TECHNOLOGY FOCUS - BIOLOGY - Preferred Components: The microbial biomass is obtained from bacteria, algae or fungi. The bacteria is selected from genera Shewanella species, Lactobacillus species, Geobacter species, Escherichia species, Pseudomonas species, Bacillus species, Lactococcus species or Magnetospirillum species.    TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Components: The obtained microbial biomass is selected from proteins, DNA, glycocalyx, glycoproteins or biopolymers.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The composition comprises at least a second component which is present with catalytic properties; and microbial biomass (1-95 wt.%).    TECHNOLOGY FOCUS - METALLURGY - Preferred Method: In the method (M1), at least a second component with catalytic properties is present during the mechanical alloying process. The mechanical alloying process involves: mechanofusion, dry impact blending, ball milling, spray drying, impaction coating and/or ultra-fine grinding, and executed in a planetary ball mill, hybridizer, pin mill, jet mill, drum mill, ultrasonic mill, electromagnetic mill, elliptical rotor mixer, pearl mill or attrition mill. Preferred Components: The component is alloyed to the surface of the at least second component. The component comprising metallic nanoparticles is selected from palladium, platinum, silver, ruthenium, nickel, zinc, gold, vanadium, cerium or copper. The second catalytic component is selected from palladium, iron, platinum, gold, aluminum oxide, ruthenium, copper, silver, silver oxide, magnesium, zinc, titanium dioxide, vanadium, cerium or nickel. The metallic nanoparticles have a size smaller than 100 nm. In the method (M1), the component comprising metallic nanoparticles and/or the second component are in dry powder form. The component comprising metallic nanoparticles is obtained by a microbial biomass reduction step. The component comprising metallic nanoparticles and the second component are dispersed in a liquid phase or slurry. EXAMPLE - No suitable example given.