Most of the research indicated that biosurfactants were only produced using either oxygen or nitrate as terminal electron acceptors. However, when testing various microbial enhanced oil recovery (MEOR) formulations, I noticed signs of continued biosurfactant production after dissolved oxygen and added nitrate were depleted. We also suspected similar biosurfactant activity in collection systems and grease traps where conditions were anaerobic.
In the August issue of the Journal of Biotechnology, there is an article on the non-oxygen or nitrate production of biosurfactants. The study looked at oil field microbiotia and found microbes that could produce biosurfactants by fermentative respiration. The microbes identified by 16s and cpn60 testing were Pseudomonas sp (similar to a P. fluorescens) and Bacillus mojavensis. At Aster Bio we have been working with both strains for biosurfactant production. We have used both strains in high FOG wastewater, bioremediation, and microbial enhanced oil recovery (MEOR). It is great to see peer reviewed papers confirming our lab and field testing of microbes and their metabolic products.
Here is a link to the abstract: Yurly Kryachko et al. "Enrichment and identification of biosurfactant-producing oil field microbiota utilizing electron acceptors other than oxygen and nitrate," Journal of Biotechnology Vol. 231, August 2016. pp 9 - 15.