Environmental Biotechnology Laboratory, The University of Hong Kong, Pokfulam Road, Hong Kong, Hong Kong.
Appl Microbiol Biotechnol. 2011 May;90(3):1137-45. doi: 10.1007/s00253-011-3107-8. Epub 2011 Feb 1.
The diversity and abundance of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in the sediment of the Pearl River Estuary were investigated by cloning and quantitative real-time polymerase chain reaction (qPCR). From one sediment sample S16, 36 AOA OTUs (3% cutoff) were obtained from three clone libraries constructed using three primer sets for amoA gene. Among the 36 OTUs, six were shared by all three clone libraries, two appeared in two clone libraries, and the other 28 were only recovered in one of the libraries. For AOB, only seven OTUs (based on 16S rRNA gene) and eight OTUs (based on amoA gene) were obtained, showing lower diversity than AOA. The qPCR results revealed that AOA amoA gene copy numbers ranged from 9.6 × 10(6) to 5.1 × 10(7) copies per gram of sediment and AOB amoA gene ranged from 9.5 × 10(4) to 6.2 × 10(5) copies per gram of sediment, indicating that the dominant ammonia-oxidizing microorganisms in the sediment of the Pearl River Estuary were AOA. The terminal restriction fragment length polymorphism results showed that the relative abundance of AOB species in the sediment samples of different salinity were significantly different, indicating that salinity might be a key factor shaping the AOB community composition.
采用克隆文库和实时定量 PCR(qPCR)技术研究了珠江口沉积物中氨氧化古菌(AOA)和氨氧化细菌(AOB)的多样性和丰度。从一个沉积物样品 S16 中，使用三种 amoA 基因引物构建的三个克隆文库中获得了 36 个 AOA 操作分类单元(OTU，3%截断值)。在这 36 个 OTU 中，有 6 个 OTU 存在于所有三个克隆文库中，有 2 个 OTU 存在于两个克隆文库中，其余 28 个 OTU 仅存在于一个文库中。对于 AOB，仅获得了 7 个基于 16S rRNA 基因的 OTU 和 8 个基于 amoA 基因的 OTU，其多样性低于 AOA。qPCR 结果表明，AOA amoA 基因拷贝数范围为 9.6×10(6)5.1×10(7)拷贝/克沉积物，AOB amoA 基因拷贝数范围为 9.5×10(4)6.2×10(5)拷贝/克沉积物，表明珠江口沉积物中优势的氨氧化微生物为 AOA。末端限制性片段长度多态性(T-RFLP)结果表明，不同盐度沉积物样品中 AOB 物种的相对丰度存在显著差异，表明盐度可能是塑造 AOB 群落组成的关键因素。
