Biosurfactants classes

Microbially produced biosurfactants can also have important effects on increasing bioavailability and biodegradation (Zhang Miller, 1992). A new PCB-degrading strain was recently isolated and found to produce a bio-emulsifier (Rothmel et al., 1993). Experiments show that the bio-emulsifier stimulates the extent of PCB degradation well beyond the levels seen before with other Type strains of its class, and that the bio-emulsifier can stimulate the extent of PCB biodegradation of added co-cultures as well. 

Micro-foam, or colloidal gas aphrons have also been reportedly used for soil flushing in contaminated-site remediation [494—498], These also have been adapted from processes developed for enhanced oil recovery (see Section 11.2.2.2). A recent review of surfactant-enhanced soil remediation [530] lists various classes of biosurfactants, some of which have been used in enhanced oil recovery, and discusses their performance on removing different type of hydrocarbons, as well as the removal of metal contaminants such as copper and zinc. In the latter area, the application of heavy metal ion complexing surfactants to remediation of landfill and mine leachate, is showing promise [541]. 

Ito S, Imura T, Fukuoka T, Morita T, Sakai H, Abe M, Kitamoto D (2007) Kinetic studies on the interactions between glycolipid biosurfactant-assembled monolayers and various classes of immunoglobulins using surface plasmon resonance. Colloids Surf Biointerfaces 58 165-171... 

Metabolites that are composed of structures of quite different oxidation states. Certain secondary metabolites and biosurfactants M into dus class since they have both carbohydrates and fatty adds in their structures. 

Other uses for glycosylamides have also been described in the literature. Amphiphilic glycosylamides have been demonstrated to be a valuable class of non-ionic biosurfactants (/O). Also, Kunz has used N-glycosylamides as an anomeric protecting group in glycosylation sequences (4). 

Surfactants are classified on the basis of the charge carried by the polar head group as anionic, cationic, nonionic, or amphoteric. Tables 2.1 through 2.4 show the chemical structures of typical examples of these classes. Lecithin, cephalin, and the bile acids are ususally classified as biosurfactants. The bile acids and their conjugates have different properties in solution from surfactants with a long alkyl chain. ... 

Biosurfactants are classified based on their chemical composition and microbial origin. The chemical structure of biosurfactants contains hydrophilic and hydrophobic groups. Amino acids, peptides and polysaccharides can be present as hydrophilic moieties and saturated or unsaturated fatty acids can be present as hydrophobic moieties in the structure. Structure based classification has following major classes of biosurfactants (Guerra-Santos et al., 1987 Kooper and Goldenberg, 1987) (i) Glycolipids (Rhamnolipids, Trehalolipids and Sophorolipids) (ii) Lipopeptide and lipoprotein (iii) Fatty acids, phospholipids and neutral lipids (iv) Pol5mieric biosurfactants, and (v) Particulate biosurfactants. 

As demands placed on surfactants have become more stringent, new classes of materials have been developed that do not conveniently fit into the classical groupings of conventional hydrocarbon-based materials. These newer classes include those in which fluorine replaces hydrogen atoms on the carbon chain, silicone-based surfactants, and more recently so called biosurfactants that can be a witch s brew of protein, carbohydrate, and/or hydrocarbon units. 

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