Comparative analysis of duckweed cultivation with sewage water and SH media for production of fuel ethanol

• Published in: PloS one Vol. 9; no. 12; p. e115023
• Main Authors: Yu, Changjiang, Sun, Changjiang, Yu, Li, Zhu, Ming, Xu, Hua, Zhao, Jinshan, Ma, Yubin, Zhou, Gongke
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 17.12.2014; Public Library of Science (PLoS)
• Subjects: Amylopectin; Amylopectin - metabolism; Amylose; Amylose - metabolism; Analysis; Aquatic plants; Araceae - growth & development; Araceae - metabolism; Biodiesel fuels; Biofuels; Biology and Life Sciences; Biomass; Comparative analysis; Cultivation; Culture media; Culture Media - chemistry; Culture Techniques - methods; Duckweed; Efficiency; Energy; Engineering and Technology; Environmental pollution; Ethanol; Ethanol - metabolism; Ethanol fuels; Fermented food; Floating plants; Glucose; Growth rate; Heavy metals; Hydrolysates; Laboratories; Lemna; Lemna aequinoctialis; Lemna minor; Phosphorus; Phosphorus removal; Purification; Raw materials; Sewage; Sewage - chemistry; Starch; Starch - metabolism; Studies; Water pollution; Water purification; Water resources; Water treatment; Yeast; Yeasts
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0115023

Energy crises and environmental pollution have caused considerable concerns; duckweed is considered to be a promising new energy plant that may relieve such problems. Lemna aequinoctialis strain 6000, which has a fast growth rate and the ability to accumulate high levels of starch was grown in both Schenk & Hildebrandt medium (SH) and in sewage water (SW). The maximum growth rates reached 10.0 g DW m(-2) day(-1) and 4.3 g DW m(-2) day(-1), respectively, for the SH and SW cultures, while the starch content reached 39% (w/w) and 34% (w/w). The nitrogen and phosphorus removal rate reached 80% (SH) and 90% (SW) during cultivation, and heavy metal ions assimilation was observed. About 95% (w/w) of glucose was released from duckweed biomass hydrolysates, and then fermented by Angel yeast with ethanol yield of 0.19 g g(-1) (SH) and 0.17 g g(-1) (SW). The amylose/amylopectin ratios of the cultures changed as starch content increased, from 0.252 to 0.155 (SH) and from 0.252 to 0.174 (SW). Lemna aequinoctialis strain 6000 could be considered as valuable feedstock for bioethanol production and water resources purification.