*8.7. Type of Natural Sources*

The nature of organisms used in NP fabrication processes significantly influences the nature of the resulting NPs. Biomolecules such as pigments, proteins, polysaccharides, etc. vary between different organisms and in strains of the same species, and this leads to variations in an organism's potentiality to produce NPs [30]. Recently, Ag-NPs were produced using three different strains (*Nostoc* sp. Bahar M [58], *Nostoc* HKAR-2,98 [181], and *Nostoc muscorum* NCCU-442,56 [60]). These strains produced Ag-NPs with a range of different sizes including 8.5–26.44 mm, 51–100 mm, and 42 nm, respectively.
