Upon request of the governor, board of regents, board of control or other governing body of any state institution, or other person or persons authorized as aforesaid, it shall be the duty of the attorney general of the state, or when directed by the attorney general, the prosecuting attorney of the county where the land is situated, on behalf of the board of regents, board of control or other governing body, if a body corporate under the law of its creation, and in behalf of the people of the state of Michigan if such governing body is not a body corporate, of any state institution, to cause a petition to be made in the name of the people of the state of Michigan and filed in the proper court, signed by the attorney general, or prosecuting attorney of the county, and by the secretary of such governing board, if a body corporate, and if not a majority of such trustees, board of control or other governing body, or other properly authorized person, as the case may be, addressed to the court setting forth, with reasonable certainty a description of the land sought to be acquired, the names of all persons owning or having an interest therein, so far as disclosed by the records of titles of the county in which the land is situated, or can be ascertained from actual occupants; that the petition is made and presented for the purpose of acquiring the title and ownership of the land described in the petition, to and for the use of the state of Michigan, and specifying generally the purpose for which it is to be used. And the petition shall ask that all persons interested in the premises, or any part thereof, be summoned to appear and answer the petition, and show cause, if any they have, against the same. Upon filing the petition, summons shall issue in accordance with the prayer thereof, against the persons named therein, returnable on a day to be named, which shall not be less than 5 days from the issuing and test thereof, and shall be served at least 3 days before the return day, by the sheriff or other officer authorized to serve process of summons according to the rules and practice of the circuit court in other cases at law. If there are minors or persons of unsound mind interested in the premises, service may be made upon the guardian of any such person or the court may appoint a guardian ad litem for any such person, who may appear and defend for the person he represents. If there are non-resident or absent persons upon whom service cannot be obtained within the county, the court may order service upon any such person wherever he may be found, and in such manner as may be directed. The person serving any such process on such non-resident or absent person shall make proof of service by affidavit, stating the place, time, and manner of service. Or the court may order and cause notice to be given to such absent or non-resident person, by publication in such newspaper printed and published in the county as the court shall designate, and for such length of time as the court may think proper, not less than 3 weeks, once in each week; and any such service out of the county, or notice by publication, shall be as effectual for all the purposes of such proceeding and in the condemnation of the land as though the persons had been personally served within the county.