The bonds authorized by Sections 17-17-101 through 17-17-135 and the income therefrom, all trust indentures and mortgages executed as security therefor, all lease agreements made pursuant to the provisions hereof, and all projects, when owned by the municipality, and the revenues derived from any agreement with respect thereto shall be exempt from all taxation by the state of Mississippi, and by any political subdivision thereof, except for inheritance, estate or transfer taxes and except further the contractors tax levied by Section 27-65-21.