Before revision:  Rev. E {\bf 83}, 042903 (2011)], a simple model for  the translation of messenger RNA  by ribosomes is provided, and the expression of translational ratio of protein is given. In this comments, varied methods to get this ratio are addressed. Depending on a different method of protein from mRNA to degradation rate \omega_p of protein, is obtained.
After revision:  Rev. E {\bf 83}, 042903 (2011)], a simple model for the translation of messenger RNA by ribosomes is presented, and an expression of the translational ratio r, defined as the ratio of translation rate \omega_{\rm tl of protein from mRNA to degradation rate \omega_p of protein, is obtained.