1) Acidophil 2) Bacteria 3) Bacterium 
Acidophiles or acidophilic organisms are those that thrive under highly acidic conditions (usually at pH 2.0 or below). These organisms can be found in different branches of the tree of life, including Archaea, Bacteria, and Eukaryotes. ==List of acidophilic organisms== A list of these organisms includes: ==Mechanisms of adaptation to acidic envir...[histology] An acidophile (or acidophil, or, as an adjectival form, acidophilic) describes is a term used by histologists to describe a particular staining pattern of cells and tissues when using haematoxylin and eosin stains. Specifically, the name refers to structures which `love` acid, and take it up readily. It describes the microscopic...
organism that grows best in acidic conditions.
<microbiology> Describes any microorganism that can or must live in an acidic environment (pH below 6). ... (06 May 1997) ... 
Preferring to grow on acid soils
Any organism that grows best under acidic conditions (low pH).
Preferring to grow on acid soils
acidophil, acidophile 1. An organism that grows well in a highly acid media. 2. A cell that stains readily with acidic dyes.
organism that grows optimally at a pH near 3.0