Thermophilic bacteria. False colour light micrograph of the thermophilic bacteria Archaeoglobus fulgidus. This organism occurs in hot sediments near submarine hydrothermal vents, and has optimal function at an ambient temperature of 83 Celsius. Unlike other genera of thermophilic (high temperature liking) bacteria, A.fulgidus is able to reduce sulphates for anaerobic growth; the other genera all reduce elemental sulphur. A.fulgidus has been identified as a metabolic 'bridge' between the rest of the extreme thermophilic genera and the methanogenic bacteria. Magnification x10,000 at 6x4.5cm size.