Nutrition Component Adjustment of Distilled Dried Grain with Solubles via Aspergillus niger and Its Change about Dynamic Physiological Metabolism

Abstract

The low fiber digestibility and unbalanced amino acids restricted the use of DDGS in swine diets. Key nutrition components dynamic monitoring and key regulatory pathways analysis were performed to find the rules of nutrition changes for DDGS fermented by Aspergillus niger. Cellulose and hemicellulose were reduced to 15.3% and 15.2%. 1,4-D-Xylobiose was decreased from 16.8 μg/mL to 0.2 μg/mL. Lys, Arg, and Thr were increased to 3.00%, 2.89%, and 4.40%, and met the requirements of pigs. The whole fermentation process was divided into three stages. Cellulose degradation and Lys and Arg synthesis occurred in the early stage, while Asp synthesis occurred in the last stage. α-Ketoglutarate was the key factor for Aspergillus niger degrading cellulose to synthesize Lys and Arg. The key active metabolic pathways that respond to the changes in nutrition were identified which preliminarily revealed the rules of nutrition adjustment of DDGS during fermentation with Aspergillus niger.

Solid-State Fermentation of Distiller’s Dried Grains with Solubles Improves Digestibility for European Seabass (Dicentrarchus labrax) Juveniles

“…In the present study, SSF of DDGS with A. ibericus increased nitrogen content by about 16%, and soluble protein content was 18 times higher than with the unfermented DDGS. Similarly, SSF of DDGS with A. niger increased protein content circa 22%, from 9.5% to 11% wet weight [66]. SSF with Pleurotus sapidus also increased rice bran protein content from 7.4% to 12.8% [67].…”

Antioxidant activity increased due to dynamic changes of flavonoids in orange peel during Aspergillus niger fermentation

“…The DW of mycelium continued to increase to 0.80 ± 0.04 and 0.88 ± 0.02 g/100 mL within 96 h in OP and PDB media, respectively. However, it decreased to 0.76 ± 0.01 g/100 mL in PDB, while that in OP tended to be flat between 96 and 120 h. One possible explanation for this is that it takes longer for A. niger to reach the recession stage in OP because of the decomposition of OP cellulose (Fan et al ., 2022). The OP powder had the carbohydrate consisted of about 20% lignin, 69% cellulose and 9% hemicellulose for strain consumption, which could not be used up by strain without first being enzymatically hydrolysed to monosaccharides (Ayala et al ., 2021).…”

A study revealing mechanisms behind the stone cell of Yali pear degradation by mixed‐culture fermentation of lactic acid bacteria and yeast

“…Zhang also found that the main metabolites involved in the TCA cycle stimulate cellulose degradation by bacteria belonging to the phylum Bacteroidetes (Zheng et al, 2021). In addition, malic acid can also be produced by glycolaldehyde and mesaconic acid because α-ketoglutarate is a precursor for the synthesis of lysine, and α-ketoglutarate is not only consumed in the TCA cycle, but it is also consumed by the synthesis of lysine, which is also the reason why the content of oxoglutaric acid does not change significantly (Fan et al, 2022). Glucose was not detected in either the stone cell group or the supernatant group, probably because glucose was converted to pyruvate and then entered the TCA cycle, which also provided more energy for microbial growth.…”