Selection of efficient strains is a continuous process and it should never stop to fulfill the commercialization needs. It needs to launch a massive strain selection program across the globe. Different microalgae species have been studied under various experimental designs with respect to nutrient starvation and heterotrophic conditions to evaluate their lipid contents and the lipid productivity. The Chlorella sp. has been reported to be the most suitable for such systems (Chu et al. 2009; Bhatnagar et al. 2010). Among these, C. kessleri was shown to produce a very high biomass density (2.01 g L-1) when cultivated using municipal waste water (Li et al. 2011a). Naturally, a consortium of microalgae (Chlorella spp., Micractinium spp., Actinastrum spp.) may be established when cultivated in waste water for treatment purposes. A maxi­mum lipid productivity of 24 mg L-1 day-1 has been reported (Woertz et al. 2009) in such cases. Other microalgae, for instance, Botryococcus braunii is widely distrib­uted in freshwater, brackish, and saline lakes and is capable to accumulate unsatu­rated long-chain hydrocarbons at a concentration of 15-75 % of its dry biomass (An et al. 2003; Orpez et al. 2009) but still needs optimization of growth conditions for each water source. An efficient strain of Scenedesmus sp. LX1 showed biomass yield @ 0.11 g L_1, lipid contents ranging from 31 to 33 % with a lipid productivity @8 mg L-1 day-1 in a batch culture study using secondary effluent as growth medium (Xin et al. 2009). Moreover, LX1 was shown to remove total nitrogen and phospho­rous as high as 90.4 % and nearly 100 %, respectively. When ammonium was used as the nitrogen source, LX1 reached a very high specific growth rate of 0.82 day-1 (Xin et al. 2010). Similar findings have been reported in literature (Zhou et al. 2012a, b). Chlamydomonas reinhardtii is another microalga with the potential to treat waste water along with oil production. It was cultivated in waste water collected at three different stages (influent, effluent and centrate) of a municipal waste water treatment plant. In this case, a lipid productivity of 505 mg L-1day-1 was achieved, which may be the highest lipid productivity reported for microalgae production in waste water (Kong et al. 2010). The use of olive mill waste water as media for biomass produc­tion from Scenedesmus dimorphus and Arthrospira platensis was reported to be another hopeful strategy, recently (Cicci et al. 2013).