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Tailor‐made olefinic medium‐chain‐length poly[( R )‐3‐hydroxyalkanoates] by Pseudomonas putida GPo1: Batch versus chemostat production
Author(s) -
Hartmann René,
Hany Roland,
Pletscher Ernst,
Ritter Axel,
Witholt Bernard,
Zinn Manfred
Publication year - 2006
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.20756
Subject(s) - chemostat , pseudomonas putida , dilution , polyhydroxyalkanoates , chemistry , monomer , carbon fibers , nitrogen , food science , chromatography , organic chemistry , bacteria , materials science , biology , enzyme , genetics , physics , polymer , composite number , composite material , thermodynamics
Functionalized medium‐chain‐length polyhydroxyalkanoates (mclPHAs) have gained much interest in research on biopolymers because of their ease of chemical modification. Tailored olefinic mclPHA production from mixtures of octanoic acid and 10‐undecenoic acid was investigated in batch and dual (C,N) nutrient limited chemostat cultures of Pseudomonas putida GPo1 (ATCC 29347). In a batch culture, where P. putida GPo1 was grown on a mixture of octanoic acid (58 mol%) and 10‐undecenoic acid (42 mol%), it was found that the fraction of aliphatic monomers was slightly lower in mclPHA produced during exponential growth than during late stationary phase. Thus, the total monomeric composition changed over time indicating different kinetics for the two carbon substrates. Chemostat experiments showed that the dual (C,N) nutrient limited growth regime (DNLGR) for 10‐undecenoic acid coincided with the one for octanoic acid. Five different chemostats on equimolar mixtures of octanoic acid and 10‐undecenoic acid within the DNLGR revealed that the monomeric composition of mclPHA was not a function of the carbon to nitrogen (C 0 /N 0 ) ratio in the feed medium but rather of the dilution rate. The fraction of aliphatic monomers in the accumulated mclPHA was slightly lower at high dilution rates and increased towards low dilution rates, again indicating different kinetics for the two carbon substrates in P. putida GPo1. © 2005 Wiley Periodicals, Inc.