Considering the increasing use of cement base materials in mining and construction projects and the weakness of these materials against bending, the development of cementitious materials resistant to cracking and crack expansion seems necessary. Also, the repair or replacement of these materials is generally associated with environmental hazards, which is why the development of cement-based base materials is becoming more and more complex. The use of nano-fibers as a reinforcing agent in concrete and its positive effect on concrete strength is one of the most attractive subjects of research in recent years. With the increasing use of cement base materials, this study attempts to examine the effect of this biological agent on the improvement of physical and mechanical properties of cement mortar. Therefore, in order to achieve the objectives of this study, the effect of Gluconacetobacter Xylinus bacteria as a cellulosic nano-fiber producing microorganism on physical properties and surface restoration of polypropylene fibers was investigated. For this purpose, the products of this bacterium were used in the manufacture of cement mortar and polypropylene fiber surface restoration, and its effect on flexural strength, compressive strength and porosity of the samples was evaluated. The results of the flexural strength test indicated that the flexural strength increased after 28 days, up to 104% compared to the control and 22% increase in compressive strength in the samples containing cellulose nanofibers. The effect of nanopowder on mechanical properties of samples is far more than that of nanogel, which can be attributed to the proper dispersion of fibers between the matrix of the mortar. Comparison of the effect of Bacterial nanocellulose on the improvement of polypropylene fibers surface showed an increase of 56% in flexural strength and a 14% increase in compressive strength compared to simples containing polypropylene fibers. The use of fiber coated by Bacterial nanocellulose in the production of samples reduced water absorption and porosity of these samples compared to control samples, which could increase the durability of cement mortar against invasive materials.