I've inoculated desulfovibrio vulgaris culture on Brucella anaerobic agar to isolate a single colony

I'm sure that the media itself isn't contaminated.

After 2 days of inoculation, I'm seeing these white colonies but I'm not sure whether they are

vulgaris strain. Do you think this is another strain? I think my culture is majorly desulfovibrio vulgaris but contaminated minorly with some other bacteria.

+Of course, I'm incubating them in an anaerobic chamber.