Currently Marmotta uses OpenRDF Sesame 2.7.x. We could move to 2.8.x (
MARMOTTA-592) or 2.9.x ( MARMOTTA-635) with some internal changes. But it'd be more interesting to port Marmotta (core, kiwi and all modules) to the new Eclipse RDF4J 4.x.
The project has provided a detailed migration guide that would be relevant: http://docs.rdf4j.org/migration/