Biogas-based polyhydroxyalkanoates production by Methylocystis hirsuta: A step further in anaerobic digestion biorefineries
Biogas-based polyhydroxyalkanoates production by Methylocystis hirsuta: A step further in anaerobic digestion biorefineries
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DOI：
10.1016/j.cej.2017.09.185
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发表时间：
2018-02-01
影响因子：
15.1
通讯作者：
Munoz, Raul
中科院分区：
文献类型：
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作者：
Lopez, Juan C.;Arnaiz, Esther;Munoz, Raul
在有氧条件下，分批评估沼气（有和没有H2S）和挥发性脂肪酸（VFA）支持微生物生长和聚羟基链烷酸酯（PHA）在II型甲烷氧化菌中积累的潜力。甲基孢囊藻能够在人工沼气（70%CH_4，29.5%CO_2，0.5%H_2S）中生长并积累高达45 +/- 1%（wt.%）的PHA。在N限制条件下。CO_2和H_2S的存在对M. hirsuta相比，控制测试提供了类似浓度的纯CH 4。同样地，以100-200 mg L-1的初始浓度向培养液中添加VFA不会妨碍该菌株在人工沼气上的生长。实际上，以单独VFA形式添加10%额外碳导致最大PHA产率和最终PHA含量增加至0.45-0.63 gPHA g底物（1）和48-54%（重量%），以更高的能量需求为代价。补充戊酸支持生物复合材料中最高的3-羟基戊酸含量（13.5%）。在此背景下，本研究首次证明了由M.多毛类植物不依赖CH 4同化。
The potential of biogas (with and without H2S) and volatile fatty acids (VFAs) to support microbial growth and accumulation of polyhydroxyalkanoates (PHAs) in type II methanotrophs was evaluated batchwise under aerobic conditions. Methylocystis hirsuta was able to grow on artificial biogas (70% CH4, 29.5% CO2, 0.5% H2S) and accumulate PHA up to 45 +/- 1% (wt.%) under N-limited conditions. The presence of CO2 and H2S did not significantly influence the growth and PHA synthesis in M. hirsuta compared to control tests provided with pure CH4 at similar concentrations. Likewise, the addition of VFAs to the cultivation broth at initial concentrations of 100-200 mg L-1 did not hamper the growth of this strain on artificial biogas. Indeed, the addition of 10% extra carbon in the form of individual VFAs resulted in an increase in the maximum PHA yield and final PHA content up to 0.45-0.63 gPHA gSubstrate(1) and 48-54% (wt.%), respectively, at the expense of a higher energy demand. Valeric acid supplementation supported the highest 3-hydroxyvalerate content (13.5%) within the biocomposite. In this context, this study demonstrated for the first time that 3-hydroxyvalerate synthesis by M. hirsuta did not depend on CH4 assimilation.