Single colonies formed by T . sp. RQ7 cells. (a) Embedded growth. Cells were mixed with hot SVO medium containing 0.3% Gelrite and were poured to Petri dishes before solidification. (b) Surface growth. Cells were spread evenly on the surface of freshly-made SVO plates containing 0.3% Gelrite and 0.7% agar. The number on each plate indicates the dilution factor of each culture.