Banca de DEFESA: ROSY DAYANNE FERNANDES NASCIMENTO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ROSY DAYANNE FERNANDES NASCIMENTO
DATE: 27/10/2023
TIME: 14:30
LOCAL: Google Meet
TITLE:

STUDY OF THE LIGHT EFFECT AND BIOFIXATION OF CO2 IN MICROALGAL CULTIVATION UNDER THE YIELD OF FUNCTIONAL BIOCOMPOUNDS FROM THE SPECIES Chlorella vulgares AND Limnospira maxima

KEY WORDS:

Cultivation; Microalgae; Light; CO2 biofixation; biocompounds.

PAGES: 61
BIG AREA: Outra
AREA: Ciências Ambientais
SUMMARY:

Microalgae are photosynthetic beings with relevant applicability and biotechnological use in various areas of the food, pharmaceutical, cosmetics, biofuels, biofertilizer sectors, among others. The species Chorella vulgaris and Limnospira maxima have attracted interest due to their resistance and ability to adapt to different climatic conditions, CO₂ capture and pH changes, being robust species, and with a high quantity of primary functional biocompounds (proteins, lipids and carbohydrates) that can be synthesized through environmental stress. The challenge faced in increasing the viability of biomass production is in optimizing the process of transforming light energy, photosynthesis, and capturing the CO₂ that reaches microalgae cultivations.An essential strategy to promote photosynthetic improvement and efficiency, by manipulating light intensity and capturing CO₂ using biological fixation exerted by microalgae. Therefore, the objective of the present work was to analyze the effect of light (luminous) and the potential of CO₂ on the growth and productivity of microalgal cultivation and the yield of primary functional biocompounds. The species were grown in 4L drums under a 12h:12h photoperiod with two types of lights (LED and Fluorescent) and pH, salinity and temperature control. Optical density, absorbance, dry weight and cell count were evaluated during the experimental period.To quantify proteins, lipids and total carbohydrates, specific methodologies were used in accordance with the literature. The same steps were applied and verified for microalgal cultivation as a supplementary carbon source using a CO₂ cylinder using two operating modes: (i) CO₂ injection during the light phase of the photoperiod (12h) for 30min; (ii) CO₂ injection (12hs) 60min and aerated control with atmospheric air (24h) without CO₂ enrichment. The results of light cultivation showed cell growth exposed to white LED light for both species.The protein content was significantly higher in LED light for the species Limnospira maxima (45.13± 2.232). There was no significant difference between carbohydrate content in both species. The lipid contents of Limnospira maxima were significantly higher in white LED light (17.77 ± 1.254) and for the species Chlorella vulgaris it showed a higher yield in fluorescent light 4.10 ± 1.391. In cultivation with CO₂ supplementation, the growth curves of crops that received CO₂ supplementation for 60 minutes showed a higher growth rate. The composition of microalgal biomass for proteins were not significant. For carbohydrates, the highest index was for the treatment with the addition of CO₂ for 30 minutes (39.15±1.93). In the lipid fraction, treatment with addition of CO₂ for 60min showed better yield (10.67±2.43).Therefore, white LED light is the most suitable for the production of biomass, proteins and lipids in the species Limnospira maxima and for Chlorella vulgaris it is observed that fluorescent light showed better and greater adaptation and microalgal yield. CO₂ supplementation to the culture medium provided greater cell density and productivity in Chlorella vulgaris cultures, and influenced the yield of functional biocompounds.

COMMITTEE MEMBERS:
Presidente - 1221519 - DÁRLIO INÁCIO ALVES TEIXEIRA
Interna - 1516627 - JULIANA ESPADA LICHSTON
Externo à Instituição - RANILSON DE SOUZA BEZERRA - UFPE