Growth of microbes in an oil‐continuous environment

Abstract

The growth of microorganisms in fermentations where oil had been maintained as the continuous phase was examined to determine whether advantage could be gained from the increased solubility of oxygen in hydrocarbon. Although cell concentrations were highest in the aqueous phase of oil‐continuous systems, due to the large oil fraction, productivities achieved per unit fermenter volume were generally equivalent to those obtained from water‐continuous systems. With the oil‐continuous emulsions, the power requirement for aeration and mixing was less, and phase reversal resulted in a threefold concentration of cells in the aqueous medium, thereby facilitating their recovery.

Utilization of n-Alkanes by Cladosporium resinae

“…Similar phenomenon has been reported previously for a hydrocarbon-utilizing Candida species (17). A likely explanation seems to be the higher oxygen availability to the aqueous medium, with the imposition of a discrete layer of hydrocarbon (4,12).…”

Impact of Oil-Based Drilling Fluids Emulsification on Tolerance and Hydrocarbon-Degrading Potential of Ralstonia pickettii and Alcaligenes piechandii

“…Microorganisms have been shown to adhere and grow on the surface of the hydrocarbon droplets dispersed in water. In invert emulsions, microorganisms were also able to attach to the oil-water interface, but grew only in water droplets [7,18]. Thus, the type of emulsion may determine the ability of microorganisms to grow and degrade hydrocarbons in oil-water biphasic systems.…”

“…Since hydrocarbon oxidation is performed by intracellular enzymes, the solubilization of hydrocarbons enhances the mass transfer rate of hydrocarbons to water phase and into microbial cells, and hence, increases the degradation rate. Additionally, emulsification increases bioavailability of hydrocarbons, and hence biodegradation rate, due to increased oil-water interface available for microbial growth [7]. Thus, surfactant addition and emulsification of oil have a marked impact on hydrocarbon degradation.…”

The enzymatic transformation of water-insoluble reactants in nonaqueous solvents. Conversion of cholesterol to cholest-4-ene-3-one by a Nocardia sp.

“…The mechanism by which the reactants reach the microorganisms under these conditions is not known, but the situation may be similar to that with microorganisms growing on hydrocarbons. 9,10 There is one report 11 where the hydrocarbon was the major phase. A similar situation arises when microbial contamination of oils occurs.…”