Microaerophilic Bacteria

This short clip shows a mixed population of micoorganisms from an Azotobacter enrichment culture. The preparation by Yen Ha.

There is a gradient of decreasing oxygen concentration from the air bubble in the lower left toward the upper right. A dense population of microaerophilc (and aerotactic) bacteria has aggregated in a discrete band at a position in the gradient where they find their optimum oxygen level.

Notice that the ciliated protozoans are strictly confined to the aerobic zone near the air bubble. You can see several of them execute rapid 180 degree flip turns when they encounter the aerobic/anaerobic transition.

Category:

Education

Tags:

• Microaerophilic
• Bacteria