Microorganisms on Burrow Walls of Infauna: Predictable or Fortuitous Occurrence?

大型水生生物的洞穴通常是微生物活动强烈的场所，通常是大量微生物的避难所。由于不同的动物物种在其生物学（例如，摄食行规，运动），特别是在它们的洞穴建设和通风方面存在很大差异，因此可以合理地预测它们洞穴的微生物学也会有所不同。该项目将测试洞穴中微生物丰度和活动的增加是否仅仅代表了环境微生物的增强，或者是否有特定的微生物种群可预测地发生在洞穴中，独立于环境微生物群落。对这些复杂微生物群落的全面评估将需要非选择性方法；微生物的磷脂，酯链脂肪酸（PLFA），在真细菌和真核生物的膜脂的主要成分将被检查。这些PLFA已经从洞穴和周围沉积物的现场样本中提取出来，是测定微生物生物量、组成甚至生理状况的强大的鉴别工具。这些生化标记将用于比较五个动物物种的穴居微生物，代表三个门，在六个地点取样。将采用多变量分析在种间和种内水平上进行比较。这个项目将测试一个有趣的生物地球化学假设，并冲击非常有吸引力的“微生物园艺”概念。

The burrows of macro-infaunal organisms are generally sites of intense microbial activity and often harbor abundant populations of microorganisms. Since the various infaunal species differ greatly in their biology (e.g., feeding guild, motility) and specifically, in aspects of their burrow construction and ventilation, it is reasonable to anticipate that the microbiology of their burrows will also vary. This project will test whether a burrows' increased microbial abundance and activity simply represents enhancement of ambient microorganisms or whether there are specific microbial populations that predictably occur in burrows, independent of the ambient microbial community. A comprehensive assessment of these complex microbial communities will require non-selective methods; the microbes' phospholipid, ester-linked fatty acids (PLFA), the chief constituent of membrane lipids in eubacteria and eukaryotes will be examined. These PLFA, which have already been extracted from field samples of burrows and ambient sediments, are powerful, discriminating tools for determining microbial biomass, composition, and even physiological condition. These biochemical markers will be used to compare the burrow microbes of five infaunal species, representing three phyla, sampled across six sites. Comparisons will be made at interspecific and intraspecific levels using multivariate analysis. This project will test an intriguing biogeochemical hypothesis and impinge on the very attractive concept of "microbial gardening".