Micro-algae assisted green bioremediation of water pollutants rich leachate and source products recovery.

Water management and treatment are high concern fields with several challenges due to increasing pollutants produced by human activity. It is imperative to find integral solutions and strategic measures with robust remediation. Landfill leachate production is a high concern emerging problem. Especially in low middle-income countries due to no proper local waste disposition regulation and non-engineered implemented methods to dispose of urban waste. These landfills can accumulate electronic waste and release heavy metals during the degradation process. Similar phenomena include expired pharmaceuticals like antibiotics. All these pollutants accumulated in leachate made it hard to dispose of or treat. Leachate produced in non-engineered landfills can permeate soils and reach groundwater, dragging different contaminants, including antibiotics and heavy metals, which eventually can affect the environment, changing soil properties and affecting wildlife. The presence of antibiotics in the environment is a problem with particular interest to solve, mainly to avoid the development of antibiotic-resistant microorganisms, which represent a future risk for human health with possible epidemic implications. It has been reported that the use of contaminated water with heavy metals to produce and grow vegetables is a risk for consumers, heavy metals effects in humans can include carcinogenic induction. This work explores the opportunities to use leachate as a source of nutrients to grow microalgae. Microalgae stand out as an alternative to bioremediate leachate, at the same time, microalgae produce high-value compounds that can be used in bioplastic, biofuels, and other industrial applications.

Elucidate microbial characteristics in a full-scale treatment plant for offshore oil produced wastewater.

Oil-produced wastewater treatment plants, especially those involving biological treatment processes, harbor rich and diverse microbes. However, knowledge of microbial ecology and microbial interactions determining the efficiency of plants for oil-produced wastewater is limited. Here, we performed 16S rDNA amplicon sequencing to elucidate the microbial composition and potential microbial functions in a full-scale well-worked offshore oil-produced wastewater treatment plant. Results showed that microbes that inhabited the plant were diverse and originated from oil and marine associated environments. The upstream physical and chemical treatments resulted in low microbial diversity. Organic pollutants were digested in the anaerobic baffled reactor (ABR) dominantly through fermentation combined with sulfur compounds respiration. Three aerobic parallel reactors (APRs) harbored different microbial groups that performed similar potential functions, such as hydrocarbon degradation, acidogenesis, photosynthetic assimilation, and nitrogen removal. Microbial characteristics were important to the performance of oil-produced wastewater treatment plants with biological processes.

Diesel and Crude Oil Biodegradation by Cold-Adapted Microbial Communities in the Labrador Sea.

Oil spills in the subarctic marine environment off the coast of Labrador, Canada, are increasingly likely due to potential oil production and increases in ship traffic in the region. To understand the microbiome response and how nutrient biostimulation promotes biodegradation of oil spills in this cold marine setting, marine sediment microcosms amended with diesel or crude oil were incubated at in situ temperature (4°C) for several weeks. Sequencing of 16S rRNA genes following these spill simulations revealed decreased microbial diversity and enrichment of putative hydrocarbonoclastic bacteria that differed depending on the petroleum product. Metagenomic sequencing revealed that the genus Paraperlucidibaca harbors previously unrecognized capabilities for alkane biodegradation, which were also observed in Cycloclasticus. Genomic and amplicon sequencing together suggest that Oleispira and Thalassolituus degraded alkanes from diesel, while Zhongshania and the novel PGZG01 lineage contributed to crude oil alkane biodegradation. Greater losses in PAHs from crude oil than from diesel were consistent with Marinobacter, Pseudomonas_D, and Amphritea genomes exhibiting aromatic hydrocarbon biodegradation potential. Biostimulation with nitrogen and phosphorus (4.67 mM NH4Cl and 1.47 mM KH2PO4) was effective at enhancing n-alkane and PAH degradation following low-concentration (0.1% [vol/vol]) diesel and crude oil amendments, while at higher concentrations (1% [vol/vol]) only n-alkanes in diesel were consumed, suggesting toxicity induced by compounds in unrefined crude oil. Biostimulation allowed for a more rapid shift in the microbial community in response to petroleum amendments, more than doubling the rates of CO2 increase during the first few weeks of incubation. IMPORTANCE Increases in transportation of diesel and crude oil in the Labrador Sea will pose a significant threat to remote benthic and shoreline environments, where coastal communities and wildlife are particularly vulnerable to oil spill contaminants. Whereas marine microbiology has not been incorporated into environmental assessments in the Labrador Sea, there is a growing demand for microbial biodiversity evaluations given the pronounced impact of climate change in this region. Benthic microbial communities are important to consider given that a fraction of spilled oil typically sinks such that its biodegradation occurs at the seafloor, where novel taxa with previously unrecognized potential to degrade hydrocarbons were discovered in this work. Understanding how cold-adapted microbiomes catalyze hydrocarbon degradation at low in situ temperature is crucial in the Labrador Sea, which remains relatively cold throughout the year.

Recent advances in the biodegradation of azo dyes.

As dye demand continues to rapidly increase in the food, pharmaceutical, cosmetic, paper, textile, and leather industries, an industrialization increase is occurring. Meanwhile, the degradation and removal of azo dyes have raised broad concern regarding the hazards posed by these dyes to the ecological environment and human health. Physicochemical treatments have been applied but are hindered by high energy and economic costs, high sludge production, and chemicals handling. Comparatively, the bioremediation technique is an eco-friendly, removal-efficient, and cost-competitive method to resolve the problem. This paper provides scientific and technical information about recent advances in the biodegradation of azo dyes. It expands the biodegradation efficiency, characteristics, and mechanisms of various microorganisms containing bacteria, fungi, microalgae, and microbial consortia, which have been reported to biodegrade azo dyes. In addition, information about physicochemical factors affecting dye biodegradation has been compiled. Furthermore, this paper also sketches the recent development and characteristics of advanced bioreactors.

AIE-active polyelectrolyte based photosensitizers: the effects of structure on antibiotic-resistant bacterial sensing and killing and pollutant decomposition.

A facile and effective multifunctional platform with high bacterial detection sensitivity, good antibacterial activity, and excellent dye decomposition efficiency holds great promise for wastewater treatment. To explore the design rationality and mechanism of material platforms with various integrated components into a single molecule for wastewater treatment applications, herein, four kinds of polyelectrolyte photosensitizers with aggregation-induced emission (AIE) fluorescent units are synthesized and systematically studied to investigate the structure-property relationship that influences the level of conjugation and the hydrophobicity-hydrophilicity balance. By improving the strength of the conjugation, the new AIE photosensitizers DBPVEs (including DBPVE-4 and DBPVE-6) generate a reactive oxygen species (ROS), and a decomposition efficiency of around 55% is obtained for dyes when they are exposed to DBPVEs under white light irradiation, which is higher than those of DBPEs (including DBPE-4 and DBPE-6). More importantly, owing to the longer and more flexible aliphatic chains of DBPVE-6 that facilitate efficient intercalation into cell membranes, the staining ability of DBPVE-6 for methicillin-resistant S. epidermidis (MRSE) is greatly enhanced as compared to that of DBPVE-4. It should be noted that the antibacterial experiment indicates that DBPVE-6 displays potent toxicity to MRSE with 99.9% killing efficiency under white light irradiation. This work provides essential theoretical and experimental guidance on the designing of new photosensitizers for wastewater treatment.

Arsenic level in bladder tumor of patients from an exposed population: association with progression and prognosis.

Aims: To elucidate the impact of arsenic on progression and prognosis of bladder cancer. Patients & methods: Total arsenic in 145 tumors (80 non-muscle-invasive [NMIBC] and 65 muscle-invasive bladder cancer [MIBC]) was measured and associated with Ki67 expression, tumor-clinicopathological parameters and patient outcome. Results: Tumor arsenic concentration was higher in exposed than unexposed patients (256 µg/kg vs 77 µg/kg; p < 0.0001) and positively correlated (r = 0.65; p < 0.0001) with arsenic content of patient's drinking water. Arsenic concentration showed significant association with Ki67-overexpression (p = 0.001) and advanced tumor stages (NMIBC vs MIBC; p = 0.0009). In NMIBC, high tumor arsenic (>100 µg/kg) and Ki67 overexpression was established as predictors for recurrence (hazard ratio [HR]: 4.68; p = 0.005 and HR: 3.91; p = 0.018) and progression (HR: 6.04; p = 0.023 and HR: 6.87; p = 0.013). In MIBC, association of high arsenic remained significant with increased risk of recurrence (HR: 4.58; p = 0.04). Conclusion: In NMIBC, high arsenic and Ki67 overexpression and in MIBC, only high arsenic showed prognostic importance in predicting poor patient outcome.

Lay abstract Research work suggests arsenic as risk factor for bladder cancer. In developing countries such as India, arsenic contamination of underground drinking water is a major health problem. The present study aimed to evaluate impact of arsenic on parameters of bladder cancer aggressiveness and clinical outcome of patients from West Bengal, India. Our data showed accumulation of arsenic in bladder tumor of patients exposed mainly through contaminated drinking water. Arsenic content in tumor favored aggressive phenotypes in bladder cancer (higher cell proliferation and advanced tumor stages) and was found to be a potential predictor for cases of death and disease recurrence in patients after receiving primary treatment measures. Therefore, arsenic content in bladder tumor may be used to improve existing protocols for better prediction of patient outcomes in populations with a similar type of exposure.

Microplastics in beach sediments and cockles (Anadara antiquata) along the Tanzanian coastline.

Little is known about the prevalence of microplastics (MPs) in East Africa. In the present study, sediments were sampled at 18 sites along the Tanzanian coast that exhibit different levels of anthropogenic activity and were extracted using floatation methodology. Cockles (Anadara antiquata) were collected only from eight sites and MPs were extracted following NaOH digestion. MPs were most abundant at Mtoni Kijichi Creek (MKC, 2972 ± 238 particles kg-1 dry sediment), an industrial port in Dar es Salaam, and significantly higher than all other sites where the abundance range was 15-214 particles kg-1 dry sediment (p < 0.05, one-way ANOVA). Fragments and fibers were found at all sites. Polypropylene and polyethylene were identified polymers. MPs were found in cockles from all sampled sites with both frequencies of occurrence and MPs per individual subject to site-specific variation. This study provides a baseline of MP data in a previously uninvestigated area.

Experimental and Theoretical Studies of Glyphosate Detection in Water by an Europium Luminescent Complex and Effective Adsorption by HKUST-1 and IRMOF-3.

Designing an effective and simple detection method to quantify glyphosate (GLY) herbicide is desirable. Current chromatography-mass spectrometry and electrochemical methods can be used for this purpose, but these methods are difficult to be made portable and need high-cost equipment. Here, we evaluate a luminescent ß-diketonate-Eu-ethylenediaminetetraacetic acid complex for GLY quantification in aqueous media on the basis of the luminescent quenching process. This complex successfully measured GLY at concentrations ranging from 5 × 10-7 to 10-5 mol L-1. Theoretical methods (LUMPAC) are also performed to identify the complex most probable structure in solution. We also demonstrate that the metal-organic frameworks HKUST-1 and IRMOF-3, easily synthesized, effectively adsorb GLY in water in about 30 min of contact.

In vivo and in vitro studies on inactivation of selenium containing protein- glutathione peroxidase 3 in mice nephrocytes caused by lead.

Glutathione peroxidases (Gpxs) play vital roles in elimination of hydroperoxide and other reactive oxygen species through catalyzing reduced glutathione to protect from oxidative stress caused by heavy metals such as lead. Among the family of Gpxs, Gpx3 is the only extracellular enzyme synthesized in the kidney and actively secreted into the plasma. This study investigated mechanisms of lead-induced GPx3 inactivation both at the animal and molecular levels. Six-week-old mice were randomly divided into 4 groups, and exposed to different lead concentrations (0, 1, 2 and 4 g/L) in their drinking water for 4 weeks. Contents of GPx3 in blood serum were tested by enzyme-linked immunosorbent assay (ELISA) and the mRNA levels of Gpx3 in mice nephrocytes were determined by quantitative real-time PCR (qPCR), both of which showed significantly inhibited at higher lead concentrations accompanied by the decreased Gpx3 activities and the elevated levels of malondialdehyde (MDA) in nephrocytes, which indicated that lead could induce strongly oxidative stress through affecting Gpx3 function. So we further investigated molecular mechanisms of GPx3 inactivation caused by lead with multiple spectroscopic techniques, isothermal titration calorimetry (ITC) and molecular docking studies in vitro. Results showed that lead statically quenched GPx3 fluorescence by tightly binding to the structural domain of GPx3 in a 3:1 ratio with high binding affinity (K = 3.1(±0.087) × 107 mol-1). Further investigation of the conformation of GPx3 by UV-visible spectroscopy and circular dichroism (CD) spectroscopy indicated that lead changed the secondary structure of GPx3 by loosening the GPx3 skeleton and decreasing the hydrophobicity around tryptophan residues. This work proved in vivo and in vitro experiments that lead could induce oxidative stress in mice nephrocytes by interacting with GPx3.

Marine Protists and Rhodotorula Yeast as Bio-Convertors of Marine Waste into Nutrient-Rich Deposits for Mangrove Ecosystems.

This paper represents a comprehensive study of two new thraustochytrids and a marine Rhodotorula red yeast isolated from Australian coastal waters for their abilities to be a potential renewable feedstock for the nutraceutical, food, fishery and bioenergy industries. Mixotrophic growth of these species was assessed in the presence of different carbon sources: glycerol, glucose, fructose, galactose, xylose, and sucrose, starch, cellulose, malt extract, and potato peels. Up to 14g DW/L (4.6gDW/L-day and 2.8gDW/L-day) of biomass were produced by Aurantiochytrium and Thraustochytrium species, respectively. Thraustochytrids biomass contained up to 33% DW of lipids, rich in omega-3 polyunsaturated docosahexaenoic acid (C22:6, 124mg/g DW); up to 10.2mg/gDW of squalene and up to 61µg/gDW of total carotenoids, composed of astaxanthin, canthaxanthin, echinenone, and ß-carotene. Along with the accumulation of these added-value chemicals in biomass, thraustochytrid representatives showed the ability to secrete extracellular polysaccharide matrixes containing lipids and proteins. Rhodotorula sp lipids (26% DW) were enriched in palmitic acid (C16:0, 18mg/gDW) and oleic acid (C18:1, 41mg/gDW). Carotenoids (87µg/gDW) were mainly represented by ß-carotene (up to 54µg/gDW). Efficient growth on organic and inorganic sources of carbon and nitrogen from natural and anthropogenic wastewater pollutants along with intracellular and extracellular production of valuable nutrients makes the production of valuable chemicals from isolated species economical and sustainable.

Isolation and molecular identification of Aspergillus flavus and the study of its potential for malathion biodegradation in water.

In spite of the fact that pesticides enhanced the quality and yield of the agricultural production however do have certain serious effects on the environment. This study was carried out for isolation and molecular identification of microorganisms from water for malathion biodegradation in aquatic system. PCR analysis was used for identification of the isolated fungus. The growth kinetics of A. flavus in the presence of malathion under different environmental factors (pH, temperature and malathion concentration) were evaluated. Furthermore, the degradation kinetics of malathion by A. flavus in aqueous media under different environmental factors was evaluated. The isolated microorganism was identified as A. flavus with respect to it relation to the data from the gene bank and the lowest nucleotide diversity value between the tested isolate and A. flavus. The identified isolate grew successfully in a media supplemented with malathion much faster than without it. Hundred percent of malathion initial concentration was degraded within 36 days of incubation with A. flavus. The temperature of 30 °C, pH value of 7 and malathion initial concentration of 5 mg/l were the optimum conditions of A. flavus for growth and degradation of malathion. Bioremediation of malathion residues in water using A. flavus isolate are promising and considered the first report.

Natural history matters: Plastics in estuarine fish and sediments at the mouth of an urban watershed.

The extent to which small plastics and potentially associated compounds are entering coastal food webs, especially in estuarine systems, is only beginning to be realized. This study examined an estuarine reach at the mouth of urbanized Chollas Creek in San Diego, California to determine: 1) the extent and magnitude of microplastics pollution in estuarine sediments and fish, 2) the extent and magnitude of SVOC contamination in estuarine fish, and 3) whether fish preferentially ingested certain types of microplastics, when compared with the microplastic composition of creekbed sediments. Surface sediments (0-5 cm depth) contained about 10,000 small plastic pieces per m2, consisting mostly (90%) of fibers, and hard and soft pieces. Nearly 25% of fish contained small plastics, but prevalence varied with size and between species. Of the 25 types of small plastics found in sediment, fish preferred about 10 types (distinct colors and forms). Several SVOCs, both water soluble and sediment-associated compounds, were found in the two species of fish tested. This study revealed that a species' natural history may influence contamination levels, and warrants further study to better understand the pathways of plastics and associated contaminants into and throughout coastal food webs, and the potential health risks for small and/or low-trophic level organisms.

Intensified nutrients removal in a modified sequencing batch reactor at low temperature: Metagenomic approach reveals the microbial community structure and mechanisms.

To achieve efficient biological nutrients removal at low temperature, a modified sequencing batch reactor (SBR) was developed at 10 °C by extending sludge retention time (SRT), shortening aerobic stage and compensating anoxic stage. The average removal rates of ammonium (NH4+-N), total nitrogen (TN) and total phosphorus (TP) were 98.82%, 94.12% and 96.04%, respectively. Variation of carbon source in a typical cycle demonstrated the maximum synthesis of poly-ß-hydroxybutyrate (PHB) (60 mg/L) occurred after feast period. Furthermore, the TP in sludge reached 50.4 mg/g mixed liquor suspended solids (MLSS) (78.4% was inorganic phosphorus and 21.6% was organic phosphorus) after 120 days of operation, indicating an excellent P-accumulating capacity was achieved in this system. Ammonia oxidizing bacteria (AOB) activity inhibition test verified both AOB and ammonia oxidizing archaea (AOA) were involved in ammonia-oxidizing process and the latter accounted for 17%-19%. Metagenomic-based taxonomy revealed the dominant genera were Candidatus Accumulibacter (12.18%), Dechloromonas (7.54%), Haliangium (6.69%) and Candidatus Contendobacter (3.40%). As described from the denitrifying genes perspective, with the exception of nitrite reduction (performed by denitrifiers), denitrifying phosphorus-accumulating organisms (DPAOs) played a leading role in denitrification pathway, showing that poly-ß-hydroxyalkanoates (PHA)-driven nutrients removal was the dominate process.

Marine Microbial Assemblages on Microplastics: Diversity, Adaptation, and Role in Degradation.

We have known for more than 45 years that microplastics in the ocean are carriers of microbially dominated assemblages. However, only recently has the role of microbial interactions with microplastics in marine ecosystems been investigated in detail. Research in this field has focused on three main areas: (a) the establishment of plastic-specific biofilms (the so-called plastisphere); (b) enrichment of pathogenic bacteria, particularly members of the genus Vibrio, coupled to a vector function of microplastics; and (c) the microbial degradation of microplastics in the marine environment. Nevertheless, the relationships between marine microorganisms and microplastics remain unclear. In this review, we deduce from the current literature, new comparative analyses, and considerations of microbial adaptation concerning plastic degradation that interactions between microorganisms and microplastic particles should have rather limited effects on the ocean ecosystems. The majority of microorganisms growing on microplastics seem to belong to opportunistic colonists that do not distinguish between natural and artificial surfaces. Thus, microplastics do not pose a higher risk than natural particles to higher life forms by potentially harboring pathogenic bacteria. On the other hand, microplastics in the ocean represent recalcitrant substances for microorganisms that are insufficient to support prokaryotic metabolism and will probably not be microbially degraded in any period of time relevant to human society. Because we cannot remove microplastics from the ocean, proactive action regarding research on plastic alternatives and strategies to prevent plastic entering the environment should be taken promptly.

Degradability and biofouling of oxo-biodegradable polyethylene in the planktonic and benthic zones of the Arabian Gulf.

Little is known about the degradability of oxo-biodegradable polyethylene (OXO-PE) and its surface fouling bacterial communities in the marine environment. The degradation of OXO-PE, PE and polyethylene terephthalate (PET) was compared at two depths (2 m and 6 m) in the Arabian Gulf. Scanning electron microcopy (SEM) revealed more fissure formation on OXO-PE and PE than on PET, indicating physical degradation. The formation of hydroxyl groups and carbonyl bonds, by Fourier-transform infrared spectroscopy (FTIR), suggests chemical degradation of OXO-PE. Plastisphere bacterial communities on OXO-PE and PE were different than on PET. Proteobacteria, Bacteriodetes and Planctomycetes were detected on all plastics, however, sequences of Alteromonas and Zoogloea were OXO-PE-specific suggesting a possible involvement of these bacterial genera in OXO-PE degradation. We conclude that OXO-PE shows increased signs of degradation with time owing to the combination of abiotic and biotic processes, and its degradation is higher in the benthic than in the planktonic zone.

Spatial variation in aquatic invertebrate and riparian songbird mercury exposure across a river-reservoir system with a legacy of mercury contamination.

Mercury (Hg) loading and methylation in aquatic systems causes a variety of deleterious effects for fish and wildlife populations. Relatively little research has focused on Hg movement into riparian food webs and how this is modulated by habitat characteristics. This study characterized differences in Hg exposure in aquatic invertebrates and riparian songbirds across a large portion of the Willamette River system in western Oregon, starting at a Hg-contaminated Superfund site in the headwaters (Black Butte Hg Mine) and including a reservoir known to methylate Hg (Cottage Grove Reservoir), all downstream reaches (Coast Fork and Willamette River) and off-channel wetland complexes (Willamette Valley National Wildlife Refuge Complex). After accounting for year, date, and site differences in a mixed effects model, MeHg concentrations in aquatic invertebrates varied spatially among habitat categories and invertebrate orders. Similarly, THg in songbird blood varied by among habitat categories and bird species. The highest Hg concentrations occurred near the Hg mine, but Hg did not decline linearly with distance from the source of contamination. Birds were consistently elevated in Hg in habitats commonly associated with enhanced MeHg production, such as backwater or wetlands. We found a positive but weak correlation between aquatic invertebrate MeHg concentrations and songbird THg concentrations on a site-specific basis. Our findings suggest that Hg risk to riparian songbirds can extend beyond point-source contaminated areas, highlighting the importance of assessing exposure in surrounding habitats where methylmercury production may be elevated, such as reservoirs and wetlands.

A succession of marine bacterial communities in batch reactor experiments during the degradation of five different petroleum types.

Marine microbial communities might be subjected to accidental petroleum spills; however, some bacteria can degrade it, making these specific bacteria valuable for bioremediation from petroleum contamination. Thus, characterizing the microbial communities exposed to varying types of petroleum is essential. We evaluated five enriched microbial communities from the northwest Gulf of Mexico (four from the water column and one from sediments). Enrichments were performed using five types of petroleum (extra light, light, medium, heavy and extra heavy), to reveal the microbial succession using a 16S rDNA amplicon approach. Four communities were capable of degrading from extra light to heavy petroleum. However, only the community from sediment was able to degrade the extra heavy petroleum. Successional changes in the microbial communities' structures were specific for each type of petroleum where genus Dietzia, Gordonia, Microvirga, Rhizobium, Paracoccus, Thalassobaculum, Sphingomonas, Moheibacter, Acinetobacter, Pseudohongiella, Porticoccus, Pseudoalteromonas, Pseudomonas, Shewanella, and Planctomyces presented differential abundance between the treatments.

Evaluation of degradation behavior over tetracycline hydrochloride by microbial electrochemical technology: Performance, kinetics, and microbial communities.

Tetracycline hydrochloride (TCH), as a typical antibiotic-pollutant, is desired to enhance its removal from public environment, due to its toxicity and persistence. Microbial electrochemical technology (MET) is a series complex microorganisms-driven processes with characteristics of simultaneous wastewater treatment and electricity generation. The study was presented to evaluate the TCH removal behavior and power generation performance through the co-metabolism under constant glucose with different TCH concentrations using MET. It was found that the TCH removal efficiency arrived at 40% during the first 6 h, when TCH concentrations ranged from 1 to 50 mg/L. It was interesting that TCH degradation rate increased to a maximum of 4.15 × 10-2 h-1 with its concentrations varying from 1 to 20 mg/L, however, the further increase to 50 mg/L in TCH concentration resulted in a reverse 66% reduction. In the meantime, the generated bioelectricity declared a similar fluctuation trend with a maximum power density of 600 mW/m2 under the condition of 20 mg/L TCH co-degradation with glucose. What's more, the TCH inhibition effect fitted well with Haldane's model, indicating that the microbial electrochemical system had a better potency toward TCH toxicity than that reported (EC50 = 2.2 mg/L). Thauera as mainly functional aromatics-degrading bacteria and Bdellovibrio against bacterial pathogens, only existed in the mixed cultures with TCH and glucose, indicating extremely remarkable changes in bacterial community with TCH addition. In summary, a new approach for the anaerobic biodegradation of TCH was explored through co-metabolism with glucose using MET. The results should be useful for antibiotics wastewater disposal of containing TCH.

The effect of the microalgae-bacteria microbiome on wastewater treatment and biomass production.

The use of microalgae for wastewater treatment has been proposed as a cost-effective method to produce biofuels while remediating waste streams. This study examined the microalgae biomass production rate, wastewater treatment efficiency, and prokaryotic organism microbiome associated with microalgae Chlorella sorokiniana cultivated on anaerobic digestate effluent. Final microalgae biomass concentrations from nine photobioreactors were highly variable and had values that ranged between 0.14 g/L and 0.90 g/L. Nutrient removal efficiencies for TN (total nitrogen), N-NH4 (ammonium nitrogen), and COD (chemical oxygen demand) ranged from 34% to 67%, 65% to 97%, and-60% to 14%, respectively. Analysis of individual OTUs (operational taxonomic units) from the microbial community revealed that microalgae biomass concentrations were significantly correlated with the relative abundance of OTUs in the genus Pusillimonas. Predictive metagenomic analyses identified additional correlations associated with biomass production and nutrient removal. These results suggest that the microbial community present during microalgae cultivation on wastewater can impact the performance of the system for biomass production and wastewater treatment.

Phytoplankton community and algal toxicity at a recurring bloom in Sullivan Bay, Kabetogama Lake, Minnesota, USA.

Kabetogama Lake in Voyageurs National Park, Minnesota, USA suffers from recurring late summer algal blooms that often contain toxin-producing cyanobacteria. Previous research identified the toxin microcystin in blooms, but we wanted to better understand how the algal and cyanobacterial community changed throughout an open water season and how changes in community structure were related to toxin production. Therefore, we sampled one recurring bloom location throughout the entire open water season. The uniqueness of this study is the absence of urban and agricultural nutrient sources, the remote location, and the collection of samples before any visible blooms were present. Through quantitative polymerase chain reaction (qPCR), we discovered that toxin-forming cyanobacteria were present before visible blooms and toxins not previously detected in this region (anatoxin-a and saxitoxin) were present, indicating that sampling for additional toxins and sampling earlier in the season may be necessary to assess ecosystems and human health risk.