Show simple item record

dc.contributor.authorLambert, Bennett  Concept link
dc.date.accessioned2019-01-04T16:42:23Z
dc.date.available2019-01-04T16:42:23Z
dc.date.issued2019-02
dc.identifier.urihttps://hdl.handle.net/1912/10810
dc.descriptionSubmitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Oceanographic Engineering at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 2019.en_US
dc.description.abstractMarine microbes are key drivers of biogeochemical transformations within the world’s oceans. Although seawater appears uniform at scales that humans often interact with and sample, the world that marine microbes inhabit can be highly heterogeneous, with numerous biological and physical processes giving rise to resource hotspots where nutrient concentrations exceed background levels by orders of magnitude. While the impact of this microscale heterogeneity has been investigated in the laboratory with microbial isolates and theoretical models, microbial ecologists have lacked adequate tools to interrogate microscale processes directly in the natural environment. Within this thesis I introduce three new technologies that enable interrogation of microbial processes at the microscale in natural marine communities. The IFCB-Sorter acquires images and sorts individual phytoplankton cells, directly from seawater, allowing studies exploring connections between the diversity of forms present in the plankton and genetic variability at the single-cell level. The In Situ Chemotaxis Assay (ISCA) is a field-going microfluidic device designed to probe the distribution and role of motility behavior among microbes in aquatic environments. By creating microscale hotspots that simulate naturally occurring ones, the ISCA makes it possible to examine the role of microbial chemotaxis in resource acquisition, phytoplankton-bacteria interactions, and host-symbiont systems. Finally, the Millifluidic In Situ Enrichment (MISE) is an instrument that enables the study of rapid shifts in gene expression that permit microbial communities to exploit chemical hotspots in the ocean. The MISE subjects natural microbial communities to a chemical amendment and preserves their RNA in a minute-scale time series. Leveraging an array of milliliter-volume wells, the MISE allows comparison of community gene expression in response to a chemical stimulus to that of a control, enabling elucidation of the strategies employed by marine microbes to survive and thrive in fluctuating environments. Together, this suite of instruments enables culture-independent examination of microbial life at the microscale and will empower microbial ecologists to develop a more holistic understanding of how interactions at the scale of individual microbes impact processes in marine ecosystems at a global scale.en_US
dc.description.sponsorshipI’d like to thank the Gordon and Betty Moore Foundation, the National Science Foundation, and NSERC for funding portions of my research.en_US
dc.description.sponsorshipI’d like to thank the Gordon and Betty Moore Foundation, the National Science Foundation, and NSERC for funding portions of my research.
dc.language.isoen_USen_US
dc.publisherMassachusetts Institute of Technology and Woods Hole Oceanographic Institutionen_US
dc.relation.ispartofseriesWHOI Thesesen_US
dc.subjectMicroorganisms
dc.subjectBacteria
dc.subjectMarine ecology
dc.subjectScientific apparatus and instruments
dc.subjectPlankton
dc.subjectPlankton--Growth
dc.subjectPhytoplankton
dc.subjectChemical oceanography
dc.subjectAntarctic Ocean
dc.titleObserving microbial processes at the microscale with in situ technologyen_US
dc.typeThesisen_US
dc.identifier.doi10.1575/1912/10810


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record