Using cascading bloom filters to improve the memory usage for de brujin graphs

Abstract. De Brujin graphs are widely used in bioinformatics for pro-cessing next-generation sequencing (NGS) data. Due to the very large size of NGS datasets, it is essential to represent de Bruijn graphs compactly, and several approaches to this problem have been proposed recently. In this work, we show how to reduce the memory required by the algorithm of Chikhi and Rizk (WABI, 2012) that represents de Brujin graphs using Bloom filters. Our method requires 30 % to 40 % less memory with re-spect to their method, with insignificant impact to construction time. At the same time, our experiments showed a better query time compared to their method. This is, to our knowledge, the best practical representation for de Bruijn graphs.