Ethanol Production from Cheese Whey and Expired Milk by the Brown Rot Fungus <i>Neolentinus lepideus</i>

• Main Authors: Kenji Okamoto, Saki Nakagawa, Ryuichi Kanawaku, Sayo Kawamura
• Format: Article
• Language: English
• Published: MDPI AG 2019-06-01
• Series: Fermentation
• Subjects: ethanol production; lactose; cheese whey; cow’s milk; basidiomycete fungus; <i>Neolentinus lepideus</i>
• Online Access: https://www.mdpi.com/2311-5637/5/2/49

The basidiomycete brown rot fungus <i>Neolentinus lepideus</i> is capable of assimilating and fermenting lactose to ethanol with a conversion yield comparable to those of lactose-fermenting yeasts. The ability of the fungus to ferment lactose is not influenced by the addition of glucose or calcium. Therefore, <i>N. lepideus</i> may be useful in ethanol production from materials composed mainly of lactose, such as cheese whey or expired cow&#8217;s milk. Whey is a by-product of cheese manufacturing, and approximately 50% of the total worldwide production of whey is normally disposed of without being utilized. We found that <i>N. lepideus</i> produced ethanol directly from cheese whey with a yield of 0.35 g of ethanol per gram of lactose consumed, and it also fermented expired milk containing lactose, protein, and fat with a similar yield. Our findings revealed that the naturally occurring basidiomycete fungus possesses a unique ability to produce ethanol from cheese whey and expired milk. Thus, <i>N. lepideus</i> may be useful in facilitating ethanol production from dairy wastes in a cost-effective and environmentally friendly manner.