Determination of the Effects of Combined use of Paenibacillus sp. S1S22 Strain and Ulva lactuca Extract on Seed Germination and Growth of Tomato Plant

Abstract

In recent years, plant growth promoting bacteria (PGPB) have been used as biofertilizers that increase agricultural productivity and plant resistance to changing environmental conditions such as drought, salinity and heat stress. One of the proposed new approaches to increase plant productivity, especially under stress conditions, is using algae extracts, which usually consist of naturally occurring bioactive compounds. Paenibacillus sp. S1S22 isolated from sediment was tested for its performance in indole acetic acid production (IAA), nitrogen (N) fixation, phosphate solubilization, proteolytic activity, and cellulose activity. Its antimicrobial activity was also determined against different pathogens of Paenibacillus sp. S1S22. Tomato seeds were incubated with the S1S22 strain, and the S1S22 strain supplemented with U. lactuca. The seeds incubated with deionized water were used as control. As a result, we demonstrated that the addition of U. lactuca extract to tomato seedlings incubated with Paenibacillus sp. S1S22 strain increased the root and stem length compared to the control. The results indicate that macroalgae in combination with PGPR may be a much more effective way of promoting plant growth.