Isolation of bacterial strains with lipolitic activity from dairy industry waste waters.

IGNACIO SANTECCHIA; FLORENCIA FICARRA; SERGIO ALARCON; CHRISTIAN MAGNI; MARTÍN ESPARIZ

Rosario

Congreso; L Reunión Anual. Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2014

Dairy industries generate up to 10 L of wastewater per liter of processed milk causing a significant environmental problem. Since these wastewaters are rich in biodegradable organic molecules, their treatment usually involves bacteria addition. The aim of this work was to isolate bacterial strains for their use in the degradation of dairy wastewater fats. With this attempt, lipase producing strains were screened from a wastewater treatment lagoon of a local dairy industry. Exoenzyme profiles were performed for 58 isolates. Then, phylogenetic clustering of 49 strains was performed by RAPD analysis. 10 strains were evaluated for their capability to adapt to wastewater specific environmental conditions. For this, selected isolates were grown individually in sterile wastewater medium supplemented with glucose or oil as carbon source. Lipolytic activities in supernatants and bacterial growth rate (µ) were monitored. Four strains showed a µmax higher than the mean µmax in both media. Finally, 16S rRNA and/or housekeeping gene sequences of selected strains were determined. We identified strains with highest shared identity with Bacillus, Desemzia, Aeromonas, and Acinetobacter species. In summary, in this work we select strains based on their true-lipase activity against low degradability rate triglycerides and their suitable growth in wastewater media.