Task: Sentence Expansion
Input (English): Streptococcus is a genus of spherical Gram-positive bacteria belonging to the phylum Firmicutes and the lactic acid bacteria group .
Output (English): Streptococcus is a genus of gram-positive " " ( plural ) or spherical bacteria that belongs to the family Streptococcaceae , within the order Lactobacillales ( lactic acid bacteria ) , in the phylum Firmicutes .