Preliminary Evaluation: Hydrocarbons, Cobalt, & Urea Enhance Bacteria Benefits to Plants

Abstract

Aim: Develop a method to induce PGPB to biosynthesize nitrile compounds that may act as a reliable and repeatable means to increase seed germination in plant species. Study Design: The germination experiment was conducted in a completely randomized design with two replications and 40 pots (80 seedlings) per experimental unit, following a 1x1 factorial design for each culture, treated or untreated soil and 1 germination period for both conditions. The nitrile hydratase experiment was conducted in a completely randomized design with 3 replications and 3 soil samples per experimental unit, following a 1x1 factorial design for each cultivar, induced or non-induced soil and 1 cultivation period. Place and Duration of Study: Germination work was executed at G & A Innovative Solutions, LLC, GA., April - May 2017. Nitrile Hydratase Assay work was executed at Georgia State University, Applied Environmental Microbiology Dept., Atlanta, GA. November 2010-August 2011. Methodology: Rhodococcus and Bacillus species were induced with short chained-hydrocarbons, cobalt, and urea in a triphasic system for 3 d to potentially make nitrile compounds to benefit seed germination. Increased NHase activity has been previously correlated to production of these nitrile compounds and an increased ability to affect plant development. NHase activity was measured after bacteria were suspended in soil for 6-7 d. Results: The induction method sustained and increased NHase activity by 200%, during suspension in soil. Induced Bacillus increased germination by 34%, shoot & root length by 67% & 10%. Conclusion: Enhancing biosynthesis of nitriles in PGPB may enhance bacteria ability increase seed germination rates.  Measuring NHase activity may indirectly measure efficacy of PGPB in soil. The results are preliminary and require additional studies to confirm results.