Effect of Electrical Stimulation on Fruit Body Formation in Cultivating Mushrooms

Abstract

The effect of high-voltage electrical stimulation on fruit body formation in cultivating mushrooms was evaluated using a compact pulsed power generator designed and based on an inductive energy storage system. An output voltage from 50 to 130 kV with a 100 ns pulse width was used as the electrical stimulation to determine the optimum amplitude. The pulsed high voltage was applied to a sawdust-based substrate of Lyophyllum decastes and natural logs hosting Lentinula edodes, Pholiota nameko, and Naematoloma sublateritium. The experimental results showed that the fruit body formation of mushrooms increased 1.3–2.0 times in terms of the total weight. The accumulated yield of Lentinula edodes for four cultivation seasons was improved from 160 to 320 g by applying voltages of 50 or 100 kV. However, the yield was decreased from 320 to 240 g upon increasing the applied voltage from 100 to 130 kV. The yield of the other types of mushrooms showed tendencies similar to those of Lentinula edodes when voltage was applied. An optimal voltage was confirmed for efficient fruit body induction. The hypha activity was evaluated by the amount of hydrophobin release, which was mainly observed before the fruit body formation. The hydrophobin release decreased for three hours after stimulation. However, the hydrophobin release from the vegetative hyphae increased 2.3 times one day after the stimulation.

A 21st century miniguide to sporophore morphogenesis and development in Agaricomycetes and their biotechnological potential

“…A pulsed high-voltage stimulation technique has been applied as an electrical stimulation to accelerate fruiting and increase yield in woody substrates used for mushroom cultivation (Ohga et al, 2004;Takaki et al, 2009). Takaki et al (2014) applied electrical stimulation to a sawdustbased substrate of Lyophyllum decastes and natural logs, in which Lentinula edodes, Pholiota nameko, and Naematoloma sublateritium were grown, and observed fruit body induction and hydrophobin release from the vegetative hyphae (in Lentinula edodes) one day after the stimulation. It was suggested that the pulsed electric field affects the hyphae through an electrostatic force, increasing the hypha activity (Takaki et al, 2014).…”

High-Voltage Methods for Mushroom Fruit-Body Developments

“…The application of a pulsed high voltage to improve the yield in edible mushroom cultivation has also been attempted by some research groups. The fruiting capacity of shiitake mushroom (L. edodes) was remarkably promoted by applying a high voltage to cultivation bed-log (wood) [3]. This effect was also recognized in L. edodes fruiting on a mature sawdust substrate [5,6].…”

“…A scanning electron microscope observation indicated that the synthesis of crump connections was accelerated with electrical stimulation [2,5]. Some types of enzymes, including laccase and protease, were activated by the electrical stimulation [3,5,9].…”

“…After that, the high-voltage pulsed power supplies were designed to generate an output voltage from 50 to 130 kV for the electrical stimulation on mushroom cultivation bed. The promotion effects of high-voltage stimulation on sawdust-based substrate of L. decastes and natural logs hosting L. edodes, Pholiota microspora and Hypholoma lateritium were evaluated using the developed compact pulsed power generator [3]. Typical stimulation effects are shown in Figure 1 as a photograph of cultured L. edodes taken on the same day.…”

“…Time-history of the total amount of harvested fruit bodies for various stimulation voltages[3].Physical Methods for Stimulation of Plant and Mushroom Development…”