Variations of Soybean Meal and Corn Mixed Substrates in Physicochemical Characteristics and Microbiota During Two-Stage Solid-State Fermentation

Abstract

Corn germ meal (CGM) and corn gluten feed (CGF) are the two main corn byproducts (CBs) obtained from corn starch extraction. Due to their high fiber content, low protein content, and severe imbalance of amino acid, CBs are unable to be fully utilized by animals. In this study, the effect of microorganism, proteases, temperature, solid–liquid ratio, and time on nutritional properties of CB mixture feed (CMF) was investigated with the single-factor method and the response surface method to improve the nutritional quality and utilization of CBs. Fermentation with Pichia kudriavzevii, Lactobacillus plantarum, and neutral protease notably improved the nutritional properties of CMF under the fermentation conditions of 37°C, solid–liquid ratio (1.2:1 g/ml), and 72 h. After two-stage solid-stage fermentation, the crude protein (CP) and trichloroacetic acid-soluble protein (TCA-SP) in fermented CMF (FCMF) were increased (p < 0.05) by 14.28% and 25.53%, respectively. The in vitro digestibility of CP and total amino acids of FCMF were significantly improved to 78.53% and 74.94%, respectively. In addition, fermentation degraded fiber and provided more organic acids in the CMF. Multiple physicochemical analyses combined with high-throughput sequencing were performed to reveal the dynamic changes that occur during a two-stage solid-state fermentation process. Generally, Ascomycota became the predominant members of the community of the first-stage of fermentation, and after 36 h of anaerobic fermentation, Paenibacillus spp., Pantoea spp., and Lactobacillales were predominant. All of these processes increased the bacterial abundance and lactic acid content (p < 0.00). Our results suggest that two-stage solid-state fermentation with Pichia kudriavzevii, Lactobacillus plantarum, and protease can efficiently improve protein quality and nutrient utilization of CMF.

Dynamics of the fermentation quality and microbiotsa in Ephedra sinica treated native grass silage

“…Our results suggest that no significant effect of E. sinica was found on native grass fermentation. The higher OTUs number and Chao1 index were observed in the CEa3 group compared to the FM and other silages, which is in disagreement with the previous studies that ensiling could reduce diversity and richness (Dong et al, 2019;Su et al, 2021), and the sufficient carbohydrate resources in the CEa3 group are beneficial for the growth of microorganism may be the main reason. In the present study, the coverage in raw materials and silages was higher than 99%, indicating the sequencing can directly reflect the bacterial community (Yang et al, 2019).…”

Dynamics Changes of Microorganisms Community and Fermentation Quality in Soybean Meal Prepared with Lactic Acid Bacteria and Artemisia argyi through Fermentation and Aerobic Exposure Processes

“…In the present study, the content of CP in FSBM at 30 d was greater in all groups than that at 3 d, which may be mainly due to the fact that during the fermentation process, beneficial bacteria consume part of the organic material by respiration, thus releasing CO 2 and H 2 O and reducing the total amount of products, resulting in a “concentration effect” of the protein. The protein levels in ZA3 were significantly higher both after the first 7 d ( Figure 3 a) and after 30 d of fermentation and then 3 d of aerobic exposure ( p < 0.05) ( Figure 3 b), and similar effects were also reported by Su et al [ 28 ] that after SSF, the contents of CP and trichloroacetic-acid-soluble protein increased ( p < 0.05) by 14.28% and 25.53%, respectively. This is probably a result of the bacteriological proteins and inorganic ammonium salts of the fermentation process being converted by LAB and the plant protein in SBM being metabolized and utilized by microorganisms to be converted into bacterial proteins, which also changed the quality of the proteins in the SBM even more.…”

Microbial Population Succession and Community Diversity and Its Correlation with Fermentation Quality in Soybean Meal Treated with Enterococcus faecalis during Fermentation and Aerobic Exposure

“…The artificial addition of inoculated microorganisms not only increased the number of added microorganisms but promoted the formation of symbiosis between some other functional microorganisms and inoculated microorganisms [ 48 ]. In this study, Enterococcus was positively correlated with LA and negatively with pH value, meanwhile LA was negatively correlated with Pediococcus , Weissella , Acetobacter and Bacillus , which were out-competed by Enterococcus at low pH condition and inhibited because a high LA concentration was observed after 3 d fermentation.…”

“…Based on the SFT experiment results, the orthogonal test with three factors and three levels was designed to obtain the optimal fermentation conditions. Taking the protease activity produced in ZZUPF95 fermented SBM as the response value, the effect of different fermentation time (24,36,48, 60 h and 3 d), ZZUPF95 inoculum amount (5, 7.5, 10, 12.5 and 15%) and material-water ratio (1:0.8, 1:0.9, 1:1, 1:1.1 and 1:1.2) on protein protease activity were measured by the Flint-phenol method [16].…”