Restructuring upstream bioprocessing: technological and economical aspects for production of a generic microbial feedstock from wheat.
Restructuring and optimization of the conventional fermentation industry for fuel and chemical production is necessary to replace petrochemical production routes. Guided by this concept, a novel biorefinery process has been developed as an alternative to conventional upstream processing routes, leading to the production of a generic fermentation feedstock from wheat. The robustness of Aspergillus awamori as enzyme producer is exploited in a continuous fungal fermentation on whole wheat flour. Vital gluten is extracted as an added-value byproduct by the conventional Martin process from a fraction of the overall wheat used. Enzymatic hydrolysis of gluten-free flour by the enzyme complex produced by A. awamori during fermentation produces a liquid stream rich in glucose (320 g/L). Autolysis of fungal cells produces a micronutrient-rich solution similar to yeast extract (1.6 g/L nitrogen, 0.5 g/L phosphorus). The case-specific combination of these two liquid streams can provide a nutrient-complete fermentation medium for a spectrum of microbial bioconversions for the production of such chemicals as organic acids, amino acids, bioethanol, glycerol, solvents, and microbial biodegradable plastics. Preliminary economic analysis has shown that the operating cost required to produce the feedstock is dependent on the plant capacity, cereal market price, presence and market value of added-value byproducts, labor costs, and mode of processing (batch or continuous). Integration of this process in an existing fermentation plant could lead to the production of a generic feedstock at an operating cost lower than the market price of glucose syrup (90% to 99% glucose) in the EU, provided that the plant capacity exceeds 410 m(3)/day. Further process improvements are also suggested.
Koutinas
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Satake Centre for Grain Process Engineering, Department of Chemical Engineering, UMIST, P.O. Box 88, Manchester M60 1QD, United Kingdom. c.webb@umist.ac.uk
Wang
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Webb
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D001230:Aspergillus / Q000166:cytology / Q000378:metabolism*; D019149:Bioreactors / Q000191:economics* / Q000382:microbiology*; D001709:Biotechnology / Q000191:economics / Q000379:methods; D018929:Cell Culture Techniques / Q000191:economics / Q000379:methods; D003246:Conservation of Energy Resources / Q000379:methods; D003362:Cost-Benefit Analysis / Q000379:methods; D005240:Feasibility Studies; D005947:Glucose / Q000096:biosynthesis* / Q000191:economics*; D007218:Industrial Microbiology / Q000191:economics / Q000379:methods; D014908:Triticum / Q000191:economics* / Q000382:microbiology*; D006113:United Kingdom
D005947:Glucose