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Full-Text Articles in Life Sciences

Genes Related To Redox And Cell Curvature Facilitate Interactions Between Caulobacter Strains And Arabidopsis, Louis Berrios, Bert Ely Apr 2021

Genes Related To Redox And Cell Curvature Facilitate Interactions Between Caulobacter Strains And Arabidopsis, Louis Berrios, Bert Ely

Faculty Publications

Bacteria play an integral role in shaping plant growth and development. However, the genetic factors that facilitate plant-bacteria interactions remain largely unknown. Here, we demonstrated the importance of two bacterial genetic factors that facilitate the interactions between plant-growth-promoting (PGP) bacteria in the genus Caulobacter and the host plant Arabidopsis. Using homologous recombination, we disrupted the cytochrome ubiquinol oxidase (cyo) operon in both C. vibrioides CB13 and C. segnis TK0059 by knocking out the expression of cyoB (critical subunit of the cyo operon) and showed that the mutant strains were unable to enhance the growth of …


Detrital Nutrient Content And Leaf Species Differenitally Affect Growth And Nutritional Regulation Of Detritivores, Halvor M. Halvorson, Chris L. Fuller, Sally A. Entrekin, J. Thad Scott, Michelle A. Evans-White Oct 2018

Detrital Nutrient Content And Leaf Species Differenitally Affect Growth And Nutritional Regulation Of Detritivores, Halvor M. Halvorson, Chris L. Fuller, Sally A. Entrekin, J. Thad Scott, Michelle A. Evans-White

Faculty Publications

© 2018 The Authors Resource nutrient content and identity are common bottom–up controls on organismal growth and nutritional regulation. One framework to study these factors, ecological stoichiometry theory, predicts that elevated resource nitrogen (N) and phosphorus (P) contents enhance organism growth by alleviating constraints on N and P acquisition. However, the regulatory mechanisms underlying this response – including whether responses depend on resource identity – remain poorly understood. In this study, we tested roles of detrital N and P contents and identity (leaf species) in constraining growth of aquatic invertebrate detritivores. We synthesized results from seven detritivore species fed wide …


Individual Cell Growth Rates Of Marine Bacteria, Measured By Bromodeoxyuridine Incorporation, Koji Hamasaki, Richard A. Long, Farooq Azam May 2004

Individual Cell Growth Rates Of Marine Bacteria, Measured By Bromodeoxyuridine Incorporation, Koji Hamasaki, Richard A. Long, Farooq Azam

Faculty Publications

We tested the application of 5-bromo-2’-deoxyuridine (BrdU), a thymidine analogue that becomes incorporated into DNA during growth, to measure growth rates of individual marine bacteria cells. Immunocytochemical detection of BrdU incorporation into bacterial DNA has the potential for single-cell-based growth measurement. Optimized procedure for immunocytochemistry was applicable to 14 marine heterotrophic bacterial isolates belonging to g-proteobacteria, α-proteobacteria, Cytophaga-Flavobacterium-Bacteroides (CFB) group and Gram-positive bacteria. The relationship between cell-specific fluorescence intensity and specific growth rate was linearly correlated among CFB group isolates, which indicated a potential of the method for quantitative measurement. Analysis of the detection limit indicated …


Responses Of Phytoplankton And Pfiesteria-Like Dinoflagellate Zoospores To Nutrient Enrichment In The Neuse River Estuary, North Carolina, Usa, James L. Pinckney, Hans W. Paerl, Elin Haugen, Patricia A. Tester Jan 2000

Responses Of Phytoplankton And Pfiesteria-Like Dinoflagellate Zoospores To Nutrient Enrichment In The Neuse River Estuary, North Carolina, Usa, James L. Pinckney, Hans W. Paerl, Elin Haugen, Patricia A. Tester

Faculty Publications

The recently described toxic dinoflagellate Pfiestena piscicida and morphologically similar Pfiesteria-like dinoflagellates have become a major water quality issue with possible fish mortality and reported human health implications. The linkages between accelerated nutrient loading, eutrophication, and the proliferation of this group of dinoflagellates, however, are not well established for natural Systems. Phytoplankton pnmary production may provide a key link between nutrient inputs and potential outbreaks of Pfiesteria-like biflagellated zoospores in the Neuse River Estuary, North Carolina. The impacts of nutrient (NO3- -nitrogen and PO43- -phosphorus) supply rates, sediment-water column exchange, water column mixing, and phytoplankton prey …


Coupling Between Bacterioplankton Species Composition, Population Dynamics, And Organic Matter Degradation, Jarone Pinhassi, Farooq Azam, Johanna Hemphälä, Richard A. Long, Josefina Martinez, Ulla Li Zweifel, Åke Hagström Apr 1999

Coupling Between Bacterioplankton Species Composition, Population Dynamics, And Organic Matter Degradation, Jarone Pinhassi, Farooq Azam, Johanna Hemphälä, Richard A. Long, Josefina Martinez, Ulla Li Zweifel, Åke Hagström

Faculty Publications

To study the effect of substrate addition on short term bacterial population dynamics and species composition in seawater mesocosms were maintained with water collected off Scripps Pier (La Jolla, California USA) Protein enrichment (BSA) triggered a dynamic response from the microbial food web, whereas enrichment with starch had no effect. In the protein enriched mesocosm the number of both nucleoid-containing cells and metabolically active cells increased by 3.0 X 105 cells ml-1 from Day 1 to Day 4 In the same time period the density of a set of 31 phylogenetically different bacteria (α- and g-Proteobactena as well …


Age And Growth Of King Mackerel, Scomberomorus Cavalla, From The Atlantic Coast Of The United States, Mark R. Collins, David J. Schmidt, C. Wayne Waltz, James L. Pinckney Jan 1989

Age And Growth Of King Mackerel, Scomberomorus Cavalla, From The Atlantic Coast Of The United States, Mark R. Collins, David J. Schmidt, C. Wayne Waltz, James L. Pinckney

Faculty Publications

Whole sagittae from 683 and sectioned sagittae from 773 "adult" (age> 0 ; 437-1.310 mm FL), and lapilli from 29 larval (2-7 mm SL) and 69 young-of-the-year (79-320 mm FL) king mackerel, were examined. All fish were from waters off the Atlantic coast of the southeastern United States (Cape Canaveral, Florida to Cape Fear. North Carolina). Back-calculated lengths at ages and von Bertalanffy growth equations were calculated from both whole and sectioned sagittae. Ages determined from sectioned sagittae were significantly greater than ages determined from whole sagittae, and the magnitude of the difference increased with age (from sections). Rings on …