The estimation of growth yield and maintenance parameters for photoautotrophic growth

Lee, H. Y.; Erickson, Larry E.; Yang, Shouping

doi:10.1002/bit.260260817

Cited by 21 publications

(4 citation statements)

References 26 publications

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“…This demonstrates that in experiment 24 the light reached places within the culture where it could be used more efficiently. The same effect was obtained by Winokur (Lee, Erickson & Yang 1984) with Chlorella cultures, but with agitation: the agitated cultures doubled the photosynthetic efficiency of those that were not agitated because in the latter the frequency of exposure to light was decreased.…”

Section: Photosynthetic Efficiencysupporting

confidence: 67%

Outdoor turbidostat culture of the marine microalga Tetraselmis sp.

et al. 1994

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Abstract. Biomass productivity, photosynthetic efficiency and fatty acid profiles of the marine microalga Tetraselmis sp. in a turbidostat culture system using an outdoor photobioreactor are described. The maximum productivity depended on the units in which it was expressed; it reached 5·41 × 10−3 g/l/h in volumetric units, and 7·26g/m2/day in surface units, the former at the smallest culture depth (0·12m) and the latter at the greatest culture depth (0·25 m). Data from the experiments were adjusted to an equation for light limitation. The comparison of fatty acid composition at both depths showed that biosynthesis of polyunsaturated fatty acids (PUFAs), including eicosapentaenoic acid (EPA), was favoured when available light was low (0·17 m). Moreover, fatty acid 16:0 seemed to be an indicator of the type of limitation in the culture, i.e. nutrient or light limitation.

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Section: Photosynthetic Efficiencysupporting

confidence: 67%

Outdoor turbidostat culture of the marine microalga Tetraselmis sp.

et al. 1994

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“…These results show that thermodynamic efficiency must be defined from energy balances and from the entropy dissipation function rather than from the enthalpy balance as many authors have suggested (Aiba and Ogawa, 1977;Lee and Pirt, 1982;Aiba and Ogawa, 1983;Lee et al, 1984, Iehana, 1987Lee et al, 1987). In addition, the fraction of the dissipated energy corresponding to the maintenance of the microorganisms can be determined from experiments performed in different conditions of volumetric rate of radiant energy absorbed if the local energy profiles are calculated.…”

Section: Aiche Journalmentioning

confidence: 90%

“…This analysis is necessary in order to ascertain which processes become possible through coupling, that is, using the entropy production of another process (Prigogine, 1967). This analysis implicitly includes thermodynamic efficiency and enthalpy efficiency for which the definitions for photobioconversions are still being debated (Aiha and Ogawa, 1977;Lee and Pirt, 1982;Aiba and Ogawa, 1983;Lee et al, 1984;Iehana, 1987;Lee et al, 1987).…”

Section: Introductionmentioning

confidence: 99%

Conversion of radiant light energy in photobioreactors

Cornet¹,

Dussap²,

Gros³

1994

AIChE Journal

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“…The stoichiometry of biomass growth has often relied on the detailed compositional analysis of E. coli , CH 1.776 N 0.165 O 0.495 [20,25], which corresponds to 9.6% nitrogen by mass (10.4 g biomass/gN). This biomass composition gives a 30% ammonium composition (Δ = 0.3) in our mixed nitrogen source media design (Equation 6).…”

Section: Introductionmentioning

confidence: 99%

Achieving pH control in microalgal cultures through fed-batch addition of stoichiometrically-balanced growth media

2013

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BackgroundLack of accounting for proton uptake and secretion has confounded interpretation of the stoichiometry of photosynthetic growth of algae. This is also problematic for achieving growth of microalgae to high cell concentrations which is necessary to improve productivity and the economic feasibility of commercial-scale chemical production systems. Since microalgae are capable of consuming both nitrate and ammonium, this represents an opportunity to balance culture pH based on a nitrogen feeding strategy that does not utilize gas-phase CO2 buffering. Stoichiometry suggests that approximately 36 weight%N-NH4+ (balance nitrogen as NO3-) would minimize the proton imbalance and permit high-density photoautotrophic growth as it does in higher plant tissue culture. However, algal media almost exclusively utilize nitrate, and ammonium is often viewed as ‘toxic’ to algae.ResultsThe microalgae Chlorella vulgaris and Chlamydomonas reinhardtii exclusively utilize ammonium when both ammonium and nitrate are provided during growth on excess CO2. The resulting proton imbalance from preferential ammonium utilization causes the pH to drop too low to sustain further growth when ammonium was only 9% of the total nitrogen (0.027 gN-NH4+/L). However, providing smaller amounts of ammonium sequentially in the presence of nitrate maintained the pH of a Chlorella vulgaris culture for improved growth on 0.3 gN/L to 5 gDW/L under 5% CO2 gas-phase supplementation. Bioreactor pH dynamics are shown to be predictable based on simple nitrogen assimilation as long as there is sufficient CO2 availability.ConclusionsThis work provides both a media formulation and a feeding strategy with a focus on nitrogen metabolism and regulation to support high-density algal culture without buffering. The instability in culture pH that is observed in microalgal cultures in the absence of buffers can be overcome through alternating utilization of ammonium and nitrate. Despite the highly regulated array of nitrogen transporters, providing a nitrogen source with a balanced degree of reduction minimizes pH fluctuations. Understanding and accommodating the behavior of nitrogen utilization in microalgae is key to avoiding ‘culture crash’ and reliance on gas phase CO2 buffering, which becomes both ineffective and cost-prohibitive for commercial-scale algal culture.

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The estimation of growth yield and maintenance parameters for photoautotrophic growth

Cited by 21 publications

References 26 publications

Outdoor turbidostat culture of the marine microalga Tetraselmis sp.

Outdoor turbidostat culture of the marine microalga Tetraselmis sp.

Conversion of radiant light energy in photobioreactors

Achieving pH control in microalgal cultures through fed-batch addition of stoichiometrically-balanced growth media

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