Title : Biostimulatory effect of hydrolysate derived from sardine waste on growth enhancement of tomato (Solanum lycopersicum L) and sorghum (Sorghum bicolor (L.).
Fish by-products are generally recognized as low value resources. In order to increase their value, fish by-products need to be converted into new products with high functionality, such as fish protein hydrolysates (FPH), which have attracted enormous interest in different fields, especially in agriculture, due to their wide spectrum of bioactivities. In this study, FPHs made from sardine (Sardina pilchardus) using different temperatures and proportions of water were investigated. Hydrolysis reactions were conducted under the action of an organic acid and at different temperatures (25°C and 40°C). A control treatment (without addition of water) was applied. The hydrolysates were characterized with respect to the proximal composition of N, P and K. The germination stimulation activity of tomato and sorghum seeds of the hydrolysate was also observed. The temperatures and added water ratios of hydrolysis significantly affected the characteristics of FPH. The highest nitrogen yield, with a degree of hydrolysis of 53.05 ± 1%, was obtained at room temperature after 30 days of incubation. In addition, FPH had stimulating activity in the germination phase of tomato and sorghum seeds (95 ± 0.55%). The results suggest that FPH produced with endogenous enzymes represents a promising product for agricultural applications..
Keywords: Sardine, Fish-by product, Fish protein hydrolysate, proteins.