Decommissioned dates: chemical composition and fermentation substrate for the production of extracellular catalase by an Aspergillus phoenicis mutant

Abstract

The recovery of dates downgraded as a fermentation medium for the production of extracellular catalase by Aspergillus phoenicis K30 was studied. Analysis of the chemical composition of pulp and kernel flour of dates showed that the pulp had a considerably greater carbohydrate content compared to the kernel (84 vs 2.93% respectively). However, the kernel flour was richer in nitrogen (0.68% vs 0.34), mineral elements (3.63 vs 1.28%) and in essential fatty acids C18: 2 vs C18: 3 than the pulp flour. The soluble extract of the date flour showed that sugars solubilised at 90% consisted of sucrose, fructose and glucose. Therefore, this extract, being an important source of carbon and energy, was used in the current study as a fermentation medium (after supplementation with 20% of corn steep) for the production of extracellular catalase by A. Phoenicis K30. During the course of this fermentation, the biomass was estimated at 18.6 g / L after 72 h of culture, while the maximum concentration of extracellular catalase (47.5 U / ml) was reached at 96 h of fermentation. The mycelium obtained in pellet form is suitable for industrial exploitation of this process.

Optimization of Baker’s Yeast Production on Date Extract Using Response Surface Methodology (RSM)

“…Algeria records a remarkable lack in beet and cane molasses production, indeed, it imports about 18,000 and 13,000 tons per year of each one, respectively, and also imports the yeast strain S. cervisiae used as a baker’s leaven [ 8 ]. However, Algeria has an enormous potential of dates [ 9 , 10 ]. In addition, the production of S. cerevisiae biomass from a low quality date variety could constitute an economic carbon source, especially considering that the production of dates is a bountiful in Algeria.…”