Aqueous Extracts of Fermented Macrofungi Cultivated in Oilseed Cakes as a Carbon Source for Probiotic Bacteria and Potential Antibacterial Activity

Abstract

Plant biomass colonized by macrofungi can contain molecules with bioactive properties with applications to human/animal health. This work aimed to verify antibacterial activities from aqueous extracts from oil seed cakes of Jatropha curcas (JSC) and cottonseed (CSC), fermented by macrofungi for probiotic bacteria cultivation. Coriolopsis sp., Tyromyces sp., Panus lecomtei, and Pleurotus pulmonarius were cultivated in solid and submerged media. The aqueous extract of unfermented JSC was more efficient than glucose for the growth of all probiotic bacteria. Extracts from four macrofungi fermented in CSC favored Lactobacillus acidophilus growth. In solid fermentation, macrofungi extracts cultivated in JSC favored Bifidobacterium lactis growth. All fungi extracts showed more significant growth than carbohydrates among the four probiotic bacteria evaluated. Regarding antimicrobial activities, no fungal extract or bacterial supernatant showed a more significant inhibition halo for enteropathogenic bacteria than ampicillin (control). Extracts from P. lecomtei and Coriolopsis sp. in CSC showed inhibition halos for Salmonella enterica. Supernatants from L. acidophilus, B. lactis, and Lactobacillus rhamnosus resulted in more significant inhibition of Staphylococcus aureus than the control, which indicates possible antimicrobial activity. Unfermented JSC supernatant showed better results for bacterial growth, while supernatants and aqueous extracts from CSC fermentation can be used for probiotic bacteria culture.

Keywords: antimicrobial activities; biodetoxification; fermentation; macrofungi bioactive; oil seed cake.

Figure 1

Growth curves of L. acidophilus at 20 mg/mL for 48 h at 37 °C: (A) supernatants (carbon source—prebiotics) from submerged fermentations by macrofungi in cottonseed cake (SmF-CSC) and jatropha seed cake (SmF-JSC); (B) supernatants from solid-state fermentation by macrofungi in cottonseed cake (SSF-CSC) and jatropha seed cake (SSF-JSC).

Figure 1

Growth curves of L. acidophilus at 20 mg/mL for 48 h at 37 °C: (A) supernatants (carbon source—prebiotics) from submerged fermentations by macrofungi in cottonseed cake (SmF-CSC) and jatropha seed cake (SmF-JSC); (B) supernatants from solid-state fermentation by macrofungi in cottonseed cake (SSF-CSC) and jatropha seed cake (SSF-JSC).

Figure 2

Growth of L. acidophilus in LogUFC/mL with 0, 12, 24, and 48 h of incubation in MRS-C medium with 20 mg/mL of CSC submerged fermentation supernatants: (A), submerged fermentation supernatants of JSC (B), solid-state fermentation aqueous extracts of CSC (C), and solid-state fermentation extracts of JSC (D).

Figure 3

Growth curves of B. lactis at 20 mg/mL for 48 h at 37 °C: (A) supernatants from submerged fermentations by macrofungi in cottonseed cake (SmF-CSC) and jatropha seed cake (SmF-JSC); (B) supernatants from solid-state fermentation by macrofungi in cottonseed cake (SSF-CSC) and jatropha seed cake (SSF-JSC).

Figure 4

Growth of B. lactis in LogUFC/mL with 0, 12, 24, and 48 h of incubation in MRS-C medium with 20 mg/mL of CSC submerged fermentation supernatants (A), submerged fermentation supernatants of JSC (B), solid-state fermentation aqueous extracts of CSC (C), and solid-state fermentation extracts of JSC (D).

Figure 5

Growth curves of L. rhamnosus at 20 mg/mL for 48 h at 37 °C: (A) supernatants from submerged fermentations by macrofungi in cottonseed cake (SmF-CSC) and jatropha seed cake (SmF-JSC); (B) solid-state fermentation by macrofungi in cottonseed cake (SSF-CSC) and jatropha seed cake (SSF-JSC).

Figure 6

Growth of L. rhamnosus in LogUFC/mL with 0, 12, 24, and 48 h of incubation in MRS-C medium with 20 mg/mL of CSC submerged fermentation supernatants (A), submerged fermentation supernatants of JSC (B), solid-state fermentation aqueous extracts of CSC (C), and solid-state fermentation extracts of JSC (D).

Figure 7

Growth curves of L. plantarum at 20 mg/mL for 48 h at 37 °C: (A) supernatants from submerged fermentations by macrofungi in cottonseed cake (SmF-CSC) and jatropha seed cake (SmF-JSC); (B) supernatants from solid-state fermentation by macrofungi in cottonseed cake (SSF-CSC) and jatropha seed cake (SSF-JSC).

Figure 8

Growth of L. plantarum in LogUFC /mL with 0, 12, 24, and 48 h of incubation in MRS-C medium with 20 mg/mL of CSC submerged fermentation supernatants: (A), submerged fermentation supernatants of JSC (B), solid-state fermentation aqueous extracts of CSC (C), and solid-state fermentation extracts of JSC (D).