Citric acid production by Aspergillus niger using different substrates

Abstract

Aims: Citric acid is a commercially important acid that has many applications in varying sectors of industries. It is produced by various substrates through solid state or submerged fermentation. The capabilities of potato and rice as substrates for citric acid production using Aspergillus niger were tested in this experiment under submerged fermentation. Methodology and results: Potato and rice extract media were prepared and inoculated with A. niger and titrations were carried out to determine the amount of citric acid produced. It was shown that rice extract media proved more useful than potato extract media as it produced the highest citric acid production. Rice extract media was supplemented with varying concentrations of glucose and sucrose and 5% sucrose (w/v) proved to be the best as it produced the highest amount of citric acid. The rice extract media with 5% sucrose (w/v) were supplemented with varying concentrations of ammonium nitrate and ammonium sulphate and 0.25% ammonium nitrate proved more effective in citric acid production. A low pH (1.9-2.3) was found during the maximum production of citric acid. Conclusion, significance and impact of study: The results depict that potato and rice extract media can produce citric acid, hence providing an alternate substrate for citric acid production.

Isolation of citric acid-producing Aspergillus niger from soil and organic wastes

“…Lee et al [5] found sucrose to be an important carbon source in submerged fermentation with citric acid measured at pH 2. Similar findings were also reported by Chirova et al [13]. It is also important to note that the cell growth and consequent metabolic activity of a pelleted suspension occur mainly at the culture medium surface where there is access to adequate oxygen and nutrients [12].…”

Investigating the Usefulness of Wild Dioscorea esculenta (Wild Yam) Flour as Substrate for Citric Acid Biosynthesis

“…Citric acid production with potato extract media supplemented with different and varying concentration increased as the potato extract and its supplement increased" [15]. Kudzai et al [16] reported "potato and rice starch extract during citric acid production by Aspergillus niger and found that different substrates have different effects on biosynthesis of citric acid depending on their concentrations. These suggested that carbon source and its concentration had a great influence on citric acid production depending on the nature and type carbon used for fermentation".…”

Investigation of Citric Acid By-Products from Rice Produced by Microbial Fermentation on Growth Performance and Villi Histology of Thai Broiler Chicken (KKU 1)

“…Thus, the researcher and industries look for the raw materials that could reduce citric acid productions cost. Some study conducted for use some agriculture production to become citric acid as a raw material [2]. Nowadays in Thailand, rice is the major locally produced crop, which amounted to 20.7 million metric tons in 2019 [3].…”

“…Thus, rice certainly has the opportunity to be an ingredient to produce citric acid. The ability of rice and potato as an extract to produce citric acid was analyzed by Kudzai et al [2] in order to meet the high demand for citric acid. The result was shown that rice could provide the highest production of citric acid, and rice extract media proved to be more useful than potato extract media.…”

“…[6]. Obtaining citric acid production by the fermentation of rice using Aspergillus niger was studied by Kudzai et al [2]. The result showed that rice extract media contains, and readily makes, more sugars available, resulting in higher citric acid production levels.…”