Cited by 81Algal biology and biofuel productionAquatic Ecosystems and Phytoplankton DynamicsMarine and coastal ecosystems

Impact of phosphorus quota and growth phase on carbon allocation inChlamydomonas reinhardtii: an FTIR microspectroscopy study

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Dean, Andrew P., Nicholson, James M., Sigee, David C.·2008·European Journal of Phycology

Abstract

Batch cultures of Chlamydomonas reinhardtii were used to study carbon allocation in relation to growth phase and phosphorus availability. Cultures were grown at initial phosphorus (PO4-P) concentrations of 500 µg l−1 (high-P) and 50 µg l−1 (low-P). Cellular carbon allocation was monitored using Fourier transform infrared (FTIR) microspectroscopy with the ratio of the band intensities at 1736 cm−1 (lipid) and the 1180–950 cm−1 region (carbohydrate) to 1652 cm−1 (amide I) used as an index of changing carbon balance. Cellular phosphorus concentrations (P quota) were measured by energy dispersive X-ray microanalysis (EDXRMA). Both treatments entered stationary phase on day 18. Increased cell counts in the high-P treatment (max. 3.0 × 106 cells ml−1 at stationary phase) led to a rapid decrease in external P availability to <20 µg l−1 during early log phase, with a subsequent decrease in P quota from 0.5% to <0.1% DW. The fall of P quota to <0.1% led to an increase in the lipid/protein ratio (0.13 to 0.23) and carbohydrate/protein ratio (0.37 to 1.57), with ratios increasing further (lipid:protein 1.85; carbohydrate:protein 2.77) in late stationary phase. In the low-P treatment external P concentrations (<20 µg l−1 from day 1) restricted population growth (max. 0.75 × 106 cells ml−1 at stationary phase). P quotas fell to <0.1% in early log phase, with the carbohydrate/protein ratio increasing from 0.15 to 3.7 and remaining high into stationary phase while the lipid/protein ratio increased from 0.2 to 1.2. In both treatments increasing synthesis of lipid and carbohydrate storage products resulted in an increased cell volume. Transfer of P-deficient cells (late stationary) to fresh media led to a rapid stimulation of growth, a rapid reduction in lipid/protein and carbohydrate/protein ratios, and decreased cell volumes.

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  • Proportions and ratios of these bonds can elucidate information of very specific chemical compounds including lipids, proteins, carbohydrates, and silica (diatoms) and be used to characterize more specific molecules of industrial interest such as fatty acids, TAG, and beta-carotene as a precursor astaxanthin.

    “Proportions and ratios of these bonds can elucidate information of very specific chemical compounds including lipids, proteins, carbohydrates, and silica (diatoms) and be used to characterize more specific molecules of industrial interest such as fatty acids [34,35], TAG [36], and beta-carotene as a precursor astaxanthin [37].”

    From Microalgal process-monitoring based on high-selectivity spectroscopy tools: status and future perspectives (2018) · cites this paper as [35]

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  • Nitrogen and phosphorus limitation causes changes in photosynthetic activity, lipid synthesis, and biomass composition in freshwater and marine microalgae.

    “Studies have indicated changes in photosynthetic activity, lipid synthesis, and biomass composition in freshwater and marine microalgae as a result of nitrogen and phosphorus limitation [8 -11].”
  • As nutrients are depleted, the amount of proteins in microalgae cells reduces, which alters the cell metabolism to accumulate more carbohydrates (1200-1000 cm-1) and lipids in the form of TAGs (~1740 cm-1).

    “This indicates that as nutrients are depleted, the amount of proteins in microalgae cells reduces, which alters the cell metabolism to accumulate more carbohydrates (1200-1000 cm -1 ) and lipids in the form of TAGs (~1740 cm -1 )[11,14,31].”
  • Chlamydomonas sp. exhibited an increase in CH intensities (3000-2800 cm-1) with nutrient depletion (NP1) on the 10th and 20th days of growth.

    “Chlamydomonas sp. also exhibited an increase in CH intensities (3000-2800 cm -1 ) with nutrient depletion (NP1) on the 10 th (Fig.3) and 20 th (Fig.4) days of growth, in accordance with previous studies [9,13,58].”
  • Increased accumulation of lipids from 0.2 to 1.2, a sixfold increase on its 35th day of growth, has been reported for Chlamydomonas reinhardtii subjected to low phosphorus treatment.

    “Increased accumulation of lipids from 0.2 to 1.2 that amounts to a sixfold increase on its 35 th day of growth has been reported for Chlamydomonas reinhardtii , subjected to low phosphorus treatment [11]”

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Authors
Dean, A. P., Nicholson, J. M., & Sigee, D. C.
Affiliations
  • University of Manchester (GB)
  • Daresbury Laboratory (GB)
Corresponding author
Dean, Andrew P.
Venue
European Journal of Phycology
Published
2008-11
Volume
43
Issue
4
Pages
345-354
ISSN
  • 0967-0262 (ISSN-L)
  • 1469-4433
OpenAlex
W2120590341
Cited by
81
References
32
Citations by year
2026: 2 · 2025: 1 · 2024: 6 · 2023: 6 · 2022: 5 · 2021: 7 · 2020: 6 · 2019: 4 · 2018: 4 · 2017: 6 · 2016: 3 · 2015: 9 · 2014: 4 · 2013: 4 · 2012: 7
FWCI
1.32
Type
journal article
Language
en
Open access
Locations
  • European Journal of Phycology (publishedVersion)
  • Science and Technology Facilities Council (submittedVersion)
  • Research Explorer (The University of Manchester) (submittedVersion)
Funders
Leverhulme Trust (F/00 120/AO)
Topics
  • Physical Sciences › Energy › Renewable Energy, Sustainability and the Environment › Algal biology and biofuel production
  • Physical Sciences › Environmental Science › Environmental Chemistry › Aquatic Ecosystems and Phytoplankton Dynamics
  • Physical Sciences › Earth and Planetary Sciences › Oceanography › Marine and coastal ecosystems
Keywords
Chlamydomonas reinhardtii, phosphorus limitation, carbon allocation, growth phase, lipid accumulation, carbohydrate storage, lipid/protein ratio, protein-carbohydrate ratio, cell volume, stationary phase, microalgae

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