Cellulolytic characterization of the rumen-isolated Acinetobacter pittii ROBY and design of a potential controlled-release drug delivery system

Abstract

A novel cellulolytic bacterial strain, ROBY, was isolated from a bovine rumen sample using the enrichment culture method. This isolate was found to be Acinetobacter pittii, with >99 % similarity according to 16S rRNA gene sequence analysis. The potential use of this strain in combination with doxorubicin (Dox)-integrated cellulose nanoparticles (Dox-CNPs) was evaluated as a proof-of-concept study for the further development of this approach as a novel controlled-release drug delivery strategy. The isolate can utilize CNPs as the sole carbon source for growth and degrade both Dox-CNPs and empty CNPs with high efficiency. Extracellular cellulases isolated from bacteria may also be used to trigger Dox release. The results also demonstrated that the release of Dox into the environment due to nanoparticle degradation in the samples incubated with Dox-CNPs significantly affected bacterial cell viability (∼75 % decrease), proving the release of Dox due to bacterial cellulase activity and suggesting the great potential of this approach for further development.

Keywords

• Acinetobacter pittii
• Microcrystalline cellulose
• Cellulose nanoparticle
• Controlled-release drug delivery system
• Doxorubicin