## 3 Description of the State of Knowledge
### Green Biosynthesis of Silver Nanoparticles with Antifungal Properties
Another study was focused on the synthesis of AgNPs using an aqueous extract of the red seaweed _Geldiella_ acerosa as a reducing agent. The antifungal activity of these nanoparticles was tested against _Humicola insolens_, _Fusarium dimerum_, _Mucor indicius_, and _Trichoderma reesei_. The antifungal assay was performed with the agar well diffusion method. The results showed higher antifungal activity against _M. indicius_ and _T. reesei_, whereas moderate activity was revealed against _F. dimerum_ and _H. insolens_, compared with the standard antifungal agent clotmazole [53]. Dried grass was also used for the synthesis of AgNPs. The antifungal effects of the synthesized AgNPs on _Fusarium solani_ and _Rhizoctonia solani_ were evaluated using the agar dilution method. The results showed that the effect of these nanoparticles was similar to that of amphoterici B and much stronger than that of fluconazole [54]. AgNPs were also successfully synthesized using an aqueous callus extract from _Gymmena sylvestre_. The synthesized AgNPs exhibited effective antifungal activity against both _C. albicans_ and non-albicans _Candida_ species [55]. Another example is nanoparticles biosynthesized using a cell-free extract of Bacillus thuringiensis MAE 6. The nanoparticles showed activity against the four most common _Aspergillus_ species, i.e., _A. niger, A. terreus, A. flavus_, and _A. fumigatus_, at concentrations of 0.5 mg/mL [56]. Silver nanoparticles were also synthesized using _A. terreus_ and tested against _A. niger_ and _C. albicans_. In this study, _A. niger_ showed the highest susceptibility to AgNPs (MIC = 0.312 \(\upmu\)g/mL), whereas _C. albicans_ showed the highest resistance (MIC = 1.25 \(\upmu\)g/mL) [57]. Another example is the AgNP synthesis using Nigrospora oryzae. These nanoparticles displayed strong antifungal activity against _Fusarium_ spp. [58]. Using an Amaramthus retroflexus extract, it was also possible to synthesize AgNPs that showed antifungal activity. The MIC\({}_{50}\) against _Macrophomina phaseolina_, _A. alternata_, and _F. oxysporum_ was 159.80, 337.09, and 328.05 \(\upmu\)g/mL, respectively. However, these types of nanoparticles turned out to be inactive against _Trichoderma harzianum_ and _Geotrichum candidium_[59]. In the study of [PERSON] et al., seven biogenic AgNPs were obtained using the fungi species _Aspergillus tubingensis_, _Aspergillus_ spp., _Bionectria ochroleuca_, Cladosporium pini-ponderosae, _Fusarium proliferation_, _Epicoccum nigrum_, and _Exerophilum rostratum_. As NPs showed antifungal activity against clinical strains of _Candidia: C. albicans_, _C. [PERSON]_, _C. glabrata_, _C. guillermodii_, _C. parapsilosis_, and _C. tropicalis_. All of the tested AgNPs were more effective than amphotericin B, which was used as the positive control in this study [60]. One recent study on antifungal activity against _C. albicans_ involved AgNPs synthesized by green synthesis using glucose as a reducing agent and incorporated into an agar matrix to form a film (AgFilm). The AgFilm showed a high antifungal activity with an inhibition zone of 19 \(\pm\) 2 mm [61]. Corn cob xylan was also used as a green reducing and stabilizing agent in the synthesis of AgNPs. Antifungal activity was demonstrated against _C. albicans_, _C. parapsilosis_, and Cryptococcus neoformans with an MIC value of 7.5 \(\upmu\)g/mL [62]. Other publications where information about the green synthesis of silver nanoparticles and their antifungal properties can be found are listed in the table below [Table 1].