Carbon dioxide-gassed fluorocarbon enhances micropropagation of rose (Rosa chinesis Jacq.)

Multifunctional fluorocarbon photobioreactor system: a novel integrated device for CO2 segregation, O2 collection, and enhancement of microalgae growth and bioproductions

An enhanced greenhouse effect due to high CO₂ emissions has become one of the most concerning issues worldwide. Although plant/algae-mediated approaches have been extensively used for CO₂ segregation in the last decades, these methods are generally aimed at environment protection. In contrast, less attention has been given to CO₂ manipulation that has regrettably caused a decrease in the commercial availability of the associated technologies. To generate a system for practical use, a synthetic fluorocarbon photobioreactor system (FCPBRS) consisting of a CO₂ isolation unit, a gas modulation unit, an O₂ collection unit, and a microalgal culture chamber was developed in this study. After injecting a 60%-N₂/40%-CO₂ gas mixture into the CO₂ isolation unit for 10 days, the results showed that the FCPBRS enabled a > 93% CO₂ separation efficiency using a fluorocarbon liquid FC-40 as the CO₂ adsorbent. In addition, the growth rate of Nannochloropsis oculata was significantly enhanced when cultured with 20 mL min^-1 of the FC-40 flow containing 2% CO₂ throughout the time course, resulting in 4.7-, 4.6-, and 4.5-fold (P < 0.05 for each) increases in biomass, total lipid, and eicosapentaenoic acid yields, respectively, compared to the aerated group without FC-40. Moreover, approximately 1600 mL of photosynthetic O₂ with a ~ 80% collection efficiency was obtained in the O₂ collection unit within 10 days of FCPBRS operation. These outcomes indicate that the FCPBRS may provide a feasible means to simultaneously achieve CO₂ isolation, O₂ collection, and enhanced microalgae bioproductions.

Perfluorodecalin enhances in vivo confocal microscopy resolution of Arabidopsis thaliana mesophyll

*Air spaces in the leaf mesophyll generate deleterious optical effects that compromise confocal microscopy. *Leaves were mounted in the nontoxic, nonfluorescent perfluorocarbon, perfluorodecalin (PFD), and optical enhancement and physiological effect were assessed using confocal microscopy and chlorophyll fluorescence. *Mounting leaves of Arabidopsis thaliana in PFD significantly improved the optical qualities of the leaf, thereby enabling high-resolution laser scanning confocal imaging over twofold deeper into the mesophyll, compared with using water. Incubation in PFD had less physiological impact on the mounted specimen than water. *We conclude that the application of PFD as a mounting medium substantially increases confocal image resolution of living mesophyll and vascular bundle cells, with minimal physiological impact.

Beneficial effects of Pluronic F-68 and artificial oxygen carriers on the post-thaw recovery of cryopreserved plant cells

The storage of prokaryotic and eukaryotic cells at ultra-low temperature in liquid nitrogen (-196 degrees C) is a procedure that has assumed an increasingly important role in underpinning many aspects of biotechnology. For eukaryotic cells, the transition from a cryopreserved state to physiologically normal temperatures and oxygen tensions, induces respiratory imbalances that may stimulate the production of toxic oxygen radicals causing impaired cellular functions. Novel treatments, that focus specifically on enhancing oxygen delivery to cells, are important in maximising post-thaw recovery. Recently, several approaches have been evaluated with suspension cultured plant cells as a model, yet biotechnologically-important, totipotent eukaryotic cell system. Such treatments include non-ionic surfactants, primarily Pluronic F-68, and artificial oxygen carriers, the latter based on inert perfluorochemical liquids or chemically-modifed haemoglobin, as supplements to culture medium used during the post-thaw recovery phase of cell growth. When used either alone or in combination, such novel treatments stimulate significantly the post-thaw viability and biomass production of cultured plant cells. Many of these technologies will be exploitable in cryopreservation protocols for eukaryotic cells in general.

Enhancement of microalgal growth by using perfluorocarbon as oxygen carrier

The contribution of green microalgae has been recognized in the production of useful products such as chemicals, fatty acids, proteins, carotenoids, pigments, polysaccharides, and pharmaceuticals. One of the challenges to the development of profitable bioproduct markets is the design, development, modeling, and evaluation of cost-effective production systems. The photobioreactors for microalgae can be either open or closed systems in large-scale production. In various situations, it has been reported that closed photobioreactors offer many advantages over open systems. These advantages include lower contamination, higher biomass densities, and better process control. Nevertheless, for the scale-up of enclosed tubular photobioreactors, the accumulation of oxygen as a photosynthetic byproduct has been a major limitation because it severely inhibits growth of microalgae. In this study, we use the distinctive feature of liquid perfluorocarbons (PFCs) as a carrier that efficiently removes the accumulated oxygen from algal medium phase in the spinner culture flasks. The results show the growth kinetics of microalgae cultivated by this approach is significantly improved.

Perfluorochemicals: their applications and benefits to cell culture

The properties of perfluorochemical liquids, particularly their high gas solubility, enables them to be exploited in cell biotechnology. They can facilitate respiratory-gas delivery to prokaryotic and eukaryotic cells in culture; in some systems, they can stimulate production of biomass, yields of commercially important cellular products and, for plant systems, expression of totipotency. The recoverability, and hence recycleability, of perfluorochemicals from aqueous systems makes their routine use a commercially feasible option. This article reviews the applications and beneficial effects of perfluorochemicals in cultured microbial, animal and plant cells, including both aerobic and anaerobic systems.