estimated sp. of bacteria?

The term "bacteria" was traditionally applied to all microscopic, single-celled prokaryotes. However, molecular systematics showed prokaryotic life to consist of two separate domains, originally called Eubacteria and Archaebacteria, but now called Bacteria and Archaea[104] that evolved independently from an ancient common ancestor. These two domains, along with Eukarya, are the basis of the three-domain system, which is currently the most widely used classification system in bacteriology

the total number of bacterial species is not known and cannot even be estimated with any certainty. Attempts to quantify bacterial diversity have ranged from 107 to 109 total species, but even these diverse estimates may be out by many orders of magnitude.[113][114 }

The Gram stain, developed in 1884 by Hans Christian Gram, characterises bacteria based on the structural characteristics of their cell walls. The thick layers of peptidoglycan in the "Gram-positive" cell wall stain purple, while the thin "Gram-negative" cell wall appears pink. By combining morphology and Gram-staining, most bacteria can be classified as belonging to one of four groups (Gram-positive cocci, Gram-positive bacilli, Gram-negative cocci and Gram-negative bacilli). Some organisms are best identified by stains other than the Gram stain, particularly mycobacteria or Nocardia, which show acid-fastness on Ziehl–Neelsen or similar stains. Other organisms may need to be identified by their growth in special media, or by other techniques, such as serology.

Domain: Bacteria

Phyla

Actinobacteria

Aquificae

Chlamydiae

Bacteroidetes/Chlorobi

Chloroflexi

Chrysiogenetes

Cyanobacteria

Deferribacteres

Deinococcus-Thermus

Dictyoglomi

Fibrobacteres/Acidobacteria

Firmicutes

Fusobacteria

Gemmatimonadetes

Lentisphaerae

Nitrospirae

Planctomycetes

Proteobacteria

Spirochaetes

Thermodesulfobacteria

Thermomicrobia

Thermotogae

Verrucomicrobia

I've never seen a good estimate of the number of species of bacteria present.. The most accurate statement anyone can give about the number of species of bacteria there are in any given environment is that they are at least 2 orders of magnitude larger than what would be suggested by cultivation data.