Professor Sir Howard Dalton: Distinguished microbiologist

Howard Dalton, microbiologist: born New Malden, Surrey 8 February 1944; staff, Warwick University 1973-2008, Professor, Department of Biological Sciences 1983-2008; FRS 1993; Chief Scientific Adviser, Department for Environment, Food and Rural Affairs 2002-07; Kt 2007; married 1971 Kira Rozdestvensky (one son, one daughter, two stepsons); died Leamington Spa, Warwickshire 12 January 2008.

Howard Dalton was one of the most distinguished and influential microbiologists of his generation; his pioneering work on the biology of methane oxidation brought him early international recognition.

He studied the structure, function and regulation of enzymes in bacteria responsible for consuming methane in the environment, which help to mitigate the effects of global warming by this greenhouse gas. He opened up a new area of research into methane monooxygenase and related metal-containing enzymes and was considered to be one of the best scientists worldwide in his field. Dalton was also quick to realise the potential of microbes for the production of chemicals on an industrial scale using biotransformation, which yielded many seminal publications in a career generating more than 250 scientific papers. He was highly respected and popular, and discussing science with him was always immensely rewarding.

Dalton was born in New Malden, Surrey, the son of a lorry driver. He was highly intelligent, with an enquiring mind, and his early interest in science was evident from his many exploits with cocktails of chemicals, which often had explosive consequences. Having survived these early "laboratory" experiments, Dalton was eager to learn more and his mother was extremely proud of him passing the 11-plus and attending Raynes Park Grammar School. After school, Dalton was awarded a place at Queen Elizabeth College, London University, and graduated in 1965 with a BSc in Microbiology.

His research career started when he undertook a DPhil with Professor John Postgate FRS at the ARC Unit of Nitrogen Fixation, Sussex University, where he worked on nitrogen fixation in the soil bacterium Azotobacter. Dalton then worked for two years as a postdoctoral fellow with Professor Len Mortensen at Purdue University, Indiana, on the biochemistry of nitrogenase in the anaerobic bacterium Clostridium. It was in the United States that he met his future wife, Kira Rozdestvensky.

Recognising that physico-chemical spectroscopy techniques were going to be of great importance in studying metal-containing enzymes, he returned to Sussex University in 1970 to work with Professor Bob Bray on molybdenum enzymes. Dalton married Kira the following year and they settled in the village of Radford Semele near Leamington Spa when Professor Roger Whittenbury persuaded Dalton to take up a lectureship in Microbiology at the Department of Biological Sciences, Warwick University in 1973. It proved to be the start of a long and illustrious tenure there.

Dalton built up a large research group at Warwick and was awarded a Personal Chair in 1983. His groundbreaking work on enzymes involved in bacterial oxidation of methane, methane monooxygenases, brought him a much-deserved international reputation and opened up a whole new research field in microbiology. He also made extremely important contributions to research into the use of microbes to produce chemicals, which stimulated his great interest in biofuels. He was a down-to-earth, self-effacing man, outgoing and extremely generous of his time with well over 100 PhD students and postdoctoral researchers. Above all else, he made science fun and was an inspirational mentor and a much-loved colleague. His penetrating questions and insightful comments always made for lively and stimulating debate.

As his scientific career flourished, he received many accolades, including election as a Fellow of the Royal Society in 1993, appointment as President of the Society for General Micro-biology, 1997-2000, the award of the Leeuwenhoek Medal Lecture at the Royal Society in 2000 and a knighthood in the New Year's Honours list in 2007. He was Chair of Biological Sciences at Warwick, 1999-2002. His enthusiasm and knowledge of Japanese gardens resulted in the creation of two such gardens at the university.

In 2002, Dalton was seconded to become Chief Scientific Adviser to Defra, a role in which he sought to instil scientific rigour into policy making. He led the scientific advisory team generating the UK contingency plan for dealing with avian influenza virus and was instrumental in raising the profile of climate change as a significant threat, delivering lectures on this and other topics such as biofuels and GM crops.

Dalton was a great communicator and wrote an immensely entertaining and popular blog describing his two-week visit to the British Antarctic Survey in 2006 where he observed at first-hand the effects of global warming on icefields in Antarctica. Throughout his time at Defra, Dalton maintained strong links with the university, returning each Friday to look after his research group. He returned full time to Warwick in October last year and had recently delivered lectures on science policy to final-year undergraduates with his usual passion and engaging style.

Dalton had an immense zest for science and life in general and was a fine sportsman in every sense of the word. In his early days at Warwick he was a regular in the Rowington Village cricket side; a fiery fast bowler and very useful left-handed batsman. He was a lifelong Spurs supporter and a highly competitive member of the Biological Sciences football team, aptly named "Biohazard". Another great passion of his was Real Tennis and he was a member of Leamington Real Tennis Club where his competitive spirit and ability won him many tournaments. It was here, while playing in a friendly doubles tournament, that he collapsed and died.

He had just returned from a month in The Gambia assisting his wife Kira in her extensive humanitarian work, setting up new schools and medical centres. He was also lending his considerable expertise to the Gambian government on a number of important environmental issues.

Colin Murrell