Streptococcus belongs to the phylum Firmicutes.
The Firmicutes ( Latin : firmus , strong , and cutis , skin , referring to the cell wall ) are a phylum of bacteria , most of which have Gram-positive cell wall structure . Streptococcus is a genus of coccus ( spherical ) Gram-positive bacteria belonging to the phylum Firmicutes and the order Lactobacillales ( lactic acid bacteria ) .