Candida Apicola Research Articles

Sophorolipids Having Enhanced Antibacterial Activity

Sophorolipids Having Enhanced Antibacterial Activity

The Production of Volatile Compounds by Yeasts Isolated from Small Brazilian cachaça distilleries

The production of volatile compounds by 24 strains of Saccharomyces cerevisiae and one strain each of Candida apicola, C. famata, C. guilliermondii, Hanseniaspora occidentalis, Pichia subpelicullosa and Schizosaccharomyces pombe was evaluated with respect to the production of cachaca. They were isolated from small cachaca distilleries (27), industrial cachaca distilleries (2) and one sugarcane alcohol distillery, and tested in synthetic medium for the production of acetaldehyde, ethyl acetate, propanol, isobutanol, isoamyl alcohol, acetic acid and glycerol. The Saccharomyces strains showed a narrow range of variation in the production of such compounds, near 50% of the average of each volatile compound concentration. Principal component analysis showed the separation of the strains into six groups, and acetic acid production was the variable of greatest impact in the differentiation of the strains. The strains of S. pombe formed a distinct group (Group 2), and the strains of C. apicola and H. occidentalis formed a joint group (Group 6) as did Sc13 and Sc4 (Group 4). Group 1 was formed exclusively of S. cerevisiae. The closest non-Saccharomyces strains were C. apicola and H. occidentalis, with a similarity index of about 0.95. The strain P. subpelliculosa showed general characteristics more similar to those of the S. cerevisiae strains than to the non-Saccharomyces strains.

The influence of different yeasts on the fermentation, composition and sensory quality of cachaça

Cachaca (sugarcane wine) was produced using different yeast strains, six being strains of Saccharomyces cerevisiae and one each of Candida apicola, Hanseniaspora occidentalis, Pichia subpelliculosa and Schizosaccharomyces pombe. The ethanol yields (%) of the non-Saccharomyces strains were similar to those of the Saccharomyces strains. The following determinations were carried out on the cachaca: acetaldehyde, ethyl acetate, propanol, isobutyl alcohol, isoamyl alcohol, volatile acidity. The cachacas showed variations in the levels of secondary compounds, but these variations did not result in differences (P ≤ 0.05) in the sensory attributes of aroma and flavour and overall impression. Of the volatile compounds quantified in the cachacas, only propanol showed a positive correlation (P ≤ 0.05) with the flavour attributes and overall impression. The S. pombe strain was considered inadequate for the production of cachaca. The cachacas were classified into five groups in an exploratory Hierarchical Cluster Analysis as a function of the volatile compounds. Principal Component Analysis showed that 93% of the variation (PC 1) occurred among the samples, and was explained by the individual volatile compounds and the total secondary compounds, with the exception of isoamyl alcohol only 7% (PC 2) was associated with the volatile acidity. The negative correlations shown between the volatile compounds of the cachacas and the ethanol content of the sugarcane wine, with the exception of acetaldehyde, showed that the variation in ethanol content of the sugarcane wine is an important factor for standardization of the ethanol/volatiles ratio and the beverage quality.

Application of oil refinery waste in the biosynthesis of glycolipids by yeast

Candida antarctica or Candida apicola synthesized surfactants (glycolipids) in the cultivation medium supplemented with oil refinery waste, either with soapstock (from 5.0% to 12.0% v/v) or post-refinery fatty acids (from 2.0% to 5.0% v/v). The efficiency of glycolipids synthesis was determined by the amount of waste supplemented to the medium and was from 7.3 to 13.4 g/l and from 6.6 to 10.5 g/l in the medium supplemented with soapstock and post-refinery fatty acids, respectively. The studied yeast also synthesized glycolipids in the non-supplemented medium however, by the enrichment of medium with the oil refinery waste, a 7.5–8.5-fold greater concentration of glycolipids was obtained in the post-culture liquid then in the medium without addition of oil refinery waste. The yeast synthesized from 6.6 to 10.3 g dry biomass/l and the intra-cellular fat content was from 16.8% to 30.2%. The efficiency of glycolipids synthesis was determined by yeast species, medium acidity and culture period. The surface tension of the post-culture liquid separated from yeast biomass was reduced to 35.6 mN/m, which corresponded to the surface tension obtained at the critical micelle concentration of glycolipids.

Fermentation characteristics as criteria for selection of cachaça yeast

The fermentation characteristics of 24 strains of Saccharomyces cerevisiae and one strain of Candida apicola, C. famata, C. guilliermondii, Hanseniospora occidentalis, Pichia subpelicullosa and Schizosaccharomyces pombe were evaluated for the production of cachaca. They were isolated from small cachaca distilleries (27), industrial cachaca distilleries (2) and one sugarcane alcohol distillery. The yeasts showed significant differences in ethanol yield, substrate conversion, efficiency, conversion factors of substrate into ethanol (Yp/s), cells (Yx/s), organic acids (Yac/s) and glycerol (Yg/s), and maximum specific growth rate (μmax). In general the S. cerevisiae strains showed better fermentation potential, with yields between 83 and 91% and μmax between 0.450 and 0.640 h−1, several of them being comparable with the high performance yeast used in the industrial production of ethanol, which was adopted as a reference. The non-Saccharomyces strains showed high efficiency, very low ethanol yield and very high Yac/s and Yg/s values, except Pichia subpelliculosa, which behaved very similarly to the S. cerevisiae strains. Hierarchical Cluster Analysis and Principal Component Analysis showed the fermentation yield (or substrate conversion) as being the variable which contributed most to the separation of the strains into different groups.

Yeast communities associated with stingless bees.

The yeast communities associated with the stingless bees Tetragonisca angustula, Melipona quadrifasciata and Frieseomelitta varia were studied. The bees T. angustula and F. varia showed a strong association with the yeast Starmerella meliponinorum. M. quadrifasciata more frequently carried a species related to Candida apicola, but also vectored low numbers of S. meliponinorum. Some of the yeasts isolated from adult bees were typical of species known to occur in flowers. Other yeast species found in adult bees were more typical of those found in the phylloplane. S. meliponinorum and the species in the C. apicola complex, also part of the Starmerella clade, may have a mutualistic relationship with the bees studied. Many yeasts in that group are often found in bees or substrates visited by bees, suggesting that a mutually beneficial interaction exists between them.

Cytochromes P450 of the sophorose lipid-producing yeast Candida apicola: Heterogeneity and polymerase chain reaction-mediated cloning of two genes

Cytochromes P450 of the sophorose lipid-producing yeast Candida apicola: Heterogeneity and polymerase chain reaction-mediated cloning of two genes

Cytochromes P450 of the Sophorose Lipid‐producing Yeast Candida apicola: Heterogeneity and Polymerase Chain Reaction‐mediated Cloning of Two Genes

Cytochromes P450 of the Sophorose Lipid‐producing Yeast Candida apicola: Heterogeneity and Polymerase Chain Reaction‐mediated Cloning of Two Genes

Effect of ammonium ions on glycolipid production by Candida (Torulopsis) apicola

Effect of ammonium ions on glycolipid production by Candida (Torulopsis) apicola

Production of sophorose lipid by Candida (Torulopsis) apicola grown on glucose

The production of extracellular sophorose lipid by Candida apicola IMET 43747 was studied after growth on glucose as sole carbon source. In the presence of citrate and after 120 h of cultivation, the microcrystalline lactonic sophorose lipid started to appear in the medium. The lipid was shown to accumulate in the cell wall and only a minor part was liberated into the medium. By means of NMR studies it was shown that the cell wall-bound and the liberated lactonic sophorose lipid were identical and had a hydroxy Δ 8-hexadecenoic acid backbone. Biotransformation of d-[1- 13C]glucose revealed that in glucose-grown cells glucose was degraded to trioses which were rearranged and flow backward via the gluconeogenic pathway into the glycolipid as documented by scrambling of the 13C label from the C-1 position into the d-[6- 13C]glucose of sophorose. A further part of the trioses was used for de novo synthesis of the glycolipid fatty acid moiety via acetyl-CoA. By use of a mixed substrate, i.e., glucose and hexadecane, part of the glucose added was directly incorporated into the carbohydrate moiety of the lipid. These results are discussed in terms of the physiological significance of the sophorose lipid to act as extracellular carbon storage material.

Cytochrome P-450 in the sophorose-lipid-producing yeast Candida (Torulopsis) apicola

The appearance of cytochrome P-450 and of cytochrome oxidase aa3 were determined in the sophorose lipid producing yeast Candida (Torulopsis) apicola IMET 43 747 grown on a mixture of glucose and n-hexadecane. Cytochrome P-450, detectable in both the logarithmic and the stationary growth phase was not repressed by glucose. At the end of the logarithmic growth phase the content of cytochrome P-450 was three- to fivefold increased, which was connected with initiation of sophorose lipid biosynthesis. After that it dropped to the basal level, which remained constant during sophorose lipid biosynthesis. Cytochrome P-450 from logarithmic cells was cross-reactive with an antibody derived against cytochrome P-450alk from C. tropicalis. With microsomal proteins of stationary cells no cross-reactivity was obtained. The microsomal hydroxylase system of stationary cells seem to be regulated by the carbohydrate used as carbon source.

The inducible microsomal fatty alcohol oxidase of Candida (Torulopsis) apicola

In the transition phase of Candida apicola IMET 43747 from logarithmic to stationary growth a pyridine-nucleotide-independent alcohol oxidase was induced coinciding with the beginning of sophorose lipid production. This enzyme was not repressed by glucose and was measurable in stationary cells grown on glucose or on a mixture of n-hexadecane and glucose. An NAD+-dependent aldehyde dehydrogenase behaved in the same way. Both enzymes were localized in the microsomal fraction. The alcohol oxidase accepted long-chain (fatty) aliphatic alcohols (C8 to at least C16) and diols starting from decanediol. Trace activities were found with ω-hydroxy fatty acids. Aromatic, secondary and tertiary alcohols were not oxidized. In the stationary growth phase the substrate specificity of the alcohol oxidase tends to be changed to more hydrophobic substrates. The physiological role of both enzymes, the alcohol oxidase and aldehyde dehydrogenase, is discussed including their possible involvement in the synthesis of sophorose lipid.

Detection of Diverse Cytochrome P450-Dependent Biooxygenation Catalysts in Microorganisms Using a Multipurpose Inducer

Screening for new microbial cytochromes P450 to create a useful pool of oxygenating biocatalysts can be facilitated by applying multivalent inducers for it. The broad inducer spectrum for cytochrome P450 of Acinetobacter calcoaceticus EB 104 has been analyzed as a model for structure-function relationships governing the inducer recognition of hydrocarbon-oxidizing microbial cytochromes P450 with the aim to deduce structural requirements for the desired multivalent inducer. The cytochrome was induced by all compounds of adequate hydrophobicity that contain coplanar structural elements. It was concluded that due to the inherent low specificity of hydrophobic binding forces some few simple-structured hydrocarbons with a sterically flexible backbone can induce a variety of different hydrocarbon-oxidizing microbial cytochromes P450. This approach has been proved to be successfull by induction of cytochrome P450 with the help of n-hexane in Bacillus megaterium, in various strains of the genus Rhodococcus and in the yeast Candida apicola. Cytochrome P450 of Rhodococcus rhodochrous IMET 7278, that has partially been purified from n-hexane-induced cells, exhibited an induction profile differing to P450 of Acinetobacter.

Petite mutants of sophorolipid‐producing Candida yeasts

Treatment of both Candida apicola IMET 43747 and Candida bombicola ATCC 22214 with N-methyl-N'-nitro-N-nitroso guanidine resulted in formation of auxotrophic mutants and cytochrome oxidase negative mutants. The deficiency of intact cytochrome oxidase did not affect the ability to produce sophorose lipid. This indicates that intact mitochondrial energy supplying system is not necessary for the production of the extracellular sophorose lipids by both Candida yeasts.

Regulation of sophorose lipid production by Candida (Torulopsis) apicola

When growing on glucose, fructose or sucrose, Candida apicola produces large amounts of sophorose lipid during the stationary growth phase. In contrast, no sophorose lipid formation is observed with galactose or maltose independently whether hydrocarbons are present or not. The biosynthesis of the biosurfactant is therefore not simply a prerequisite for the degradation of extracellular hydrocarbon.