Almeida Juliana R, Fradinho Joana C, Carvalho Gilda, Oehmen Adrian, Reis Maria A M
Associate Laboratory i4HB-Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal.
UCIBIO-Applied Molecular Biosciences Unit, Department of Chemistry, NOVA School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal.
Microorganisms. 2022 Feb 3;10(2):351. doi: 10.3390/microorganisms10020351.
Phototrophic mixed cultures (PMC) are versatile systems which can be applied for waste streams, valorisation and production of added-value compounds, such as polyhydroxyalkanoates (PHA). This work evaluates the influence of different operational conditions on the bacterial communities reported in PMC systems with PHA production capabilities. Eleven PMCs, fed either with acetate or fermented wastewater, and selected under either feast and famine (FF) or permanent feast (PF) regimes, were evaluated. Overall, results identified Chromatiaceae members as the main phototrophic PHA producers, along with , and . The findings show that Chromatiaceae were favoured under operating conditions with high carbon concentrations, and particularly under the PF regime. In FF systems fed with fermented wastewater, the results indicate that increasing the organic loading rate enriches for , and Hyphomicrobiaceae, which together with and Chromatiaceae, were likely responsible for PHA storage. In addition, high-sugar feedstock impairs PHA production under PF conditions (fermentative bacteria dominance), which does not occur under FF. This characterization of the communities responsible for PHA accumulation helps to define improved operational strategies for PHA production with PMC.
光合混合培养物（PMC）是一种多功能系统，可应用于废水处理、增值以及生产附加值化合物，如聚羟基脂肪酸酯（PHA）。这项工作评估了不同操作条件对具有PHA生产能力的PMC系统中细菌群落的影响。对11种以乙酸盐或发酵废水为进料，并在 feast and famine（FF）或永久盛宴（PF）模式下选择的PMC进行了评估。总体而言，结果确定了着色菌科成员是主要的光合PHA生产者，以及 、 和 。研究结果表明，在高碳浓度的操作条件下，尤其是在PF模式下，着色菌科更受青睐。在以发酵废水为进料的FF系统中，结果表明，提高有机负荷率会富集 、 和 生丝微菌科，它们与 和 着色菌科一起，可能是PHA储存的原因。此外，高糖原料会损害PF条件下的PHA生产（发酵细菌占主导），而在FF条件下不会出现这种情况。对负责PHA积累的群落进行的这种表征有助于确定使用PMC生产PHA的改进操作策略。
