Yu Nakajima, Keiichi Kojima, Yuichiro Kashiyama, Satoko Doi, Ryosuke Nakai, Yuki Sudo, Kazuhiro Kogure and Susumu Yoshizaw. Bacterium Lacking a Known Gene for Retinal Biosynthesis Constructs Functional Rhodopsins. Microbes and Environments, 35(4). (2020)