Effect of n-dodecane on Crypthecodinium cohnii fermentations and DHA production

Silva, Teresa Lopes da; Candeias‐Mendes, Ana; Mendes, Rui L.; Calado, Vítor; Alves, Sebastião S.; Vasconcelos, Jorge; Reis, Alberto

doi:10.1007/s10295-006-0081-8

Cited by 62 publications

(23 citation statements)

References 51 publications

(60 reference statements)

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“…These results confirmed that n-dodecane low concentrations improve C. cohnii DHA production, which is in agreement with the results previously reported [4].…”

Section: Flow Cytometry Controlssupporting

confidence: 95%

“…8b, c). From Table 4, it can be seen that, at that fermentation time (t = 95.3 h), the unsaturated fatty acids increase was mainly due to the DHA percentage increase as the other unsaturated fatty acids (16:1x7, 18:1x9 and 22:5x3) almost remained unchanged, which is consistent with the results previously reported [4]. These results suggest that, when n-dodecane was present, the DHA increase could be due to a selective lipid (namely TAG rich in DHA) extraction solvent rather than the oxygen transfer rate increase due to the oxygen vector presence.…”

Section: Bioreactor Experimentssupporting

confidence: 93%

“…3a), suggesting that, even at these higher n-dodecane concentrations, C. cohnii cells could adapt to the organic solvent presence, by increasing their lag phase. Previously we reported that n-dodecane fractions higher than 1% (v/v) to C. cohnii shake flask cultures resulted in cell lysis, based on traditional optical microscope observations [4]. In the present work, multiparameter flow cytometry showed that, despite the higher n-dodecane concentrations that compromised the C. cohnii cell membrane integrity, the microalga was able to recover.…”

Section: Flow Cytometry Controlsmentioning

confidence: 66%

“…Recently we reported the potential use of biphasic bioreactors for enhancement of Chrypthecodinium cohnii growth and DHA production [4]. The biomass concentration, DHA and TFAs production of the fermentation with n-dodecane were higher, compared to fermentation control with no n-dodecane.…”

Section: Introductionmentioning

confidence: 98%

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The use of multi-parameter flow cytometry to study the impact of n-dodecane additions to marine dinoflagellate microalga Crypthecodinium cohnii batch fermentations and DHA production

Silva

Reis

2008

J Ind Microbiol Biotechnol

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The physiological response of Crypthecodinium cohnii batch cultivations and docosahexaenoic acid (DHA) production to n-dodecane additions were studied. Different n-dodecane concentrations [0, 0.5, 1, 2.5, 5, 10 and 20% (v/v)] were added to preliminary shake flask cultivations. The n-dodecane fraction that gave best results in terms of biomass and DHA production was 0.5% (v/v). The n-dodecane fractions of 2.5, 5, 10 and 20% (v/v) to C. cohnii preliminary shake flask cultures inhibited the microalgal growth and DHA production, although a high proportion of cells with intact cytoplasmic membrane was present in the end of these fermentations. After the addition of a pulse of n-dodecane (0.5% v/v) to C. cohnii exponential growing cells in a bioreactor, glucose uptake volumetric rate increased 2.5-fold, while biomass production volumetric rate increased 2.8-fold. The specific growth rate was increased 1.5-fold. The DHA % in biomass, DHA % of TFA and DHA concentration also increased (54, 22 and 58%, respectively), after the n-dodecane addition. At this n-dodecane fraction (0.5% v/v), multi-parameter flow cytometry demonstrated that C. cohnii cell membrane integrity was not affected. The results demonstrated that the addition of 0.5% of n-dodecane (v/v) to C. cohnii fermentations can be an easy and cheap way for enhancing the biomass and DHA production, avoiding the use of high speed rates (resulting in important power agitation costs) that affects the microalga proliferation and increases the bioprocess costs. A new strategy to improve the DHA production from this microalga in two-phase large-scale bioreactors is now in progress.

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“…These results confirmed that n-dodecane low concentrations improve C. cohnii DHA production, which is in agreement with the results previously reported [4].…”

Section: Flow Cytometry Controlssupporting

confidence: 95%

Section: Bioreactor Experimentssupporting

confidence: 93%

Section: Flow Cytometry Controlsmentioning

confidence: 66%

Section: Introductionmentioning

confidence: 98%

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The use of multi-parameter flow cytometry to study the impact of n-dodecane additions to marine dinoflagellate microalga Crypthecodinium cohnii batch fermentations and DHA production

Silva

Reis

2008

J Ind Microbiol Biotechnol

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“…de Silva et al (2006) has reported that dissolved oxygen is a critical parameter for the growth of C. cohnii cells. The sOUR of C. cohnii cells that we measured and reported in Figure 5a supports this observation.…”

Section: Potential Explanation For Apparent ''Shear Sensitivity''mentioning

confidence: 99%

Growth inhibition of dinoflagellate algae in shake flasks: Not due to shear this time!

Hu¹,

Gladue²,

Hansen³

et al. 2009

Biotechnology Progress

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Large scale algae cultures present interesting challenges in that they exhibit characteristics of typical bacterial and animal cell cultures. One current commercial food additive, docosahexaenoic acid (DHA), is produced using the dinoflagellate algae, Crypthecodinium cohnii. Like animal cell culture, the perceived sensitivity of algae culture to hydrodynamic forces has potentially limited the agitation and aeration applied to these systems. However, the high density cultivation of C. cohnii required for an economically feasible process inevitably results in high oxygen demand. In this study, we demonstrated what first appeared to be a problem with shear sensitivity in shake flasks is most probably a mass transfer limitation. We subsequently demonstrated the limit of chronic and rapid energy dissipation rate, EDR, that C. cohnii cells can experience. This limit was determined using a microfluidic device connected in a recirculation loop to a stirred tank bioreactor, which has been previously used to repeatedly expose animal cells to high levels of EDR. Inhibition of cell growth was observed when C. cohnii cells were subjected to an EDR of 5.9 x 10(6) W/m(3) with an average frequency of 0.2/min or more. This level of EDR is sufficiently high that C. cohnii can withstand typically encountered hydrodynamic forces in bioprocesses. This result suggests that at least one dinoflagellate algae, C. cohnii, is quite robust with respect to hydrodynamic forces and the scale-up of process using this type of algae should be more concerned with providing sufficient gas transfer given the relatively high oxygen demand.

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Effects of phosphorous, nitrogen, and carbon limitation on biomass composition in batch and continuous flow cultures of the heterotrophic dinoflagellate Crypthecodinium cohnii

Pleißner¹,

Eriksen²

2012

Biotech & Bioengineering

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We have used phosphate, nitrogen, or carbon limited batch and continuous flow cultures to study how growth and biochemical composition of the dinoflagellate Crypthecodinium cohnii CCMP 316 is affected by nutrient limitation. Specific contents of phosphorous, proteins, and starch were differently affected by nutrient limitation. The specific phosphorous content in C. cohnii varied 10-20 times depending on phosphate availability in the medium. When phosphate was available it was taken up in excess and stored to be re-utilized during phosphate limitation. The specific protein content varied twofold. At most conditions, proteins made up 12-15% of the biomass dry weight but when cells were nitrogen limited, the specific protein content was only half this value. Floridean starch was the major cell constituent of C. cohnii accounting for 40-50% of the biomass dry weight. Only during carbon limitation did the specific starch content decrease. In contrast was the specific lipid content almost unaffected by nutrient availability and lipids accounted for 12-15% of the biomass dry weight irrespectively of which nutrient that was limiting. Lipid production does therefore not depend on nutrient limitation in C. cohnii and lipids are produced even by carbon limited cells. Cultures grown under phosphate limitation resulted in formation of cells with maximal specific contents of all the three major cell constituents; starch, lipid, and protein.

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Effect of n-dodecane on Crypthecodinium cohnii fermentations and DHA production

Cited by 62 publications

References 51 publications

The use of multi-parameter flow cytometry to study the impact of n-dodecane additions to marine dinoflagellate microalga Crypthecodinium cohnii batch fermentations and DHA production

The use of multi-parameter flow cytometry to study the impact of n-dodecane additions to marine dinoflagellate microalga Crypthecodinium cohnii batch fermentations and DHA production

Growth inhibition of dinoflagellate algae in shake flasks: Not due to shear this time!

Effects of phosphorous, nitrogen, and carbon limitation on biomass composition in batch and continuous flow cultures of the heterotrophic dinoflagellate Crypthecodinium cohnii

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