# A novel, cheap and easy preparing selective medium for isolation of Pythium species

## TL;DR

This paper introduces a new, affordable, and safe selective medium called FANS to isolate Pythium and Globisporangium species from natural sources.

## Contribution

The novel contribution is the development of a cost-effective and safer selective medium (FANS) for isolating Pythium and Globisporangium species.

## Key findings

- FANS medium effectively promotes growth and reproduction of Pythium and Globisporangium while inhibiting other microbes.
- FANS outperformed existing media like NARM and NARF in promoting mycelial growth and spore production.
- FANS is a safer and more affordable alternative to previously used selective media.

## Abstract

Isolation of Pythium and Globisporangium (Chromista, Oomycota) from their natural sources is very difficult due to the heavy contamination with other microbes, which hinders obtaining them in pure form. This study aims to develop a new, cheap and safe selective medium to isolate Pythium and Globisporangium species from their natural sources, despite the previous presence of more than 3 types of selective media including: VP3 (Vancomycin + PCNB + Penicillin + Pimaricin), NARM (Nystatin + Ampicillin + Rifampicin + Miconazole), and NARF (Nystatin + Ampicillin + Rifampicin + Fluazinam) used to isolate Oomycota. The elevated expense of antibiotics, along with alerts regarding potential contamination, toxicity, and tumor proliferation, renders them undesirable. Safe and inexpensive antibiotics from pharmaceutical sources were used with fixed formulations and concentrations. A selective medium was developed, called FANS (Fluconazole + Ampicillin + Nystatin + Sulbactam) with the following concentrations (1200 mg + 500 mg + 100,000 IU + 250 mg) respectively/L Corn Meal Agar promotes only the growth and formation of reproductive structures of Pythium and Globisporangium. On the other hand, these antibiotics completely inhibited the growth of other contaminated fungi and bacteria. Mycelial growth, zoospore formation, and oospore production for (Pythium aphanidermatum, Pythium oligandrum, and Globisporangium ultimum var. ultimum) were highest in FANS, followed by NARM, then NARF, while VP3 gave the lowest results compared to the control sample. It can be concluded that the use of FANS selective medium made the process of Pythium isolation easier, safer, and less expensive for worldwide researchers especially in developing and low-income countries.