Is it possible for ecosystems to exist without plant organisms?

There are misconceptions that any ecosystem cannot exist without plants. Actually this is not true. Indeed, animals cannot exist without plants. But bacteria and viruses can exist without vegetation. They produce food themselves, thanks to their body structure. There may also be mushrooms in this system. Mushrooms do not belong to plants, as they are a separate animal kingdom. In this system, there may be some insects that do not need plants, but feed on fungi. Such systems have been repeatedly created in laboratory conditions.