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Biosynthesis of Poly(3‐hydroxybutyrate‐ co ‐3‐hydroxyvalerate) from Ethanol and Pentanol by Alcaligenes eutrophus
Author(s) -
Park ChangHo,
Damodaran Vijay K.
Publication year - 1994
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1021/bp00030a006
Subject(s) - chemistry , ethanol , alcohol , fermentation , nuclear chemistry , yield (engineering) , valerate , polymer , zymomonas mobilis , copolymer , valeric acid , alcaligenes , organic chemistry , ethanol fuel , bacteria , materials science , acetic acid , pseudomonas , butyrate , biology , metallurgy , genetics
An alcohol utilizing Alcaligenes eutrophus NCIMB 12080 produced a copolymer, poly‐(hydroxybutyrate–valerate) (PHBV), in a computer‐controlled 7‐L fed‐batch fermentor when the alcohol feed contained pentanol. Pentanol as a sole carbon source was not efficient either for cell growth or for PHBV production. To achieve better cell growth and polymer production, two kinds of alcohol switch experiments were performed. The first was initial cell growth on a mixture of 50% ethanol (0.25 g/L) plus 50% pentanol (0.25 g/L) and a subsequent switch to 100% pentanol (0.5 g/L). After the alcohol switch, PHBV with 99 mol % hydroxyvalerate was produced for 7–11 h. Afterward, the hydroxybutyrate (HB) composition increased and the hydroxyvalerate (HV) mol % decreased to 63.1 mol %. The total cell mass was 5.4 g/L. The second alcohol switch was from 100% ethanol (0.5 g/L) to a mixture of 80% ethanol (0.4 g/L) plus 20% pentanol (0.1 g/L). A large amount of copolymer (47 g/L) was produced with a high polymer yield (0.64 g of polymer/g of alcohol), but the HV mol % did not exceed 13.5%. Residual biomass was 8.0 g/L.