When I was a graduate student at the University of Tokyo, Japan, I read a paper titled ‘Dynamics of adaptation and diversification: a 10,000-generation experiment with bacterial populations’. This paper was published in PNAS by R. E. Lenski’s group in 1994. At that time, I was studying the genetics and biochemistry of the ribosomal RNA, and I did not know even the name of R. E. Lenski. It was lucky for me that I could accidentally meet with this paper. They reported there that they divided a clonal ancestor of E. coli B into 12 independent lineages on the first day, serially-transferred them into fresh medium every day for 1500 days, and observed changing phenotypes. As they used glucose-limited minimal medium (0.025g/l) for this experiment, bacteria were forced to starve constantly, but the moment just after they transferred was much better than when they had completely exhausted poor nutrition 24 hours later. Such condition must have been a ‘new’ environment for these strains, because laboratory strains of E. coli usually maintained in richer medium.
I inoculated full-growth culture of E. coli strain W3110 into fresh medium in this morning, and they are now growing very well. As seen in the monitor, I inoculated to flasks no. 1 and 3. Flask no. 2 is a blank.