Isolation and characterization of a novel hydrolase-producing probiotic Bacillus licheniformis and its application in the fermentation of soybean meal

Abstract

Soybean meal (SBM) is one of the most important sources of plant-based protein in the livestock and poultry industry. However, SBM contains anti-nutritional factors (ANFs) such as glycinin, β-conglycinin, trypsin inhibitor and phytic acid that can damage the intestinal health of animals, inevitably reducing growth performance. Fermentation using microorganisms with probiotic potential is a viable strategy to reduce ANFs and enhance the nutritional value of SBM. In this study, a novel potential probiotic Bacillus licheniformis (B4) with phytase, protease, cellulase and xylanase activity was isolated from camel feces. The ability of B4 to tolerate different pH, bile salts concentrations and temperatures were tested using metabolic activity assay. It was found that B4 can survive at pH 3.0, or 1.0% bile salts for 5 h, and displayed high proliferative activity when cultured at 50°C. Furthermore, B4 was capable of degrading glycinin, β-conglycinin and trypsin inhibitor which in turn resulted in significant increases of the degree of protein hydrolysis from 15.9% to 25.5% (p < 0.01) and crude protein from 44.8% to 54.3% (p < 0.001). After fermentation with B4 for 24 h, phytic acid in SBM was reduced by 73.3% (p < 0.001), the neutral detergent fiber (NDF) and the acid detergent fiber of the fermented SBM were significantly decreased by 38.40% (p < 0.001) and 30.20% (p < 0.05), compared to the unfermented SBM sample. Our results suggested that the effect of solid-state fermented SBM using this novel B. licheniformis (B4) strain, could significantly reduce phytic acid concentrations whilst improving the nutritional value of SBM, presenting itself as a promising alternative to phytase additives.

Hydrolase Activities of Sourdough Microorganisms

“…According to the authors, B. licheniformis MVS1 exhibited the highest cellulase activity (0.120 ± 0.012 IU/mL) when wheat straw was the Cellulase has been associated with improvements in bread, particularly those with a high dietary fiber content [64,65]. It has been described that the presence of peptidases and cellulases of B. licheniformis isolated from camel feces can reduce allergenic compounds and improve the nutrition properties of soybean meal, which is a source of protein for animal feeds [66]. B. licheniformis MVS1 and Bacillus sp.…”

Effect of microbial fermentation on the quality of soybean meal

“…There is an increasing evidence that lactic acid bacteria have the ability to degrade proteins during fermentation and lactic acid bacteria with high intestinal adhesion also have antibacterial properties (Ma et al ., 2022). Antioxidant, anti‐inflammatory and antihypertensive activities were also found in fermented soybean meal (Cui et al ., 2020; Yao et al ., 2021; Qi et al ., 2023). Further research has shown that the fermented soybean meal can improve intestinal barrier function and reduce inflammation of piglets, which is more suitable for poultry feed and aquaculture (Cheng et al ., 2019a).…”

Bacillus licheniformis-based intensive fermentation of Tibetan tea improved its bioactive compounds and reinforced the intestinal barrier in mice

“…Bacillus licheniformis is the dominant bacterium involved in the fermentation of Tibetan tea. It is a probiotic bacterium with high-temperature tolerance; it can grow in a high-temperature environment and possesses phytase, protease, cellulase, and xylanase activities (Qi et al, 2023 ).…”