Proteins - continued energy cost

The high capital and energy costs associated with conventional corn wet-milling, and the continued growth of the industry, has renewed interest in developing alternative starch production methods. These new processes attempt to lower capital and energy requirements and, in some cases, may result in new value-added products. The alternative processes can be divided into processes which decrease diffusion time, which use mechanical shear to enhance separation of starch and protein, and which use a different chemistry to create separation of starch and protein. 

Table 20 indicates the cost expressed in mmol ATP for anaerobic glucose-limited continuous culture at D = 0.20 h" on mineral media [41] protein polymerization and solute transport account for 70% of the total cost. The predicted ATP requirement is 38.5 mmol per gram biomass. This value represents the minimal cost predicted from biochemistry and does not take into account sub-optimal energy coupling at the cell level. 

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