Evaluation of the Cultivation of Aspergillus oryzae on Organic Waste-Derived VFA Effluents and Its Potential Application as Alternative Sustainable Nutrient Source for Animal Feed

Abstract

Considering the projected demand for protein supplementation in animal feed, as well as prioritizing plant-based protein provision for the growing human population, great stress is imposed on conventional protein sources, calling for new sustainable alternatives. In this regard, the production and application of single-cell proteins (SCPs) has proven to be a promising alternative. Therefore, in this study, volatile fatty acids (VFAs) effluents recovered from anaerobically digested FW, CKM, CM, and their combinations were applied for the cultivation of edible filamentous fungi Aspergillus oryzae. The biomass was further evaluated considering its protein, fat and alkali insoluble material contents. The maximum fungal biomass yielded of 0.47 ± 0.00 and 0.37 ± 0.00 g dry biomass/g tVFAsCODeq.consumed, with up to 47% protein and 5% fat content successfully cultivated in shake flasks and bench scale reactors, respectively. In addition to the production of protein-rich biomass, significant reductions in medium COD (25–58%) and ammonium (33–48%) were achieved. The results presented in this research work imply that using waste-derived VFAs for the production of animal feed grade SCP is an innovative approach that can contribute to the economy and sustainability of animal feed production process.

Evaluation of in vitro digestibility of Aspergillus oryzae fungal biomass grown on organic residue derived-VFAs as a promising ruminant feed supplement

“…The obtained fungal biomass protein content results were found to be comparable with previously reported crude protein contents of A. oryzae (37%–41%) and strains cultivated on short-chain carboxylic acids [ 9 ]. Rapeseed meal is abundantly used as feed ingredients for various animal species such as poultry, pigs, cattle and fish [ 29 ].…”

“…Certain filamentous fungal species, like Aspergillus spp., Rhizopus spp., Neurospora spp., and Fusarium spp., are considered safe for food and feed applications due to their use in East and Southeast Asian fermented foods, (e.g., oncom, koji and miso) and beverages (e.g., sake, shoyu, and vinegar) [ 5 , 6 ]. Filamentous fungi, such as Aspergillus oryzae (A. oryzae), have shown the ability to grow well on low-value organic residues and yielding valuable products such as enzymes, alcohols, organic acids, and protein-rich biomass, as reported by numerous research studies [ 7 – 9 ]. Fungal biomass can contain approximately 60% crude protein (CP) and possess an amino acids and fatty acids profile similar to traditional ruminant feed protein sources like soybean meal, rapeseed meal and fish meal [ 10 ].…”

“…These VFAs, composed mainly of acetic, propionic and butyric acids and other valuable nutrients, can be valuable resources for producing protein-edible fungal biomass without additional chemical supplementation [ 11 ]. Previous studies successfully used VFAs from anaerobic digestion of animal manure and food waste to produce A. oryzae fungal biomass, exhibiting similar protein content to familiar animal feed protein sources like soybean and rapeseed meals [ 9 ].…”

Innovations and developments in single cell protein: Bibliometric review and patents analysis

“…An interesting survey was recently released by the Good Food Institute (GFI) which reported the launch of Brave Robot ice cream by the company Perfect Day in the year 2021.This product is a whey protein ice cream produced via the fermentation process of the microflora of fungi grown in tanks (Reference GFI website). Another attractive proposal has been the fermentation of agro-industrial residues for the production of animal feed with higher protein content (Yunus et al, 2017;Zhou et al, 2017;Patsios et al, 2020;Uwineza et al, 2021;Vethathirri et al, 2021).…”

Co-Fermenting Pyrolysis Aqueous Condensate and Pyrolysis Syngas with Anaerobic Microbial Communities Enables L-Malate Production in a Secondary Fermentative Stage

“…oryzae belongs to the Ascomycetes group and its industrial application spans from food processing to commodity chemical production [45,46]. Several studies have evaluated the potential of producing biochemicals, biofuels or cell biomass (single-cell proteins) with A. oryzae from VFA rich waste streams or from acetate [47][48][49]. Moreover, the fungus was reported to tolerate small concentrations of pyrolysis oils and various PAC components [50] and to be able to grow on the acetate contained in pre-treated PAC from wheat straw [15].…”