How Probiotics Work in Waste Water Treatment

Lactic Acid Bacteria

Lactic acid bacteria produce various antimicrobial substances including hydrogen peroxide, organic acids (lactic acid, acetic acid), diacetyl, acetyldehyde, D-isomers of amino acids, bacteriocins and reuterin. Lactic acid bacteria have been successfully shown to control many human pathogens including Salmonella spp., Listeria monocytogenes, Listeria innocua, Escherichia coli, Streptococcus faecium, Staphylococcus aureus, Pseudomonas aeruginosa, Proteus mirabilis, Bacillus cereus, Klebsiela pneumonia, Streptococcus pneumonia, Giardia intestinalis and Giardia lamblia.

LAB’s commonly produce hydrogen peroxide. Hydrogen peroxide in the presence of UV light forms the hydroxyl radical, which has a very high oxidation potential. Hydroxyl radicals have the ability to degrade phenols, carbohydrates and other persistent organic compounds in wastewater treatment. This oxidation process by hydrogen peroxide and UV light is best at low pH. Hydrogen peroxide also oxidizes odour compounds such as hydrogen sulphide, mercaptans and amines. The addition of LAB to wastewater will significantly reduce the organic load and pH levels. Highly un-buffered organic acids produced by LAB are the cause of the lower pH so it will be neutralized quickly under aerobic conditions and the need to add lime is unnecessary.

LAB produce short chain fatty acids as food for PNSB thereby stimulating their activity.


Yeast have been successfully used in the treatment of high salinity, high organic load, carbohydrate rich, soyabean processing and oil-containing wastewater resulted in a COD removal rates of up to 96.9%. The use of yeasts for membrane water treatment also results in less membrane clogging.

Purple Non Sulphur Bacteria

PNSB have been isolated from the surface water of ditches, flooded rice paddy fields, tidal pools, activated sludge, food waste industrial wastewater activated sludge, photosynthetic sludge, poultry slaughterhouse wastewater, microbial mats used for the bioremediation of heavy metals and organic chemical pollutants, swine wastewater ponds and colored microbial mats found in swine wastewater ditches.

The optimum growth conditions for PNSB are high strength organic rich wastewater, the presence of short chain fatty acids, reductive environments, minimum dissolved oxygen levels, natural light and an even food to microbe mass ratio. The stirring of wastewater is essential to stimulate PNSB activity.

PNSB are stimulated by co-culture with acidogenic lactic acid bacteria and yeast and the addition of fermented fruit or vegetable wastes, which is a source of short chain fatty acids.

In wastewater treatment PNSB
1. Reduce COD’s/BOD’s
2. Remove phosphates and heavy metals through bioaccumulation/biosorption,
3. Remove nitrogen through de-nitrification
4. Control odours by reducing the amount of volatile organic compounds and H2S
5. Reduce methane emissions.

PNSB have been shown to be successful in the treatment of carbohydrate rich wastewater, soya processing wastewater, sewerage wastewater, dairy wastewater, swine wastewater, abattoir wastewater, fish processing wastewater, cooking oil wastewater, olive oil wastewater, brewery wastewater, pharmaceutical/high organic load wastewater, latex processing wastewater and tannery wastewater.

Since PNSB do not readily flocculate the more they are present in a wastewater treatment plant the lower the sludge content and accumulation over time. Due to the lower oxygen requirement and reduced sludge accumulation, aeration and sludge disposal costs are drastically reduced per liter of wastewater treated. With the addition of membrane technology the PNSB can be captured and beneficiated as high value single celled protein for animal feed, used as an agricultural bio fertilizer, a source of carotenoids or a source of poly-Bhydroxybutyrate for bioplastic production.

sanit and sanit seed create a healthy environment by populating the area with beneficial microorganisms so they dominate toxic, disease-causing organisms. Produced through a natural fermentation process, it promotes the growth of naturally occurring beneficial microbes. When applied consistently and following the proper usage guidelines, this powerful probiotic concentrate will help improve water quality parameters.