Lipid Analysis of Neochloris oleoabundans by Liquid State NMR

This study is an evaluation of liquid state NMR as a tool for analyzing the lipid composition of algal cultures used for biodiesel production. To demonstrate the viability of this approach, C-13 NMR was used to analyze the lipid composition of intact cells of the algal species, Neochloris oleoabundans (UTEx #1185) Two cultures were used in this study One culture was "healthy" and grown in conventional media, whereas the other culture was "nitrogen-starved" and grown in media that lacked nitrate Triglyceride was determined to be present in both cultures by comparing the algal NMR spectra with published chemical shifts for a wide range of lipids and with a spectrum obtained from a triglyceride standard (glyceryl mole:He) In addition, it is shown that (1) the signal-to-noise ratio of the similar to 29.5 ppm methylene peak is indicative of the lipid content and (2) the nitrogen-starved culture contained a greater lipid content than the healthy culture, as expected. Furthermore, the nitrogen-starved culture produced spectra that primarily contained the characteristic peaks of triglyceride (at similar to 61 8 and similar to 68 9 ppm), whereas the healthy culture produced spectra that contained several additional peaks in the glycerol region, likely resulting from the presence of monoglyceride and diglyceride Finally, potential interferences are evaluated (including the analysis of phospholipids via P-31 NMR) to assess the specificity of the acquired spectra to triglyceride These results indicate that NMR is a useful diagnostic tool for selectively identifying lipids in algae, with particular relevance to biodiesel production

Tidal saline wetland regeneration of sentinel vegetation types in the Northern Gulf of Mexico: An overview

Tidal saline wetlands in the Northern Gulf of Mexico (NGoM) are dynamic and frequently disturbed systems that provide myriad ecosystem services. For these services to be sustained, dominant macrophytes must continuously recolonize and establish after disturbance. Macrophytes accomplish this regeneration through combinations of vegetative propagation and sexual reproduction, the relative importance of which varies by species. Concurrently, tidal saline wetland systems experience both anthropogenic and natural hydrologic alterations, such as levee construction, sea-level rise, storm impacts, and restoration activities. These hydrologic alterations can affect the success of plant regeneration, leading to large-scale, variable changes in ecosystem structure and function. This review describes the specific regeneration requirements of four dominant coastal wetland macrophytes along the NGoM (Spartina alterniflora, Avicennia germinans, Juncus roemerianus, and Batis maritima) and compares them with current hydrologic alterations to provide insights into potential future changes in dominant ecosystem structure and function and to highlight knowledge gaps in the current literature that need to be addressed