John Peters (IMAGE) University of Oklahoma Caption John Peters, Ph.D., chair of the Department of Chemistry and Biochemistry, Dodge Family College of Arts and Sciences at the University of Oklahoma, and fellow researchers explore the way bacteria regulate the expression of genes related to nitrogen fixation – the conversion of nitrogen in the air into ammonia that can help plants grow. Credit Photo provided by the University of Oklahoma Usage Restrictions None License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.