Peptostreptococcus

Peptostreptococcus spp. convert Trp to Indole-3-Acrylate (IAC / IA) and IPA
Wlodarska et al. 2017 Cell Host Microbe 22: 25-37

The genus Peptostreptococcus includes gram-positive bacteria (cocci). The bacteria are primarily saccharolytic and amino acid fermenting bacteria that metabolize sugar, starch, cellulose and produce acetate, and lactate
Macfarlane et al. 1995 In Gastrointestinal and Oesophageal Pathology, 2nd ed., pp. 249-274 [R Whitehead, editor]. Edinburgh: Churchill Livingstone