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The development of efficient and commercially viable bioprocesses is essential for reducing the need for fossil-derived products. Increasingly, pharmaceuticals, fuel, health products and precursor compounds for plastics are being synthesized using bioprocessing routes as opposed to more traditional chemical technologies. Production vessels or reactors are required for synthesis of crude product before downstream processing for extraction and purification. Reactors are operated either in discrete batches or, preferably, continuously in order to reduce waste, cost and energy. This review describes the oscillatory baffled reactor (OBR), which, generally, has a niche application in performing ‘long’ processes in plug flow conditions, and so should be suitable for various bioprocesses. We report findings to suggest that OBRs could increase reaction rates for specific bioprocesses owing to low shear, good global mixing and enhanced mass transfer compared with conventional reactors. By maintaining geometrical and dynamic conditions, the technology has been proved to be easily scaled up and operated continuously, allowing laboratory-scale results to be easily transferred to industrial-sized processes. This is the first comprehensive review of bioprocessing using OBRs. The barriers facing industrial adoption of the technology are discussed alongside some suggested strategies to overcome these barriers. OBR technology could prove to be a major aid in the development of commercially viable and sustainable bioprocesses, essential for moving towards a greener future.

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Thermochemical processing methods such as pyrolysis are of growing interest as a means of converting biomass into fuels and commodity chemicals in a sustainable manner. Macroalgae, or seaweed, represent a novel class of feedstock for pyrolysis that, owing to the nature of the environments in which they grow coupled with their biochemistry, naturally possess high metal contents. Although the impact of metals upon the pyrolysis of terrestrial biomass is well documented, their influence on the thermochemical conversion of marine-derived feeds is largely unknown. Furthermore, these effects are inherently difficult to study, owing to the heterogeneous character of natural seaweed samples. The work described in this paper uses copper(II) alginate, together with alginic acid and sodium alginate as model compounds for exploring the effects of metals upon macroalgae thermolysis. A thermogravimetric analysis–Fourier transform infrared spectroscopic study revealed that, unusually, Cu 2+ ions promote the onset of pyrolysis in the alginate polymer, with copper(II) alginate initiating rapid devolatilization at 143°C, 14°C lower than alginic acid and 61°C below the equivalent point for sodium alginate. Moreover, this effect was mirrored in a sample of wild Laminaria digitata that had been doped with Cu 2+ ions prior to pyrolysis, thus validating the use of alginates as model compounds with which to study the thermolysis of macroalgae. These observations indicate the varying impact of different metal species on thermochemical behaviour of seaweeds and offer an insight into the pyrolysis of brown macroalgae used in phytoremediation of metal-containing waste streams.

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Many approaches have been taken to determine the nutritive value of ruminant feeds, most of which rely upon the measurement of end-points of digestibility and ignore the importance the kinetics of the process. A new method which enables the determination of rates of gas accumulation from in vitro fermentations was described recently (Theodorou et al, 1994, Anim Feed Sci Technol, 48, 185 -197 The automated system was assessed by comparing it to the manual gas production technique using pure cellulose as the substrate. The volume of gas produced (ml) versus time (h) profiles for both systems were very similar. The rate of gas production was almost identical with the time taken to reach half the final gas volume being ca 37 and 40 h respectively for the automated and manual methods. The overall final gas pool size after 100 h was also similar at 230 and 260 ml respectively for the automated and manual systems.In conclusion the automated technique has great potential because it can be used routinely and with continuous monitoring there is reduced labour input compared to the manual method. So as a tool for studies concerned with the nutritive value of feeds and feed supplements, this equipment shows considerable promise.

We have looked at the growth and enzymatic activity of three different species of fungal isolate using gas production and HPLC techniques. Preliminary data suggests there are significant differences in both the profile and the resulting phenolics produced between all isolates studied. The relevance of the enzymatic difference will be discussed with reference to the role of fungal genera within the rumen ecosystem.