Microbial Production Of Citric Acid Research Articles

Citric acid: fermentative production using organic wastes as feedstocks

Abstract Citric acid is the most important organic acid produced in tonnage and is used extensively in the pharmaceutical, chemical and food industries due to its low cost and high efficiency compared to other acidulates. Citric acid is produced by fungi, bacteria and yeasts under solid-state and submerged state fermentations. Aspergillus niger is one of the most dominant producer of citric acid. Different fruit wastes and agricultural residues are employed as surplus resources for microbial production of citric acid. In this review, the microbial sources and different organic wastes involved in citric acid production have been discussed. Furthermore, the recovery, purification and application of citric acid in different human utilities have also been reviewed.

Review on production of citric acid by fermentation technology

Citric acid is the most important organic acid produced in tonnage and is extensively used in food and pharmaceutical industries. It is produced mainly by submerged fermentation using Aspergillus niger or Candida sp. from different sources of carbohydrates, such as molasses and starch-based media. In view of surges in demand and growing markets, there is always a need for the discovery and development of better production techniques and solutions to improve production yields and the efficiency of product recovery. To support the enormous scale of production, it is necessary and important for the production process to be environmentally friendly by utilizing readily available and inexpensive agro-industrial waste products, while maintaining high production yields. This review article for fermentation of citric acid and Microbial production of citric acid, Substrates and strategies of citric acid production for Surface fermentation, Submerged fermentation, Solid-state fermentation and also the effects of various Factors affecting of citric acid fermentation conditions are Carbon source, Nitrogen limitation, Phosphorus source, Lower Alcohols, pH of culture medium, Trace elements, Aeration and Other factors. citric acid recovery options and the numerous applications of citric acid, based on the literature review information of citric acid production by fermentation technology.

Effect of the nutrient solution in the microbial production of citric acid from sugarcane bagasse and vinasse

Abstract The process known as “solid-state cultivation” (SSC) refers to microbial growth on solid supports under limited water conditions. Citric acid is a bioproduct with several industrial applications, and its production is traditionally microbial. The present work evaluated the production of citric acid by microbial consortium of Aspergillus niger and Trichoderma reesei in sugarcane bagasse with vinasse and ethanol as inducer of the metabolic production of this organic acid. The results indicate that the highest yields of glucose in citric acid, productivity and specific production rate for the conditions having vinasse and vinasse/ethanol as nutrient solution. In addition, the kinetic parameters for the citric acid and glucose profiles indicate that only vinasse as a nutrient solution, has a maximum citric acid concentration of 734 mg L−1 in 48 h.

Current strategies and future prospects for enhancing microbial production of citric acid.

Aspergillus niger and Yarrowia lipolytica are highly important in citric acid (CA) production. To further minimize the cost of CA bio-production using A. niger and Y. lipolytica, some strategies (e.g., metabolic engineering, efficient mutagenesis, and optimal fermentation strategies) were developed to enhance CA production and low-cost carbon sources were also utilized to decrease CA bio-production cost. In this review, we summarize the recent significant progresses in CA bio-production, including metabolic engineering, efficient mutagenesis and screening methods, optimal fermentation strategies, and use of low-cost carbon sources, and future prospects in this field are also discussed, which could help in the development of CA production industry.

Comparison of citric acid production from Aspergillus niger in solid and suspension state fermentation

Aim: Due to huge demand of citric acid, there is a need to find alternatives for its efficient production either using low-cost substrates or by improving the potency of the fermentation microorganisms. Materials and Methods: In this study, microbial production of citric acid was performed by Aspergillus niger. Solid and suspension state fermentation was carried out using biodiesel waste, i.e. the oilseed cake of Pongamia pinnata (honge) as a substrate for the comparative study of citric acid production using A. niger. After the estimation, the concentration of citric acid was found to be more in suspension state fermentation than in solid state. Hence, the further analysis was carried out using suspension culture. In the first stage, weight was varied, and the optimum weight was found out to be 12.5 g. Then keeping this optimum weight as constant, the inoculum size was varied, also keeping the optimum pH 6 and temperature 32°C constant. The rpm of suspension state was kept 100. Through this, optimum inoculum size was obtained. Results and Discussion: The yield of citric acid in solid state fermentation (SSF) was found to be 4.74 mg in 12.5 g of substrate and suspension state was 9.6 mg/ml. Conclusion: Suspension state fermentation method gives a higher yield of citric acid using oil seed cake as the substrate from A. niger than SSF method. The highest yield of 10.43 mg/ml of citric acid was obtained by taking substrate weight 12.5 g and inoculum size 275*104 spores/ml by suspension state fermentation method.

Citric Acid Production by Wild and UV – Treated Strains of Aspergillus niger on Two Different Mineral Salt Media

Microbial production of citric acid by a novel Aspergillus niger EE-12 and its UV – treated strain (UV-1) were carried out in shake flask cultures using mineral salt media containing sucrose or fructose as the carbon and energy sources. The highest citric acid concentration (36.1g/l) was obtained with the UV – treated strain UV-1 after 144 hours in medium containing sucrose and this was significantly higher (p<0.05) than the concentration produced by its parent strain EE-12. Citric acid production using medium containing sucrose (Sucrose salt medium) was significantly higher (p<0.05) than from medium containing fructose (Fructose salt medium) for both organisms. Product and growth yield coefficients (YCA/S, YCA/F, YCA/X, YX/S, YX/F) and volumetric rates (QF, QS, QCA, QX) were studied and compared for each of the test organisms based on the media (sucrose and fructose salt media) using students t-test analysis. This research indicated that the fungi strains are efficient for citric acid production using sucrose based medium.DOI: http://dx.doi.org/10.3126/ijasbt.v1i3.8358 Int J Appl Sci Biotechnol, Vol. 1(3) 2013 : 145-153

Production of citric acid from ram horn hydrolysate by Aspergillus niger

Ram horn hydrolysate (RHH) was used as a substrate for the microbial production of citric acid using Aspergillus niger NRRL 330 in a submerged culture. Ram horns were hydrolyzed by treating with acid (6N–H 2SO 4) and neutralizing the solution. The amounts of protein, nitrogen, ash, some minerals, total sugars, total lipids and amino acids of the RHH were determined. The effect of different concentrations (1–10% v/v) of RHH on the production of biomass was investigated and a concentration of 8% RHH was found to be optimal. The content of citric acid in the culture broth containing 8% RHH (78 g/l) for 6 d was 26% higher than that of the control culture broth (62 g/l). From this result, RHH was demonstrated to be a suitable substrate for citric acid production. RHH may be a valuable supplement in biotechnology.

Citric acid production from apple pomace in multi-layer packed bed solid-state bioreactor

Apple pomace was used as a substrate for microbial production of citric acid using Aspergillus niger. A packed-bed bioreactor consists of jacket and four stages with dimensions of 100×16 cm 2 was constructed and operated for solid state fermentation. The operation of this bioreacter was optimised using Taguchi statistical method of analysis. The optimum parameters was obtained as: aeration rate; 0.8 l min −1; bed height, 10 cm; particle size, 0.6–2.33 mm moisture content, 78% (w/w). Under these optimised conditions, 124 g citric acid was produced from 1 kg dry apple pomace with yield of 80% based on total sugar.

Optimization of citric acid production from Candida lipolytica Y-1095 using n-paraffin

Currently, the majority of worldwide microbial production of citric acid utilizes Aspergillus niger in a carbohydrate based submerged fermentation. Due to their high carbon content, hydrocarbons also have the potential of producing high concentrations of citric acid. Initial lab experiments conducted using 1875 ml batch fermentations with n-paraffin found that Candida lipolytica NRRL-Y-1095 assimilated the feedstock and had a citric acid productivity of 47 mg l −1 h −1. To determine the optimum level of initial biomass concentration, n-paraffin concentration, iron concentration and temperature for the production of citric acid, a central composite design was developed using 200 ml batch fermentations. The design involved conducting 31 batch fermentations under various combinations of high and low values of these four parameters. From this investigation empirical models were developed describing the interactions between the experimental parameters and citric acid production. It was found that the maximum concentration of citric acid produced was 9.8 g l −1 and the optimum levels of each parameter for citric acid production were, 10–12% volume for initial biomass concentration, 10–15% volume for n-paraffin concentration, 10 mg l −1 for ferric nitrate concentration, and 26–30 °C for temperature.

Microbial production of citric acid

Citric acid is the most important organic acid produced in tonnage and is extensively used in food and pharmaceutical industries. It is produced mainly by submerged fermentation using Aspergillus niger or Candida sp. from different sources of carbohydrates, such as molasses and starch based media. However, other fermentation techniques, e.g. solid state fermentation and surface fermentation, and alternative sources of carbon such as agro-industrial residues have been intensively studied showing great perspective to its production. This paper reviews recent developments on citric acid production by presenting a brief summary of the subject, describing micro-organisms, production techniques, and substrates, etc.

Microbial production of citric acid in fixed-bed column bioreactors

Aspergillus niger NRRL 567 was cultured on the solid substrate, fruit pomace, in fixed-bed column bioreactors to produce citric acid. The rates of substrate consumption and citric acid production were strongly influenced by (1) the rate of aeration, (2) the fermentation temperature, (3) the initial moisture content of the substrate, and (4) the size of the inoculum. This culture method yielded approximately 130 g of citric acid per kg of apple pomace fermented under optimum conditions.

Microbial Production of Citric Acid by Solid State Fermentation of Kiwifruit Peel

ABSTRACTA solid‐state fermentation method was developed for the production of citric acid from kiwifruit peel by Aspergillus niger NRRL 567. This method produced about 100g citric acid per kg of kiwifruit peel fermented in the presence of 2% methanol at 30°C in 4 days. The yield was more than 60% based on the amount of fermentable sugar consumed.

The relationship of some metal ions with citric acid production by Aspergillus niger using tamarind seed powder as raw material

Tamarind seed powder (TSP) was used as raw material for microbial production of citric acid. The maximum citric acid production was observed when the TSP-basal medium (TSP with inorganic nitrogen and phosphorus source) was supplemented with Mg 2+, Fe 2+, Cu 2+ and Zn 2+. The use of methanol and ferrocyanide as a modulator for citric acid production was studied. On methanol supplementation to the medium, ammonium nitrate was found to be better than ammonium carbonate as a source of inorganic nitrogen. Addition of ferrocyanide after sterilization to the medium containing methanol gave the maximum citrate production of 363 μg/ml.

Grape pomace: A novel substrate for microbial production of citric acid

Apple pomace, the residue left from juice extraction, can be employed as a substrate for citric acid production using Aspergillus niger as the fermentation agent.

Microbial production of citric acid

Microbial production of citric acid

Effect of Vitamins on Microbial Production of Citric Acid by Aspergillus niger

The effect of different concentrations of ascorbic acid, biotin, p-aminobenzoic acid (PABA), riboflavin and thiamine on the growth and activity of Aspergillus niger strain AL 29 was studied at different incubation periods. It was observed that ascorbic acid and PABA inhibited the growth and activity of the mould, while the presence of thiamine and riboflavin stimulated the citric acid formation to the extent of 59.09% and 50.36%, respectively. However, biotin was found to be most suitable for increasing the mycelial growth and also enhancing the production of citric acid (66.4%).

Effect of Amino Acids on Microbial Production of Citric Acid by Aspergillus niger

The effect of different concentrations of cysteine, serine, lysine, aspartic acid, and glutamic acid on the growth and fermenting activity of Aspergillus niger AL 29 was studied at different incubation periods. It was observed that the presence of glutamic acid and aspartic acid stimulated the citric acid production to the extent of 79.6% and 76.7%, respectively. Lysine was effective in producing citric acid by 62%. However, serine could not influence the yield (50.4%) to a greater extent, while the effect of cysteine was found to be detrimental. The yield of citric acid was determined on sugar consumption basis.

Protein and energy value of vinasse for pigs

A vinasse, originating as the condensed molasses residue from the microbial production of citric acid, was chemically analyzed and given to growing pigs to determine its protein and energy value. It contained, per kg dry matter (62.6%), 185 g crude protein, 538 g N-free extracts, 48 g total sugar, 277 g ash and 12.8 MJ gross energy. Ammonia, betaine and amino acids (about half glutamic acid) accounted for 3.5, 9.1 and 28.6%, respectively, of the crude-protein N. In a 25-day balance trial with the final 10 days as collection period, ten pigs initially weighing 33 kg were pair-fed daily an average of about 1 kg of dry matter of either a basal diet (95% ground barley plus 5% cellulose) or of a mixed diet composed of, on dry basis, 77% basal diet plus 23% vinasse. Partial digestibility of components in the vinasse was: organic matter, 52%; crude protein, 45%; N-free extract, 58%; ash, 83%; and gross energy, 42%. Average daily gain and N retention were not different between dietary groups. The vinasse contained, per kg dry matter, 5.40 MJ DE and 3.61 MJ ME compared with 14.96 MJ DE and 14.48 MJ ME for the dry basal diet. The conclusion is that this vinasse, according to its low protein and energy value, can provide only a small percentage of the daily ration for pigs.

The Influence of Ultrasonic Waves, Alone and in Presence of Certain Salts on the Microbial Production of Citric Acid by Aspergillus niger

The influence of ultrasonic waves, alone and in presence of different (0.1, 0.5, and 1.0%) concentrations of NaCl, KH2PO4 and NH4Cl on the microbial production of citric acid by Aspergillus niger was studied. It was observed that in presence of sonic waves alone the yield of citric acid was generally better than that of control. Besides, some morphological changes in the diameter of the conidiophore of the of the mould was also noted. The effect of sonics in presence of NaCl was inconspicuous since at all sonic doses taken for the study, the yield of citric acid was less in comparison to the control. However, in presence of 0.5% KH2PO4 the yield was comparatively better (42.2%) over the control. The best result obtained amongst these treatments was found with the effect of sonics in presence of 0.5% NH4Cl in which the optimum yield of citric acid produced was greater than that of the control by 52.4%.

Biosynthesis of citric acid. The influence of hydrogens ion concentration on the microbial production of citric acid by various Aspergillus niger strains.

TheA. niger strain 363 is better in its citric acid producing capacity than other strains studied. The pH value of the culture media differs from strain to strain for the good yield of citric acid. When there is good yield of citric acid the sugar consumption is less and mycelial growth is also less.