Biological properties and structural characterization of a novel rhamnolipid like-biosurfactants produced by Lactobacillus casei subsp. casei TM1B.

2020-06-25
Biotechnology and applied biochemistry 68(3)

PubMed: 32497351
DOI: 10.1002/bab.1966

Study Design

Methods: a strain isolated from a Cameroonian fermented milk "pendidam" and identified as Lactobacillus casei subsp. casei TM1B was used for biosurfactants production; the biosurfactants produced by L. casei TM1B with molasses as the substrate were analyzed using chemical, Fourier transform infrared spectroscopy, gas chromatography-mass spectrometry, and NMR analysis

Biosurfactants are microbial surface-active compounds with antimicrobial and antioxidant activities that display a range of physiological functions. In this study, a strain isolated from a Cameroonian fermented milk "pendidam" and identified as Lactobacillus casei subsp. casei TM1B was used for biosurfactants production. The biosurfactants produced by L. casei TM1B with molasses as the substrate had a good surface (40.77 mN/m) and emulsifying (84.50%) activities. The scavenging of the ABTS^+• radical (IC₅₀ value of 0.60 ± 0.03 mg/mL) by the biosurfactants was found to be higher than that of DPPH^• radical (IC₅₀ value of 0.97 ± 0.13 mg/mL). The maximum chelating activity of biosurfactants (82.29%) was observed at 3.5 mg/mL. The biologically active compound of the biosurfactants produced by L. casei TM1B was identified as 2,5-O-methylrhamnofuranosyl-palmitate, a novel rhamnolipid-like biosurfactant by using chemical, Fourier transform infrared spectroscopy, gas chromatography-mass spectrometry, and NMR analysis. The biosurfactants were bactericidal against several Gram-negative and Gram-positive pathogens (minimum inhibitory concentration values ranged from 3.22 to 12.83 mg/mL), and scanning electron microscope analysis revealed bacterial cell walls and membranes as main targets.

Research Insights

Supplement	Dose	Health Outcome	Effect Type	Effect Size	Source
Lactobacillus casei	—	Increased Antioxidant Activity	Beneficial	Moderate	View source The scavenging of the ABTS+• radical (IC50 value of 0.60 ± 0.03 mg/mL) by the biosurfactants was found to be higher than that of DPPH• radical (IC50 value of 0.97 ± 0.13 mg/mL).
Lactobacillus casei	—	Reduced Metal Ion Burden	Beneficial	Moderate	View source The maximum chelating activity of biosurfactants (82.29%) was observed at 3.5 mg/mL.