Citric Acid Production from Nontreated Beet Molasses by a Novel Aspergillus niger Strain: Effects of pH, Sugar and Ingredients

Abstract

Effects of factors on the citric acid production from non-treated beet molasses were studied in Aspergillus niger OE55. Maximum amount of citric acid (19.13 and 34.62 g/L) was achieved when the initial pH of fermentation medium was 6.0 from 200 g/L and 150 sugar respectively. Citric acid production and biomass formation continuously increased during fermentation period in the media initially containing 200 g/L sugar. Remaining sugar (from 3.20 to 6.03 g/L) was higher at the end of fermentation in the media initially containing 160 g/L sugar than 200 g/L sugar. Yield of citric acid after 4 days of fermentation were ranged from 0.16 to 0.28 g/g from 160 g/L sugar. The high phosphorus and nitrogen levels stimulated biomass formation and reduced citric acid production. The optimum incubation for maximal citric acid production varies both with the sugar concentration in non-treated molasses and fermentation conditions for the novel A. niger strain. pH of fermentation media cannot have reduced below 4.72 and 3.35 in the media containing 200 and 160 g/L sugar, respectively, during fermentation, therefore citric acid production was not increased over 19.96 and 34.58 g/L respectively. This would be due to the formation of nitrogenous and polysaccharide compounds from molasses. Strain development in the citric acid production from wild strains depends mainly on the fermentation conditions.

USE OF MULBERRY POMACE AS SUBSTRATE FOR CITRIC ACID PRODUCTION BY Aspergillus niger MT-4

“…On day 5, CA concentration and CA yield (Yp/s) were determined as 24.6 g/L and 0.2 g CA/g MP, respectively. The CA yield achieved in submerged culture was similar to those reported in previous studies (Alben & Erkmen 2004, Guc & Erkmen 2017.…”

Optimization of citric acid production by Aspergillus niger using two downgraded Algerian date varieties

“…Yield of citric acid using beet molasses after 4 days of fermentation were ranged from 0.16 g/g to 0.28 g/g from 160 g/L sugar ( Guc and Erkmen, 2017 ) comparing with the yield from our substrates at 0.28 g/g for the MECH DEGLA and 0.32 g/g for the GHARS, with the sugar measuring at 142.85 g/L for the GHARS and 131.05 for the MECH DEGLA.…”

Decolorization and biodegradation of melanoidin contained in beet molasses by an anamorphic strain of Bjerkandera adusta CCBAS930 and its mutants

“…The annual sugar production in Poland is estimated at 1700 thousand tons (Kowalczyk-Juśko et al 2014 ), which is associated with production of 510 thousand tons of molasses. As reported by Guc and Erkurer ( 2017 ), the annual production of beet molasses in Turkey in 2014 exceeded 710 thousand tons. The main application of molasses is the production of bioethanol (Razmovski and Vučurović 2012 ).…”

“…Another application of molasses in the fermentation industry is the production of organic acids, i.e. oxalic, citric, lactic, and acetic acids (Gur et al 2001 ; Kotzamanidis et al 2002 ; Guc and Erkmen 2017 ), and amino acids (Kahraman and Yesilada 2003 ). Molasses is also a raw material for production of feed and baker's yeast in the yeast industry (Kahraman and Yesilada 2003 ; Li et al 2015 ).…”