PRODUCTION OF BIODEGRADABLE PLASTICS FROM BRASSICA CARINATA OIL WITH HIGH CONTENT OF ERUCIC ACID AND FROM VERY LONG CHAIN FATTY ACIDS

摘要

Use of materials based on fatty acids with aliphatic chains of more than 20 carbon atoms, in the form or free acids or of the corresponding triglycerides, as a carbon source for the production by biosynthesis, by means of microorganisms of the Pseudomonas genus, of medium chain length poly(3- hydroxyalkanoates). Very long chain fatty acids (VLCFA), longer than C20, have been employed for the production of medium chain length poly(3-hydroxyalkanoates) (mcl-PHA) by Pseudomonas aeruginosa. In order to keep the production costs low, Brassica carinata oil (erucic acid content 35 - 48%) has been employed as the intact triglyceride containing VLCFA. As free fatty acids erucic acid (C22:1) and nervonic acid (C24:1) have been employed. The 3-hydroxyacids making up the repeating units of such polymers are saturated and unsaturated, with a higher content of the latter in the case of PHAs obtained from B. carinata oil. The PHAs from erucic and nervonic acids are partially crystalline, with rubbery characteristics and a melting point (Tm) of 50°C, while the increase of unsaturation degree in the repeating units of PHA from B. carinata oil affords a totally amorphous material, with a glass transition temperature (Tg) of -47°C.