Biotechnology and oleochemicals: Changing patterns

Abstract

Biotechnology will have a broad impact on the oleochemicals industry. Only a narrow range of this interface is discussed: (a) the use of organic solvents in the enzymatic synthesis of lipid derivatives, (b) the effect of the chemical nature of the feedstock on the production of microbial monoesters, and (c) temperature as a determinant of the level of onsaturation in biosynthetic lipids. Interest in running enzymatic reactions in high concentrations of organic solvents is increasing. The implications of such processes for the oleochemical industry is illustrated by examples of ester synthesis and interesterification of oils and fats. The dramatic effect of feedstock chemistry on the final monoester product mix produced by Acinetobacter sp. HO1-N is also discussed. Products resulting from using n-alkaues (C 16-C20), acetic and propionic acids and, most recently, ethanol and propanol, are illustrated. They range from a monoester mix resembling sperm oil to one similar to jojoba oil. In general, temperature inversely affects biolipid unsaturation: the lower the temperature, the greater the unsaturation. The major function of this response is to preserve fluidity and function in biological membranes. The effect is universal in nature, occurring in animals, plants and microorganisms. Controlled laboratory studies have supported these observations made in nature. We have investigated the effect of temperature on the unsaturation of monoesters produced by the bacterium, Acinetobacter sp. tlO1-N. The inverse relationship between temperature and unsaturation is clearly shown. The enzymatic basis for these results and the possibility of chemical or genetic modification of plants and microorganisms to produce more or less unsaturated lipids is briefly discussed. Organic solvents, feedstock chemistry and temperature stress in biocatalysis are but three of the variables at the interface of biotechnology and the oleochemicals industry that will cause changing patterns.

A Novel Post-translational Modification Involving Bromination of Tryptophan

“…4 The mature peptide purified from venom is encoded at the extreme C-terminal end of the predicted prepropeptide precursor. The bromotryptophan residue is encoded in the mRNA by the codon for tryptophan.…”

“…Brominated Conus Peptides in the General Context of Brominated Amino Acids and Natural Products-A wide variety of haloperoxidases are known that can brominate tyrosine residues in humans and animals, including myeloperoxidases and lactoperoxidases (4). In addition, bromoperoxidases have been isolated from several species of algae (4,36).…”

“…Co-elution of Natural and Synthetic Bromosleeper Peptide N-terminal (1)(2)(3)(4) Fragment-Approximately equal amounts of the endoproteinase Asp-N-digested N-terminal fragment of the bromosleeper peptide and the synthetic peptide Trp*-Ala-Thr-Ile-OH were mixed (where Trp* ϭ bromotryptophan). The mixture was applied onto a C 18 analytical column and eluted at 1 ml/min using a gradient of acetonitrile in 0.085% trifluoroacetic acid.…”

“…One notable set of modified amino acids are halogenated derivatives of tyrosine and histidine. Naturally occurring halogenated tyrosine and histidine residues have previously been identified from proteins (1)(2)(3)(4). A particularly well documented example of in vivo posttranslational halogenation of an amino acid residue in a protein is afforded by thyroglobulin (5).…”

“…After iodination of several tyrosine residues, selective cleavages release the iodinated thyroid hormones thyroxine (3,5,3Ј,5Ј-tetraiodothyronine or T 4 ) 1 ; 3,5,3Ј-triiodothyronine (T 3 ), and 3,3Ј-di-iodothyronine. The presence of free T 3 and T 4 has also been shown in protochordates, suggesting a primitive thyroid function exists in tunicates (2).…”