The Effect of Iron on Gluconic Acid Production by Aureobasidium pullulans

Abstract

New processes have been previously described for the continuous and discontinuous production of gluconic acid by Aureobasidium pullulans (de bary) Arnaud. Little is known about the regulatory mechanisms of gluconic acid production by A. pullulans. The response of growth and gluconic acid metabolism to a variable profile of iron concentrations was studied with A. pullulans in batch and chemostat cultures. A surprisingly high optimum N-dependent iron ion concentration in the feed medium, in the range between 0.5 mM and 3.0 mM Fe (optimum 1-2 mM), was found to be particular requirement for economically profitable continuous production of gluconic acid with 3 g/l NH 4 Cl. Increased iron concentration promoted growth on defined glucose medium. 223.3 g/l gluconic acid were continuously produced at a formation rate of the generic product (R j ) of 16.8 g/(l h) and a specific gluconic acid productivity (m p ) of 2.5 g/(g h) at 13 h residence time (RT) with 1mM iron, compared with 182 g/l reached at 0.1 mM. The product selectivity (product yield based on glucose) increased continuously by raising iron concentration following a saturation curve, reaching a maximum of about 98% (mol/mol) at 2 mM Fe and 76.2% conversion, compared with only 84.3% determined at 0.1 mM. The process is not obligatory growth limiting or growth related and residual nitrogen was found in all of continuous experiments, e.g. 197 mg/l of nitrogen at 0.1 mM and 201 mg/l at 2 mM of iron.

Glucose oxidase production using a medicinal plant:Inula viscosaand optimization with TaguchiDOE

“…One of the main aims of this study was to achieve GOX production with minimal medium components; thus, calcium carbonate was used in lower concentrations to prevent possible precipitation of the calcium salts. Iron sulfate was reported as a stimulator for GOX production for Aspergillus strains with KCl and a similar observation was reported for Penicillium strains (Anastassiadis et al, 2008; Munk et al, 1963; Nakamatsu et al, 1975); hence, iron sulfate and KCl were added to the medium.…”

“…GOX production by microorganisms requires high glucose concentrations; however, in the current study, there was no additional glucose in the medium used, since I. viscosa (L.) Aiton was used as sole carbon source. Glucose concentrations between 40 and 400 g/L were reported in the literature (Anastassiadis et al, 2008; Liu et al, 2017; Qian et al, 2019; Ramachandran et al, 2006; Singh et al, 2003); also, high glucose concentrations had a positive effect for A. niger CICC 40350 cultures of GOX activity. In this context, the extreme osmotic conditions imposed by high glucose concentrations led to the upregulation of the gene responsible for GOX synthesis (Qian et al, 2019).…”

“…On the other hand, if glucose addition to the medium is above 15%, supersaturation occurs and calcium salts precipitate on the culture and hamper the oxygen transfer (Fernandes et al, 2021; Ramachandran et al, 2006). In a previous paper, calcium carbonate was used in lower concentrations for gluconic acid production (Anastassiadis et al, 2008). One of the main aims of this study was to achieve GOX production with minimal medium components; thus, calcium carbonate was used in lower concentrations to prevent possible precipitation of the calcium salts.…”

Application of Yarrowia lipolytica in fermented beverages

“…Most focus on the use of Y. lipolytica has, until today, been from a biotech point of view. Particular emphasis has been on optimising the production of one or more metabolites of particular interest, and Y. lipolyticas' ability to secrete a myriad of interesting compounds has been thoroughly tested and optimised both in wild strains and in engineered strains, e.g., citrate, iso-citrate, 2-phenylethanol, γdecalactone, sugar alcohols, Single Cell Oils (SCO), and Single Cell Proteins (SCP) (Anastassiadis et al, 2002;Finogenova et al, 2002;Papanikolaou et al, 2002;Anastassiadis et al, 2007;Iucci et al, 2007;Patrignani et al, 2007;Mansour et al, 2008;Bankar et al, 2009;Beopoulos et al, 2009;Celińska et al, 2013;2015;Groenewald et al, 2014;Sibirny et al, 2014;Zinjarde, 2014;Braga and Belo, 2015;Morgunov, 2017 Sarris et al, 2017;Kamzolova et al, 2018;Madzak, 2018;Carsanba et al, 2020;Fickers et al, 2020;Małajowicz et al, 2020 Kamzolova andMorgunov, 2021;Kothari et al, 2022). Only non-engineered strains will be discussed in the current review due to general consumer reluctance to food produced using engineered strains (Curtis et al, 2004).…”

Kinetics of gluconic acid production and cell growth in a batch bioreactor by Aspergillus niger using breadfruit hydrolysate

“…The biochemical method through fermentation has many advantages for the gluconic acid production, which includes: low production cost, mild reaction conditions, and the use of renewable resources as raw materials. Other advantage is the conversion of nearly 100% of glucose to gluconic acid under appropriate conditions (Anastassiadis, Kamzolova, Morgunov, & Rehm, ). These make the process exclusively useful for commercial production of gluconic acid, due to its high and still growing demand of about 60,000 tons per annum in United States (Betiku et al, ; Shindia, El‐Sherbeny, El‐Esawy and Sheriff, ; Singh, Jain, & Singh, ).…”