GROWTH OF CHLORELLA PYRENOIDOSA IN RECYCLED MEDIUM.

Area of Science:

• * Biotechnology and Algal Cultivation
• * Environmental Microbiology

Background:

• * Sustainable microalgae cultivation requires efficient nutrient recycling strategies.
• * Potential autotoxicity and bacterial contamination are key challenges in reusing algal media.

Purpose of the Study:

• * To evaluate the feasibility of maintaining dense Chlorella pyrenoidosa cultures using recycled medium.
• * To assess the impact of minimal salt supplementation on culture stability and growth.
• * To investigate the influence of high bacterial populations on algal performance in recycled media.

Main Methods:

• * Bench-scale cultivation of Chlorella pyrenoidosa 7-11-05 in a 4-liter vessel.
• * Utilized a used and recycled nutrient medium, supplemented with minimal salts.
• * Monitored cultures over several weeks, up to 72 days, assessing algal density and bacterial presence.

Main Results:

• * Dense algal cultures were successfully maintained for extended periods (up to 72 days).
• * Minimal salt supplementation effectively prevented autoinhibition, despite the use of recycled medium.
• * High bacterial populations did not inhibit algal growth or culture density.

Conclusions:

• * Recycled medium, with minimal salt supplementation, is a viable strategy for sustained, dense microalgae cultivation.
• * Chlorella pyrenoidosa exhibits resilience to autotoxic compounds and high bacterial loads in recycled media.
• * This approach offers a promising avenue for cost-effective and sustainable algal biomass production.