High-Activity ACC Deaminase-Producing Pseudomonas: Screening and Activity Analysis

Analysis of Results

Screening and Activity Determination of ACC Deaminase-Producing Pseudomonas

Screening of High-Activity Strains with ACC Deaminase

Apple root tissue samples were collected and multiple endophytic bacteria capable of producing fluorescence were obtained through initial screening on KB medium. After qualitative enrichment using ACC as the sole nitrogen source medium, the bacteria were evenly spread on ADF solid medium and incubated at a constant temperature of 25ﾰC for 3 days. The bacteria grown on the medium were passaged and purified multiple times, resulting in the isolation of 9 strains with ACC deaminase activity, named PG-1 to PG-9.

ACC deaminase activity of the 9 strains of fluorescent endophytic bacteria was determined (Figure 1). The results showed significant differences in ACC deaminase activity among the 9 strains. The enzyme activity of the 9 strains ranged from 1.76 to 13.76 U/mg, with PG-5, PG-7, and PG-9 strains having ACC deaminase activities of 13.76 U/mg, 13.46 U/mg, and 12.67 U/mg, respectively, significantly higher than the other strains (P<0.05). The enzyme activity of all three strains exceeded 12.00 U/mg and was higher than that reported in the literature for similar strains, indicating their potential application value.