@article{song_liu_wang_dai_liu_liu_zhao_wang_zheng_2014,  title={Enhanced Production of Vitamin K<sub>2</sub> from   <i>Bacillus subtilis (natto)  </i>by Mutation and Optimization of the Fermentation Medium},  volume={57},  ISSN={1516-8913},  url={https://doi.org/10.1590/S1516-8913201402126},  DOI={10.1590/S1516-8913201402126},  number={4},  journal={Brazilian Archives of Biology and Technology},  publisher={Instituto de Tecnologia do Paraná - Tecpar},  author={Song, Junying and Liu, Hongxia and Wang, Li and Dai, Jun and Liu, Yan and Liu, Hui and Zhao, Genhai and Wang, Peng and Zheng, Zhiming},  year={2014},  month={Jul},  pages={606–612} }