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[1] This study is a proof of concept of the sensitivity of grassfire propagation to vertical shear in the near-surface environmental flow found through four comparative grassfire numerical simulations with a coupled wildfire-atmosphere model. A unidirectional constant wind field, under neutral atmospheric conditions, no surface friction, Coriolis force or topography, and homogeneous fuel, prescribes the model environment. By using the same surface (at 6.2 m above ground level) wind speed for all simulations, analyses of the results can suggest when the behavior and spread rate of the fire may depend more on the interaction of the fire plume with the shear in the above surface wind or more on the magnitude of the mean upstream surface wind speed at the surface. Three aspects of wildfire behavior are investigated: impact of unidirectional vertical shear on surface flow properties and fire line propagation; variability in fire spread and area burnt due to the evolution of the surface flow; and implications of low-level vertical wind shear on the prediction of wildfire, especially extreme or erratic, behavior.

To conserve freshwater resources, domestic and industrial wastewater is recycled. Algal systems have emerged as an efficient, low-cost option for treatment (phycoremediation) of nutrient-rich wastewater and environmental protection. However, industrial wastewater may contain growth inhibitory compounds precluding algal use in phycoremediation. Therefore, extremophyte strains, which thrive in hostile environments, are sought-after. Here, we isolated such an alga - a strain of Synechocystis sp . we found to be capable of switching from commensal exploitation of the nitrogen-fixing Trichormus variabilis , for survival in nitrogen-deficient environments, to free-living growth in nitrate abundance. In nitrogen depletion, the cells are tethered to polysaccharide capsules of T. variabilis using nanotubular structures, presumably for nitrate acquisition. The composite culture failed to establish in industrial/domestic waste effluent. However, gradual exposure to increasing wastewater strength over time untethered Synechocystis cells and killed off T. variabilis . This switched the culture to a stress-acclimated monoculture of Synechocystis sp ., which rapidly grew and flourished in wastewater, with ammonium and phosphate removal efficiencies of 99.4% and 97.5%, respectively. Therefore, this strain of Synechocystis sp . shows great promise for use in phycoremediation, with potential to rapidly generate biomass that can find use as a green feedstock for valuable bio-products in industrial applications.

Fossil-fuel processing and consumption contaminates air, soil, and water resources through the release of hazardous chemicals. The harnessing of renewable energy resources and development of sustainable technologies have become prime targets of research and increased investment to protect the environment. The use of bio-based feedstocks in energy production provides a valuable pollutioncurbing pathway with sustainability credentials, especially when wastewater is used to provide the nutrient requirements. The filamentous cyanobacterium Trichormus variabilis has attracted substantial attention from researchers due to its potential for dual industrial functions in bioenergy production and bioremediation. This species can use the power of sunlight energy efficiently to fix atmospheric CO 2 and to generate valuable chemical compounds, such as carbohydrates and fatty acids, which can be converted to biofuels. As it grows in nutrient-rich wastewater (industrial effluent) it can serve as a bioabsorbant and replace costly chemical catalysts and nano-materials traditionally used for the removal of nutrients and metals. However, no recent review has presented the potential for state-of-the-art T. variabilisdriven phycoremediation-bioenergy production systems. This review suggests possible routes from phycoremediation to energy production as a strategy for developing the industrial application of T. variabilis. It brings important research results on this species together and highlights major related challenges and opportunities. It explores the current status of the use of algae in bioremediation and the production of liquid and gaseous fuels utilizing wild-type and mutants of T. variabilis. Finally, key points underlying the potential for future research on optimization of robust technologies for supplying sustainable bioenergy using this organism are presented.