Pseudomonas putida KT2442 as a platform for the biosynthesis of polyhydroxyalkanoates with adjustable monomer contents and compositions

摘要

The β-oxidation weakened Pseudomonas putida were established as a platform for the production of polyhydroxyalkanoates (PHA) with adjustable monomer compositions and micro-structures. When mutant P. putida KTOYO6δC (phaPCJ_(A.c)) was cultivated on mixtures of sodium butyrate and sodium hexanoate (C4:C6), random copolymers of P(3HB-co-3HHx) consisting of 3-hydroxybutyrate (3HB), 3-hydroxyhexanoate (3HHx), were accumulated with 3HHx content ranged from 19mol% to 75mol%. While recombinant P. putida KTQQ20 grown on mixtures of sodium hexanoate and decanoic acid (C6:C10), produced random copolymers of P(3HHx-co-3HD) consisting of 3-hydroxyhexanoate (3HHx) and 3-hydroxydecanoate (3HD), the monomer fraction of 3HHx ranged from 16mol% to 63mol%. The comonomer compositions were easily regulated by varying the fatty acid concentrations. P. putida KTQQ20 produced a novel diblock copolymer P3HHx-b-P(3HD-co-3HDD) consisting of 49mol% P3HHx and 51mol% P(3HD-co-3HDD) [35.25mol% 3HDD (3-hydroxydodecanoate)], which was characterized by ~13C NMR, HMBC NMR, DSC, GPC and universal testing machine.