Agro-industrial oily wastes as substrates for PHA production by the new strain Pseudomonas aeruginosa NCIB 40045:Effect of culture conditions

摘要

Production of poly(3-hydroxyalkaonates)(PHA)by Pseudomonas aeruginosa 42A2 from agro-industrial oily wastes was studied.PHA accumulation,throughout the cell cycle,was observed as intracellular accumulation associated to polyphosphate granules.A 54.6% PHA accumulation was obtained when technical oleic acid(TOA)was used as carbon source.Molecular weight of the polymer was 54.7 Da.The polymer was amorphous,with glass transition at-47.5 deg C and thermal degradation at 293 deg C.PHA production and monomer composition were affected by K_(La)and temperature.The most relevant characteristic of the polymer produced at low aeration rates(K_(Lu),0.06 s~(-1))were the unusual C_(14:2)(13%)and the increase of C_(12:1)(42.2%).The highest amount of unsaturated monomers was found in the polymer produced at 18deg C(64.4%).PHA accumulation ranged between 66.1% when waste-free fatty acids from soybean oil(WFFA)were used as carbon substrate,29.4% when waste frying oil(WFO)was used and 16.8% when glucose was used.Depending on the substrate supplied a wide range of components was observed.Major saturated or unsaturated components of the polymer found were C_(10:0),C_(12:0)and C_(8:0)or C_(12:1)and C_(14:1),respectively.When glucose was used as carbon substrate C_(9:0),C_(11:0)and C_(16:0)were found.