Fermentation biocidal

Starch is subject to fermentation by many microorganisms and, unless the mud is saturated with salt or the pH is >11.5, a preservative or biocide must be added if the mud is to be used for an extended period of time. The most common biocide until the mid-1980s was paraformaldehyde [9002-81-7]. This material has been largely replaced by isothia2olones (at 5—10 ppm cone) (74), carbamates, and glutaraldehyde [111-30-8]. Alternatively, the biocide may be incorporated during the processing of the starch and is present in the commercial product. 

More complex reactor systems for biofilm growth under defined conditions, i.e. controlled hydrodynamic conditions with the possibility of subsequent biocide treatment, include the RotoTorque (rotating annular reactor) (Characklis, 1990), Robbins Device (McCoy et al., 1981), constant-depth film fermenters (Atkinson and Fowler, 1974 Peters and Wimpenny, 1988, 1989) or the radial flow (Fowler and McKay, 1980) and rotating disc reactors (Loeb et al., 1984). An introduction to these reactor systems is given by Gilbert and Allison (1993). 

Glucose Syrup and Com Syrup. Undiluted glucose syrup is an extremely viscous transparent Newtonian material with a viscosity of about 150 Pa s at room temperature. Com syrap has similar properties and has a viscosity of about 18 Pa s in undiluted form. At high viscosities both are extremely stable and will keep for a long period of time (months even). Once diluted with water (to about 1000 cP) biocide and fungicide should be added if solutions are to be kept for more than a day, as fermentation will take place, rendering the fluid unusable and producing an extremely unpleasant odor. 

PD has interesting applications, such as adhesives, resins, detergents, cosmetics, to produce biocides for industrial sterilization, and in animal feed. The large-scale production of 1,3-PD by companies, such as Shell, resulted in the commercialization of 1,3-PD-based polyester with excellent properties for fiber and textile applications (direct fermentation Papanikolaou et al., 2000 Zeng and Biebl, 2002). 

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