Utilization of a partially reflective fiber Bragg grating in the development of a multiwavelength Brillouin-erbium fiber laser is proposed. A ring cavity with a preamplified Brillouin pump configuration is implemented to demonstrate much better performance in comparison with the previously reported results obtained with different configurations. The combination of a $7\mathrm{km}$ long single-mode fiber and a $10\mathrm{m}$ long erbium-doped fiber ultimately yields the generation of up to twenty-one Brillouin Stokes lines. The laser configuration provides a greater tuning range of $21\mathrm{nm}$ at a Brillouin pump power of $2\mathrm{mW}$ and 980 nm pump power of $20\mathrm{mW}$ , and requires a much lower pump power to initiate lasing.