A new species of Desmodesmus sp. from high altitude area was discovered and its isolated, purification, amplification culture and species identification were studied

Plateau microalgae play a key role in maintaining water quality in these lakes and rivers on the Qinghai-Tibet plateau. Plateau microalgae have wide application prospects in environmental purification, biotechnology, medicine and cosmetics, food industry and renewable energy. In order to get the high biomass of microalgae that exist in nature, microalgae with the largest biomass was screened from natural water samples by filtration, preculture and plate scribing separation. Microalgae with the largest biomass was screened from natural water samples by filtering first, pre-culturing and agar plate scribing separation. Identified by 18S rRNA as Desmodesmus sp. and constructed an neighbor-joining phylogenetic tree based on 18S rRNA sequences; Further studies have been made on the light-absorbing properties of plateau Desmodesmus sp. . The characteristic absorption peak of Desmodesmus sp. on the plateau was found at 689nm in the visible region by full wavelength scanning with UV-Vis spectrophotometer. For Desmodesmus sp. which is easy to settle in the process of amplification culture. By monitoring the change trend of total nitrogen, total phosphorus, pH and electrical conductivity in algae solution system, it was determined that logarithmic phase of the growth and the best transfer time of Desmodesmus sp. were 15-20 days.