Feeding value improvement by co-fermentation of corn-ethanol co-product and agro-industrial residues with Rhizopus oryzae

• Published in: Process biochemistry (1991) Vol. 111; pp. 144 - 153
• Main Authors: Sun, Xiao, Chen, Yan, Luo, Lina, Heidari, Fatemeh, Tiffany, Douglas G., Urriola, Pedro E., Shurson, Gerald G., Hu, Bo
• Format: Journal Article
• Language: English
• Published: Barking Elsevier Ltd 01-12-2021; Elsevier BV
• Subjects: Agricultural wastes; Amino acids; Ammonia; Animals; Biodegradation; Carbohydrates; Carbon/nitrogen ratio; Corn; Cottonseed meal; Degradation; Drying; Ethanol; Feasibility studies; Fermentation; Fungi; Glucan; Mixing ratio; Nutritive value; Phytic acid; Residues; Rhizopus oryzae; Solid state fermentation; Soybeans; Stillage; Structural carbohydrates; Substrates; Amino acids; Solid-state fermentation; Rhizopus oryzae; Structural carbohydrates; Phytic acid
• ISSN: 1359-5113; 1873-3298
• DOI: 10.1016/j.procbio.2021.10.029

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•Rhizopus oryzae improved feeding value in mixtures of WDGS with agro-residues.•Mixing with high-protein residues benefits degradation of structural carbohydrates.•Mixing fiber-rich residues produces less ammonia and improves phytate degradation.•Lower mixing ratio of agro-residue is preferable for protein concentration.
Corn dried distiller’s grain with solubles (cDDGS) is a feeding ingredient for monogastric animals but with limited inclusion rate due to its imbalanced amino acids, high fiber content, and anti-nutritional compounds. Moreover, production of cDDGS is costly and energy intensive. This study investigated fungal fermentation of corn stillage mixing with other dry agro-industrial residues which could by-pass the energy-intensive drying process while improving nutritional value of the mixed substrates. Rhizopus oryzae was used to ferment WDGS blended with canola meal (CM), cottonseed meal (CSM), sugar beet pulp (SP) and soybean hull (SH) at different ratio at 28 ℃ for 12 days. Results suggested that short incubation period (4 days) was favorable for improvement of protein and key amino acids profile. Substrate mixture with C/N ratio above 3 effectively reduced ammonia generation. Significant reduction (p < 0.05) of structural carbohydrates (mainly glucan with degradation by 20–30 %) occurred after fermenting WDGS mixing with CM and SP. Substrate with all mixing ratio of SP or SH, and lower ratio (less than 50 %) of CM or CSM showed phytate degradation by 30–75 %. This study proved the feasibility of solid-state fermentation in improving feeding value of WDGS and agro-residues for monogastric animals.