John Raymond Postgate (24 June 1922 – 22 October 2014), FRS[2][1] was an English microbiologist and writer, latterly Professor Emeritus of Microbiology at the University of Sussex.

[14] Postgate's research was to study sulfonamide action on a species of bacteria that required PABA from the environment as a vitamin; it gave him valuable experience of competition in enzymology.

A small microbiology group, led by K R Butlin,[15] was researching their role in iron corrosion and other civil and industrial nuisances.

They are difficult to culture and to separate from other soil bacteria in the laboratory, but Butlin's group had isolated a few pure strains.

[16] He went on to obtain biochemical evidence on how they consume sulphates and carbon sources,[17][18] but his most influential finding was cytochrome C3.,[19][20] a discovery that has been described as "seminal".

[10] Cytochromes are iron-containing proteins found in the cells of all air-breathing creatures from bacteria and plants to humans; they were known to be part of the aerobic respiratory apparatus and were widely understood to be absent from anaerobes.

However soon it became accepted and the concept emerged of "anaerobic respiration", based on reducing nitrate, carbonate or similar oxygen-containing minerals.

[22] The trip caught the attention of the press, and the microbiological production of sulphur became Butlin's pet project, with Postgate advising.

The group expanded and widened its remit to encompass the microbiological production of sulphur and the treatment of chemical effluents; it also took over the National Collection of Industrial Bacteria.

His extensive paper on the survival of starvation by klebsiella bacteria reopened a research topic largely dormant since the 1920s and introduced the concept of cryptic growth (a sort of necrophagy) in the persistence of bacterial populations in ancient isolated environments such as salt inclusions or fossils.

In 1962 he was given leave to take up a Visiting Professorship of Microbiology at the University of Illinois, in the United States, to finish off some earlier research on sulphate-reducing bacteria and undertake some teaching duties.

Its approach ranged from biochemical enzymology to microbial physiology and general microbiology, and in due course it introduced the genetics, and was genuinely collaborative, with everyone, including Postgate, working at the bench.

Outstanding papers were: a series deducing mode of action of nitrogenase, the enzyme responsible for the initial attack of nitrogen, which is an oxygen-sensitive complex of two proteins, iron and molybdenum, which requires energy in the form of Adenosine triphosphate (ATP) to function and which releases hydrogen from water while fixing nitrogen;[26] the elucidation of oxygen-screening processes in an oxygen-tolerant species of nitrogen fixer and the discovery in that microbe of a second nitrogenase containing vanadium in place of molybdenum alongside the regular one;[27] the elucidation of a cluster of some 21 genes which code for the whole nitrogen-fixing system, the creation of mobile genetic elements carrying that cluster and the transfer therewith of the ability to fix nitrogen to wholly new bacteria by genetic manipulation.

His admired popular science books Microbes and Man,[6][11] and The Outer Reaches Of Life,[33][34] were influential and widely translated.

Microbes and Man was first published by Penguin Books in 1969, and remains in print in its 4th edition (Cambridge University Press, 2000).

[4] He served on several Royal Society or Government Committees and Working Parties on diverse matters: Space Biology; the Nitrogen Cycle; Terrestrial Microbiology; Scientists' Archives; and Genetic engineering.

His recent studies of nitrogen fixation provided the first evidence for the direct involvement of metals; he has made major contributions by his purification of the nitrogenase of K. pneumoniae, by his demonstrations of oxygen exclusion mechanisms in Azotobacter, and by his recent success in transferring genes that specify nitrogen fixation from K. pneumoniae to E.

[48] Postgate was self-taught and never able to read music, but he led the Oxford University Dixieland Bandits on cornet from 1943-8, then played with Eric Conroy's Jazzmen, 1950–51, and then on irregular gigs.

He played fortnightly at Chiddingly, East Sussex for over twenty years, gaining a decent following, and also with local informal groups.