The Leeuwenhoek Lecture, 1975 Bacterial sporulation: a problem in the biochemistry and genetics of a primitive developmental system

In 1958 Keilin gave the Leeuwenhoek Lecture and in it he described fairly extensively the observations that Leeuwenhoek had made of the dormant state among micro-organisms. There would be no point in going over this material; instead it will be useful to take up the story again in 1877. This was when Robert Koch wrote a classical paper on the work he had done with the rod-shaped bacteria that were known to cause anthrax. He developed a technique for culturing these in aqueous humour and he demonstrated clearly that the spore and the vegetative cell which differ enormously in size, appearance and staining properties are, in fact, interconvertible forms of the same organism (Koch 1877). In making this observation he had discovered the most primitive of life cycles and one which was subsequently found to occur in a variety of Gram-positive bacilli. From that time onwards bacterial spores have remained of interest for medical and veterinary reasons and also in the food preservation industry and in agriculture. More recently sporulation in bacilli has been studied as a developmental system that might be susceptible to analysis in terms of modern biochemistry. A considerable amount of work has now been done and it seems an appropriate moment to stop and enquire how successful these efforts have been.