Abstract
Mixotrophic cultivation of microalgae provides a very promising alternative for producing carbohydrate-rich biomass to convert into bioethanol and value-added biocompounds, such as vitamins, pigments, proteins, lipids and antioxidant compounds. Spirulina platensis may present high yields of biomass and carbohydrates when it is grown under mixotrophic conditions using cheese whey. However, there are no previous studies evaluating the influence of this culture system on the profile of fatty acids or antioxidant compounds of this species, which are extremely important for food and pharmaceutical applications and would add value to the cultivation process. S. platensis presented higher specific growth rates, biomass productivity and carbohydrate content under mixotrophic conditions; however, the antioxidant capacity and the protein and lipid content were lower than that of the autotrophic culture. The maximum biomass yield was 2.98 ±0.07 g/L in growth medium with 5.0% whey. The phenolic compound concentration was the same for the biomass obtained under autotrophic and mixotrophic conditions with 2.5% and 5.0% whey. The phenolic compound concentrations showed no significant differences except for that in the growth medium with 10.0% whey, which presented an average value of 22.37±0.14 mg gallic acid/g. Mixotrophic cultivation of S. platensis using whey can be considered a viable alternative to reduce the costs of producing S. platensis biomass and carbohydrates, shorten cultivation time and produce carbohydrates, as it does not require adding expensive chemical nutrients to the growth medium and also takes advantage of cheese whey, an adverse dairy industry byproduct.
Highlights
Microalgae have great biotechnological potential and can be used in several segments of the chemical, food, pharmaceutical and cosmetic industries and for biofuel production [1]
S. platensis was grown under autotrophic and mixotrophic conditions with 2.5%, 5.0% and 10.0% cheese whey for 17 consecutive days until reaching the early stationary phase of growth to evaluate important kinetic parameters, such as maximum biomass concentration, maximum yield and specific growth rate
Mouther [31] showed that the optimal cheese whey concentration for S. platensis mixotrophic cultivation was 3.0%, and inhibition occurs at higher whey concentrations
Summary
Microalgae have great biotechnological potential and can be used in several segments of the chemical, food, pharmaceutical and cosmetic industries and for biofuel production [1]. These microorganisms are an abundant source of natural proteins, lipids, carbohydrates, vitamins, pigments and enzymes [2] [3]. Phenolic compounds, including simple phenols, flavonoids, tannins, lignins, and phenolic acids and their derivatives, are potential candidates for scavenging free radicals due to their redox properties [6]. Phenolic acid molecules consist of benzene ring carboxylic groups and one or more hydroxyl or methoxy group, and the donation of electron or hydrogen atoms stabilizes the free radicals, conferring their antioxidant activity [1]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
