Scientific African (Jul 2023)
Impact of substrate methionine content on lovastatin potentiation and morphological parameters of Pleurotus ostreatus
Abstract
In developing countries, most of which are characterized by limited financial resources, the demand for protein-rich food is more important. The population can rely on non-timber forest products such as mushrooms to meet this demand. They are considered as foods with several medicinal properties, including cholesterol-lowering activities due to their lovastatin content. However, it has been shown that the different substrates used in mushroom culture impact on its functional properties. Methionine has been demonstrated to be a good precursor of lovastatin but yet, this hypothesis has not been taken into account in solid substrate Pleurotus growth. Thus, based on their methionine content, agricultural wastes available locally were selected for the cultivation of Pleurotus ostreatus (P. ostreatus) to evaluate their effect on the morphological parameters and lovastatin concentration. For this purpose, maize cobs (Mc), rice hulls (Rh), and the mixture of both (McRh) (ratio 1:1 w/w) were used in a total randomized experiment as growth substrates. The spawn used was produced from maize seed (Ms), sorghum seed (Ss), and the mixture of both seed (MsSs) (ratio 1:1 w/w). No significant difference was observed between the foot lengths and cap widths of mushrooms produced on the different substrates. The highest number of stands at harvest was 2.5, while the highest number of caps counted was 19, with mushrooms growth on Mc-Ms and Mc-MsSs, respectively. The best biological efficiency; 36.5%, and the highest quantity of harvested mushrooms, 532.1 kg/bag, were obtained using McRh-MsSs as production substrate. The best lovastatin concentration obtained with mushrooms produced on Mc using spawns from Ms was 676.2 µg/g of dried mushroom. This lovastatin concentration was higher than the best raise observed in the literature using P. ostreatus fructification. These results indicate that agro-waste choice based on their methionine content is an excellent solution to potentiate lovastatin in P. ostreatus.
