The authority formed under this part, the property and income of the authority, whether used by it or leased to others, all bonds issued by the authority, the income from such bonds or from any other sources, the interest and other profits from such bonds enuring to and received by the holders thereof, conveyances by and to the authority, and leases, mortgages, and deeds of trust by and to the authority shall be exempt from all taxation in the state. The authority shall not be obligated to pay any fees, taxes, or costs to the Judge of Probate of Houston County in connection with its incorporation or with any amendment to its certificate of incorporation or otherwise or to any judge of probate of any county in connection with the recording by it of any document or otherwise, the authority being hereby exempted from the payment of any such fees, taxes, and costs. No license or excise tax may be imposed by any authority with respect to the privilege of engaging in any of the activities authorized by this article, provided, however, that nothing contained in this section shall be construed to exempt the property of the authority from any ad valorem taxes levied by the State of Alabama or exempt the authority from sales and use taxes levied by the state but this proviso shall only apply to such taxes levied by the state and shall not apply to such taxes levied by any county, municipality, or other political subdivision.