MME collaborators and friends Prof. Wolfgang Hess (University of Freiburg, Germany) and Dr. Stephan Kl?hn (Helmholtz Centre for Environmental Research-UFZ, Germany) visited us on Sep. 22nd, 2019. During the three day's visiting, Prof. Hess shared the new progress of our joint project. He and Dr. Kl?hn gave us valuable suggestions on the experimental details of cyanobacterial biology. German guests also enjoyed a trip to our microalgae pilot plant in Laixi town.