Bani Alessia, Parati Katia, Pozzi Anna, Previtali Cristina, Bongioni Graziella, Pizzera Andrea, Ficara Elena, Bellucci Micol
Istituto Sperimentale Lazzaro Spallanzani, Localita' La Quercia, 26027 Rivolta d'Adda (CR), Italy.
Gruppo Ricicla labs., Dipartimento di Scienze Agrarie e Ambientali - Produzione, Territorio, Agroenergia (DiSAA), Università degli studi di Milano, Via Celoria 2, 20133 Milano, Italy.
Microorganisms. 2020 Nov 8;8(11):1754. doi: 10.3390/microorganisms8111754.
This study aimed at examining and comparing the nutrient removal efficiency, biomass productivity and microbial community structure of two outdoor pilot-scale photobioreactors, namely a bubble column and a raceway pond, treating the liquid fraction of an agricultural digestate. Bacterial and eukaryotic communities were characterized using a metabarcoding approach and quantitative PCR. The abundance, composition, diversity, and dynamics of the main microbes were then correlated to the environmental conditions and operational parameters of the reactors. Both photobioreactors were dominated either by sp. or sp. in function of temperature, irradiance and the nitrogen compounds derived by nitrification. Other species, such as and , were sporadically present, demonstrating that they have more specific niche requirement. sp. always dominated the bacterial community in both reactors, except in summertime, when a bloom of occurred in the raceway pond. In autumn, the worsening of the climate conditions decreased the microalgal growth, promoting predation by sp. The study highlights the factors influencing the structure and dynamics of the microbial consortia and which ecological mechanisms are driving the microbial shifts and the consequent reactor performance. On these bases, control strategies could be defined to optimize the management of the microalgal-based technologies.
本研究旨在考察和比较两个室外中试规模光生物反应器（即鼓泡塔和跑道式池塘）处理农业沼液液相部分时的养分去除效率、生物质生产力和微生物群落结构。采用元条形码方法和定量PCR对细菌和真核生物群落进行表征。然后将主要微生物的丰度、组成、多样性和动态与反应器的环境条件和运行参数相关联。根据温度、辐照度和硝化作用产生的含氮化合物，两个光生物反应器中占主导地位的分别是 种或 种。其他物种，如 种和 种，偶尔出现，表明它们有更特殊的生态位需求。 种在两个反应器中始终主导细菌群落，但在夏季跑道式池塘中出现 种大量繁殖时除外。秋季，气候条件恶化降低了微藻生长，促进了 种的捕食作用。该研究突出了影响微生物聚生体结构和动态的因素，以及哪些生态机制驱动微生物变化和随之而来的反应器性能。基于这些，可制定控制策略以优化基于微藻技术的管理。
