How to simply analyze a diesel fuel?

How to simply analyze a diesel fuel?

This gasoil from a storage tank in an oil depot was subjected to a microbiological analysis on a Petri dish using the SAFRAN method and a SAFRAN AQPS 490 Special Process Qualification Certificate.

The results are as follows:

Bacteria: 4600 germs/ml

Yeast: 0 germ/ml

Mushrooms: 8500 sprouts/ml

These results are illustrated by photos of the Petri dishes.