Phospholipid, ester-linked fatty acids (PLFA) can be used as measures of the viable microbial biomass and community structure in complex environments. Methodology is described, reviewed and tested for the specific analysis of PLFA with minimal artifacts or contamination. In addition, a hexane/isopropanol extraction system is shown to be equivalent to the standard chloroform/methanol system allowing lipid analyses to be done off Nuclepore filters and other materials that will dissolve in chloroform. The reproducibility of PLFA profiles for prokaryotic communities was also examined. A homogeneous, estuarine benthic microbial community was sub-divided randomly to give identical microcosms. These microcosms were nutrient supplemented and incubated either aerobically or anaerobically. The PLFA profiles of independent microcosms treated identically had less variance than those treated differently such that statistically significant differences for treatment effect could be described. The PLFA changes during long-term starvation in Vibrio cholerae were also examined. A progressive, reproducible, and significant increase in the PLFA trans/cis ratio was seen as well as an increase in the cyclopropyl PLFA. These changes may be an adaptation to starvation-survival. There is, however, no known de novo biosynthetic pathway for trans-monounsaturated PLFA. To prove that one exists, Pseudomonas atlantica, which has three cis/trans PLFA pairs, was incubated with ('14)C-acetate. The PLFA isomers were physically separated, the trans content was directly verified by FT-IR, and the specific activity of the trans PLFA was shown to be equivalent to the saturated PLFA verifying de novo synthesis of trans-monounsaturated PLFA from acetate. / Source: Dissertation Abstracts International, Volume: 47-07, Section: B, page: 2723. / Thesis (Ph.D.)--The Florida State University, 1986.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_75891 |
| Contributors | GUCKERT, JAMES BREMER., Florida State University |
| Source Sets | Florida State University |
| Detected Language | English |
| Type | Text |
| Format | 182 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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