The Use of Sugar Cane Waste (Molasses) in the Production of Lactic Acid by L. paracasei CAU 9836 and its Identification by Infrared Spectrum (FT.IR)

Abstract

A total of twelve bacterial isolates from different samples of yoghurt and milk purchased from local markets in Diwaniyah Governorate. The preliminary screening was carried out all bacterial isolates by gram staining. The six isolates were selected based on the intensity of colour variation in the fermentation medium and were identified according to phenotypic, microscopic, and biochemical examinations, which included twelve isolates of Lactobacillus spp. Vitek II Compact instrument was used with all isolates to confirm the initial identification. The secondary screening was performed for isolates of Lactobacillus spp.species. Given the amount of the produced lactic acid, the L.casei strain 1859 had the highest lactic acid production, which was 64.32 g/L. The 16S rRNA test allowed the identification of this isolate. The results showed that the best conditions for acid production were 62.76 mg/L and the L.casei strain 9836 grown on the alternative medium containing 50 % whey, 7% molasses, and pH 6.9, incubated on an orbital shaker at 38°C for 24 hours, and agitated at 250 rpm. FTIR techniques were used to identify the nucleus of the hydrogen atom (proton) 1 H and the carbon atoms 13 C in the presence of standard lactic acid for comparison. The results revealed the peaks and bands of the produced acid were some similar to that of the standard acid.