Application of Response Surface Method for Studying the Role of Dissolved Oxygen and Agitation Speed on Gamma-Linolenic Acid Production

Ahmed, Syed Ubaid; Singh, S. N.; Pandey, Ashok; Kanjilal, Sanjit; Prasad, Ruchipad B. N

doi:10.1007/s12010-008-8256-6

Cited by 9 publications

(4 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this study, the GLA content of TFAs was significantly increased with certain amino acids, particularly with proline for AUMC 11616.A and tryptophan for AUMC 6696.A. In other studies, GLA has been shown to play an important role in humans, improving the health of patients suffering from diabetes, aging, cancer, and immune diseases ( 26 , 41 ). The highest yield of GLA in this study was significantly more than that obtained from other species of Mucorales and some other Zygomycotina, which are considered potential candidates for the application in the industrial production of PUFAs and other valuable compounds ( 34 ).…”

Section: Discussionsupporting

confidence: 54%

Evaluation of Different Standard Amino Acids to Enhance the Biomass, Lipid, Fatty Acid, and γ-Linolenic Acid Production in Rhizomucor pusillus and Mucor circinelloides

et al. 2022

View full text Add to dashboard Cite

In this study, 18 standard amino acids were tested as a single nitrogen source on biomass, total lipid, total fatty acid (TFA) production, and yield of γ-linolenic acid (GLA) in Rhizomucor pusillus AUMC 11616.A and Mucor circinelloides AUMC 6696.A isolated from unusual habitats. Grown for 4 days at 28°C, shaking at 150 rpm, the maximum fungal biomass for AUMC 6696.A was 14.6 ± 0.2 g/L with arginine and 13.68 ± 0.1 g/L with asparagine, when these amino acids were used as single nitrogen sources, while AUMC 11616.A maximum biomass was 10.73 ± 0.8 g/L with glycine and 9.44 ± 0.6 g/L with valine. These were significantly higher than the ammonium nitrate control (p < 0.05). The highest levels of TFA were achieved with glycine for AUMC 11616.A, 26.2 ± 0.8% w/w of cell dry weight, and glutamic acid for AUMC 6696.A, 23.1 ± 1.3%. The highest GLA yield was seen with proline for AUMC 11616.A, 13.4 ± 0.6% w/w of TFA, and tryptophan for AUMC 6696.A, 12.8 ± 0.3%, which were 38% and 25% higher than the ammonium tartrate control. The effects of environmental factors such as temperature, pH, fermentation time, and agitation speed on biomass, total lipids, TFA, and GLA concentration of the target strains have also been investigated. Our results demonstrated that nitrogen assimilation through amino acid metabolism, as well as the use of glucose as a carbon source and abiotic factors, are integral to increasing the oleaginicity of tested strains. Few studies have addressed the role of amino acids in fermentation media, and this study sheds light on R. pusillus and M. circinelloides as promising candidates for the potential applications of amino acids as nitrogen sources in the production of lipids.

show abstract

Section: Discussionsupporting

confidence: 54%

Evaluation of Different Standard Amino Acids to Enhance the Biomass, Lipid, Fatty Acid, and γ-Linolenic Acid Production in Rhizomucor pusillus and Mucor circinelloides

et al. 2022

View full text Add to dashboard Cite

show abstract

“…Because all of the experiments were conducted under the same operating conditions excluding the aeration rate, increase in growth and GLA content with changes in the aeration rate are attributed to improved mixing and better oxygen availability. It is well documented that dissolved oxygen is essential for the desaturation of linoleic acid (C18:2) by Δ-6-desaturase in the production of GLA (1, 23). It is significant to attribute this cause to increase in oxygen availability, promoting both growth and the production of GLA by the enzyme.…”

Section: Resultsmentioning

confidence: 99%

“…NADPH-cytochrome b 5 reductase, cytochrome b 5 , and a terminal desaturase, are involved in the synthesis of unsaturated fatty acids (6). In addition, oxygen is also required for unsaturated fatty acid synthesis (1). In algae, the desaturation of linoleic acid (C18:2 ω6) is facilitated by either Δ-6 desaturase or Δ-15-desaturase, resulting in the production of 18:3ω6 or 18:3ω3, respectively; these fatty acids ultimately form higher PUFAs, viz.…”

Section: Introductionmentioning

confidence: 99%

Aeration effect on Spirulina platensis growth and γ-linolenic acid production

Ronda¹,

Bokka²,

Ketineni³

et al. 2012

Braz. J. Microbiol.

View full text Add to dashboard Cite

The influence of aeration on algal growth and gamma-linolenic acid (GLA) production in a bubble column photobioreactor was investigated. Studies were performed in a 20-L reactor at different aeration rates (0.2– 2.5 vvm). Static, continuous, and periodic operation of air resulted in 41.9%, 88.4%, and 108% air saturation of dissolved oxygen, for which the corresponding values of GLA were 2.3, 6.5, and 7.5 mg·g-1 dry cell weight, respectively. An increase in the aeration rate from 0.2 to 2.5 vvm enhanced both the specific growth rate and GLA content under periodic sparging in the bicarbonate medium. With a 6-fold increase in the aeration rate, the GLA content of the alga increased by 69.64% (5.6–9.5 mg· g-1 dry cell weight). In addition, the total fatty acid (TFA) content in dry biomass increased from 2.22% to 4.41%, whereas the algae maintained a constant GLA to TFA ratio within the aeration rate tested. The dependence of GLA production on the aeration rate was explained by interrelating the GLA production rate with the specific growth rate using the Luedeking and Piret mixed growth model.

show abstract

“…Higher aeration rates are usually bene cial for cell growth by improving mass transfer of substrate, product and oxygen and enhancing the oxygen availability since oxygen is an electron acceptor [20]. Agitation can also facilitate the transfer of mass and heat in the reactor, but high agitation rate will inevitably cause stronger shear forces, leading to morphological changes and might even damage the cell structure [21,22]. In this study, the effect of different DO concentrations expressed as partial pressure of oxygen (pO 2 ) regulated by agitation and aeration on cell growth, lipid production, POA accumulation and ethanol generation were comprehensively investigated.…”

Section: Introductionmentioning

confidence: 99%

Production of palmitoleic acid by oleaginous yeast Scheffersomyces segobiensis DSM 27193 using systematic dissolved oxygen regulation strategy

Zhou¹,

Zhou²,

Bao³

et al. 2021

Preprint

View full text Add to dashboard Cite

Background: Recently, a newly isolated oleaginous yeast strain Scheffersomyces segobiensis DSM 27193 was identified with the capability of accumulating high contents of palmitoleic acid (POA) in its intracellular lipid (13.8%). However, high amounts of ethanol as the main by-product were also produced in this system. To eliminate ethanol formation and to further improve POA production, process optimization focused on dissolved oxygen (DO) regulation was conducted in this study.Results: As a result, agitation control was found to be highly beneficial for cell growth and lipid production. When keeping pO2>40% through dynamic agitation control, significant improvements toward lipid (70.12% increase) and POA (1.44 fold) production have been obtained, and the accumulation of ethanol was decreased to 2.3 g/L. While increasing the aeration rate to 2 vvm, no significant decrease has been found in ethanol accumulation. Further application of a two-stage agitation regulation (600 rpm in the first 48 h fermentation then adjusted the agitation speed to 1000 rpm) gave 10.23 g/L of lipid (50% increase) with 2.02 g/L of POA (1.15 fold) production. At last, under the best condition of 1000 rpm of agitation and 1 vvm of aeration, no ethanol was detected during the whole fermentation process, while a dry biomass concentration of 44.8 g/L with 13.43 g/L of lipid and 2.93 g/L of POA was achieved. Transcription analysis revealed that ethanol synthetic pathway was down regulated under the condition of high agitation, while the expression of the key enzymes responsible for lipid and POA accumulation were enhanced.Conclusion: This study introduces the oleaginous yeast chassis S. segobiensis DSM 27193 and an effective pO2 regulation strategy for efficient biological production of POA.

show abstract

Application of Response Surface Method for Studying the Role of Dissolved Oxygen and Agitation Speed on Gamma-Linolenic Acid Production

Cited by 9 publications

References 15 publications

Evaluation of Different Standard Amino Acids to Enhance the Biomass, Lipid, Fatty Acid, and γ-Linolenic Acid Production in Rhizomucor pusillus and Mucor circinelloides

Evaluation of Different Standard Amino Acids to Enhance the Biomass, Lipid, Fatty Acid, and γ-Linolenic Acid Production in Rhizomucor pusillus and Mucor circinelloides

Aeration effect on Spirulina platensis growth and γ-linolenic acid production

Production of palmitoleic acid by oleaginous yeast Scheffersomyces segobiensis DSM 27193 using systematic dissolved oxygen regulation strategy

Contact Info

Product

Resources

About