Isolation and characterization of glycolipid biosurfactant produced by a Pseudomonas otitidis strain isolated from Chirimiri coal mines, India

Abstract

Background: Biosurfactants (BSs) are amphipathic, surface active molecules produced by microorganisms and can reduce the surface tension and interfacial tension. The present study emphasizes the isolation and structural characterization of the BS produced by Pseudomonas otitidis P4.Results: An efficient BS producing bacterial strain isolated from the unexplored coal mining site of Chirimiri, India was identified as P. otitidis P4 based on morphological, biochemical and 16S rRNA gene sequence analysis. The surface tension of the culture medium was reduced from 71.18 to 33.4 mN/m. The surface tension and emulsification activity of the BS remained stable over a wide range of temperature, pH and salt concentrations indicating its scope of application in bioremediation, food, cosmetics, and pharmaceutical industries. Structural attributes of BS were determined by biochemical tests, thin layer chromatography (TLC), Fourier transform infrared (FTIR) and nuclear magnetic resonance ( 1 H NMR) spectroscopy analyses, which confirmed the glycolipid nature of BS. Lipid and sugar fractions were the main constituents of the extracted BS. Thermogravimetric (TG) and Differential scanning calorimetry (DSC) analyses showed the thermostable nature of BS. As determined from TGA graph, the degradation temperature of biosurfactant was found to be 280 °C while complete weight loss was observed after 450 °C. Conclusion:The BS isolated from P. otitidis P4 was identified as glycolipid and showed high emulsification activity and stability in a wide range of temperature, pH and salinity which makes it suitable for various industrial and environmental applications.

Novel Bioformulations Developed from Pseudomonas putida BSP9 and Its Biosurfactant for Growth Promotion of Brassica juncea (L.)

“…The Fourier transform infrared spectroscopy (FTIR) analysis of the biosurfactant produced from BSP9 clearly reveals the presence of functional groups that typically belong to glycolipids. The spectrum ( Figure 1 ) was consistent with the structure of glycolipids already reported in the literature [ 58 , 59 , 60 ]. The IR spectrum shows absorption bands ranging between 3650–3134 cm −1 , which indicate the presence of free -OH group arising as a result of H bonding of polysaccharides and/or –OH stretching of carboxylic acid.…”

“…Two bands at wavenumber 1748 cm −1 and 1712 cm −1 denote –C=O stretching arising from the ester groups of lipids and fatty acids (-C=O in COOH), and bands at wavenumber 1396 cm −1 signify C-H and OH deformation vibrations of carbohydrates that may be arising due to the presence of rhamnose units in the biosurfactants [ 61 ]. A small peak at wavenumber 2358 cm −1 is likely due to the presence of phosphines (P-H 3 ) in the biosurfactant [ 59 ]. The range of spectra below 1000 cm −1 represents C-H, C-O and CH 3 vibrations [ 62 ].…”

Improved Biosurfactant Production by Enterobacter cloacae B14, Stability Studies, and its Antimicrobial Activity

“…Emulsion layers formed by B14 BS obtained when cells are grown on an optimum culture medium, were stable under a wide range of pH (2–10), and temperature (30–37°C). This result was in agreement with the glycolipid derived from Pseudomonas otitidis , isolated from a coal mine, whose E24 could still be detected when exposed to pH 3–11, and the temperature was as high as 80–100°C ( Singh and Tiwary 2016 ). The stability studies on glycolipid BS derived from P. aeruginosa HAK01 indicated that this BS was able to function under a wide range of temperatures (40–121°C) and pH (4–10) ( Khademolhosseini et al 2019 ).…”

“…In order to investigate our glycolipid potential application, antimicrobial activity of cell-free broth containing B14 BS derived from cultures grown on an optimized medium was tested. Although biosurfactant will typically be used in actual application in the form of pure compounds, the cell-free supernatant could be used as a pre-screening process for stability studies and antimicrobial tests ( Singh and Tiwary 2016 ; Mouafo et al 2018 ). At this stage, we then selected to use the cell-free supernatant from strain B14 for these studies, as it is also less time-consuming.…”

Optimization and characterization of a glycolipid produced by Achromobacter sp. to use in petroleum industries

“…TMB1 has utilized NaNO 3 as the best nitrogen source for maximum growth and production of biosurfactant at optimum temperature (30 °C) and pH (7.2). Singh and Tiwary reported yeast extract as the best nitrogen source for the yield of biosurfactants by Pseudomonas otitidis P4 strain . But for Achromobacter sp.…”