The influence of Bacillus subtilis 87Y isolated from Eisenia fetida on the growth of pathogenic and probiotic microorganisms

Abstract

Bacillus subtilis strain 87Y, isolated from the earthworm Eisenia fetida, decreases the growth of pathogenic Salmonella spp. and Staphylococcus aureus and promotes the growth of probiotic Lactococcus spp. Preserving viability in acidic conditions as well as in bile salts, B. subtilis 87Y meets two of the requirements of a probiotic strain. Thanks to the production of the biosurfactant surfactin, B. subtilis 87Y limits the growth of the Gram-positive bacterium S. aureus. In the presence of sucrose, B. subtilis produces levan, which contributes to promoting the growth of other probiotics. Our in vitro studies justify the continuation of enriching rapeseed meal waste from solid-state fermentation with B. subtilis 87Y, to produce high-value animal feed supplements.

Effect of Fermented Rapeseed Meal on the Gastrointestinal Microbiota and Immune Status of Rabbit (Oryctolagus cuniculus)

“…RSM was fermented using the strain Bacillus subtilis 87Y from the strain collection of InventionBio Ltd. (Bydgoszcz, Poland). The bacteria were multiplied on Lysogeny Broth (LB) medium (10 g/L NaCl, 10 g/L peptone, 5 g/L yeast extract), from which a bacterial suspension of OD 600 = 0.1 was obtained in MIM1 medium (8.4 g/L Na 2 HPO 4 , 3.9 g/L NaH 2 PO 4 , 2.3 g/L urea, 0.5 g/L MgSO 4 , 60 g/L saccharose, 1.2 mg/L FeSO 4 , 1.6 mg/L CuSO 4 , 5 mg/L MnSO 4 ), [ 20 ]. Prior to fermentation the RSM was sterilised for 15 min and then inoculated with the previously prepared bacterial suspension in a 1:1 ratio while maintaining 50% moisture by adding sterile water and aerating at 50 L/min.…”

Multifaceted applications of probiotic Bacillus species in aquaculture with special reference to Bacillus subtilis

“…In addition to acid resistance, bile salt tolerance is also very crucial for a probiotic bacterium to sustain and overcome the horse acidic gastric environment and the presence of bile salts (Widanarni & Wahjuningrum 2012). Reports indicate that both the vegetative cells and spores of B. subtilis possess high bile tolerance (Sansawat & Thirabunyanon 2009;Andriani et al 2017;Jeon et al 2017;Liu et al 2017;Szmigiel et al 2019).…”

Xylan Decomposition in Plant Cell Walls as an Inducer of Surfactin Synthesis by Bacillus subtilis

“…Furthermore, Schmiedel and Hillen (1995) have shown that B. subtilis 168 cannot grow using xylose as a sole carbon source [33]. However, our previous study showed that B. subtilis 87Y strain utilizes various sugars, including xylose [15]. Enriching RSM with sucrose and xylan (samples SX, Figure 3A) resulted in increased SU synthesis accompanied by growing xylanases activity.…”

“…Bacillus subtilis 87Y used in the study was previously isolated from the soilworm Eisenia fetida [15]. Bacterial inoculum with optical density OD600 = 0.1 was prepared by resuspending B. subtilis precultures in minimal MIM1 medium (sucrose 60 g/L, urea 2.3 g/L, MgSO4 0.5 g/L, Na2HPO4 8.4 g/L, NaH2PO4 3.9 g/L, FeSO4 1.2 mg/L, CuSO4 1.6 mg/L, MnSO4 5 mg/L, pH = 7.0).…”

“…Hence, we decided to investigate the relationship between degradation of oat cell wall components and SU production. In this study, we used B. subtilis 87Y previously isolated from soilworm Eisenia fetida [15] We decided to use the SSF process, which provides many benefits. Compared to liquid state fermentation, SSF requires lower energy, produces less wastewater, is environment-friendly, and most importantly, it resolves the huge problem of solid waste or by-product disposal [16,17].…”