Abstract

Pleurotus ostreatus (Jacq.) P. Kumm. 1871 is a widely cultivated edible mushroom known for its high nutritional and therapeutic value. However, its nutrient composition is often inconsistent due to environmental and substrate variability. This study investigated the potential of induced mutagenesis using sodium azide (NaN₃) and cobalt-60 (⁶⁰Co) gamma irradiation to enhance the nutritional properties of P. ostreatus. Spawn samples were treated with different concentrations of NaN₃ at 50, 100, 200, and 300 ppm for 30 minutes and irradiated with ⁶⁰Co at 9.4722 µGy/s for 3, 6, 12, and 24 minutes. Treated spawns were cultivated on sterilized corn cob–rice bran substrates (70:30), incubated under harmattan conditions with temperature and relative humidity of 18–38°C; and 20–58% RH respectively, and harvested after fruiting (approximately 28 days).. Proximate analyses were conducted using international standard methods to assess dry matter, crude fiber, protein, oil, ash, and carbohydrates. Significant increases were observed in crude fiber from 9.26 to 13.44 g/100 g (12 min irradiation), oil from 1.13 to 1.92 g/100 g (300 ppm NaN₃), and ash from 10.41 to 16.13 g/100 g (12 min irradiation), with p-values < 0.05, while dry matter, protein, and carbohydrate contents remained statistically unchanged. This research addresses the problem of inconsistent nutrient profiles in Pleurotus ostreatus and justifies the application of mutagenesis to achieve targeted nutritional enhancement. The findings suggest that low-dose NaN₃ and ⁶⁰Co treatments can serve as effective tools for nutrient enrichment of this edible mushroom. It is recommended that further molecular and toxicological evaluations be conducted to validate the genetic stability and safety of treated strains before commercial deployment.