Date of Publication

3-4-2023

Document Type

Master's Thesis

Degree Name

Master of Science in Chemical Engineering

Subject Categories

Chemical Engineering

College

Gokongwei College of Engineering

Department/Unit

Chemical Engineering

Thesis Advisor

Cynthia F. Madrazo

Defense Panel Chair

Joseph R. Ortenero

Defense Panel Member

Nathaniel P. Dugos
Allan N. Soriano

Abstract/Summary

C-phycocyanin (CPC) is a valuable compound due to its applications in the pharmacological, cosmetics, and food industries. Because of large expenses in the industrial CPC production due to cyanobacteria culturing, extraction, and purification, it is pertinent to examine the capability of novel cyanobacterial strains, such as C. aponinum AL20115, to produce CPC and to model and optimize its cyanobacterial growth and CPC production, consequently minimizing the cost from culturing. Cultivation of the strain in BG-11 medium was accomplished using a double-layer system with varying carbonate and bicarbonate solutions and a photobioreactor with varying CO2-air mixtures and NH4Cl concentrations. Cyanobacterial growth was then monitored for six days, and CPC was extracted for analysis. From the experimental results, the addition of CO2 and bicarbonate generally increased biomass growth and CPC production. A higher nitrogen concentration increased CPC production but illustrated toxic effects on cyanobacterial growth, while a lower nitrogen concentration caused earlier nitrogen starvation and decrease in CPC. Characterization of the antioxidant activity of the crude extract showed 55.79% DPPH, 26.17% hydroxyl, and 16.49% superoxide radicals scavenged. Moreover, the bacterial inhibition zones in E. coli MG1655 were measured to be 1.03 cm and 1.60 cm in diameter for a 30 μL and 60 μL drop of the crude extract, respectively. Modelling of biomass growth suggested that the Monod equation best described the growth and CPC production of C. aponinum AL20115 by comparing the least value of the norm of residuals of all models. Based on the results of the cultivation, the characterization of its antioxidant and antibacterial activities, and the modelling and estimation of kinetic parameters, C. aponinum AL20115 may potentially be a feasible alternative feedstock for CPC production. It is recommended that future research be done to further corroborate the results of the study and provide more insight regarding the viability of the novel strain to produce CPC.

Abstract Format

html

Language

English

Format

Electronic

Keywords

Cyanobacteria

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Embargo Period

4-24-2024

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