Valorizing food wastes: assessment of novel yeast strains for enhanced production of single-cell protein from wasted date molasses

In the current study, several non-conventional yeast strains were screened and adapted to produce single-cell protein (SCP) at high productivities and yields from wasted date molasses (WDM). Among the tested yeasts, Hanseniaspora guilliermondii JQ690237, Hanseniaspora uvarum JQ690236, Issatchenkia orientalis JQ690240, and Cyberlindnera fabianii JQ690242 emerged as the highest producers of biomass during small-scale batch experiments, leading to yields up to 700 g dry biomass/kg of WDM after 48 h of incubation. It was shown that the supplementation of the WDM medium with either organic or inorganic nitrogen sources, enhanced significantly the bioconversion efficiency of WDM into single-cell protein, with H. guilliermondii and I. orientalis exhibiting the highest production of biomass, with a protein content of up to 54.3%. The scaling up of the process confirmed its efficiency, indicating that newly isolated yeasts are promising SCP producers for possible industrial exploitation of the specific waste toward animal feed. Graphical abstract: [Figure not available: see fulltext.]