Open AccessStudies on polyhydroxyalkanoate (PHA) accumulation in a PHA synthase I‐negative mutant of Burkholderia cepacia generated by homogenotization
Author(s) -
Andrade Rodrigues Maria Filomena,
Vicente Elisabete José,
Steinbüchel Alexander
Publication year - 2000
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2000.tb09421.x
Subject(s) - polyhydroxyalkanoates , mutant , burkholderia , atp synthase , biology , gene , biochemistry , microbiology and biotechnology , chemistry , bacteria , genetics
In the genome of Burkholderia cepacia strain IPT64, which accumulates a blend of the two homopolyesters poly(3‐hydroxybutyrate), poly(3HB), and poly(3‐hydroxy‐4‐pentenoic acid), poly(3H4PE), from sucrose or gluconate as single carbon source, the polyhydroxyalkanoate (PHA) synthase structural gene was disrupted by the insertion of a chloramphenicol‐resistant gene cassette ( phaC1::Cm ). The suicide vector pSUP202 harboring phaC1::Cm was transferred to B. cepacia by conjugation. The inactivated gene was integrated into the chromosome of B. cepacia by homologous recombination. This mutant and also 15 N ‐methyl‐ N ′‐nitrosoguanidine (NMG)‐induced mutants still accumulated low amounts of PHAs and expressed low PHA synthase activity. The analysis of the mutant phaC1::Cm showed that it accumulated about 1% of PHA consisting of 68.2 mol% 3HB and 31.8 mol% 3H4PE from gluconate. The wild‐type, in contrast, accumulated 49.3% of PHA consisting of 96.5 mol% 3HB and 3.5 mol% 3H4PE. Our results indicated that the genome of B. cepacia possesses at least two PHA synthase genes, which probably have different substrate specificities.