Lourens G. M. Baas Becking (1895-1963). Inspirator for many (micro)biologists.

having been the habitat of three outstanding founders of modern microbiology: Anthony van Leeuwenhoek in the 16th century, Martinus W. Beijerinck at the end of the 19th century and later in this century his successor in the chair of microbiology Albert J. Kluyver. Lourens G. M. Baas Becking might have become a fourth name in this honourable series had he continued his studies at the technical university in Delft. But early in his career he switched to biology at the University of Utrecht, where he became an assistant professor at the Plant Physiology Department, under the famous plant physiologist F. A. F. C. Went. Becking’s scientific interest was heavily influenced and inspired by the great microbiologists from Delft, especially by the work of Bejerinck. It was Beijerinck’s application of the use of selective nutrient media which became the base for Baas Becking’s general view of the role of bacteria in the cycle of nutrients in the biosphere and the interactions between life and earth. Long before Lovelock’s Gaia hypothesis, Becking introduced the concept of Gaia for these mutual interactions in his inaugural address “Gaia or Life and Earth” as professor of general botany at the University of Leiden in 1931 [2]. Lourens Baas Becking was born in Deventer on January 4th, 1895. After his final examination in biology in Utrecht he moved to the USA, where he worked at the laboratory of the renowned geneticist T. H. Morgan. His thesis after his return to Utrecht, “Radiation and Vital Phenomena”, was based mainly on work done in the USA. In 1923 he was appointed professor at Stanford University in Palo Alto, California, USA, where he taught economic botany and plant physiology. There he became fascinated with life under extreme environmental conditions, like those in salt-lakes, and soon his main interest turned to the interactions between living organisms and their environment. His appointment as director of the Jacques Loeb Marine Laboratory in Pacific Grove gave him the best opportunity for research in this field. In 1930 an appointment as professor of general botany at the University of Leiden brought him back to the Netherlands. His arrival in Leiden must have been perceived as a thunder-storm in the still conventional atmosphere of 69