Analysis of functional relationships between the cell quantification variables in the microalgae Chlorella sorokiniana

Abstract

The applications of microalgae are being increasingly explored, as they have a high rate of cell duplication and accumulation of lipids, ranging from 20-50% of their dry weight, reaching up to 80% under appropriate conditions. Their cultivation in artificial conditions has also increased, which has made it important to explore different microalga quantification methods and evaluate its growth kinetics. For algal quantification, it appears that both quantification methods by direct counting in a Neubauer chamber (density) and indirect counting methods such as reading in spectrophotometry (optical density) and dry weight (biomass), are important to validate the results quantification. The objective of this study was to verify the existence of a functional relationship between the variables used to quantify the microalgae Chlorella sorokiniana. For this purpose, linear regression analysis was applied to the variables of cell density, optical density, and dry biomass that were obtained by cultivating the microalgae at different concentrations. Using the equations generated from the regression analysis in Chlorella sorokiniana, it was possible to obtain ​​cell density values between 3 and 3.8 × 106 mL-1 and dry biomass values between 0.1 and 4.3 mg.mL-1 from the optical density values acquired using spectrophotometry with extreme precision, and this method was found to be highly feasible.

The effect of flow rates and composition of culture medium in Chlorella Pyrenoidosa cultivation by CO2 injection method

“…The purpose of optical density measurement is to obtain the quantity of microalgae or biomass for each variable, and is also used to determine microalgae concentration, which means we can determine the growth of microalgae [20] . Measurement of optical density using a UV-VIS spectrophotometer with a wavelength for the microalgae Chlorella pyrenoidosa is 690 nm.…”

Euglena sp. CULTIVADA COM SUPLEMENTAÇÃO DE RESÍDUOS SEPARADOS DE CERVEJARIA ARTESANAL E SEU POTENCIAL ANTIOXIDANTE

“…fósforo e outros vários nutrientes durante seu crescimento, os convertendo em biomassa através da sua atividade fotossintética (BATISTA et al, 2014;GOUVEIA et al, 2016;MARCHÃO et al, 2017;OLIVEIRA et al, 2019).…”

“…Foi realizado o monitoramento do crescimento da microalga através de espectrofotômetro na região do visível, no comprimento de onda (λ) de 680 nm e a rendimento de biomassa através de biomassa seca e contagem celular em câmera Sedgwick-Rafter (NUNES et al, 2020). Os cultivos foram centrifugados a 3600 rpm e secos em estufa a 50° C por 48h, a biomassa foi armazenada para análise.…”

The Effect of NaHCO3 and Mg2+ Addition in Haematococcus pluvialis Cultivation by Carbon Injection Method

“…Optical density measurement has a purpose in the world of microalgae cultivation, besides of obtaining the quantity of microalgae or biomass for each variable, and also used to determine microalgae concentration (Nunes et al, 2021), optical density measurement can re-validate the data obtained in order to determine more precisely growth phase (Rinawati and Prasetyo, 2020). Measurement of optical density using a UV-VIS spectrophotometer with a wavelength for the microalgae Haematococcus pluvialis is 684 nm.…”