Cereal‐based biorefinery development: Integrated enzyme production for cereal flour hydrolysis

Abstract

Restructuring the traditional fermentation industry into viable biorefineries for the production of fuels, chemicals and plastics is essential in order to replace (petro)chemical processing. This work presents engineering aspects of Aspergillus awamori submerged fermentation for on-site production of an enzymatic consortium that contains glucoamylase, protease and phosphatase. The crude broth filtrate was used for the production of wheat flour hydrolysates. Improvements on traditional starch hydrolysis carried out in two stages (liquefaction and saccharification) were attempted through integration of unit operations and reduction of processing temperature and reaction duration. An initial increase of temperature to 68 degrees C and a subsequent decrease to 60 degrees C for the rest of the enzymatic hydrolysis resulted in a starch to glucose conversion yield of 94 and 92% when a wheat flour concentration and commercial starch concentration of 225 g L(-1) was used, respectively. The use of crude broth filtrates resulted in the simultaneous hydrolysis of wheat protein and phytic acid, as was indicated by the increase in free amino nitrogen and phosphorus concentration, respectively.

A Threshold-Based Weather Model for Predicting Stripe Rust Infection in Winter Wheat

“…Although A. awamori is known to be an efficient producer of glucoamylases, it can also produce hydrolytic enzymes, such as amylases, proteases, cellulases and xylanases when growing on complex substrates, such as mixed FW in SSF [24,25]. It has been reported that fermented solids obtained from the SSF of babassu cake with A. awamori contained considerable activities of proteases, xylanases and cellulase activities besides amylases [25].…”

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

“…Currently, commercially viable SSF processes involve solid substrates for producing products ranging from biofuels, bioethanol, biomethanol, biogas, and biodegradable plastics to commodity, platform, and specialty chemicals like succinic acid and pharmaceutical products. This is achieved by microbial bioconversions or enzymatic biotransformation (Koutinas et al, 2007a). Using food and agro-industry solid materials provides almost complete nutrient sources (Koutinas et al, 2007b).…”

“…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.…”

Enrichment of fermentation media and optimization of expression conditions for the production of EAK16 peptide as fusions with SUMO

“…The enzymes required to hydrolyze wheat components were produced by fungal fermentation of the strain Aspergillus awamori 2B 361 U2/1 (ABM Chemicals Ltd., Woodley, Cheshire, UK) on 85 g/L pearled wheat flour. Extensive description on fungal fermentations and the methodology followed for the production of wheat flour hydrolysates and fungal extracts are provided in other publications (Koutinas et al, , 2005(Koutinas et al, , 2007b. A set of shake flask experiments was carried out on mixtures of wheat hydrolysates, fungal autolysates, and sterile distilled water.…”

“…A novel wheat-based biorefinery that bioconverts wheat into case-specific feedstocks for microbial fermentations leading to the production of fuels, chemicals, and plastics has been developed (Koutinas et al, , 2007aWebb et al, 2004). This process is exploiting on-site fungal fermentations for the production of enzymes that are subsequently used for complete conversion of starch into glucose and partial conversion of wheat protein (gluten) into amino acids (Koutinas et al, 2007b). The solids from the fungal fermentation containing mainly fungal cells are autolysed for the production of fungal extracts that constitute nutrient-rich fermentation supplements (Koutinas et al, 2005).…”