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Luminescence, a physical phenomenon that producing cool light in vivo, has been found in bacteria, fungi, and animals but not yet in terrestrial higher plants. Through genetic engineering, it is feasible to introduce luminescence systems into living plant cells as biomarkers. Recently, some plants transformed with luminescent systems can glimmer in darkness, which can be observed by our naked eyes and provides a novel lighting resource. In this review, we summarized the bioassay development of luminescence in plant cells, followed by exampling the successful cases of glowing plants transformed with diverse luminescent systems. The potential key factors to design or optimize a glowing plant were also discussed. Our review is useful for the creation of the optimized glowing plants, which can be used not only in scientific research, but also as promising substitutes of artificial light sources in the future. [ABSTRACT FROM AUTHOR]

Microalgae present great potential to replace land crops for the efficient production of large volumes of biomass for food, feed, fuels, and chemicals, as well as to treat wastewater and capture carbon. However, the commercialization of these technologies for bulk commodities requires a great reduction in the current microalgal biomass production cost. The bioreactor is the core of bioprocess engineering and is the premise for the commercial application of certain types of biotechnology. The challenges of phototrophic cultivation are completely different from those of heterotrophic processes because the efficiency of phototrophic cultivation is limited by the energy density of the input sunlight and the inorganic carbon supply. Thus, the development of microalgae cultivation technologies with low manufacturing and operating costs is key to addressing this problem, and floating photobioreactors (PBRs) are a promising solution. PBRs are deployed on the water surface without any land requirements, and wave energy provides free mixing energy. Additionally, the surrounding water can be used to control the culture temperature and to supply nutrients for microalgae growth. In this mini-review, the development of floating PBRs and their recent progress are presented. The effect of the carbon supply approach on the mixing and scaling-up of floating PBRs are critically discussed. The limitations and challenges in commercial applications of floating PBRs are analysed, and the need for future research is proposed. Finally, it is noted that microalgae farming on the ocean is a promising solution for human society to address the challenge of land space exhaustion due to the global population boom. [ABSTRACT FROM AUTHOR]

Background: Mixing in traditional algae culture system consumes intensive electricity. This should be replaced by nature force to reduce energy cost and, more importantly, to realize positive energy balance of algal biofuel production. This study aims to develop a horizontal photobioreactor, in which mixing can be provided with rocking movement driven by nature force. Results: Simple boxes were used as small-scale horizontal photobioreactors on a rocking platform for culture of alkalihalophilic Euhalothece sp. ZM001. There was no CO gas bubbling since 1.0 M NaHCO supplied sufficient inorganic carbon in it. Effect of culture depth, rocking cycle, and light intensity to algal biomass production, pH change, and DO accumulation were investigated in this system. Biomass concentration of 2.73 g/L was achieved in culture with 2.5 cm depth, and maximum productivity of 17.06 g/m/day was obtained in culture with 10 cm depth. k a in PBR with different culture depths and rocking cycles was measured, and it was from 0.57 to 33.49 h, showing great variation. To test this system at large scale, a plastic bag with a surface area of 1 m was placed on a rocking platform driven by water power, and it resulted in a biomass concentration of 1.88 g/L. Conclusion: These results proved feasibility of a novel photobioreactor system driven by nature force, as well as low cost of manufacturing, and easy scaling-up. [ABSTRACT FROM AUTHOR]