In early 1973, I returned to Israel from a post-doctoral fellowship at Harvard University, and was accepted as a lecturer in the Department of Applied Microbiology at the Hebrew University of Jerusalem. Shortly after my return, Professor Richard Mateles, who at that time was head of the Department, suggested that I purchase a good and comprehensive book on single cell protein (SCP) in order to expand my general knowledge in the subject I had started then to work on; that was microbial utilization of one-carbon (C ) compounds. l Naturally, I took his advice (after all, he was the Boss) and bought the book, which was