Mich. Comp. Laws § 324.50515: Pledge.

Sec. 50515.

A pledge made by the authority shall be valid and binding from the time the pledge is made. The money or property pledged and then received by the authority immediately is subject to the lien of the pledge without a physical delivery or further act. The lien of a pledge is valid and binding as against parties having claims of any kind in tort, contract, or otherwise against the authority, and is valid and binding as against the transfers of the money or property pledged, irrespective of whether parties have notice. Neither the resolution, the trust agreement, nor any other instrument by which a pledge is created need be recorded in order to establish and perfect a lien or security interest in the property so pledged.