The use of date waste for lactic acid production by a fed-batch culture using <italic>Lactobacillus casei</italic> subsp. <italic>rhamnosus</italic>

Abstract

The production of lactic acid from date juice by Lactobacillus caseisubsp. rhamnosus in batch and fed-batch cultures has been investigated. The fed-batch culture system gave better results for lactic acid production and volumetric productivity. The aim of this work is to determine the effects of the feeding rate and the concentration of the feeding medium containing date juice glucose on the cell growth, the consumption of glucose and the lactic acid production by Lactobacillus casei subsp. rhamnosus in fed-batch cultures. For this study, two concentrations of the feeding medium (62 and 100 g/L of date juice glucose) were tested at different feeding rates (18, 22, 33, 75 and 150 mL/h). The highest volumetric productivity (1.3 g/L.h) and lactic acid yield (1.7 g/g) were obtained at a feeding rate of 33 mL/h and a date juice glucose concentration of 62 g/L in the feeding medium. As a result, most of the date juice glucose was completely utilised (residual glucose 1 g/L), and a maximum lactic acid production level (89.2 g/L) was obtained.

Optimization of carotenoids production by Rhodotorula mucilaginosa (MTCC-1403) using agro-industrial waste in bioreactor: A statistical approach

“…Different combinations of carbon and nitrogen sources (OP + MBH, OP + PP, PS + MBH, PS + PP) were made using agricultural wastes in 1:1 ratio. These wastes were prepared by two methods, aqueous extraction and acidic extraction according to the method described by Nancib et al with little modifications [15]. The prepared powders of carbon and nitrogen sources from agricultural waste materials were taken in equal amounts and aqueous extracts were prepared using distilled water at a ratio of 5:1 (Distilled water: Agricultural waste powder mix).…”

Screening for efficient nitrogen sources for overproduction of the biomass of the functionally probiotic L. plantarum strain RPR42 in a cane molasses-based medium

“…For inoculation of the screening and either production media an inoculum size of 10% (v/v) was considered. The starting optical density of the inoculated cultures was ~ 0.12 ± 0.005, corresponding to ~ 1.75 × 10 7 CFU/mL (Krzywonos and Eberhard 2011;Nancib et al 2015).…”

Characterization and cytotoxic activity of pigment extracted from Rhodotorula mucilaginosa to assess its potential as bio-functional additive in confectionary products

“…The slurry was then filtered, and centrifugation was done at 10,0009g for 20 min. The clear supernatant was used as agro-industrial waste substrate for further fermentation batches (Nancib et al 2015).…”