Evaluation of various techniques for microalgal biomass quantification.

Area of Science:

• Biotechnology
• Microalgal cultivation
• Biomass measurement

Background:

• Biomass concentration is a critical parameter in biotechnological processes.
• Accurate measurement relies on cellular physical, chemical, or biological properties.
• Evaluating diverse techniques is essential for optimizing microalgal cultivation.

Purpose of the Study:

• To assess various methods for measuring microalgal biomass concentration.
• To compare the effectiveness of different techniques against dry cell weight (DCW) as a reference.
• To determine the optimal measurement range for each technique.

Main Methods:

• Comparative analysis of multiple biomass measurement techniques.
• Utilizing dry cell weight (DCW) as the gold standard for calibration.
• Employing optical density, dielectric permittivity sensors, RGB image analysis with Fourier equation, flow cytometry, hemocytometry, and oxygen production rate measurements.

Main Results:

• Optical density and dielectric permittivity sensors provided reliable measurements up to 20 g/L.
• RGB image analysis combined with Fourier equation extended reliable measurement range to 6 g/L.
• Flow cytometry demonstrated good linearity with DCW in washed samples, while hemocytometry and automated microscopy were limited; oxygen production rate correlated linearly below 1 g/L.

Conclusions:

• Different methods offer varying ranges and accuracies for microalgal biomass concentration measurement.
• Selection of the appropriate technique depends on the required concentration range and sample characteristics.
• Optical sensors and image analysis show promise for robust biomass monitoring in microalgal biotechnology.