Dear Mr. Reazei, inquisitive question indeed. Cyanobacteria form tiny lenses similar to the human eye to detect light and move towards its source. For more-

https://physicsworld.com/a/bacteria-act-as-tiny-lenses-to-move-towards-light/

It will move towards light if they are photo-tactic, they can move away from light if they are photo-repelling or have no effect. The explanation is given in answer above.

Thank u so much

so what about E.coli or B.subtilis ?do you have any idea about these two?

Definitely bacteria move towards light, the phenomenon is known as phototaxis. E.coli and B.subtilis are both observed to be phototactic.

thank u,indeed

.is it possible to introduce me a suitable source to read about?

Dear Mr. Reazei .

no