Restructuring upstream bioprocessing: technological and economical aspects for production of a generic microbial feedstock from wheat

Abstract

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.

Production of Industrial Proteins in Plants

“…The use of amylase-producing Aspergillus awamori has been tested to ferment part of the feedstock (wheat fl our) and obtain degradation of the polymers (Koutinas et al 2004 ) . Other investigations have proposed the use of immobilized amylases as part of corn starch bioconversion (Krishnan 2000 ;Mandavilli 2000 ) .…”

Modern microbial solid state fermentation technology for future biorefineries for the production of added-value products

“…On top of that, advanced biorefining strategies have been restructured in order to reduce environmental impact, improve overall economics, and meet market and societal needs Koutinas et al, 2004Koutinas et al, , 2005Koutinas et al, , 2007aKoutinas et al, , 2007bKoutinas et al, , and 2010Melikoglu, 2008;Melikoglu et al, 2013a and b;Webb, 2017). The promising results taken from these research activities have led to the conclusion that biomass from renewable resources, such as food and agro-industry waste, has practical benefits and should be further taken advantage of within future biorefining strategies.…”

Production of Chemicals from Biomass

“…Fermentative conversion of saccharides into platform chemicals would be dependent on the development of viable biorefineries (Koutinas et al, 2004a;Koutinas et al, 2004b;Webb et al, 2004;Koutinas et al, 2006;Koutinas et al, 2007a;Koutinas et al, 2007b;Koutinas et al, 2007c;Koutinas et al, 2007d). A generic strategy leading to fermentative conversion of various biomass resources into platform chemicals is shown in Figure 4.2.…”