Lemna Minor Cultivation for Biofuel Production

Abstract

Abstract In this paper we consider usage of duckweed for national economy: for lifestock feed, for bioethanol and biogas production, in medicine and for phytoremediation. Cultivation of duckweed Lemna minor in conditions of St.Petersburg was carried out in order to obtain biomass. Two cultivation variants were studied: in a natural reservoir and in an artificial reservoir during a period from May to July 2017. The following cultivation conditions were determined: lighting, temperature. The population growth intensity was estimated. The most favourable conditions appeared to be at natural pond in Petergof. Daylight features, lightning intensity of the Leningrad Oblast’ are less favourable than that for south Russian regions, so biomass production rate is drastically lower. The obtained L. minor biomass was dried out under the infrared lamp up to constant weight. The obtained dry biomass was used to produce lipids extracts by Sohxlet technique. Lipids output was 4% of dry biomass for duckweed grown in natural pond and 6% for duckweed grown in artificial pond. Most likely it is driven by stress factor of duckweed growth, which is limited by insufficient solar illumination. The lipid output of duckweed is not high, but we are planning to choose optimum cultivation conditions for duckweeds, which will result in increased lipids output.