Marisia - Maros Megyei Múzeum Évkönyve 35/2. (2015)
Zoology
THE GROWTH OF HALOPHILIC MICROORGANISMS IN THE PRESENCE OF WASTE GLYCEROL AND ITS CONVERSION IN GLYCIDOL AND GLYCEROL CARBONATE Simona NEAGU1, Roxana COJOC1, Mädälin ENACHE1, Ioana GOMOIU1, George GHEMES2, Andreea GHEORGHE2, Mädälina TUDORACHE2 1 Institute of Biology Bucharest of the Romanian Academy, Spl. Independentei 296, Sect. 6, P.O. Box 56-53, RO-060031 Bucharest, e-mail: madalin.enache@ibiol.ro 2 University of Bucharest, B-dul M. Kogalniceanu, no. 36—46, RO-050107 Bucharest Abstract: Waste glycerol representing most important secondary product resulted in the biodiesel industry and rising environmental problems with storage. A lot of researches were conducted in order to transform this glycerol in value added products. In this work were identified several halophilic microorganisms which harbor capacity to convert waste glycerol to value added products, namely glycerol carbonate and glycidol. The tested glycerol was supplied from biodiesel production from rapeseed oil, sun flower oil, palm oil. All tested microbial strains showed capacity to grow on culture media supplemented with 1% waste glycerol. The biocatalytic activity of the cell-biomass and supernatant cultures were investigated in the conversion of waste glycerol to value-added products (glycerol carbonate and glycidol). GC-FID technique was used for the determination of the reaction products. The higher contents were detected in the supernatant of halotolerant strain 1—9 isolated from water sample in Balta Albä salt lake. Keywords: halophilic microorganisms, waste glycerol, salt lakes, glicidol, Balta Albä Introduction Waste glycerol is the most important by-product in the production of biodiesel from biomass. As a direct consequence, waste glycerol (unpurified) was produced in quantities which soon will exceed current market demands leading to serious environmental problems by its storage. Taking into account these considerations in the last years several researchers were conducted in order to use crude glycerol as carbon source (Sarma et al., 2013) for obtaining hydrogen (Sarma et al. 2012) or other value added products (Kumar et al., 2014). According to Global Biodiesel Market, it appears that five nations in the world, namely USA, Germany, France, Argentina and Brazil cover around 68% of total biodiesel productions (ref. 18 and 19) and the market of this product is estimated at 12.6 billion US$ in 2014 (ref 19). The effluent resulted from the production of 100 tones of biodiesel is around 10% (10 tones) and is containing methanol, oil, soap, salts and 73% glycerol (Kumar et al., 2014; Sarma et al., 2013; Maru et al., 2012, 2013; Tan et al., 2013). Several microbial strains harbor the potential to convert glycerol by fermentation to various products. Thus, Anaerobiospirillum succiniciproducens converts glycerol to succinic acid (Lee et al., 2001), Yarrowia lipolytica to citric acid (Papanikolaou and Aggelis, 2002), Clostridium butyricum to butyric acid, acetic acid and 1,3-propanediol (Papanikolaou et M A R I S I A, XXXV, p. 67-74
