Bioprospecting surfactants produced by Pseudomonas spp. isolated from soil for potential application in biotechnology
type: CreativeWork
description: Bacteria produce a range of surface-active compounds called biosurfactants that reduce the surface tension of liquid and exhibit different oil-water behaviours. These are used in various biotechnological applications including agriculture, cosmetics, medical and food. A recent study has predicted a limit to bacterial surface tension-reducing ability. If this limit exists, it has strong negative consequences in surveys for more active compounds. In this work, the aim is to (i) investigate this prediction more robustly by using chemical media and (ii) study the diversity amongst the best-performing surfactants produced by Pseudomonas spp. with the intention of finding novel surfactants that could be used in different biotechnological applications. A total of 251 Pseudomonas spp. were isolated from soil. Strains were first screened for liquid surface tension-reducing ability (LSTRA) using qualitative drop-collapse assay before quantitative surface tension measurement. Of the 58 LSTRA strains, only 46 significantly reduced the surface tension of sterile media. Individual Distribution Identification (IDI) analysis was used to determine the predicted limit for surfactant activity in KB* and M9Glu media, and results were found to be in agreement with earlier studies. To investigate the chemical structural diversity amongst the best performing surfactants, a collection of 25 key strains producing a limited range of very low surface tension in liquid culture media (~24 – 26 mN/m) were examined. Initial phenotypic characterisation including biochemical, metabolic profiling and 16S rDNA sequencing confirmed strains were a diverse collection of Pseudomonas spp.. A series of behaviour assays including emulsion formation, foam stabilisation and oil displacement assays to investigate behavioural diversity among surfactants expressed by the key strains were then undertaken. For the oil displacement, diesel, mineral, vegetable, and used lubricating oils were tested with the underlyi…
abstract: Bacteria produce a range of surface-active compounds called biosurfactants that reduce the surface tension of liquid and exhibit different oil-water behaviours. These are used in various biotechnological applications including agriculture, cosmetics, medical and food. A recent study has predicted a limit to bacterial surface tension-reducing ability. If this limit exists, it has strong negative consequences in surveys for more active compounds. In this work, the aim is to (i) investigate this prediction more robustly by using chemical media and (ii) study the diversity amongst the best-performing surfactants produced by Pseudomonas spp. with the intention of finding novel surfactants that could be used in different biotechnological applications. A total of 251 Pseudomonas spp. were isolated from soil. Strains were first screened for liquid surface tension-reducing ability (LSTRA) using qualitative drop-collapse assay before quantitative surface tension measurement. Of the 58 LSTRA strains, only 46 significantly reduced the surface tension of sterile media. Individual Distribution Identification (IDI) analysis was used to determine the predicted limit for surfactant activity in KB* and M9Glu media, and results were found to be in agreement with earlier studies. To investigate the chemical structural diversity amongst the best performing surfactants, a collection of 25 key strains producing a limited range of very low surface tension in liquid culture media (~24 – 26 mN/m) were examined. Initial phenotypic characterisation including biochemical, metabolic profiling and 16S rDNA sequencing confirmed strains were a diverse collection of Pseudomonas spp.. A series of behaviour assays including emulsion formation, foam stabilisation and oil displacement assays to investigate behavioural diversity among surfactants expressed by the key strains were then undertaken. For the oil displacement, diesel, mineral, vegetable, and used lubricating oils were tested with the underlyi…
author: Kabir, Kamaluddeen
language: eng
keywords: Surfactants, Pseudomonas spp, Limit, Diversity, Biotechnology, Surface tension, LSTRA, Bioprospecting
date published: 2017-8-18
date modified: 2026-07-24T00:50:03Z
provider: Abertay University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Abertay University