Development of Black Oyster Mushroom Production Technology on Rice Straw Substrate Supplemented with Selenium for Enhanced Nutritional Value and Yield

Abstract

Black Oyster Mushroom is a high-nutritional vegetable with increasing market demand, but cultivation using pure rice straw may not yield optimal production and quality. This research aimed to develop Black Oyster Mushroom (Pleurotus ostreatus) production technology using rice straw as the main substrate supplemented with Selenium (Se) at various levels to study effects on growth, yield, and Se accumulation in mushroom biomass to become health-enhancing mushrooms. The experiment was designed using a Completely Randomized Design (CRD) with 6 treatments: Selenium levels of 0, 1.5, 3, 5, 10, and 15 parts per million (ppm) with 3 replications per treatment over a 3-month period. Substrates were sterilized at 121°C and inoculated with 10% spawn rate. Results showed that rice straw substrate supplemented with Selenium at 3 and 5 ppm yielded the best results for mycelial growth rate, fresh yield, and fruiting body quality, with higher Biological Efficiency compared to the control group significantly. Specifically, yield increased by approximately 20% compared to untreated straw. Selenium supplementation above 10 ppm was found to inhibit growth and reduce mushroom quality due to toxicity. Additionally, Selenium accumulation in mushroom biomass ranged from 140-930 µg/kg (dry weight), increasing with supplementation levels, meeting dietary requirements. In conclusion, Selenium supplementation technology at 3-5 ppm in rice straw can be effectively used to enhance nutritional value and increase Black Oyster Mushroom yield safely for consumers, offering a new option for mushroom farming development in Laos and addressing protein deficiency issues.