%0 Journal Article
%T Effect of Mixing on Microorganism Growth in Loop Bioreactors
%A A. M. Al Taweel
%A Q. Shah
%A B. Aufderheide
%J International Journal of Chemical Engineering
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/984827
%X The impact of mixing on the promotion of microorganism growth rate has been analyzed using a multiphase forced-circulation pipe-loop reactor model capable of identifying conditions under which it is possible to convert natural gas into Single-Cell Protein. The impact of mixing in the interphase mass transfer was found to exert a critical role in determining the overall productivity of the bioreactor, particularly at the high cell loadings needed to reduce the capital costs associated with the large-scale production needed for the production of relatively low-value SCP in a sustainable manner. 1. Introduction Industrial biotechnology uses living cells or cellcomponents (yeast, moulds, bacteria, plants, and enzymes) to synthesize products that are easily degradable, require less energy to produce, and create less waste during their production, all of which helps to decrease the environmental impact of this promising manufacturing approach. It is already used to generate large quantities of biobased products in sectors such as: chemicals, food and feed, detergents, pulp and paper, health care, textiles, bioenergy (e.g., biofuels, biogas), photocatalytic algae production, wastewater treatment, bioleaching, and biological site remediation. It also holds the promise of being a credible method for the sustainable development of many other products because it uses renewable raw materials and is capable of achieving very high efficiencies while converting nonrenewable resources to final products with minimum generation of undesirable byproducts/waste. Nevertheless, the shift to the bioprocessing route will happen only if the economic process and market demands justify the transition. However, the growing environmental pressures combined with the rapid developments in the science supporting biotechnology (sequencing of industrial bacterial and yeast genomes, metabolic engineering, bioinformatics and computer-based modeling, and process optimization) are opening up opportunities for new products and cost reductions. One of the main factors affecting the economic viability of many of the aforementioned operations is the rate at which interphase mass transfer can take place since it is often the parameter limiting the growth rates of microorganisms encountered in many of these biotechnological processes [1¨C5]. The use of forced-circulation loop reactors holds the promise of overcoming such limitations in a cost-effective fashion particularly for large-scale operations [6¨C11]. Whereas the achievement of high productivity is usually not a high priority issue in the
%U http://www.hindawi.com/journals/ijce/2012/984827/