On 2017 Sep 30, Misha Koksharov commented:

When using firefly luciferases as an output signal in synthetic biology circuits in bacteria, it is really beneficial to use thermostable versions because they are dramatically brighter at 37°C (and other elevated temperatures) - as exemplified on the following slide:

http://forumbgz.ru/user/upload/file593017.jpg

Though, when growing bacteria at common room temperatures (or lower) this is not that important (as can be seen above). The reason for these effects is relatively low thermostability of WT firefly luciferases (P. pyralis, L. mingrelica, etc) combined with poor efficiency of bacterial chaperones in keeping luciferase properly folded at elevated temperatures.

On 2017 Sep 30, Misha Koksharov commented:

When using firefly luciferases as an output signal in synthetic biology circuits in bacteria, it is really beneficial to use thermostable versions because they are dramatically brighter at 37°C (and other elevated temperatures) - as exemplified on the following slide:

http://forumbgz.ru/user/upload/file593017.jpg

Though, when growing bacteria at common room temperatures (or lower) this is not that important (as can be seen above). The reason for these effects is relatively low thermostability of WT firefly luciferases (P. pyralis, L. mingrelica, etc) combined with poor efficiency of bacterial chaperones in keeping luciferase properly folded at elevated temperatures.