Pathak Ashish, Stothard Paul, Chauhan Ashvini
Environmental Biotechnology Laboratory, School of the Environment, 1515 S. Martin Luther King Jr. Blvd., Suite 305B, FSH Science Research Center, Florida A&M University, Tallahassee, FL 32307, USA.
Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G2P5, Canada.
Microorganisms. 2021 Feb 27;9(3):490. doi: 10.3390/microorganisms9030490.
The eastern oysters serve as important keystone species in the United States, especially in the Gulf of Mexico estuarine waters, and at the same time, provide unparalleled economic, ecological, environmental, and cultural services. One ecosystem service that has garnered recent attention is the ability of oysters to sequester impurities and nutrients, such as nitrogen (N), from the estuarine water that feeds them, via their exceptional filtration mechanism coupled with microbially-mediated denitrification processes. It is the oyster-associated microbiomes that essentially provide these myriads of ecological functions, yet not much is known on these microbiota at the genomic scale, especially from warm temperate and tropical water habitats. Among the suite of bacterial genera that appear to interplay with the oyster host species, pseudomonads deserve further assessment because of their immense metabolic and ecological potential. To obtain a comprehensive understanding on this aspect, we previously reported on the isolation and preliminary genomic characterization of three species isolated from minced oyster tissue ( strain OT69); oyster mantle fluid ( strain MF28) and the water collected from top of the oyster reef ( strain WC55), respectively. In this comparative genomic analysis study conducted on these three targeted pseudomonads, native to the eastern oyster and its surrounding environment, provided further insights into their unique functional traits, conserved gene pools between the selected pseudomonads, as well as genes that render unique characteristics in context to metabolic traits recruited during their evolutionary history via horizontal gene transfer events as well as phage-mediated incorporation of genes. Moreover, the strains also supported extensively developed resistomes, which suggests that environmental microorganisms native to relatively pristine environments, such as Apalachicola Bay, Florida, have also recruited an arsenal of antibiotic resistant gene determinants, thus posing an emerging public health concern.
东部牡蛎是美国重要的关键物种，尤其是在墨西哥湾的河口海域，同时还提供了无可比拟的经济、生态、环境和文化服务。最近受到关注的一种生态系统服务是牡蛎通过其特殊的过滤机制以及微生物介导的反硝化过程，从为它们提供养分的河口水中吸收杂质和营养物质（如氮）的能力。正是与牡蛎相关的微生物群落基本上提供了这些众多的生态功能，但在基因组尺度上对这些微生物群落的了解还很少，特别是来自暖温带和热带水域栖息地的微生物群落。在一系列似乎与牡蛎宿主物种相互作用的细菌属中，假单胞菌因其巨大的代谢和生态潜力而值得进一步评估。为了全面了解这一方面，我们之前报道了分别从碎牡蛎组织（菌株OT69）、牡蛎外套膜液（菌株MF28）和牡蛎礁顶部采集的水（菌株WC55）中分离出的三个物种的分离和初步基因组特征。在对这三种源自东部牡蛎及其周围环境的目标假单胞菌进行的比较基因组分析研究中，进一步深入了解了它们独特的功能特性、所选假单胞菌之间保守的基因库，以及通过水平基因转移事件和噬菌体介导的基因整合在其进化历史中获得的赋予代谢特性独特特征的基因。此外，这些菌株还具有广泛发育的抗性组，这表明相对原始环境（如佛罗里达州阿巴拉契科拉湾）中的环境微生物也获得了一系列抗生素抗性基因决定因素，从而引发了新出现的公共卫生问题。
