Effects of Beneficial Bacterial Inoculation on Arsenic Hyperaccumulation Ability of <i>Pteris vittata</i> under Planthouse Conditions

The widespread problem of arsenic buildup in soil is often addressed through phytoremediation techniques. <i>Pteris vittata</i>, an herbaceous fern known as the Chinese ladder brake, exhibits exceptional arsenic hyperaccumulation, storing over 27,000 mg of arsenic per kilogram in its aboveground biomass as dry weight. Planting <i>P. vittata</i> in arsenic-contaminated areas emerges as a promising strategy, facilitating the fern’s absorption and accumulation of arsenic from the soil and, consequently, mitigating environmental arsenic levels. This study was conducted to assess the impact of two bacterial strains, <i>Bacillus</i> sp. 3P20 (CCB-MBL 5013) and <i>Enterobacter</i> sp. 3U4 (CCB-MBL 5014), on arsenic hyperaccumulation by <i>P. vittata</i>. The total arsenic content in both soil and plant samples was quantified using inductively coupled plasma-optical emission spectrometry. The results showed a significant difference (P < 0.0001) between <i>P. vittata</i> inoculated with <i>Bacillus</i> sp. 3P20 and spiked with 200 and 500 mg/L arsenic, having a total arsenic content of 240 and 255.25 mg/kg, respectively, compared to the control (un-inoculated), which has 143 mg/kg. Additionally, there was a significant difference (<i>P</i> < 0.0001) between <i>P. vittata</i> inoculated with <i>Enterobacter</i> sp. 3U4 and spiked with 200 and 500 mg/L arsenic. Although no significant increase in the leaf greenness value of the plant was observed in the first and fourth weeks a noteworthy increase was recorded after the eighth week of transplanting. These indicate that the bacterial strains promoted plant growth and significantly enhanced the efficiency of arsenic hyperaccumulation by the fern.