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Biosynthesis of PHB tercopolymer by Bacillus cereus UW85
Author(s) -
Lstrok;abużek S.,
Radecka I.
Publication year - 2001
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1046/j.1365-2672.2001.01253.x
Subject(s) - bacillus cereus , gel permeation chromatography , chemistry , cereus , chloroform , substrate (aquarium) , chromatography , bioplastic , biopolymer , biodegradation , nuclear chemistry , food science , bacteria , organic chemistry , biology , polymer , ecology , genetics
Aims: The study was attempted to determine the ability of a Gram‐positive Bacillus cereus UW85 strain to biosynthesize poly (3‐hydroxybutyrate) copolymers when ɛ‐caprolactone, or ɛ‐caprolactone and glucose, were used as carbon sources. Methods and Results: Bacillus cereus was grown for 24 h under nitrogen‐limited conditions in a mineral salts medium. Growth was monitored by measurement of turbidity. Glucose level was determined by the colorimetric anthrone method. The ɛ‐caprolactone concentration was determined by gas chromatography. The bacterial biopolymers were extracted with chloroform in a Soxhlet extractor and then characterized by nuclear magnetic resonance and gel permeation chromatography. When ɛ‐caprolactone was used as a carbon substrate, the bacterial strain produced tercopolymer with 3‐hydroxybutyrate, 3‐hydroxyvalerate and 6‐hydroxyhexanoate units. However, when caprolactone and glucose were supplied together, only homopolymer of poly (3‐hydroxybutyrate) was produced. Conclusions: All tercopolymers isolated from B. cereus UW85 cells were obtained with yields up to 9% (w/w) and low number‐average molecular weight compared with the homopolymer PHB. Significance and Impact of the Study: Bacillus cereus UW85 produced tercopolymer with a low molecular weight from one substrate (ɛ‐caprolactone) used as a carbon source. The results are significant for the potential future application of Bacillus biopolymers to bioplastics production.