In 2018 the United States produced over 67 million tons of paper and paperboard waste. According to the EPA, 68% of this waste got recycled, around 6% got burned to produce electricity, and roughly 26% find its way to the landfill.
To address this issue, I want to talk about a research paper that investigated the recycling of paperboard waste by producing oyster mushrooms.
The paperboard waste was cut into 5×5 cm pieces and mixed with wheat straw. For the control, the authors used 100% paperboard and 100% wheat straw.
The substrates were soaked for 24 hours in water and afterward pasteurized for 2 hours. After the drainage of the excess water, the authors added 5% calcium sulfate (dry weight) to the mix.
The substrates were then layer spawned and incubated at 23 to 25°C (°F) in the dark. To initiate the fruiting, the temperature was dropped down to 10°C (°F) for 48 hours.
The bags there then transferred into the fruiting room and maintained at 23 to 25°C (°F) and a relative humidity of 80 to 90%.
The first plot shows the number of fruiting bodies per bag for two different bag sizes. For the 30×50 cm bag, we get between 3 and 10 fruit bodies. While for the 20×25 cm bag 11 to 24. With substrate S3 the highest number of fruiting bodies.
The bag type has no influence on the cap diameter, stipe diameter, and the stipe as the authors got similar results.
But when it comes to the yield, the picture is different. Here the yield for the 30×50 cm bag ranges from 31 to 136 g, while for the 20×25 cm bag, from 17 to 73g. The highest yield could be found on the substrate S2 using the 30×50 cm bag.
But the biological efficiency is for the 20×25 cm bag higher than for the 30×50 cm bag. The highest biological efficiency could be found on substrate S2 using the 20×25 cm bag.
If we compare the two substrates more closely, we see that the yield for substrate s1, which is 100% wheat straw, is higher than for substrate s2, which is 100% paperboard.
Besides, the results indicate that there is a positive correlation with paperboard and a negative correlation with wheat straw.
Talk to you in the next video.
📝Mustafa Nadhim Owaid, Ahmed Mahali Abed, Burhan Majed Nassar. Recycling cardboard wastes to produce blue oyster mushroom Pleurotus ostreatus in Iraq. Emirates Journal of Food and Agriculture. 2015. 27(7): 537-541. doi: 10.9755/ejfa.2015.04.118.