Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, Denmark.
Interdisciplinary Nanoscience Centre (iNANO) and Department of Biological Sciences, University of Aarhus, Ny Munkegade, DK-8000 Aarhus C, Denmark.
Microbiology (Reading). 2012 Jul;158(Pt 7):1818-1825. doi: 10.1099/mic.0.058818-0. Epub 2012 May 10.
Microbiology in wastewater treatment has mainly been focused on problem-causing filamentous bacteria or bacteria directly involved in nitrogen and phosphorus removal, and to a lesser degree on flanking groups, such as hydrolysing and fermenting bacteria. However, these groups constitute important suppliers of readily degradable substrates for the overall processes in the plant. This study aimed to identify glucose-fermenting bacteria in a full-scale enhanced biological phosphorus removal (EBPR) wastewater treatment plant (WWTP), and to determine their abundance in similar WWTPs. Glucose-fermenting micro-organisms were identified by an in situ approach using RNA-based stable isotope probing. Activated sludge was incubated anaerobically with (13)C(6)-labelled glucose, and (13)C-enriched rRNA was subsequently reverse-transcribed and used to construct a 16S rRNA gene clone library. Phylogenetic analysis of the library revealed the presence of two major phylogenetic groups of gram-positive bacteria affiliating with the genera Tetrasphaera, Propionicimonas (Actinobacteria), and Lactococcus and Streptococcus (Firmicutes). Specific oligonucleotide probes were designed for fluorescence in situ hybridization (FISH) to specifically target the glucose-fermenting bacteria identified in this study. The combination of FISH with microautoradiography confirmed that Tetrasphaera, Propionicimonas and Streptococcus were the dominant glucose fermenters. The probe-defined fermenters were quantified in 10 full-scale EBPR plants and averaged 39 % of the total biovolume. Tetrasphaera and Propionicimonas were the most abundant glucose fermenters (average 33 and 4 %, respectively), while Streptococcus and Lactococcus were present only in some WWTPs (average 1 and 0.4 %, respectively). Thus the population of actively metabolizing glucose fermenters seems to occupy a relatively large component of the total biovolume.
在废水处理中，微生物学主要集中在引起问题的丝状菌或直接参与氮磷去除的细菌上，而对侧群（如水解和发酵细菌）的关注较少。然而，这些群体构成了工厂整体过程中可快速降解基质的重要供应者。本研究旨在鉴定全规模强化生物除磷（EBPR）污水处理厂中的葡萄糖发酵细菌，并确定它们在类似污水处理厂中的丰度。使用基于 RNA 的稳定同位素探测的原位方法鉴定葡萄糖发酵微生物。将厌氧条件下的活性污泥与（13）C（6）标记的葡萄糖孵育，随后反转录（13）C 富集的 rRNA，并用于构建 16S rRNA 基因克隆文库。文库的系统发育分析显示，存在两个主要的革兰氏阳性细菌分类群，与 Tetrasphaera、Propionicimonas（放线菌）和 Lactococcus 和 Streptococcus（厚壁菌门）属有关。设计了特定的寡核苷酸探针用于荧光原位杂交（FISH），以特异性靶向本研究中鉴定的葡萄糖发酵细菌。FISH 与微放射性自显影的结合证实了 Tetrasphaera、Propionicimonas 和 Streptococcus 是主要的葡萄糖发酵菌。用探针定义的发酵菌在 10 个全规模 EBPR 工厂中进行了定量，并平均占总生物量的 39%。Tetrasphaera 和 Propionicimonas 是最丰富的葡萄糖发酵菌（平均分别为 33%和 4%），而 Streptococcus 和 Lactococcus 仅存在于一些污水处理厂中（平均分别为 1%和 0.4%）。因此，活跃代谢葡萄糖发酵菌的种群似乎占据了总生物量的相对较大组成部分。
