Before entering upon the duties of his office the commissioner shall qualify by taking and subscribing an oath as prescribed by the constitution and by executing a bond to the state in the penal sum of fifty thousand dollars ($50,000), conditioned for the faithful performance of the duties of his office, and which bond, together with said oath, shall be filed in the office of the secretary of state. If such bond be executed by a surety company, the expense thereof shall be paid out of the state lands maintenance fund.