Production of L(+) lactic acid from sweet sorghum, date palm, and golden syrup as alternative carbon sources

Abstract

Lactic acid production has been carried out using (a) Lactobacillus delbruckii, (b) optimal production medium comprised of 10% carbon source derived from sweet sorghum (SS) (Sorghum bicolor)/golden syrup (GS; molasses after glucose crystallization)/date palm (DP) juice (Phoenix dactylifera L.), 1% yeast extract, 0.6% sodium acetate, 0.5% KH2PO4, and 0.5% MgSO4 · 7H2O, (c) in batch mode, (d) at 45 ± 1°C, 150 rpm, anaerobic condition, and pH 5.5 ± 0.1, and (e) sterilized CaCO3 powder at regular intervals for neutralization to promote optimal utilization of sugar. The lactic acid (LA) productivity was higher from the use of GS and less from SS as well as DP juice. Decolorization of carbon sources prior to use in fermentation gave LA, meeting food grade specifications.

Date and their processing byproducts as substrates for bioactive compounds production

“…The addition of five B vitamins at less than 25 mg/L to date juice could enhance the production of lactic acid. Yadav et al (2011) produced lactic acid using L. delbruckii, under optimal production medium comprising (%) 10 date syrup, 1 yeast extract, 0.6 sodium acetate, 0.5 KH 2 PO 4 , and 0.5 MgSO 4 .7H 2 O. High lactic acid productivity was obtained.…”

L‐lactic acid production by Rhizopus oryzae MBG‐10 using starch‐rich waste loquat kernels as substrate

“…Lactic acid occurs naturally in two optical isomers: D(À)-lactic acid and L(þ)-lactic acid. Since elevated levels of the D-isomer are harmful to humans, L(þ)-lactic acid is the preferred isomer for food-related and pharmaceutical industries [1][2][3][4]. Lactic acid can be produced commercially by either chemical synthesis or fermentation.…”

Chemical-free Processing of Sweet Sorghum Juice of Cultivar Sucrosorgho 506

“…It is important to emphasize that utilization of sweet sorghum turned to the production of other chemical compounds from the carbohydrate content of the raw juice such as lactic acid [34][35][36][37], butanol [38], hydrogen [28,39,40], acetone [41], lipids [42] gained more importance. Among the platform molecules levulinic acid could play a key role in the chain [43], since it is the raw material of a proposed platform chemical (gamma-valerolactone) that can be obtained by its selective hydrogenation [44][45][46][47][48].…”