The fate of glycerol trinitrate when exposed to microbial attack has been investigated. Contrary to some earlier reports, this compound was readily biodegraded by employing batch or continuous techniques under a variety of cultural conditions. Breakdown of glycerol trinitrate took place stepwise via the dinitrate and mononitrate isomers, with each succeeding step proceeding at a slower rate. After a residence time of 8 to 15 h, none of the glycerol nitrates could be detected in the effluent from a continuous-culture apparatus (chemostat) supplied with an influent containing 30 mg of glycerol trinitrate per liter. Glycerol trinitrate (GTN) is manufactured in large quantities for use as a component of explosives and propellants and as a pharmaceutical compound (16). Industrial wastewater from the manufacture and processing of nitroglycerine poses difficult treatment and disposal problems because GTN and incompletely nitrated byproducts comprising glycerol dinitrate (GDN) and glycerol mononitrate (GMN) isomers are relatively soluble in water. Their solubilities range from 1.8 g of GTN per liter to more than

The current Association of Official Analytical Chemists method for testing tuberculocidal activity of disinfectants has been shown to be inaccurate and to have a high degree of variability. An alternate test method is proposed which is more accurate, more precise, and quantitative. A suspension of Mycobacterium bovis BCG was exposed to a variety of disinfectant chemicals and a kill curve was constructed from quantitative data. Data are presented that show the discrepancy between current claims, determined by the Association of Official Analytical Chemists method, of selected commercially available products and claims generated by the proposed method. The effects of different recovery media were examined. The data indicated that Mycobacteria 7H11 and Middlebrook 7H10 agars were equal in recovery of the different chemically treated cells, with Lowenstein-Jensen agar having approximately the same recovery rate but requiring incubation for up to 3 weeks longer for countability. The kill curves generated for several different chemicals were reproducible, as indicated by the standard deviations of the slopes and intercepts of the linear regression curves.

Revision of the official test method for the determination of the tuberculocidal activity of disinfectants is being undertaken. The current procedure lacks precision and accuracy and is not quantitative. Variability associated with carriers and the lack of temperature control were evaluated in this paper. The use of porcelain versus stainless steel carriers was also evaluated. When carriers of either type were contaminated with Mycobacterium bovis BCG, the number of organisms on the carriers varied by as much as 1.0 on the loglo scale. The average number of organisms attached to each porcelain carrier was 1.10 x 105 CFU (range, 2.7 x 104 to 2.7 x 105 CFU), whereas the average number of organisms attached to each stainless steel carrier was 1.38 x 105 CFU (range, 2.9 x 104 to 4.0 x 105 CFU). The average number of cells attached to the carrier was directly

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