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Preliminary characterization and antimicrobial activity of crude biosurfactant extract from potential bacterial isolates

Authors :
Wan Nur Aishah Natasha Wan A.R. Azizan
Fatin Nabilah Jeffry
Zainatul `Asyiqin Samsu
Source :
Materials Today: Proceedings. 31:A72-A78
Publication Year :
2020
Publisher :
Elsevier BV, 2020.

Abstract

This research was done in order to extract and characterize biosurfactants produced by isolates obtained from used engine oil-contaminated soil. Biosurfactants from three isolates 2c, 2k and 2m were extracted to determine their stability over pH and temperature ranges. The functional group of the extract was analysed by Fourier-transform infrared spectroscopy and the antimicrobial activity of biosurfactants against selected Gram-positive and Gram-negative bacteria was studied. The biosurfactants demonstrated good stability as shown by oil displacement assay after being exposed to temperature from 27 °C to 70 °C and pH ranging from 4 to 12 for 24 h. Furthermore, the antimicrobial activity of the extract of isolates 2k and 2m was discovered through the inhibition of Bacillus subtilis. The biosurfactants of isolates 2c and 2m were identified to possibly be from rhamnolipid group where they possessed O–H functional group within the range of 3550 to 3200 cm−1. Meanwhile, biosurfactants of isolate 2k was possibly a lipoptide biosurfactants as N–H functional group was observed at 3400 to 3300 cm−1. Thus, the three isolates chosen were shown to be the potential producer of rhamnolipid and lipopeptide type of biosurfactants and the extract did show good stability within the pH and temperature range tested.

Details

ISSN :
22147853
Volume :
31
Database :
OpenAIRE
Journal :
Materials Today: Proceedings
Accession number :
edsair.doi...........cf5028e5fcc61d64e46da673be8aa952
Full Text :
https://doi.org/10.1016/j.matpr.2020.12.439