n-Butanol production by Saccharomyces cerevisiae from protein-rich agro-industrial by-products

Abstract

n-Butanol is a renewable resource with a wide range of applications. Its physicochemical properties make it a potential substitute for gasoline. Saccharomyces cerevisiae can produce n-butanol via amino acid catabolic pathways, but the use of pure amino acids is economically unfeasible for large-scale production. The aim of this study was to optimize the production of n-butanol by S. cerevisiae from protein-rich agro-industrial by-products (sunflower and poultry offal meals). By-products were characterized according to their total protein and free amino acid contents and subjected to enzymatic hydrolysis. Protein hydrolysates were used as nitrogen sources for the production of n-butanol by S. cerevisiae, but only poultry offal meal hydrolysate (POMH) afforded detectable levels of n-butanol. Under optimized conditions (carbon/nitrogen ratio of 2 and working volume of 60%), 59.94 mg/L of n-butanol was produced using POMH and glucose as substrates. The low-cost agro-industrial by-product showed great potential to be used in the production of n-butanol by S. cerevisiae. Other protein-rich residues may also find application in biofuel production by yeasts.

Optimization of Microbial Hydrolysis Parameters of Poultry By-Products Using Probiotic Microorganisms to Obtain Protein Hydrolysates

“…When carrying out enzymatic hydrolysis of wastes, hydrolysates with a high degree of hydrolysis (DH) and yield are obtained [11,18]. The degree of hydrolysis (DH) characterizes the degree of enzymatic peptide cleavage of the protein substrate under the influence of various factors: hydrolysis time, reaction pH, and enzyme concentration.…”

“…The potential of chicken by-products as substrates for the production of protein hydrolysates with various functional properties and biological activity has been noted by many researchers [6,10,11]. It is noted that proteins that are currently used as animal feed can be modified and improved for human consumption.…”

Physicochemical, Functional, and Technological Properties of Protein Hydrolysates Obtained by Microbial Fermentation of Broiler Chicken Gizzards

“…In the process of such treatment, mainly enzymatic protein hydrolysates are obtained from meat raw materials and offal [4]. Many researchers have noted the potential of chicken by-products as substrates for the production of protein hydrolysates with various functional properties and biological activity [5][6][7]. Protein hydrolysates are obtained in different ways, but the most economical and environmentally friendly is the enzymatic hydrolysis of protein raw materials, entailing the use of enzymes to break down molecules and change the chemical, functional, and sensory properties of proteins without reducing their nutritional value.…”