title: Magnetic immobilization of Bacillus subtilis natto cells for menaquinone-7 fermentation.
abstract: Production of menaquinone-7 (MK-7) by Bacillus subtilis natto is associated with major drawbacks. To address the current challenges in MK-7 fermentation, studying the effect of magnetic nanoparticles on the bacterial cells can open up a new domain for intensified bioprocesses. This article introduces the new concept of application of iron oxide nanoparticles (IONs) as a pioneer tool for MK-7 process intensification. In this order, IONs with the average size of 11 nm were successfully fabricated and characterized for possible in situ removal of target substances from the fermentation media. The prepared particles were used for decoration and immobilization of B. subtilis natto cells. Presence of iron oxide nanoparticles significantly enhanced the MK-7 specific yield (15 %) as compared to the control samples. In addition, fabricated IONs showed a promising ability for in situ recovery of bacterial cells from the fermentation media with more than 95 % capture efficiency. Based on the results, IONs can be implemented successfully as a novel tool for MK-7 production. This study provides a considerable interest for industrial application of magnetic nanoparticles and their future role in designing an intensified biological process.
authors.affiliation: Department of Medical Biotechnology, School of Medicine and Noncommunicable Diseases Research Center, Fasa University of Medical Sciences, Fasa, Iran.|School of Engineering, Faculty of Science and Engineering, The University of Waikato, Hamilton, New Zealand.
authors.forename: Alireza
authors.initials: A
authors.lastname: Ebrahiminezhad
authors.affiliation: School of Engineering, Faculty of Science and Engineering, The University of Waikato, Hamilton, New Zealand.
authors.forename: Vikas
authors.initials: V
authors.lastname: Varma
authors.affiliation: School of Engineering, Faculty of Science and Engineering, The University of Waikato, Hamilton, New Zealand.
authors.forename: Shuyi
authors.initials: S
authors.lastname: Yang
authors.affiliation: School of Engineering, Faculty of Science and Engineering, The University of Waikato, Hamilton, New Zealand. aydin.berenjian@waikato.ac.nz.
authors.forename: Aydin
authors.initials: A
authors.lastname: Berenjian
mesh_terms: D001412:Bacillus subtilis / Q000378:metabolism*; D018914:Cells, Immobilized / Q000378:metabolism*; D005285:Fermentation; D005290:Ferric Compounds; D008280:Magnetics; D053758:Nanoparticles / Q000737:chemistry; D024482:Vitamin K 2 / Q000031:analogs & derivatives* / Q000378:metabolism
chemical_list: D005290:Ferric Compounds; D024482:Vitamin K 2; C000499:ferric oxide; C062629:menaquinone 7
keywords: Cell immobilization; Iron oxide nanoparticles; MK-7; Magnetic nanoparticles; Magnetic separation; Processes intensification