Related Experiment Video
Updated: Mar 22, 2026
09:39
Cultivation of the Marine Pelagic Tunicate Dolioletta gegenbauri Uljanin 1884 for Experimental Studies
Published on: August 9, 2019
13.3K
PHOSPHORUS CONTENT AND RATE OF GROWTH IN THE DIATOMS CYCLOTELLA NANA AND THALASSIOSIRA FLUVIATILIS
1Division of Laboratories and Research, New York State Department of Health, Albany, New York 12201.
Journal of Phycology
|April 21, 2016
Summary
Marine diatoms like Cyclotella nana and Thalassiosira fluviatilis show growth rates directly related to their internal phosphorus (P) content. Optimal P levels are crucial for maximizing diatom growth and understanding nutrient limitation in aquatic ecosystems.
Area of Science:
- Marine biology
- Phytoplankton physiology
- Nutrient dynamics
Background:
- Phosphorus (P) is an essential nutrient for phytoplankton growth.
- Understanding P limitation is key to marine ecosystem productivity.
- Diatoms are significant primary producers in marine environments.
Purpose of the Study:
- To investigate the relationship between cellular phosphorus content and growth rate in marine diatoms.
- To determine the impact of varying phosphorus concentrations on diatom physiology.
- To explore the influence of environmental factors on phosphorus uptake and utilization.
Main Methods:
- Culturing Cyclotella nana and Thalassiosira fluviatilis in chemostat and turbidostat systems.
- Manipulating phosphorus concentrations to induce nutrient limitation.
- Measuring cell numbers, growth rates, and cellular P content.
- Analyzing changes in cell composition and P distribution.
Main Results:
- Diatom growth rate followed a saturation curve with respect to intracellular P content.
- A minimum cellular P level was required for growth; half-maximal growth occurred at twice this minimum.
- Altered P content significantly impacted cell composition, including P fractions and organic carbon.
- An abnormal growth curve was observed for C. nana under specific light and temperature conditions.
Conclusions:
- Cellular phosphorus content is a critical determinant of diatom growth rate.
- Phosphorus uptake kinetics, not just external concentration, influences growth.
- Further research using different experimental approaches is needed to fully understand P uptake mechanisms.
Related Concept Videos
01:21The Phosphorus Cycle
44.8K
Unlike carbon, water, and nitrogen, phosphorus is not present in the atmosphere as a gas. Instead, most phosphorus in the ecosystem exists as compounds, such as phosphate ions (PO43-), found in soil, water, sediment and rocks. Phosphorus is often a limiting nutrient (i.e., in short supply). Consequently, phosphorus is added to most agricultural fertilizers, which can cause environmental problems related to runoff in aquatic ecosystems.
44.8K
01:19Other Algae
575
The group Stramenopiles include some phototrophic microorganisms. Members of this group possess flagella covered in numerous short, hairlike extensions, a feature that inspired the group's name, derived from the Latin words for "straw" and "hair." Some of the main categories of Stramenopiles include diatoms, golden algae, and brown algae.Diatoms are unicellular, photosynthetic eukaryotes, with over 200 known genera. They play a key role in the planktonic communities of both marine and...
575
01:06Primary Production
26.0K
The total amount of energy acquired by primary producers in an ecosystem is called gross primary production (GPP). However, of this energy, producers use some for metabolic processes, and some is lost as heat, decreasing the amount of energy available to the next trophic level. The remaining usable amount of energy is called the net primary productivity (NPP). In terrestrial ecosystems, NPP is driven by climate, while light penetration and nutrient availability drive NPP in aquatic ecosystems.
26.0K
01:21Green Algae
1.0K
Green algae, also referred to as chlorophytes, are different from red algae in having the chloroplasts containing chlorophylls a and b, which give them their distinct green hue. However, they lack phycobiliproteins, preventing them from developing the red or blue-green pigmentation seen in red algae. In terms of photosynthetic pigment composition, green algae closely resemble plants and share a close evolutionary relationship with them. Taxonomically Green algae belong to Phylum Chlorophyta in...
1.0K
01:29Factors Influencing Microbial Growth: pH
1.6K
Microorganisms are classified as acidophiles, neutrophiles, or alkaliphiles based on their pH growth preferences, reflecting their adaptations to specific environments. Maintaining a stable intracellular pH is critical for macromolecular stability and enzymatic activity, which can be challenged by external pH variations.Neutrophiles, such as Escherichia coli, grow optimally between pH 5.5 and 8.0. These microorganisms inhabit neutral or slightly acidic environments and employ mechanisms like...
1.6K
01:29Exponential Growth
146
Bacterial populations exhibit exponential growth when conditions such as nutrient availability and temperature are favorable. In this phase, cells reproduce through binary fission, where each cell divides into two identical daughter cells. This process causes the population to double at regular intervals, resulting in a growth rate that is directly proportional to the current number of cells. As the population increases, the number of new cells formed during each generation also grows, creating...
146