Jd. Rouse et al., INFLUENCE OF SURFACTANTS ON MICROBIAL-DEGRADATION OF ORGANIC-COMPOUNDS, Critical reviews in environmental science and technology, 24(4), 1994, pp. 325-370
Surfactants have the ability to increase aqueous concentrations of poo
rly soluble compounds and interfacial areas between immiscible fluids,
thus potentially improving the accessibility of these substrates to m
icroorganisms. However, both enhancements and inhibitions of biodegrad
ation of organic compounds in the presence of surfactants have been re
ported. The mechanisms behind these phenomena are not well understood.
To better understand the factors involved and the current state of kn
owledge in this field, a search of the literature concerning the influ
ence of commercial surfactants and biosurfactants on microbial metabol
ism has been conducted. Factors pertaining to surfactant-substrate int
eractions such as emulsification, solubilization, and partitioning of
hydrocarbons between phases, all of which can influence accessibility
of substrates to microorganisms, are of concern. Also, due to the dire
ct interaction of surfactants with microorganisms, it appears that ste
ric or conformational compatibility of surfactants with cell membrane
lipids and enzymes is an important metabolic factor. Weaknesses in the
general data base are evident, such as the lack of research involving
Gram-positive organisms and ionic surfactants. It is also worthy to n
ote that research involving commercial surfactants and mixed microbial
cultures has shown a correlation between inhibited biodegradation of
hydrocarbons and surfactant concentrations above the critical micelle
concentration. This is a significant point of interest when remedial e
fforts involving indigenous organisms in natural environments are bein
g considered.