Kucera Dan, Novackova Ivana, Pernicova Iva, Sedlacek Petr, Obruca Stanislav
Faculty of Chemistry, Brno University of Technology, Purkynova 118, 612 00 Brno, Czech Republic.
Material Research Centre, Faculty of Chemistry, Brno University of Technology, Purkynova 118, 612 00 Brno, Czech Republic.
Bioengineering (Basel). 2019 Aug 26;6(3):74. doi: 10.3390/bioengineering6030074.
The terpolymer of 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), and 4-hydroxybutyrate (4HB) was produced employing sp. DSM 19379. Growth in the presence of γ-butyrolactone, ε-caprolactone, 1,4-butanediol, and 1,6-hexanediol resulted in the synthesis of a polymer consisting of 3HB and 4HB monomers. Single and two-stage terpolymer production strategies were utilized to incorporate the 3HV subunit into the polymer structure. At the single-stage cultivation mode, γ-butyrolactone or 1,4-butanediol served as the primary substrate and propionic and valeric acid as the precursor of 3HV. In the two-stage production, glycerol was used in the growth phase, and precursors for the formation of the terpolymer in combination with the nitrogen limitation in the medium were used in the second phase. The aim of this work was to maximize the Polyhydroxyalkanoates (PHA) yields with a high proportion of 3HV and 4HB using different culture strategies. The obtained polymers contained 0-29 mol% of 3HV and 16-32 mol% of 4HB. Selected polymers were subjected to a material properties analysis such as differential scanning calorimetry (DSC), thermogravimetry, and size exclusion chromatography coupled with multi angle light scattering (SEC-MALS) for determination of the molecular weight. The number of polymers in the biomass, as well as the monomer composition of the polymer were determined by gas chromatography.
采用嗜甲基菌DSM 19379生产3-羟基丁酸酯（3HB）、3-羟基戊酸酯（3HV）和4-羟基丁酸酯（4HB）的三元共聚物。在γ-丁内酯、ε-己内酯、1,4-丁二醇和1,6-己二醇存在的条件下生长，可合成由3HB和4HB单体组成的聚合物。采用单阶段和两阶段三元共聚物生产策略，将3HV亚基纳入聚合物结构中。在单阶段培养模式下，γ-丁内酯或1,4-丁二醇作为主要底物，丙酸和戊酸作为3HV的前体。在两阶段生产中，甘油用于生长阶段，第二阶段使用三元共聚物形成的前体并结合培养基中的氮限制。这项工作的目的是使用不同的培养策略，以高比例的3HV和4HB最大化聚羟基脂肪酸酯（PHA）的产量。所获得的聚合物含有0-29摩尔%的3HV和16-32摩尔%的4HB。对选定的聚合物进行了材料性能分析，如差示扫描量热法（DSC）、热重分析法和尺寸排阻色谱联用多角度光散射法（SEC-MALS）以测定分子量。通过气相色谱法测定生物质中聚合物的数量以及聚合物的单体组成。
