Ozone can remove a myriad of biological contaminants.

As ozone comes into contact with various bacteria, fungi, molds, and viruses, the ozone molecule attacks the cell wall of the organism and breaks it down in a process known as cell lysing. Once the cell wall is penetrated, the cell's cytoplasm is released and the cell becomes dormant almost instantly. There is no chance for organisms to develop an immunity to ozone and therefore chemical rotation is not necessary. In cooling water treatment, a rotation of biocides is typically used to treat scale and biological build up. With ozone treatment, no rotation is needed. 

There are many biological contaminants and organisms that ozone can reduce. This is an incomplete list because further research is underway and more is needed.

 
BACTERIA BACTERIA VIRUS FUNGUS & MOLD SPORES
Achromobacter butyri NCI-9404 Salmonella enteritidis Adenovirus (type 7a) Aspergillus candidus
Aeromonas harveyi NC-2 Salmonella typhimurium Bacteriophage (E.coli) Aspergillus flavus (yellowish-green)
Aeromonas salmonicida NC-1102 Salmonella typhosa Coxackie A9, B3, & B5 Aspergillus glaucus (bluish-green)
Bacillus anthracis Salmonella paratyphi Cryptosporidium Aspergillus niger (black)
Bacillus cereus Sarcina lutea Echovirus 1, 5, 12, &29 Aspergillus terreus, saitoi & oryzac
B. coagulans Seratia marcescens Encephalomyocarditis Botrytis allii
Bacillus globigii Shigella dysenteriae Hepatitis A Colletotrichum lagenarium
Bacillus licheniformis Shigella flexnaria GD V11 Virus Fusarium oxysporum
Bacillus megatherium sp. Shigella paradysenteriae Infectious hepatitis Grotrichum 
Bacillus paratyphosus Spirllum rubrum Influenza Mucor recomosus A & B (white-gray)
B. prodigiosus Staphylococcus albus Legionella pneumophila Mucor piriformis
Bacillus subtilis Staphylococcus aureus Polio virus (Poliomyelitus) 1, 2 & 3 Oospora lactis (white)
B. stearothermophilus Streptococcus 'C' Rotavirus Penicillium cyclopium
Clostridium botulinum Streptococcus faecalis Tobacco mosaic P. chrysogenum & citrinum
C. sporogenes Streptococcus hemolyticus Vesicular Stomatitis Penicillium digitatum (olive)
Clostridium tetoni Streptococcus lactis   Penicillium glaucum
Cryptosporidium Streptococcus salivarius FUNGAL PATHOGENS Penicillium expansum (olive)
Coliphage Streptococcus viridans Alternaria solani Penicillium egyptiacum
Corynebacterium diphthriae Torula rubra Botrytis cinerea Penicillium roqueforti (green)
Eberthella typhosa Vibrio alginolyticus & angwillarum Fusarium oxysporum Rhizopus nigricans (black)
Endamoeba histolica Vibrio clolarae Monilinia fruiticola Rhizopus stolonifer
Escherichia coli Vibrio comma Monilinia laxa  
Escherichia coli Virrio ichthyodermis NC-407 Pythium ultimum YEAST
Flavorbacterium SP A-3 V. parahaemolyticus  Phytophthora erythroseptica Baker's yeast
Leptospira canicola   Phytophthora parasitica Candia albicans-all forms
Listeria (ozone?) PROTOZOA Rhizoctonia solani Common yeast cake
Micrococcus candidus   Rhizopus stolonifera saccharomyces cerevisiae
Micrococcus caseolyticus KM-15 Nematode eggs Sclerotium rolfsii saccharomyces ellipsoideus
Micrococcus spharaeroides Chlorella vulgaris (Algae) Sclerotinia sclerotiorum saccharomyces sp
Mycobacterium leprae All Pathogenic and Non-pathogenic forms of Protozoa    
Mycobacterium tuberculosis   ALGAE  
Neisseria catarrhalis CYSTS Chlorella vulgaris  
Phytomonas tumefaciens Cryptosporidium parvum Thamnidium  
Proteus vulgaris Giardia lamblia Trichoderma viride  
Pseudomonas aeruginosa   Verticillium albo-atrum  
Pseudomonas   Verticillium dahliae  
fluorscens (biofilms)      
Pseudomonas putida      
Salmonella choleraesuis