Methods for stimulating plant growth and/or promoting plant health using free enzymes or recombinant microorganisms that overexpress enzymes are provided. Plant seeds coated with free enzymes or recombinant microorganisms that overexpress enzymes are also provided. Compositions comprising a fertilizer and an enzyme or a recombinant microorganism that overexpresses an enzyme are provided. Modified enzymes having ACC deaminase activity, recombinant microorganisms expressing the modified enzymes, plant seeds treated with the modified enzymes or recombinant microorganisms, and methods for stimulating plant growth and/or promoting plant health using the modified enzymes or recombinant microorganisms are also provided.

Methods for stimulating plant growth and/or promoting plant health using free enzymes or recombinant microorganisms that overexpress enzymes are provided. Plant seeds coated with free enzymes or recombinant microorganisms that overexpress enzymes are also provided. Compositions comprising a fertilizer and an enzyme or a recombinant microorganism that overexpresses an enzyme are provided. Modified enzymes having ACC deaminase activity, recombinant microorganisms expressing the modified enzymes, plant seeds treated with the modified enzymes or recombinant microorganisms, and methods for stimulating plant growth and/or promoting plant health using the modified enzymes or recombinant microorganisms are also provided.

Methods for stimulating plant growth and/or promoting plant health using free enzymes or recombinant microorganisms that overexpress enzymes are provided. Plant seeds coated with free enzymes or recombinant microorganisms that overexpress enzymes are also provided. Compositions comprising a fertilizer and an enzyme or a recombinant microorganism that overexpresses an enzyme are provided. Modified enzymes having ACC deaminase activity, recombinant microorganisms expressing the modified enzymes, plant seeds treated with the modified enzymes or recombinant microorganisms, and methods for stimulating plant growth and/or promoting plant health using the modified enzymes or recombinant microorganisms are also provided.

Methods for stimulating plant growth and/or promoting plant health using free enzymes or recombinant microorganisms that overexpress enzymes are provided. Plant seeds coated with free enzymes or recombinant microorganisms that overexpress enzymes are also provided. Compositions comprising a fertilizer and an enzyme or a recombinant microorganism that overexpresses an enzyme are provided. Modified enzymes having ACC deaminase activity, recombinant microorganisms expressing the modified enzymes, plant seeds treated with the modified enzymes or recombinant microorganisms, and methods for stimulating plant growth and/or promoting plant health using the modified enzymes or recombinant microorganisms are also provided.

Methods for stimulating plant growth and/or promoting plant health using free enzymes or recombinant microorganisms that overexpress enzymes are provided. Plant seeds coated with free enzymes or recombinant microorganisms that overexpress enzymes are also provided. Compositions comprising a fertilizer and an enzyme or a recombinant microorganism that overexpresses an enzyme are provided. Modified enzymes having ACC deaminase activity, recombinant microorganisms expressing the modified enzymes, plant seeds treated with the modified enzymes or recombinant microorganisms, and methods for stimulating plant growth and/or promoting plant health using the modified enzymes or recombinant microorganisms are also provided.

Methods for stimulating plant growth and/or promoting plant health using free enzymes or recombinant microorganisms that overexpress enzymes are provided. Plant seeds coated with free enzymes or recombinant microorganisms that overexpress enzymes are also provided. Compositions comprising a fertilizer and an enzyme or a recombinant microorganism that overexpresses an enzyme are provided. Modified enzymes having ACC deaminase activity, recombinant microorganisms expressing the modified enzymes, plant seeds treated with the modified enzymes or recombinant microorganisms, and methods for stimulating plant growth and/or promoting plant health using the modified enzymes or recombinant microorganisms are also provided.

Methods for stimulating plant growth and/or promoting plant health using free enzymes or recombinant microorganisms that overexpress enzymes are provided. Plant seeds coated with free enzymes or recombinant microorganisms that overexpress enzymes are also provided. Compositions comprising a fertilizer and an enzyme or a recombinant microorganism that overexpresses an enzyme are provided. Modified enzymes having ACC deaminase activity, recombinant microorganisms expressing the modified enzymes, plant seeds treated with the modified enzymes or recombinant microorganisms, and methods for stimulating plant growth and/or promoting plant health using the modified enzymes or recombinant microorganisms are also provided.

Methods for stimulating plant growth and/or promoting plant health using free enzymes or recombinant microorganisms that overexpress enzymes are provided. Plant seeds coated with free enzymes or recombinant microorganisms that overexpress enzymes are also provided. Compositions comprising a fertilizer and an enzyme or a recombinant microorganism that overexpresses an enzyme are provided. Modified enzymes having ACC deaminase activity, recombinant microorganisms expressing the modified enzymes, plant seeds treated with the modified enzymes or recombinant microorganisms, and methods for stimulating plant growth and/or promoting plant health using the modified enzymes or recombinant microorganisms are also provided.

A method for chemical processing of sewage sludge ash comprises dissolving a start material, emanating from sewage sludge ash, in an acid comprising hydrochloric acid. The start material comprising at least silicon and iron compounds. Undissolved residues are separated, whereby a leachate remains. The amount of colloidal silica in the dissolved sewage sludge ash is controlled. At least one of iron and phosphorus is extracted from the leachate by liquid-liquid extraction with an organic solvent. At least a part of a raffinate at least partly depleted in at least one of iron and phosphorus originating from the step of extracting at least one of iron and phosphorus is recirculated for dissolving the start material, emanating from sewage sludge ash. The recirculated part of the raffinate at least partly depleted in at least one of iron and phosphorus comprises chloride ions.

The present invention relates to a fertilizer composition comprising nitrogen and phosphorus, wherein nitrogen is provided by basic L-amino acid(s) complexed to polyphosphate(s). The complex may be precipitated with multivalent metal ion(s) to provide a solid phase fertilizer composition. The basic L-amino acid is advantageously L-arginine and/or L-lysine. The fertilizer composition is capable of providing controlled release of nitrogen during prolonged periods of time.