綠色材料-生物可分解聚脂材料PHA生產、應用與分解技術開發─子計畫一：由微生物發酵生產功能性PHA及其形態探討(III)

Biosynthesis of biodegradable polymers using halophilic bacterium Haloferax
mediterranei and Pseudomonas oleovorans was conducted. Manipulations of carbon source
as well as ingredients of fermentation medium were investigated. PHA
(ployhydroxyalkanoate) incorporated with functional groups is anticipated. H. mediterranei grew most rapidly under pH 7.0, dry cell weight reached 5.6 g/L in 36
hrs. Accumulation of PHA in the cells reached a peak under pH 6.5 (Yp/x=0.09). Fermentation
with dosage of 0.1 % KH2PO4 resulted in a high cell concentration (15.59 g/L). Under a
limitation of phosphate (0.0125 % KH2PO4), high PHA content was obtained (0.63 g/L).
Olive oil and soybean oil were fed during the fermentation producing PHA. The products
obtained were PHBV (polyhydroxybutyrate-co-polyhydroxyvalerate) whose PHV contents
were 8-11 % and 7-8 %, respectively. Tm and Tg of PHBV products obtained decreased with
increase of the content of PHV.
3.07 g/L of dry cell weight were obtained using P. oleovorans and dosage of sodium
octanoates. PHA content was 13 % dry weight. 3.04 g/L of dry cell weight were obtained
under a limitation of nitrogen source. PHA content was 36 % dry cell weight.
Different products of PHA were obtained by dosage of different carbon sources. PHOs
(polyhydroxyoctanoate) were the major copolymers obtained by dosaging sodium octanoate as
a carbon source. PHU [poly(3-hydroxyundec-10-enoate)] and PHHN
[poly(3-hydroxyheptanoate-co-3-hydroxynonanoate)] copolymers were obtained as dosaging
undecylenic acid and nonanoic acid respectively as a sole carbon source. Introducing the
various functional groups into the structure of PHAs facilitates the development of
synthesizing new functionality biopolymers for many uses.