Direct optical microalgal growth assessment using 'dip stick' microcapillary strips: A case study with Parachlorella...

Area of Science:

• Biotechnology
• Environmental Science
• Analytical Chemistry

Background:

• Microalgal cultivation is vital for various industries and environmental applications.
• Current monitoring methods are labor-intensive, require specialized equipment, and are not real-time.

Purpose of the Study:

• To introduce a novel, user-friendly micro-cultivation technique for real-time microalgal growth detection.
• To assess the efficiency of this method compared to traditional approaches.

Main Methods:

• Development of a 'dip-stick' micro-cultivation system using fluorinated ethylene propylene microcapillary strips.
• Cultivation of Parachlorella kessleri in microcapillary strips without media replacement or aeration.
• Benchmarking growth rates and cell characteristics against sparged and unsparged Erlenmeyer flasks and flow cytometry.

Main Results:

• Microalgal growth in microcapillary strips matched rates in sparged Erlenmeyer flasks (0.37 /day), outperforming unsparged flasks (0.12 /day).
• Light intensity was identified as a limiting factor for growth within the microcapillary strips.
• Non-invasive monitoring allowed accurate determination of cell morphology and cell cycle events, comparable to flow cytometry.

Conclusions:

• The proposed microcapillary strip method provides a high-throughput, cost-effective solution for microalgal cultivation and monitoring.
• This bioanalytical tool is suitable for in-situ water management and assessing microalgal productivity.
• The technique simplifies microalgal analysis, reducing the need for bulky equipment and expert personnel.