ASPECTS OF THE GROWTH OF MICROCYSTIS AERUGINOSA ON AGAR

SUMMARY

Microcystis aeruginosa could be grown only on four agarmedia tested even if the medium and agar were sterilised separately. The recovery varied from one experiment to another and between replicates, ranging from nil to more than 100%. Light intensities above 10 μE m⁻² sec ⁻¹ did not have the same detrimental effect on colonies growing on agar medium as on batch cultures indicating that carbon dioxide is not a limiting factor. The temperature of 48°C used for pouring over-layers also did not influence recovery. Adjusting the pH to 8 prior to sterilisation or addition of catalase improved recovery. On certain agars however, no growth was obtained even in the presence of catalase. It was also found that different batches of Difco Bacto Agar differ in their ability to yield good recovery. The disposable plastic petri dishes used also influenced recovery in some cases.

KEY WORDS:

• Cyanobacterium
• Microcystis
• agar