streptococcaceae streptococcaceae streptococcaceae are a family of gram-positive bacteria, placed within the order lactobacillales. representative genera include lactococcus, lactovum, and streptococcus. streptococcaceae scientific classification domain: bacteria phylum: bacillota class: bacilli order: lactobacillales family: streptococcaceae genera floricoccus lactococcus lactovum okadaella streptococcus