Recent Progress on Systems and Synthetic Biology of Diatoms for Improving Algal Productivity

Microplastic pollution in aquatic ecosystems: impacts on diatom communities

In recent years, heightened concern has emerged regarding the pervasive presence of microplastics in the environment, particularly in aquatic ecosystems. This concern has prompted extensive scientific inquiry into microplastics' ecological and physiological implications, including threats to biodiversity. The robust adsorption capacity of microplastic surfaces facilitates their widespread distribution throughout aquatic ecosystems, acting also as carriers of organic pollutants. However, to comprehensively understand the broader implications of this pollution, a thorough examination of the origins, composition, and widespread distribution of microplastics within aquatic biotopes is imperative. Diatoms, unicellular photosynthetic organisms, play a pivotal role in aquatic ecosystems as primary producers, forming the base of the aquatic food web. Investigating the relationship between microplastics and diatoms, leveraging methodological advancements, holds promise in unraveling the intricate action mechanisms underlying their interactions. Such inquiry sheds light on the physiological responses elicited and provides crucial insights into the ecological dynamics within aquatic environments. This study explores the understanding of microplastic-diatom interactions, focusing on how microplastic types, sizes, and concentrations influence diatoms. Ultimately, the current study strongly advocates for transdisciplinary collaborations, such as partnerships between ecologists, materials scientists, and policymakers, as the complexity of microplastic pollution demands collective efforts to address this critical and alarming environmental issue.

Microalgae are not an umbrella solution for power industry waste abatement but could play a role in their valorization

Microalgae have long been regarded as a promising solution for biological carbon abatement from the power industry, offering renewable biomass without competing for land or water resources used for food crops. In this study, we extensively examined the application of photosynthetic microorganisms for closing carbon, nitrogen, and micronutrient loops in the power industry. Subsequently, we explored the bottom-up integration of algal biorefineries into power industry waste streams for increased economic benefits and reduced environmental impacts. Analysis of the available data indicated that microalgae integration with the power industry is primarily performed using flue-gas-assisted cultivation. This approach allows for carbon sequestration typically below one gram per liter per day, too low to significantly impact carbon abatement at achievable scales of microalgae cultivation. Alternative approaches are also being explored. For example, soluble bicarbonate platforms allow for higher biomass productivity and temporary carbon storage. Meanwhile, the use of ashes and waste heat and thermophilic strains can result in lower cultivation costs and better control of cultivation conditions. These approaches offer further incremental improvement to microalgae-based carbon abatement systems in the power industry but are unlikely to be an umbrella solution for carbon reduction. Consequently, in the near term, microalgae-based carbon valorization systems are likely to be limited to niche applications involving the synthesis of high-value products. For microalgae to truly transform carbon abatement processes radical improvements in both biology and engineering approaches are urgently needed.