Ecology and physiology of halophilic microorganisms - Thematic issue based on papers presented at Halophiles 2019 - 12th International Conference on Halophilic Microorganisms, Cluj-Napoca, Romania, 24-28 June, 2019.

In June 2019, the 12th International Conference on Halophilic Microorganisms - Halophiles 2019, was held in Cluj-Napoca, Romania. This thematic issue of FEMS Microbiology Letters contains papers based on lectures and posters presented at the conference. We here provide a short overview of past research on hypersaline environments in Romania and the microorganisms inhabiting them, and briefly present the papers published in this thematic issue.