What is the name of the bacteria present in curd ?Is it living or non-living?if the curd is kept outside the fridge for 20-30 days will the bacteria turn harmful or not?

Lactobacillus is a bacterium which is present in the curd. It forms lactic acid which results in the formation of curd from milk. It is living bacteria. If the curd is kept outside the fridge for 20-30 days, the number of bacteria will increase which will in turn spoil the curd but the bacteria in itself is not harmful.