Integration of Membrane Bioreactors with Edible Filamentous Fungi for Valorization of Expired Milk

Abstract

Around 29 million tons of milk end as waste yearly in Europe, representing an environmental issue but also a potential substrate for biological valorization given its nutritional value. Aspergillus oryzae and Neurospora intermedia are edible filamentous fungi with dissimilar metabolism when grown in expired milk. Neurospora intermedia is more devoted to lactose consumption; 68 and 57% of lactose was consumed after cultivation in expired milk and its liquid fraction, respectively. Aspergillus oryzae consumed less lactose in expired milk (14%), but led to better microfiltration characteristics of the final effluent due to fat and protein degradation. A two-stage fed-batch cultivation using membrane bioreactors (MBRs) was developed, bringing together both fungal metabolic characteristics when grown in 70% diluted expired milk. In the first MBR, A. oryzae degraded fat and protein, improved microfiltration, and produced ca 11 g/L of biomass. In the second MBR, N. intermedia consumed the remaining lactose in the permeate and originated ca 7 g/L of biomass. The developed system was successful for valorization of non-sterile milk due to the balance between consumption of bacterial growth-derived acids, consequent pH, and fungal enzymatic activities. Besides, a final clear effluent (83% reduction of COD) was obtained, which is of interest considering wastewater treatment.

Amylase and Xylanase from Edible Fungus Neurospora intermedia: Production and Characterization

“…Considering these features, several investigations have been performed on this fungus for various purposes. Valorization of numerous industrial waste streams, such as straw and bran (lignocellulosic waste) [ 13 , 14 , 15 ], whole and thin stillage (starch-to-ethanol process waste) [ 9 , 10 , 11 , 16 ], vinasse (sugar-to-ethanol process waste) [ 17 ], and cream, cheese-whey, yoghurt and milk (dairy waste products) [ 18 , 19 ], along with production of ethanol [ 10 , 11 ], protein-rich fungal biomass for feed applications [ 10 , 11 ], and pigments [ 8 , 12 ], are samples of N. intermedia applications in various fields. Despite the great potential of this fungus for industrial applications, particularly in the biorefinery, the enzyme production potential of this fungus has not yet been investigated thoroughly.…”

Airlift bioreactor–based strategies for prolonged semi-continuous cultivation of edible Agaricomycetes

“…Producing fungi in liquid media in bioreactors as opposed to using solid substrates could improve volumetric productivity (Patel et al 2023 ). Continuous culture has been investigated as an effective method to have higher volumetric productivity of microbial biomass (Wang et al 2013 ; Liu et al 2019 ); to the best of our knowledge, not many of these studies have been undertaken for edible fungi (Jin et al 2001 ; Thunuguntla et al 2018 ). We investigated five well-known fungal strains.…”

New Insights on Protein Recovery from Olive Oil Mill Wastewater through Bioconversion with Edible Filamentous Fungi

“…Therefore, it has increasingly been studied as a replacement of fish meal and soybeans in the production of animal feed, a product in increasing demand due to population growth. The growth of filamentous fungi in other fat-rich substrates such as dairy products [16][17][18] and fish processing-derived wastewaters [19,20], for protein recovery, has been reported in the literature. Research studies on protein recovery from OMWW using filamentous fungi, although scarce and more than eight years old, also exist [21][22][23].…”