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Glycolic Acid Utilization In Two Species Of Marine Bacteria, Erik S. Timsak
Glycolic Acid Utilization In Two Species Of Marine Bacteria, Erik S. Timsak
STAR Program Research Presentations
Interactions between bacteria and phytoplankton are crucial for the cycling of organic matter in marine environments. Around 50% of organic carbon taken up by marine bacteria is converted into inorganic carbon. The uptake of organic carbon by marine bacteria exuded from phytoplankton is a key factor in regulating the marine carbon cycle. One such molecule that is exuded by phytoplankton and then uptaken by marine bacteria is called glycolate - the anion of glycolic acid, a two caron molecule. Glycolate is exuded by phytoplankton during photorespiration and 10-50% of dissolved organic carbon in marine environments is comprised of glycolate. Additionally, …
Influence Of A Guanidine Riboswitch In Bacterial Cells, Erik S. Timsak, Jefferey A. Kimbrel, Chris S. Ward, Rhona K. Stuart, Michael P. Thelen
Influence Of A Guanidine Riboswitch In Bacterial Cells, Erik S. Timsak, Jefferey A. Kimbrel, Chris S. Ward, Rhona K. Stuart, Michael P. Thelen
STAR Program Research Presentations
Bacteria live in environments containing complex ecologies of other microbes that communicate and survive through the action of a variety of small metabolic compounds. One common yet relatively unstudied metabolite is guanidine. Although it can be toxic to cells, recent studies have revealed that guanidine may function as a cellular metabolite through a specialized RNA sequence known as a riboswitch. Within our overall project on improving algal productivity, the focus of this study is to: (a) describe various guanidine riboswitch sequences in bacteria that interact with biofuel producing algae; and (b) determine if guanidine has a positive or negative influence …
Composition And Function Of The Bacterial Consortium Associated With The Accessory Nidamental Gland Of The Hawaiian Bobtail Squid, Jessica Bertenshaw
Composition And Function Of The Bacterial Consortium Associated With The Accessory Nidamental Gland Of The Hawaiian Bobtail Squid, Jessica Bertenshaw
Honors Scholar Theses
The bacterial consortium associated with the accessory nidamental gland (ANG) of the Hawaiian bobtail squid, Euprymna Scolopes is posited to confer symbiotic benefits to the eggs of the squid when bacteria are transferred from the gland of the mother to the jelly coat, which surrounds the embryo in the egg. To characterize the composition of this community bacterial isolates from the egg jelly coat and from the ANG were identified using 16S sequencing. To elucidate the function of these bacteria, egg development experiments were performed to determine the effect of antibiotics on egg survival and the composition of the bacterial …
Active Fluorometry Improves Nutrient-Diffusing Substrata Bioassay, Sarah Whorley, Steven Francoeur
Active Fluorometry Improves Nutrient-Diffusing Substrata Bioassay, Sarah Whorley, Steven Francoeur
Articles & Book Chapters
Benthic algal nutrient bioassays traditionally have been done by measuring periphytic algal biomass that has grown on fertilized or unfertilized patches of habitat produced by nutrient-diffusing substrata (NDS). This method requires destruction of the accumulated periphyton communities and, thus, does not allow for convenient monitoring through time. Variable fluorescence methods of estimating algal biomass and photosynthetic activity have been used in aquatic environments, but generally not over different nutrient treatments and not for a substantial duration. We evaluated the use of a pulse amplitude modulated (PAM) fluorometer for measuring algal biomass and photosynthetic activity in conjunction with NDS over several …
Report Of Significant Findings--Las Vegas Bay/Boulder Basin Investigations, James F. Labounty, Michael Horn, Bureau Of Reclamation
Report Of Significant Findings--Las Vegas Bay/Boulder Basin Investigations, James F. Labounty, Michael Horn, Bureau Of Reclamation
Publications (WR)
Field sampling was carried out between 0830 and 1500 beginning at the confluence of Las Vegas Wash and the Inner Las Vegas Bay. Ten (10) locations were sampled, each in a similar manner. Locations of sampling stations are in line from the Wash-Bay confluence to a point midway between Saddle and Black Islands. In addition, sampling was done at a location midway between Sentinel Island and the base of Fortification Hill, and at the buoy line in front of Hoover Dam. Sampling stations are labeled from LV01, at Wash-Bay confluence, to LV17 at Hoover Dam. A significant data collection point …
Estimation Of Food Limitation In Daphnia Pulex From Boulder Basin, Lake Mead, Thomas Mark Bartanen
Estimation Of Food Limitation In Daphnia Pulex From Boulder Basin, Lake Mead, Thomas Mark Bartanen
Publications (WR)
In February, 1982 I began a year-long study to determine if growth and reproduction in Daphnia Pulex were limited by the amount of food available in Boulder Basin, Lake Mead. To determine this, I made monthly collections of Daphnia Pulex and natural lake seston from an already established station in Boulder Basin. I cultured the Daphnia Pulex under simulated field conditions in a flow-through feeding apparatus using four different food regimes; 1-natural lake seston filtered through 80 um mesh to remove other zooplankton, 2-lake seston (as above) with an enrichment of 103 cells-ml-1 of Chlamydomonas reinhardti, 3-lake …
Phytoplankton Distribution And Water Quality Indices For Lake Mead (Colorado River), Robert D. Staker, Robert W. Hoshaw, Lorne G. Everett
Phytoplankton Distribution And Water Quality Indices For Lake Mead (Colorado River), Robert D. Staker, Robert W. Hoshaw, Lorne G. Everett
Publications (WR)
Phytoplankton samples were collected in Lake Mend 6 times from September 1910 to June 1971 for 8 stations at depths of 0. 3, 5, 10, 20, and 30 m. These samples were processed through a Millipore filter apparatus and 79 planktonic algae were identified. Algal divisions represented were Bacillariophyta, 42 species; Chlorophyta, 18 ; Cyanophyta, 9; Chrysophyta, 3; Cryptophyta, 3; Pyrrophyta, 2; and Euglenophyta, 2. Blue-green algae were dominant in late summer and fall; green algae, diatoms, and, cryptomonads in winter; and green algae in spring. The early summer flora was best represented by the Chlorophyta, Cryptophyta, and Chrysophyta. Palmer's …