Aim:  To analyse the growth of Bacillus anthracis during simulations of the UK anthrax vaccine manufacturing process. Methods and Results:  Simulated vaccine production runs were performed using the toxigenic, acapsulate Sterne 34F2 strain of B. anthracis in semi‐defined medium. After rising during the logarithmic growth phase, the pH of the culture starts to fall at about 18 h from pH 8·7 to reach <7·6 at 26 h, coincident with consumption of glucose and optimal production of protective antigen (PA; 7·89 g ml−1, SD 1·0) and lethal factor (LF; 1·85 g ml−1, SD 0·29). No increased breakdown of toxin antigens was seen over the 26–32 h period. When glucose was exhausted, amino acids (principally serine) were utilized as an alternative carbon source. Sporulation was not observed during the 32 h. Conclusions:  PA and LF, the principal constituents in the UK anthrax vaccine, undergo little degradation during vaccine fermentation. The vaccine manufacturing process is robust and reproducible. Significance and Impact of the Study:  This is the first detailed analysis of the manufacturing process used for the UK acellular anthrax vaccine; insight gained into the process will support continued and safe vaccine manufacture.

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Research at pilot-scale was undertaken into autothermal aerobic digestion of sludge using oxygen to demonstrate that sufficiently high temperatures can be achieved to ensure the degree of disinfection that would satisfy the health authorities. The ova of the helminth Ascaris lumbricoides were used in the disinfection studies and the dissolved oxygen level in the sludge was used as a means of controlling oxygen consumption. The results achieved indicate that the system very rapidly attained a stable temperature which could be easily maintained and which effectively ensured disinfection of the sludge at the 2 and 4 day retention periods tested, that the treated sludge readily ferments anaerobically, that the sludge will not readily settle and is very difficult to dewater.

The City of Durban has two submarine outfall sewers designed for the disposal of approximately 365 000 m3/d of domestic and industrial effluents. Until recently these outfall sewers were only permitted to discharge settled effluents, the resultant sludge having to be treated and disposed of on land in the one instance and incinerated in the other. As the result of a two year programme of research the city has been permitted to discharge settled effluent from both outfalls to which the underflow from the sedimentation basins has been reintroduced. Retention of the sedimentation basins has permitted effective removal of floatable material. The pipelines were operated during the research period by discharging only settled effluent from the one whilst from the other the discharge consisted of the settled effluent stream to which the sludge had been reintroduced. Halfway through the programme the roles of the two pipelines were reversed. This paper briefly reviews marine disposal in South Africa, the Durban submarine outfalls, the events which preceded the research project, the design of the research programme and the results of the study in terms of bacteriological, biological and chemical monitoring, current measurements in the immediate vicinity of the pipelines and dilution calculations with the aid of more rigorous mathematical treatment.

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