Autotrophic biosynthesis of polyhydroxyalkanoate by Ralstonia eutropha from non-combustible gas mixture with low hydrogen content
Autotrophic biosynthesis of polyhydroxyalkanoate by Ralstonia eutropha from non-combustible gas mixture with low hydrogen content
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DOI：
10.1007/s10529-020-02876-3
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发表时间：
2020-04-02
影响因子：
2.7
通讯作者：
Tsuge, Takeharu
中科院分区：
文献类型：
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作者：
Miyahara, Yuki;Yamamoto, Masahiro;Tsuge, Takeharu
目的探讨利用低氢含量的非可燃混合气体进行自养生产聚羟基烷酸(PHA)的可行性。结果采用不可燃气体(H-2：O-2：CO2：N-2=3.6：7.6：12.3：76.5)摇瓶培养144h，得到两株富营养化红假单胞菌。首先，以菌株H16为出发菌株，通过营养缺乏试验，探索了聚(3-羟基丁酸酯)[P(3HB)]的生产条件。其中，氮源缺乏的培养基产细胞中聚合物含量最高，为70wt%。接下来，为了生产PHA共聚物，将重组菌株1F2在氮源缺乏的自养条件下进行培养。结果表明，含1.2mol%3-羟基-4-甲基戊酸酯单元和1.2mol%3-羟基-4-甲基戊酸酯单元的3HB共聚物的聚集量为57wt%。结论使用低氢含量的非可燃气体有利于PHA的生产，消除了氢气泄漏引起的爆炸风险。
Objectives To autotrophically produce polyhydroxyalkanoate (PHA) by Ralstonia eutropha without the risk of gas explosion, the feasibility of using a non-combustible gas mixture with low hydrogen content was investigated. Results A non-combustible gas mixture (H-2: O-2: CO2: N-2 = 3.6: 7.6: 12.3: 76.5) was used for a 144-hour flask cultivation of two R. eutropha strains. Initially, using strain H16, the production conditions for poly(3-hydroxybutyrate) [P(3HB)] were explored by examining nutrient deficiency. Of these, a nitrogen source-deficient culture medium yielded the highest polymer content of 70 wt% in cells. Next, to produce PHA copolymer, the recombinant strain 1F2 was cultured under the nitrogen source-deficient autotrophic condition. As a result, the accumulation of 3HB-based copolymer containing of 1.2 mol% 3-hydroxyvalerate unit and 1.2 mol% 3-hydroxy-4-methylvalerate unit was observed with 57 wt% of the cell content. Conclusions The use of a non-combustible gas with low hydrogen content is beneficial for PHA production in eliminating the risk of explosion due to hydrogen leakage.