Production of Citric Acid (A. Niger)

Part B

Small Scale Literature Review

Running Head: Factors Affecting Citric Acid Production by Aspergillus niger

Factors Affecting Citric Acid Production by Aspergillus niger

Ong Chia Swing, Student.

Nilai University

1. Introduction

Citric acid is a natural preservative or conservative that is used to add an acidic, sour taste to foods and beverages. In the context of biochemistry, the conjugate base of citric acid which is the citrate plays an important role as an intermediate in the citric acid cycle which occurs in the metabolism of all aerobic organisms. Due to its importance to most organisms, more than a million tonnes are produced every year via fermentation. It is used mainly as an acidifier, flavouring and as a chelating agent. B. Kristiansen et al. (1999) and A.E Bodie et al. (1994) stated that most citric acid used in foods is derived from carbohydrate fermentation by Aspergillus niger. Aspergillus niger fermentation is considered as the world’s leading source of commercial citric acid. However, in this literature review, it is hypothesised that many factors have been affecting the citric acid production by Aspergillus niger. Hence, many research studies that have been done to understand in details of which of the best factors studied being applied in producing citric acid more effectively by Aspergillus niger. The following five research articles that have been studied attempt to demonstrate and support the hypothesis:-

2.0 Body
2.1 Citric Acid Production from Whey with Sugars and Additives by A. niger

In a research paper by Murad and Khalaf (2003), a question was raised and discussed for guiding the study. The question was that, would the production rate of citric acid (CA) by Aspergillus niger ATCC9642 from whey can be affected by different specific concentration of sucrose, glucose, fructose, galactose riboflavin, tricalcium phosphate and methanol in surface culture process? The focus of the investigation was to produce citric acid by

References: B. Kristiansen, M. Mattey and J. Linden, “Citric Acid Biotechnology”, Taylor & Francis, London 1999. [Online]. Retrieved on 12th Nov 2012 from: http://onlinelibrary.wiley.com/doi/10.1021/bp030002y/abstract Benuzzi DA, Segovia RF (1996). Effect of the copper on citric production by an Aspergillus niger strain. Appl. Biochem. Biotechnol. 61: 393-397. [Online]. Retrieved on 12th Nov 2012 from: http://link.springer.com/article/10.1007%2FBF02787810?LI=true Burgstaller, W., (2006). Thermodynamic boundary conditions suggest that a passive transport step suffices for citrate excretion in Aspergillus and Penicillium. Microbiology 152, 887–893. [Online]. Retrieved on 12th Nov 2012 from: http://www.ncbi.nlm.nih.gov/pubmed/16514167 Dickman, S. R. & Cloutier, A. A. (1959). Activation and stabilization of aconitase by ferrous ions, Arch. Biochem. Biophys. 25, 229. [Online]. Retrieved on 12th Nov 2012 from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC293292/ Hossain M, Brooks JD, Moddax IS (1984). The effect of the sugar source stabilized cultures of Aspergillus niger. Appl. Microbial. Biotechnol. 19: 393-397. [Online]. Retrieved on 12th Nov 2012: http://link.springer.com/article/10.1007%2FBF00454376?LI=true Hossain M, Brooks JD, Moddax IS (1985). Galactose inhibition of citric production from glucose by Aspergillus niger. Appl. Microbial. Biotechnol. 19: 393-397. [Online]. Retrieved on 12th Nov 2012 from: http://link.springer.com/article/10.1007%2FBF00250027?LI=true Luciana P. S. Vandemberghe Carlos R. Soccol a, Ashok Pandey, J.-M. Lebeault., (2000). “Solid-state fermentation for the synthesis of citric acid by Aspergillus niger.” Bioresource Technology 74, pp 175-178. [Online]. Retrieved on 12th Nov 2012 from: http://www.aseanbiotechnology.info/Abstract/21014919.pdf Moddax IS, Hosain M, Brooks D (1986). The effect of methanol on citric acid production from galactose by Aspergillus niger. Appl. Microbial. Biotechnol. 23: 203-205. [Online]. Retrieved on 12th Nov 2012: http://link.springer.com/article/10.1007%2FBF00261914?LI=true Morrison, J. F. & Peters, R. A. (1954). Biochemistry of fluoroacetate poisoning: the effect of fluorocitrate on purified aconitase. Biochem. J. 58, 478. [Online]. Retrieved on 12th Nov 2012 from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1269923/?page=6 Ramakrishnan, C. V., Steel, R. & Lentz, C. P. (1955). Mechanism of citric acid formation and accumulation in Aspergillus niger. Arch. Biochem. Biophys. 55, 270. [Online]. Retrieved on 12th Nov 2012 from: http://www.sciencedirect.com/science/article/pii/0003986155905646