Fig. 1.

Growth of M. tuberculosis biofilms.

A. M. bovis BCG or M. tuberculosis H37Rv was cultured in a Petri dish containing Sauton's medium for 5 weeks with either a standard loose-fitting lid or with a sealed parafilm covering.

B. Bottle assay for the growth of M. tuberculosis mc²7000 biofilms. Bottle caps were kept either loose or tight for 5 weeks, or tight for the first 3 weeks and loosened for the last 2 weeks, as indicated.

C. Gases present in either loosely capped or tightly capped bottles (as indicated) were examined by GC/MS. CO₂ (44 amu) accumulates in the tightly capped bottles.