The present study focused on the influence of low pH on growth, specific biochemical parameters and antioxidants amongst Nostoc strains grown under control (pH ) and low pH (pH ) medium. Cell dry weight, chlorophyll content, total soluble proteins and extracellular ammonia release reduced due to low pH stress of growing media compared to control grown cultures. Nitrogenase activity was reduced in two and increased in remaining strains due to low pH. Proline content increased whereas glycerol decreased in all low pH tolerant Nostoc strains whereas glycine betaine and lipid peroxidation depicted a variable response. | Influence of low pH stress on growth specific biochemical parameters and antioxidants amongst selected nostoc strains