Promising Strain of Acinetobacter from Soil for Utilization of Gluconic Acid Production

Abstract

Gluconic acid, a food additive, is used in many foods to control acidity or binds metals such as calcium, iron. Acinetobacter sp. WR326, newly isolated from soil possesses high phosphate solubilizing activity and do not require pyrroloquinoline quinone (PQQ) for glucose dehydrogenase (GDH) activity. In this study the gluconic acid production potential of these bacteria was investigated. Firstly, Acinobacter sp. WR326 was incubated in tricalcium phosphate medium (TCP) with varying glucose concentrations (100, 250, 500 mM), at a temperature of 30 °C for 5 days (120 hours). The highest gluconic acid yield (59%) was observed at a glucose concentration of 100 mM. Then three different levels of gluconic acid addition to the medium (50, 100, 200 mM) were tested. When Acinetobacter sp. WR326 strain was cultivated with a 100 mM glucose and 100 mM gluconic acid the yield increased to 95.27 %. In any trials 2 -keto D-gluconic acid was not detected in the medium. As a conclusion, Acinetobacter sp. WR326 may be considered novel potential bacterial strain for gluconic acid production.