Berlanga Mercedes
Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Barcelona, Barcelona, Spain.
Int Microbiol. 2015 Sep;18(3):159-69. doi: 10.2436/20.1501.01.246..
Animal hosts typically have strong specificity for microbial symbionts and their functions. The symbiotic relationships have enhanced the limited metabolic networks of most eukaryotes by contributing several prokaryotic metabolic capabilities, such as methanogenesis, chemolithoautotrophy, nitrogen assimilation, etc. This review will examine the characteristics that determine bacterial "fidelity" to certain groups of animals (e.g., xylophagous insects, such as termites and cockroaches) over generations and throughout evolution. The hindgut bacteria of wood-feeding termites and cockroaches belong to several phyla, including Proteobacteria, especially Deltaproteobacteria, Bacteroidetes, Firmicutes, Actinomycetes, Spirochetes, Verrucomicrobia, and Actinobacteria, as detected by 16S rRNA. Termites effectively feed on many types of lignocelluloses assisted by their gut microbial symbionts. Although the community structures differ between the hosts (termites and cockroaches), with changes in the relative abundances of particular bacterial taxa, the composition of the bacterial community could reflect at least in part the host evolution in that the microbiota may derive from the microbiota of a common ancestor. Therefore, factors other than host phylogeny, such as diet could have had strong influence in shaping the bacterial community structure.
动物宿主通常对微生物共生体及其功能具有很强的特异性。共生关系通过赋予几种原核生物代谢能力，如甲烷生成、化能无机自养、氮同化等，增强了大多数真核生物有限的代谢网络。本综述将研究决定细菌在几代人乃至整个进化过程中对某些动物群体（如食木昆虫，如白蚁和蟑螂）的“忠诚度”的特征。通过16S rRNA检测发现，以木材为食的白蚁和蟑螂的后肠细菌属于几个门，包括变形菌门，尤其是δ-变形菌纲、拟杆菌门、厚壁菌门、放线菌门、螺旋体门、疣微菌门和放线杆菌门。白蚁在其肠道微生物共生体的帮助下有效地取食多种木质纤维素。尽管宿主（白蚁和蟑螂）之间的群落结构不同，特定细菌类群的相对丰度有所变化，但细菌群落的组成至少可以部分反映宿主的进化，因为微生物群可能源自共同祖先的微生物群。因此，除宿主系统发育外的其他因素，如饮食，可能对塑造细菌群落结构有很大影响。
