A novel strain of unicellular green algae was isolated from fresh water samples collected from Yesanpo National Geopark, Laishui County of Hebei Province, China. The morphological and genomic identification of this strain was carried out using 18 s rRNA analysis. This novel strain was identified as Desmodesmus sp. named as EJ15-2. Environmental factors for biomass production of Desmodesmus sp. EJ15-2 grown under autotrophic condition (BG11 medium) was optimized using response surface methodology (RSM). A high correlation coefficient (R-2 = 0.923, p <= 0.01) indicated the adaptability of the second-order equation matched well with the growth condition of this strain. The optimal conditions for a relatively high biomass production (up to 0.758 g/L) were at 30 degrees C, 98 mu mol/m(2)/s and 14:10 (LD), respectively. (C) 2013 Elsevier Ltd. All rights reserved.