Identification of a Novel Biosurfactant with Antimicrobial Activity Produced by Rhodococcus opacus R7

Abstract

Rhodococcus members excrete secondary metabolites, especially compounds which act as biosurfactants. In this work, we demonstrated the ability of Rhodococcus opacus R7 to produce a novel bioactive compound belonging to the class of biosurfactants with antimicrobial properties during the growth on naphthalene. Chemical and biochemical analyses of the isolated compound demonstrated that the biosurfactant could be classified as a hydrophobic peptide. The ESI-full mass spectrometry revealed that the isolated biosurfactant showed a molecular weight of 1292 Da and NMR spectra evidenced the composition of the following amino acid residues: Ala, Thr, Asp, Gly, Ser. Surfactant activity of the R. opacus R7 compound was quantified by the critical micelle dilution (CMD) method and the critical micelle concentration (CMC) was estimated around 20 mg L−1 with a corresponding surface tension of 48 mN m−1. Moreover, biological assays demonstrated that R. opacus R7 biosurfactant peptide exhibited antimicrobial activity against Escherichia coli ATCC 29522 and Staphylococcus aureus ATCC 6538 with the minimum inhibition growth concentration (MIC) values of 2.6 mg mL−1 and 1.7 mg mL−1, respectively. In this study for the first time, a hydrophobic peptide with both biosurfactant and antimicrobial activity was isolated from a bacterium belonging to Rhodococcus genus.

Who inhabits the built environment? A microbiological point of view on the principal bacteria colonizing our urban areas

“…Indeed, they are generally detected in humanized environments such as the air of mass transit railways and subways, settled-floor dust, and university classrooms (Hospodsky et al, 2012;Kelley and Gilbert, 2013;Adams et al, 2015;Prussin and Marr, 2015;Wilkins et al, 2016;Gilbert and Stephens, 2018;Merino et al, 2019;Rai et al, 2021). Other genera like Actinomyces, Arthobacter, Rhodococcus, and Streptomyces, primarily soil inhabitants (Hewitt et al, 2012;Wilkins et al, 2016;Zampolli et al, 2019;Cao et al, 2021;Zampolli et al, 2022), are occasionally detected indoors, reflecting their environmental presence. Bacteroidota, encompassing Gram-negative bacteria distributed in almost all environments, human gut, and skin, includes genera like Prevotella and Bacteroides which are commonly detected indoors, particularly in household air and offices (Supplementary Table S1) (Hewitt et al, 2012;Prussin and Marr, 2015;Wilkins et al, 2016;Browne et al, 2017;Gilbert and Stephens, 2018;Merino et al, 2019).…”

Prospects of Microbial Bio‐surfactants To Endorse Prolonged Conservation in the Pharmaceutical and Agriculture Industries

“…Much available research demonstrates biosurfactants' efficacy in combating various infectious agents. [23,25,146] For example, Foschi et al, [147] claimed that their compound (biosurfactant) was antibacterial against many pathogenic bacteria, including Neisseria gonorrhoeae. Table 4 lists the properties of various biosurfactants that can be used in pharmaceutical industries.…”

“…In particular, biosurfactants have bacteriostatic and bactericidal properties that can destroy biofilms, making biosurfactants an attractive tool for use as antimicrobial agents. Much available research demonstrates biosurfactants’ efficacy in combating various infectious agents [23,25,146] . For example, Foschi et al., [147] claimed that their compound (biosurfactant) was antibacterial against many pathogenic bacteria , including Neisseria gonorrhoeae .…”

Extraction, Antibiofilm Activity and Characterization of Biosurfactant Produced by Limosilactobacillus reuteri IDCC 3701

“…In summary, the unique properties of biosurfactants enable them to modify surface tension and the physicochemical characteristics of the environment, thereby disrupting microbial adhesion and impeding the formation of strong biofilm structures [29,30]. Furthermore, certain biosurfactants exhibit antimicrobial properties that directly target the viability and growth of microorganisms associated with biofilms, providing an additional barrier against biofilm development [31].…”