Multiple choice Which of the following is a pair of aerobic sulphur-oxidising bacteria? Chlorobium and Chromatium Achromatium and Chromatium Chromatium and Thiobacillus Achromatium and Thiobacillus Chlorobium and Thiobacillus Reveal answer Fill a bubble to check yourself D Correct answer Explanation Both are aerobic sulphur-oxidising bacteria.