# Significant impact of Bacillus licheniformis DW4, Salinicoccus sesuvii DW5 and Paenalcaligenes suwonensis DW7, in mitigation of seawater stress on the growth and productivity of Vicia Faba cultivated in Qalabshu semi-field soil

## TL;DR

This study shows that using specific bacteria can help Vicia faba grow better in salty soil, offering a sustainable solution for agriculture in Egypt.

## Contribution

The study introduces a novel bacterial mix that significantly improves salt stress tolerance in Vicia faba, enabling higher yields with seawater irrigation.

## Key findings

- Bacterial treatments increased Vicia faba yield by 40% under maximal salt stress.
- The B mix improved antioxidant activity and root anatomy in salt-stressed plants.
- Using seawater with PGPB reduced reliance on freshwater for crop cultivation.

## Abstract

Salinity severely limits sensitive crops like Vicia faba in newly-reclaimed lands. Costly mitigation is unsustainable; Plant Growth-Promoting Bacteria (PGPB) from halophytes provide a cheap, effective, eco-friendly solution to alleviate salt stress.

To address Egypt’s food security and overpopulation challenges, this study aimed to enhance Vicia faba growth and yield in newly-reclaimed soils using PGPB. A key goal was to conserve freshwater by testing the feasibility of cultivating faba beans with saltwater and PGPB.

Single and a mixture treatment of Paenalcaligenes suwonensis DW7 OR147937.1, Salinicoccus sesuvii DW5 OR083408.1 and Bacillus licheniformis DW4 OR083404.1 were utilized in Vicia faba seeds priming in semi-field and irrigated with different concentrations of seawater. Measurements encompassed Vicia faba’s key growth metrics, the extent of nodule formation, detailed root anatomy, concentrations of photosynthetic pigments and antioxidants, evaluations of soil fertility, comprehensive yield parameters, and the total protein content found in its seeds.

Treatments P. suwonensis DW7 and B mix (B. licheniformis DW4 + S. sesuvii DW5 + P. suwonensis DW7) consistently resulted in optimal performance across growth, physiological, and yield metrics. The improved salt tolerance stemmed from enhanced antioxidant activity, proline synthesis, and significant root anatomical changes (e.g., enlarged vascular cylinders). Critically, under maximal stress (150 mM NaCl), B mix-treated plants achieved a 40% yield increase compared to control plants grown in freshwater, while failing to produce seeds under salt stress.

This study demonstrates that the treatment P. suwonensis DW7 and the B mix, significantly enhances the yield and growth of Vicia faba within salty soil. This innovation offers a promising solution for bolstering enhanced safety of food by making it possible for salt-susceptible crops to thrive but a broader range of agricultural produce in newly-reclaimed soils. Ultimately, this approach is poised to play a crucial role in mitigating Egypt’s impending agricultural crisis.

Significant impact ofBacillus licheniformis DW4, Salinicoccus sesuvii DW5 and Paenalcaligenes suwonensis DW7 isolated from Suaeda pruinosa Lange and Arthrocnemum macrostachyum (Moric.) K.koch, in mitigation of seawater stress on the growth and productivity of Vicia faba cultivated in Qalabshu semi-field soil.

The online version contains supplementary material available at 10.1186/s12870-025-08055-8.