Main Variables Affecting a Chemical-Enzymatic Method to Obtain Protein and Amino Acids from Resistant Microalgae

Abstract

e development of microalgae uses requires further investigation in cell disruption alternatives to reduce the costs associated to this processing stage. is study aimed to evaluate the main variables affecting an extraction method to obtain protein and amino acids from microalgae. e method was based on a sequential alkaline-enzymatic process, with separate extractions and noncontrolled pH, and was applied to fresh biomass of a resistant species. e processed microalgae were composed of a consortium with Nannochloropsis sp. as predominant species. After the optimization of the pH of the alkaline reaction, the effect of the time of the alkaline reaction (30-120 min), the time (30-120 min) and temperature (40-60°C) of the enzymatic reaction, and the biomass concentration (50-150 mg·ml −1 ), on the extraction yields of protein and free amino nitrogen (FAN) and on the final concentration of protein in the extract, was studied using a response surface methodology. Even though all the variables and some interactions among them had a significant effect, the biomass concentration was the most important factor affecting the overall process. e results showed relevant information about the different options in order to maximize not only the response variables individually but also different combinations of them. Assays with optimized values reached maximum yields of 80.3% and 1.07% of protein (% of total protein) and FAN (% of total biomass), respectively, and a protein concentration in the extract of 15.2 mg·ml −1 . e study provided the essential information of an alternative approach to obtain protein and amino acids from fresh biomass of resistant microalgae with a high yield, also opening perspectives for further research in particular aspects.

Ameliorative effects of microencapsulatedSpirulina platensisin beverage; physicochemical, simulated release, and organoleptic properties

“…Meanwhile, the slight reduction of pH when the Spirulina concentration increased, was due to the decreasing of the Spirulina encapsulation efficiency. This condition is consistent with the previously published findings indicating that this drop with time is most likely due to the buffering properties of the generated proteins (Callejo-L opez et al, 2019).…”

Application of a Microalgal Peptide-Enriched Extract as Media Component in E. coli Culture

“…The resulting biomass was harvested after 7 days of culture at a final biomass concentration of 0.7–0.8 g L –1 . At this moment, cultures were within the exponential phase according to previous evaluations . This phase was selected due to microalgae achieving the maximum protein content .…”

“…The microalgal cultures were accomplished as described by Callejo-Loṕez et al 14 In brief, batch cultures were carried out in 5 L glass bottles, bubbled with air mixed with CO 2 (5−10% v/v) at a flow rate of 0.1 vvm, at room temperature (23−26 °C). LED light was supplied to the cultures at an intensity of 170 μmol photons m −2 s −1 and using a 12/12 h photoperiod.…”

“…At this moment, cultures were within the exponential phase according to previous evaluations. 14 This phase was selected due to microalgae achieving the maximum protein content. 15 The microalgal biomass was concentrated by centrifugation at 5000g at 4 °C for 10 min (Beckman Avanti JXN-26, JLA-8 rotor).…”

Characterization of Endogenous Auxins and Gibberellins Produced by Chlorella sorokiniana TH01 under Phototrophic and Mixtrophic Cultivation Modes toward Applications in Microalgal Biorefinery and Crop Research

“…In regard to biorefinery, microalgal lipids and carbohydrates are promising feedstocks for liquid biofuel (biodiesel, bioethanol, etc.) production [27], whereas proteins [28] are potential materials for feed/food formulation [29]. On the other hand, lipid and sugar extractions are prerequisite steps in biofuel production from algal biomass.…”