자료유형  

 학위논문

Control Number  

0015492943

International Standard Book Number  

9781088353462

Dewey Decimal Classification Number  

631.4

Main Entry-Personal Name  

Sharma, Kriti.

Publication, Distribution, etc. (Imprint  

[Sl] : The University of North Carolina at Chapel Hill, 2019

Publication, Distribution, etc. (Imprint  

Ann Arbor : ProQuest Dissertations & Theses, 2019

Physical Description  

167 p

General Note  

Source: Dissertations Abstracts International, Volume: 81-05, Section: B.

General Note  

Advisor: Shank, Elizabeth A.

Dissertation Note  

Thesis (Ph.D.)--The University of North Carolina at Chapel Hill, 2019.

Restrictions on Access Note  

This item must not be sold to any third party vendors.

Summary, Etc.  

요약Soils offer habitats to an unparalleled abundance and diversity of microorganisms, whose activities are critical to agriculture, ecosystem health, and biogeochemical cycling. A major barrier to understanding soil microbes within their habitats is the opacity of natural soils. Despite a long history of endeavors to visualize life in the soil, and promising advancements in this field, non-destructive approaches that allow dynamic insights into microbial life in soils are particularly lacking. Chapter 1 reviews this field and outlines the history and potential of optically transparent porous media as model soil systems amenable to non-destructive imaging of soil microorganisms within three-dimensional soil-like matrices.In Chapter 2, I introduce the utility of single-cell Raman spectroscopy (SCRS) for non-destructive stable isotope probing over time, particularly for monitoring the uptake of 13C by bacteria from complex natural polysaccharides. This spatially resolved and non-destructive approach allows us to ask the question, "Do bacterial biofilms allow bacteria to stick together in numbers large enough to initiate cooperative decomposition of necromass?'In Chapter 3, I assess the polymer Nafion and the crystal cryolite as substrates for optically transparent model soil systems called "transparent soil" (TS) microcosms. I find that both substrates are compatible with optical microscopy and enable growth, maintenance, and visualization of micron-sized bacteria in three-dimensional porous matrices over time. Both substrates are also compatible with SCRS, and enable stable isotope probing (SIP) using deuterium (D2O) as a non-destructive marker of microbial activity in situ, while cryolite-based microcosms also enable measurement of 13C label uptake in bacteria. I use D2O label tracing to show that bacterial cells attached to dead fungal hyphae within a Nafion matrix show more metabolic activity after a dry-wet cycle than cells far away from the fungal hyphae, corroborating the important role of fungi in facilitating survival of bacteria in the fluctuating conditions found in soils.In Chapter 4, I present a method for rapid and inexpensive manufacture of microfluidics devices that were used to construct TS microcosms at the lab bench. Chapter 5 summarizes the dissertation overall and offers suggestions for future research.

Subject Added Entry-Topical Term  

Microbiology

Subject Added Entry-Topical Term  

Ecology

Subject Added Entry-Topical Term  

Soil sciences

Added Entry-Corporate Name  

The University of North Carolina at Chapel Hill Biology

Host Item Entry  

Dissertations Abstracts International. 81-05B.

Host Item Entry  

Dissertation Abstract International

Electronic Location and Access  

로그인을 한후 보실 수 있는 자료입니다.

Control Number  

joongbu:569820