Several streptococci, such as Streptococcus equisimilis, Streptococcus pyogenes and Streptococcus equi, have HA synthase and produce HA (6–8). Industrial HA production has been achieved using S. equi subsp. zooepidemicus (9, 10).
However, these strains, categorized as Lancefield groups A and C are pathogenic (11, 12).
Recently, a recombinant strain of Bacillus subtilis has been reported to produce HA on a laboratory scale (13).
In Japan, useful recombinant strains are difficult to use for commercial HA production for food and cosmetics, owing to the regulations and the lack of consensus in society.