Typically, these two aldehydes are considered major inhibitors in microbial conversion processes.
A mathematical model with adequate complexity integrating hydraulics, biofilm and microbial conversion processes is successfully developed for a continuously moving bed biofilter performing tertiary nitrification.
Indeed, several studies have reported biohydrogen and biomethane production by microbial conversion processes from crude glycerol using single microbial strains or bacterial communities.
Thus, this result suggests that rca-1 is a potential engineering target for biorefineries, especially for plant biomass direct microbial conversion processes.
However, this will require the generation of carbohydrate streams from lignocellulose in a form suitable for efficient microbial conversion and downstream processing appropriate to the desired end use, making overall process development, along with selection of appropriate target molecules, crucial to the integrated biorefinery.
In fact, from the fourteen compounds produced at lab scale by microbial fermentation of glycerol showed in Table 1, ten of them are nowadays produced by chemical or microbial conversion of sugars or petrochemical processes.
A range of solutions are being explored to increase the economic viability of this process, including the direct microbial conversion of biomass by lignocellulose degrading organisms [ 3].
Key considerations are the metabolic capabilities and performance of the microbial catalyst that converts syngas into the desired biochemical, gas liquid mass transfer characteristics that determine the availability of soluble gas components for microbial conversion and the bioreactor design that affects all aspects of the conversion process.
A promising alternative is microbial conversion, as hydrogenotrophic methanogenesis is a well-known and comparatively robust process (cf. 'Microbiology and process control' section) to convert H2 and CO2 to CH4.
DOI: http://dx.doi.org/10.7554/eLife.03125.002 Microbial communities are critical drivers of nutrient and energy conversion process in natural and engineered ecosystems (Falkowski et al., 2008).
