This diploma thesis summarizes the knowledge about microalgae, their use, cultivation methods and obstacles that prevent their wider use. In the practical part of the work, a device was designed, constructed, and programmed. This device can analyze the bubbles of the tubular photobioreactor and, based on the obtained data, control its aeration. The Python programming language was used to create the program and the OpenCV library was used to analyze the photographs. The bubble detection is based on the edge detection and the subsequent refinement. The data obtained from the analysis are displayed on the device screen and the data are also stored in a csv file. The discussion lists possible improvements and lessons learned during the creation of this device.