Optimization of GA3 biosynthesis by bacteria associated with the rhizosphere of sugarcane

摘要

A total of 33 bacterial isolates (Bacillus sp. 12, Pseudomonas sp. 10, Azotobacter sp. 5 and Rhizobium sp. 6) were isolated from different rhizospheric soil of sugarcane in the vicinity of Surat city, India and characterized as per standard methods. These isolates were tested for the production of gibberellic acid (GA3) in a nutrient medium. Out of all these isolates PSG8 (Pseudomonas sp.) produce more gibberellic acid as compared with the others. Optimization of various physiological conditions (incubation temperature, pH of the growth media, incubation period, and incubation condition) were carried out to achieve maximum production of gibberellic acid. The highest 290 mg/1 of gibberellic acid production was obtained in nutrient broth when the bacteria culture was incubated at 30 °C for 78 h at pH 6.5 on rotary shaker.