Taggar, Monica SachdevaDalveer Kaur2017-08-212017-08-212016http://krishikosh.egranth.ac.in/handle/1/5810029177Five microalgae designated as MA-1, MA-2, MA-3, MA-4 and MA-5 were isolated from the waterlogged areas of district Muktsar to identify the most potent strain(s) for biofuel production. On the basis of morphological characterization, these microalgal isolates were found to be round, green coloured and unicellular in structure and were tentatively identified as Chlorella. The studies on the effect of salt concentrations, viz. 0.03, 0.05, 0.1, 0.2 and 0.3 M NaCl on the growth of microalgal isolates and C. sorokiniana (standard) revealed that the growth and viable cell count of all the isolates decreased with an increase in salt concentrations. The isolate MA-1 showed maximum growth (A600nm) and viable cell count of 3.26 and 175.2×105 cfu ml-1 at 0.03 M salt concentration. The mean total carbohydrate and lipid content of all microalgal isolates increased up to 0.1 M salt concentration and declined thereafter. The maximum total carbohydrate and lipid content of 20.34 and 18.41 per cent at 5th and 7th day after culturing was observed in isolate MA-1 at 0.1 M NaCl concentration, respectively. The total soluble protein and total chlorophyll content in all the microalgal isolates decreased with an increase in salt concentrations. In isolate MA-1, the maximum total soluble protein content of 10.22 per cent was observed at 0.03 M salt concentration and 7 DAC, while the maximum total chlorophyll content of 21.06 mg g-1 dw was observed at 0.03 M salt concentration and 5 DAC. Hence, higher accumulation of total carbohydrate and lipid content in isolate MA-1 under salt stress suggests that this isolate can be potentially used for biofuel production.ennullThesis