Acidithiobacillus thiooxidans
Acidithiobacillus thiooxidans , formerly known as "Thiobacillus thiooxidans" until its reclassification into the newly designated genus "Acidithiobacillus" of the Acidithiobacillia subclass of Proteobacteria , is a Gram-negative , rod-shaped bacterium that uses sulfur as its primary energy source . 
<triplet> Acidithiobacillus <subj> Acidithiobacillus thiooxidans <obj> taxonomic type <subj> Gram-negative <obj> Gram staining <triplet> Proteobacteria <subj> Gram-negative <obj> Gram staining