Abstract: A composition comprising a purified collagen-like polypeptide suitable as a peptizer, said polypeptide comprising [Gly-X-Y]n repeats, wherein Gly stands for glycine, X and Y represent any amino acid and n is an integer and selected such that the length of the [Gly-X-Y]n repeat is at least 2.5 kDa and wherein the amino acid sequence of said [Gly-X-Y]n repeats comprises more than 4 different amino acids and wherein said purified polypeptide is free of helix structure.

Abstract: A composition comprising a purified collagen-like polypeptide suitable as a peptizer, said polypeptide comprising [Gly-X-Y] repeats, wherein Gly stands for glycine, X and Y represent any amino acid and n is selected such that the length of the [Gly-X-Y] repeat is at least 2.5 kDa and wherein the amino acid sequence of said polypeptide comprises more than 4 different amino acids and wherein said purified polypeptide is free of helix structure.

Abstract: A composition comprising a purified collagen-like polypeptide suitable as a peptizer, said polypeptide comprising [Gly-X-Y]n repeats, wherein Gly stands for glycine, X and Y represent any amino acid and n is an integer and selected such that the length of the [Gly-X-Y]n repeat is at least 2.5 kDa and wherein the amino acid sequence of said [Gly-X-Y]n repeats comprises more than 4 different amino acids and wherein said purified polypeptide is free of helix structure.

Abstract: A tabular silver halide emulsion wherein the tabular grains account for more than 75% of the total grain projected area said emulsion comprising silver halide grains nucleated in the presence of nucleation peptizer and thereafter grown in the presence of growth peptizer, wherein at least one of the peptizers is substantially pure collagen like material prepared by genetic engineering, said peptizer having an amino acid sequence comprising more than 4 different amino acids. A process of preparing the AgX emulsion. A process of producing recombinant collagen like polypeptide comprising expression of a collagen like polypeptide encoding nucleic acid sequence by a microorganism to a degree exceeding 0.95 grammes /liter, said recombinant collagen being free of helix structure and preferably the expression occurring in a microorganism other than E. coli or Saccharomyces cerevisiae.

Abstract: The invention provides oil-in-water emulsions comprising recombinant collagen-like polymer in an amount sufficient to act as stabiliser of the emulsion. The polymer is especially a polypeptide which is free of helix structure, has an isoelectric point at least 0.5 pH units removed from the pH of the oil-in-water emulsion. Furthermore, amphiphilic recombinant collagen-like polymers are provided for use in oil-in-water emulsions.

Abstract: A tabular silver halide emulsion wherein the tabular grains account for more than 75% of the total grain projected area said emulsion comprising silver halide grains nucleated in the presence of nucleation peptizer and thereafter grown in the presence of growth peptizer, wherein at least one of the peptizers is substantially pure collagen like material prepared by genetic engineering, said peptizer having an amino acid sequence comprising more than 4 different amino acids. A process of preparing the AgX emulsion. A process of producing recombinant collagen like polypeptide comprising expression of a collagen like polypeptide encoding nucleic acid sequence by a microorganism to a degree exceeding 0.95 grammes/liter, said recombinant collagen being free of helix structure and preferably the expression occurring in a microorganism other than E. coli or Saccharomyces cerevisiae.