Yarrowia lipolytica as a potential producer of citric acid from raw glycerol

Abstract

Aims: To study the biochemical response of Yarrowia lipolytica LGAM S(7)1 during growth on raw glycerol (the main by-product of bio-diesel production units) in order to produce metabolic products of industrial signi®cance. Methods and Results: Yarrowia lipolytica was cultivated on raw glycerol or glucose in¯asks. Although nitrogen-limited media were employed, growth was not followed by production of reserve lipid. Nitrogen limitation led to citric acid excretion. Growth and citric acid production parameters on glycerol were similar to those obtained on glucose. When high initial glycerol media were used, citric acid up to 35 g l )1 (yield 0á42±0á44 g acid g )1 glycerol consumed) was produced. Conclusions: Raw glycerol was an adequate substrate for Y. lipolytica. Growth was not followed by reserve lipid accumulation, but amounts of citric acid were produced. Signi®cance and Impact of the Study: Raw glycerol is an industrial feedstock appearing in increasing quantities as the main by-product of bio-diesel production facilities. The present study describes an alternative way of glycerol valorization, with the production of remarkable amounts of citric acid, in addition to its main valorization way (production of 1,3-propanediol by bacteria).

Bioprospection of bacteria and yeasts from Atlantic Rainforest soil capable of growing in crude-glycerol residues

“…A simple visual inspection and selection of morphologically distinct colonies were effective in capturing at least part of the microbial diversity of interest, demonstrating the potential to be a practical, relatively fast and less expensive technique for screening environmental samples for given purposes. Confirmation of the presence of bacteria and yeast among the isolates was relevant, since these are two important groups from the biotechnological viewpoint (e.g., Papanikolaou et al, 2002;Dharmadi et al, 2006). Interestingly, the presence of bands of slightly different sizes after amplification with the universal primers for yeast (Figure 2) suggests that possible variants of the species identified in databases, or even new species, may have been isolated in this work.…”

Use of Wastewaters from Ethanol Distilleries and Glycerol Mixtures for Microbial Oils Production

“…The biomass concentration, substrate yields and specific growth rate of C. tropicalis and R. mucilaginosa cultured in flasks after 24 h are shown in ). Several researchers have demonstrate that cell growth and lipid content of different oleaginous yeast cells is lower in glycerol respect to other carbon source to the same concentration and showed their positive effect when it is used simultaneously with another energy source as xylose [29,30]. …”

Bioconversion from crude glycerin by Xanthomonas campestris 2103: xanthan production and characterization

“…It has been reported that the yeast Yarrowia lipolytica produces the same amount of citric acid when grown on glucose or on crude glycerin (Papanikolaou et al, 2002). Several reports have also demonstrated that xanthan gum can be obtained from agricultural and industrial wastes using less expensive carbon sources to produce it, such as citric acid (Jana and Ghosh, 1995), cassava serum (Brandão et al, 2010) and milk whey Silva et al, 2009), since the utilization of glucose or sucrose is a critical factor in the production cost of this polysaccharide (Garcia-Ochoa et al, 2000).…”

“…A promising alternative use of this byproduct is the microbial conversion of crude glycerin through biotechnological processes (Johnson and Taconi, 2007;da Silva et al, 2009) into value-added products, like poly-3-hydroxybutyrate polymers (Zhu et al, 2010); clavulanic acid (Teodoro et al, 2010); recombinant human erythropoietin (Elik et al, 2008), and citric acid (Papanikolaou et al, 2002;Rywińska et al, 2011).…”