Interspecies distances between propionic acid degraders and methanogens in syntrophic consortia for optimal hydrogen transfer
Interspecies distances between propionic acid degraders and methanogens in syntrophic consortia for optimal hydrogen transfer
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DOI：
10.1007/s00253-012-4616-9
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发表时间：
2013-10-01
影响因子：
5
通讯作者：
Gallert, Claudia
中科院分区：
文献类型：
--
作者：
Felchner-Zwirello, Monika;Winter, Josef;Gallert, Claudia
厌氧生物废物消化池的混合培养物富含丙酸盐，并用于研究丙酸盐降解菌和产甲烷菌之间的空间距离依赖的种间氢转移。从20.3 mM丙酸盐、20.8 mM乙酸盐和15.5 mM甲烷形成。最大比丙酸氧化和甲烷生成速率分别为49和23 mmol mg（-1）day（-1）。丙酸盐氧化仅被20 mM乙酸盐抑制约50%。在抑制甲烷化过程中，观察到中间体甲酸盐的形成。丙酸降解菌和产甲烷菌的空间分布和生物体积分数的总人口在聚集体形成过程中进行了测定。通过应用组特异性16 S rRNA靶向探针和3D图像分析，用荧光原位杂交法测量细菌间距离。随着孵育时间的增加，絮凝物的形成和生长可达54 μ m。丙酸盐降解菌和产甲烷菌在絮体中随机分布。产甲烷生物体积分数是高的，在开始时，并保持恒定超过42天，而丙酸盐降解物的分数随着时间的推移而增加，在丙酸盐进料。丙酸降解菌和产甲烷菌之间的细菌间距离随时间从5.30 μ m减小到0.29 μ m，导致最大可能的氢通量从1.1 nmol ml（-1）min（-1）增加到10.3 nmol ml（-1）min（-1）。最大可能的氢通量总是高于氢的形成和消耗速率，表明在复杂的生态系统中，通过聚集减少种间距离是有利的。
A mixed culture from an anaerobic biowaste digester was enriched on propionate and used to investigate interspecies hydrogen transfer in dependence of spatial distances between propionate degraders and methanogens. From 20.3 mM propionate, 20.8 mM acetate and 15.5 mM methane were formed. Maximum specific propionate oxidation and methane formation rates were 49 and 23 mmol mg(-1) day(-1), respectively. Propionate oxidation was inhibited by only 20 mM acetate by about 50 %. Intermediate formate formation during inhibited methanogensis was observed. The spatial distribution and the biovolume fraction of propionate degraders and of methanogens in relation to the total population during aggregate formation were determined. Measurements of interbacterial distances were conducted with fluorescence in situ hybridization by application of group-specific 16S rRNA-targeted probes and 3D image analyses. With increasing incubation time, floc formation and growth up to 54 mu m were observed. Propionate degraders and methanogens were distributed randomly in the flocs. The methanogenic biovolume fraction was high at the beginning and remained constant over 42 days, whereas the fraction of propionate degraders increased with time during propionate feeding. Interbacterial distances between propionate degraders and methanogens decreased with time from 5.30 to 0.29 mu m, causing an increase of the maximum possible hydrogen flux from 1.1 to 10.3 nmol ml(-1) min(-1). The maximum possible hydrogen flux was always higher than the hydrogen formation and consumption rate, indicating that reducing the interspecies distance by aggregation is advantageous in complex ecosystems.