.7 µmol photons m–2 s–1). Sub-samples were taken from each replicate to measure cell densities of algal populations at 72 h using a haemocytometer under phase contrast conditions. Cell counts were done manually. Specific growth rates (SGR) were expressed as the logarithmic increase in cell density from day i (ti) to day j (tj) as per equation (1), where SGRi-j is the specific growth rate from time i to j; Xj is the cell density at day j and Xi is the cell density at day i (OECD 2011). SGR i-j = [(ln Xj - ln Xi )/(tj - ti )] (day-1) (1) SGR relative to the solvent control treatment was used to derive chronic effect values for growth inhibition. A test was considered valid if the SGR of solvent control replicates was ? 0.92 day-1 (OECD 2011). Physical and chemical characteristics (pH, electrical conductivity and temperature) of each treatment solution was measured at 0 hr and 72 hr. Growth cabinet temperature was logged in 15-min intervals over the total test duration. Analytical samples were taken at 0 hr and 72 hr. Mean percent inhibition in SGR of each treatment relative to the control treatment was calculated as per equation (2)(OECD 2011), where Xcontrol is the average SGR of solvent control

The manuscript builds on work performed as part of the PhD project of AIMS@JCU PhD student Danilo Malara. Thesis title: Photodynamic antimicrobial chemotherapy for pathogenic Vibrio control in prawn hatcheries. Chapter 4: Sensitivity of live microalgal aquaculture feed to photo antimicrobial chemotherapy. JCU supervisors were Kirsten Heimann and Michael Oelgemoeller. Summary and Importance: Photodynamic antimicrobial chemotherapy is an emerging sterilization technique based on chemical compounds activated by light. We tested the suitability of this technique for cleaning up bacteria growing in microalgae cultures used as feed in aquaculture. We found that the cell wall of the microalgae determines if the technique is toxic to the microalgae itself. The techniques is suitable for sterilising only one of the tested microalgae-species, Nannochloropsis oculata. Instead, the technique has potential for killing unwanted microalgae in aquaria and aquaculture facilities, but this would require further studies. Description of experiments: An experiment was performed at JCU using a cationic porphyrin (TMPyP) as the photosensitizer and the following microalgae cultures: Tisochrysis lutea, Nannochloropsis oculata, Tetraselmis chui, Picochlorum atomus, Chaetoceros muelleri. A range of porphyrin concentrations (0 - 50 micromolar) and treatment times (1 - 6 hours) were tested for each microalgae species. Only Nannochloropsis oculata was resistant to the porphyrin treatment. This species was used in a disinfection experiment, where bacterial contamination was simulated by adding a naturally luminescent bacterium, Vibrio campbellii ISO7, at three different concentrations (1E3 CFUs/ml, 1E5 CFUs/ml, 1E7 CFUs/ml). In each case, an optimised disinfection protocol (based on experiments described above) was used with 20 micromolar porphyrin and 6 hour treatment. The disinfection experiment itself, including the inoculation of agar plates and most probable number (MPN) enrichment cultures, was done at JCU. Sealed agar plates and boiled cell pellets were brought to AIMS for visualisation of luminescent colonies on the gel doc system and for multiplex PCR, respectively. The data set includes: Flow cytometry data to determine microalgae viability. Dry weight and cell count determination of microalgae culture for biomass standardisation. Plate reader data (luminescence) to determine the concentration of the bacterial pure culture. Photos of agar plates showing luminescent bacterial colonies (added model bacterium) Gel photos showing results of multiplex PCRs of MPN-enrichment cultures (to quantify added model bacterium).

In 2015-2018, the U.S. Geological Survey (USGS) in cooperation with the U.S. Environmental Protection Agency Great Lakes Restoration Initiative investigated the biodegradation of microcystins in source waters and sand filters from drinking-water plants in the Western Lake Erie Basin. Four source waters and three sand filtrate samples were collected from the intakes and sand filters of Lake Erie drinking-water plants and transported to the USGS Ohio Water Microbiology Laboratory, where investigators set up microcosms to enrich for and identify indigenous bacteria capable of degrading microcystins. Quality control samples were set up in the microcosms to check analyses and included positive controls, negative controls, and replicates. Microcystin biodegradation was quantified by the disappearance of the toxin as compared to control cultures in microcosm and microplate experiments, and by the presence of a gene within microcystin-degrading bacteria that encodes for an enzyme involved in the initial steps of biodegradation. Bacteria were isolated from microcosms enriched with microcystin-LR (MC-LR) and MC-LR concentrations were measured over time by ELISA (table 1). Isolates were selected from the microcosm experiments for further growth testing in microplate experiments with various enrichment media and MC-LR over 96 hours (table 2). Biofilm formation potential for the isolates were also measured and data is shown in table 3. Isolate absorbances of ten potential microcystin degraders were incubated in a microplate with MC-LR as the sole carbon source (table 4) and concentrations of MC-LR in microplate wells were measured over time (table 5).