2.2. Growth evaluation
Growth of all the three species was monitored both in the presence and absence of BG 11 media for the total period of 27 days. Growth of the species was evaluated based on two parameters: (i) chlorophyll a content and (ii) dry cell weight.
(i)
Chlorophyll a content: Chlorophyll a was extracted and estimated using the procedure used by Chinnaswamy et al. [26]. For this, a known volume of algae biomass was suspended in the medium and centrifuged at 8000 rpm for 10 min. Biomass collected after centrifugation was again suspended in a known volume of methanol. This methanol and algae biomass suspension was then immersed in the water bath for half an hour at 60 °C in order to extract the chlorophyll from the biomass. After the stipulated time, the chlorophyll concentration in the above suspension was spectrophotometrically determined using UV visible spectrophotometer (Systronics117). The absorbance values were then substituted in Eq. (1) used for chlorophyll estimation