Tolerance Limit of the Alga Spirulina platensis to Linear Alkyl Benzene Sulphonate Polluted Wastewater

Domestic detergents carried by the urban wastewater normally accumulate in the surface water bodies in most of the Indian cities. One of the major chemical components of these detergents is linear alkyl benzene sulphonate (LAS) and its accumulation in water bodies may become toxic to aquatic flora and fauna. In the present study, the growth of a Cyanobacterium Spirulina platensis, generally used as a nutraceutical source of protein, was studied in CFTRI medium spiked with 5 levels of LAS (2, 4, 6, 8, 10 ppm). The growth of Spirulina gradually increased and became maximum at 6 ppm of LAS beyond which there was a gradual decline with the minimum growth recorded at 10ppm level. At 6 ppm level of LAS, maximum biomass yield (109.5 mg/50mL), protein (587.5 μg/mL) and nitrate reductase activity (79.2 NR μM NO₂ /hr/g FW) were observed. Maximum content of chlorophyll-a (4.324 mg/g FW) and carotenoid (0.451 mg/g FW) were observed at 4 ppm level of LAS. The results thus, showed that Spirulina platensis is able to tolerate up to 6ppm of LAS in wastewater bodies.