Dear Tan Wai Yee,

my personal recomendation would be just reisolation of the Haematococcus pluvialis from Your cultivation mixture. You need just one week for that using a classical microbiological method: the serial dilution culture method. It is very old fashion, but very effective and cheap.

Best regards

Bohuslav

As per my information I am very sure there is no such way to eradicate other algae from your mixed population.

It is better to do serial dilution and its isolation from your mixed algal population.

Hope you done well...!

You should also be able to filter out most of the smaller cells. Then re-suspend the larger cell and do the serial dilution.

Serial dilution and four flame streaking are required to isolate your algae

Serial dilution followed by cultivation is the most straight forward and sure-shot method to decontaminate your Haematococcus culture, it is the method I endorse too!

The technique being so basic and common, i assume you know about it and are looking for a different answer.

I believe there are other approaches to decontaminating a culture. for example, one can create a set of conditions that favour the growth of the targeted algae or using zooplankton that would selectively feed on the invasive species. the above approaches are being researched for use in large scale, outdoor cultivation of microalgae to prevent invasive species from taking over the initial culture.

Here are a few articles that support my statements and may be of your interest

• dx.doi.org/10.4319/lo.1957.2.2.0125 (Studies of algal antibiosis using Haematococcus and Chlamydomonas) The authors of this paper describe the dynamics of interaction between two algal systems. unfortunately though, Haematococcus failed to survive in most cases.

• Article Selective feeding of four zooplankton species on natural lak...