Fodder yeast production: A new approach for distillery vinasse treatment

By M. A. Otero Rambla, G. Saura Laria, J. A. Martínez Valdivielso, O. A. Almazán del Olmo


Biotechnology Division Cuban Institute for Research on Sugar Cane By-Products (ICIDCA)
Vía Blanca 804 & Carretera Central, Havana 11000, Cuba
Email: miguel.otero@icidca.edu.cu

Abstract


Distillery vinasse is one of the most contaminating industrial wastes and, for a full development of an ethanol industry, this problem has to be solved. The study was conducted at lab scale in a yeast factory using raw materials from industry.
Through this technology, the organic load of vinasse was reduced by 75% when the process was carried out batch wise or slightly over 60% in continuous mode. Important amounts of high quality proteins with relatively high yields (about 60 cubic metres of vinasse per tonne of yeast on a dry matter basis) can be obtained in parallel with wastewater treatment. Distillery vinasse can be utilized as the sole source of carbon in fodder yeast production. Addition of growth enhancer QZ-350 at a ratio of 1 to 3 kg/t of yeast, substitutes 1.1 tonnes of molasses.
If protein production is the main target, continuous culture is the indicated choice. However, if environmental issues prevail, batch mode is preferred since it leads to a higher depletion of organic matter (potential pollution) in the propagation medium.

Keywords : yeast, distillery vinasse, wastewaters treatment, microbial protein, bioprocess

ISSCT XXVIth CONGRESS Durban, South Africa 29th July - 2nd August 2007) http://issct.intnet.mu/ComCop2007.htm.