Vitamin K Compounds in Bacteria That Are Obligate Anaerobes

Abstract
A naphthoquinone-dependent strain of Bacteroides melaninogenicus has been used in a microbiological assay to survey bacteria for compounds of the vitamin K group. Organisms known to contain vitamin K, as well as several bacteria that are obligate anaerobes, produced substances which satisfied the naphthoquinone requirement of the assay organism. Vitamin K was chemically isolated from strains of Bacteroides melaninogenicus, Bacteroides fragilis, and Veillonella alcalescens.