6. Pressure Osmotic pressure: The pressure exerted on bacterial cell surface as a result of difference in solute concentration between the inside and out side of a cell. Osmotolerant bacteria can grow in solutions with high solute concentration. Osmophilic bacteria grow best at high hydrostatic pressure. Hydrostatic pressure: The pressure exerted by the weight of a water column. High hydrostatic pressures more than 200 atmosphere generally inactivates enzymes and disrupts membrane transport process. Barotolerant bacteriacan grow at high hydrostatic pressure. Barophilic bacteria grow best at high hydrostatic pressure.
7. Light radiation Photosynthetic bacteria require light in the visible spectrum to carry out photosynthesis.
COMMON BIOCHEMICAL TESTS
Litmus milk reduction test: Required: Litmus milk medium Wire loop Bunsen burner Test bacteria Method: . Inoculate 0.5 ml of sterile litmus milk medium with the test bacteria. . Incubate at 35-37 Oc for up to 4 hrs.