**2. Results**

In this study, wastes from the shrimp species Parapenaeus longirostris were processed to obtain four substances: (i) "Water-extract", (ii) "EtOAc-extract", (iii) "MetOH-extract" and (iv) "Nitric-extract". All these extracts were analyzed, to determine their composition in metabolites and phenolic compounds, by HPLC-ESI-MS/TOF. Then, the antifungal activity of the "dry-powder", "EtOAc-extract", "MetOH-extract" and "Nitric-extract" was preliminarily tested *in vitro* by an agar diffusion test toward several fungal and oomycete pathogens. "Dry-powder", "EtOAc-extract" and "MetOH-extract" did not demonstrate any inhibitory effect in the mycelial growth of all pathogens under study (data not shown); therefore, they were not further tested. "Nitric-extract" was the only extract that negatively affected the mycelial growth of all pathogens; the diameter of the inhibition halos consequently observed at each concentration was, therefore, recorded at the end of the incubation period (see Figure 1a–o). The most effective substance resulting from the *in vitro* test was further investigated to determine its efficiency in terms of minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC). The *in vivo* effectiveness of the selected substance in the control of post-harvest infections of fruits by *Penicillium* spp. was finally tested.

**Figure 1.** Agar diffusion test. Inhibition halos determined by the Nitric-extract at different concentrations (0, 25, 50, 75, 100%), after 3 days of incubation at 25 ◦C on PDA: (**a**) *Penicillium digitatum* P1PP0; (**b**) *P. commune* CECT 20767; (**c**) *P. expansum* CECT 2278; (**d**) *P. italicum* CECT 20909; (**e**) *Colletotrichum acutatum* UW14; (**f**) *C. karsti* CAM; (**g**) *C. gloeosporioides* C2; (**h**) *Fusarium proliferatum* CBS 145950; (**i**) *F. sacchari* CBS 145949; (**j**) *Alternaria arborescens* 803; (**k**) *A. alternata* 646; (**l**) *Plenodomus tracheiphilus* Pt2. Inhibition halos at different concentrations after 15 days of incubation at 25 ◦C on PDA: (**m**) *Phytophthora nicotianae* T2.C-M1A; (**n**) *Ph. nicotianae* T3-B-K1A; (**o**) *Ph. citrophthora* Ax1Ar.
