(a) As additional security for the payment of an obligation issued under this chapter, the board may have executed in favor of the holders of the obligations an indenture mortgaging and encumbering:
(1) the improvements, facilities, and other property acquired with the proceeds of the sale of the obligation; or
(2) all the improvements, facilities, and other property of the authority.
(b) In the encumbrance, the board may provide for granting to any purchaser at a foreclosure sale under the encumbrance a franchise to operate the improvements, facilities, and other property for a term not to exceed 50 years after the date of the purchase, subject to the laws regulating the matter.
(c) The indenture:
(1) may contain the provisions the board considers proper; and
(2) is enforceable in the manner provided by the laws of this state for the enforcement of other mortgages and encumbrances.