Biosurfactant usually refers to surfactants of microbial origin.[1] Most of the biosurfactants produced by microbes are synthesized extracellularly and many microbes are known to produce biosurfactants in large relative quantities.[2] Some are of commercial interest.[3] As a secondary metabolite of microorganisms, biosurfactants can be processed by the cultivation of biosurfactant producing microorganisms in the stationary phase on many sorts of low-priced substrates like biochar, plant oils, carbohydrates, wastes, etc. High-level production of biosurfactants can be controlled by regulation of environmental factors and growth circumstances. [4]
Classification
Biosurfactants are usually categorized by their molecular structure. Like synthetic surfactants, they are composed of a hydrophilic moiety made up of amino acids, peptides, (poly)saccharides, or sugar alcohols and a hydrophobic moiety consisting of fatty acids. Correspondingly, the significant classes of biosurfactants include glycolipids, lipopeptides and lipoproteins, and polymeric surfactants as well as particulate surfactants.[5]
Examples
Common biosurfactants include:
Bile salts are mixtures of micelle-forming compounds that encapsulate food, enabling absorption through the small intestine.[6]
Lecithin, which can be obtained either from soybean or from egg yolk, is a common food ingredient.
Microbial biosurfactants are obtained by including immiscible liquids in the growth medium.[8]
Applications
Potential applications include herbicides and pesticides formulations, detergents, healthcare and cosmetics, pulp and paper, coal, textiles, ceramic processing and food industries, uranium ore-processing, and mechanical dewatering of peat.[8][1][2]
Oil spill remediation
Biosurfactants enhance the emulsification of hydrocarbons, thus they have the potential to solubilise hydrocarbon contaminants and increase their availability for microbial degradation.[9][10] In addition, biosurfactants can modify the cell surface of bacteria that biodegrade hydrocarbons, which can also increase the biodegradability of these pollutants to cells.[11] These compounds can also be used in enhanced oil recovery and may be considered for other potential applications in environmental protection.[12]
^ abGutnick, D. L.; Bach, H. (2000). "Engineering bacterial biopolymers for the biosorption of heavy metals; new products and novel formulations". Applied Microbiology and Biotechnology. 54 (4): 451–460. doi:10.1007/s002530000438. PMID11092618. S2CID23991659.
^Oliveira, F. J. S.; Vazquez, L.; de Campos, N. P.; de França, F. P., Production of rhamnolipids by a Pseudomonas alcaligenes strain. Process Biochemistry 2009, 44 (4), 383-389
^Del'Arco JP, de França FP (2001). "Influence of oil contamination levels on hydrocarbon biodegradation in sandy sediment". Environ. Pollut. 112 (3): 515–519. doi:10.1016/S0269-7491(00)00128-7. PMID11291458.