Laue, H.*(1), Schumacher, U.K.(2), and Cook, A.M.(1)
(1)Dept.Microbial.Ecology, Univ. of Konstanz, Konstanz; (2)Dept.Med. Microbiol., Eberhard-Karls-Univ., Tuebingen, Germany

Bilophila wadsworthia RZATAU was isolated from the anaerobic digestor of a communal sewage works in taurine-mineral-salts medium containing formate as electron donor. Growth in pure culture depends on addition of 1,4-naphthoquinone as a supplement. Taurine is utilised as an electron acceptor with concomitant formation of ammonia, acetate and sulfide. Transamination catalysed by taurine: pyruvate aminotransferase and subsequent desulfonation yield acetate and putative sulfite, that is reduced to sulfide.

The transaminase was found to be synthesised constitutively, to be a major component of the soluble proteins, and it was purified.

We then aimed to compare strain RZATAU with clinical isolates of B. wadsworthia from different clinical conditions. All nine clinical isolates and strain RZATAU grew in one to three days in the taurine-minimal-salts medium and the products from each isolate were essentially identical. In contrast, growth of B. wadsworthia on Brucella agar or Bacteroides bile esculin agar takes four to seven days.

These results show the potential for an improvement in the cultivation of B. wadsworthia as a consequence of a better understanding of the physiological and biochemical characteristics of the bacterium. Thus there is a powerful method which enables growth of cells in suspension under defined conditions as a tool to explore e.g. the pathogenic mechanisms of the organism. The application of selective isolation of B. wadsworthia from different clinical specimens is under investigation.