Candida yeast strains

Table 5.8 Maximum permissible concentrations (PDKs) of Candida yeast strains approved by the FSU Ministry of Health for use in the production of single cell protein...

The cultivation of this yeast strain on pectin medium showed optimal grow conditions. The behaviour of this strain was compared with that of four strains of Candida boidinii from the Culture Collection of Yeasts. The grow curves of all strains on pectin medium showed marked plateau suggesting the presence of two existing C-sources in the pectin medium, requiring two different metabolic paths (Fig. 1). 

One of the first reports on yeast-mediated color removal by a putative process of biosorption of azo dyes by yeast (Rhodotorula sp.) biomass belongs to [31]. Yeast species such as Kluveromyces marxianus removed the diazo dye remazol black B [10], Candida catenulata and Candida kefyr removed more than 90% of amaranth by biosorption [6]. Biosorption uptake of the textile azo dyes remazol blue, reactive black, and reactive red by S. cerevisiae and C. tropicalis varied according to the selected dye, dye concentration, and exposure time [5, 7]. In a recent screening work carried out by [32], from the 44 yeast strains tested for their decolorization ability, 12 of them removed the dye Reactive Brilliant Red K-2BP by biosorption, among them the following were identified S. cerevisiae, Saccharomyces uvarum, Torulopsis Candida, and Saccharomycopsis lipolytica. 

Out of 364 other tested enterobacteria 3 E. coli strains were positive, as were 8 of 9 Candida yeast isolates. These findings are not surprising because reciprocal cross-reactions between Salmonella Cl and some E. coli strains are well known (26) and in yeasts a mannan consisting of an a,l- -6 linked poly-D-mannose backbone with branches of a,l->-2 and a,l- -3 linked D-mannose residues is a principal cell-wall constituent (27). 

Csoma, H. and Sipiczki, M. (2008). Taxonomic reclassification of Candida stellata strains reveals frequent occurrence of Candida zemplinina in wine fermentation. FEMS Yeast Res. 8, 328-336. 

In an alternate process, enantioselective microbial reduction of 6-oxobus-pirone (19, Fig. 18.6) to either (R)- and (.S )-6-hydroxybuspirone was described. About 150 microorganisms were screened for the enantioselective reduction of 19. Rhizopus stolonifer SC 13898, Rhizopus stolonifer SC 16199, Neuros-pora crassa SC 13816, Mucor racemosus SC 16198, and Pseudomonas putida SC 13817 gave >50% reaction yields and >95% ee s of (,S )-6-hydroxybuspi-rone. The yeast strains Hansenula polymorpha SC 13845 and Candida maltosa SC 16112 gave (R)-6-hydroxybuspirone in >60% reaction yield and >97% ee (Patel et aL, 2005). 

Candida tropicalis PBR-2, a yeast strain isolated from soil, is capable of carrying out the enantioselective reduction of N,N-dimethyl-3-keto-3-(2-thienyl)-l-propanamine 58 to (S)-N,N-dimethyl-3-hydroxy-3-(2-thienyl)-l-propanamine 59 (Fig. 18.18), a key intermediate in the synthesis of the chiral drug (S)-Duloxetine (Soni and Banerjee, 2005). The organism produced the enantiopure (S)-alcohol with a good yield (>80%) and almost absolute enan-tioselectivity, with an ee >99%. Parameters of the bioreduction reaction were optimized and the optimal temperature and pH for the reduction were found to be 30 °C and 7.0, respectively. The optimized substrate and the resting cell concentration were lg/1 and 250 g/1, respectively. The preparative-scale reaction using resting cells of C. tropicalis yielded the (S)-alcohol at 84-88% conversion and ee >99%. 

Yeast strains belonging to the species of Candida fahianii, Candida guilliermondii, Candida tropicalis, Deharyomyces hansenii, Saccharomyces cerevisiae, Torulopsis Candida CandidaJumata), and Williopsis satumus also exhibit the nitrile hydratase/ amidase system able to use the series of aliphatic mono- and dinitriles as well as their matching amides as the sole N-source [20]. 

Borg-von Zepelin M, Meyer I, Thomssen R, Wurzner R, Sanglard D, Telenti A, Monod M HIV-protease inhibitors reduce cell adherence of Candida albicans strains by inhibition of yeast secreted aspartic proteases. J Invest Dermatol 1999 13 747-751. 

Sanchez-Torres, R, Gonzalez-Candelas, L., Ramo, D. (1998). Heterologous expresion of a Candida molischiana anthocyanin-/3-glucosidase in a wine yeast strain. J. Agric. Food Chem. 46, 354-360. 

Acetylenic isobutylamides and polyacetylenes occurring in Echinacea have been shown to inhibit the growth of yeast strains of Saccharomyces cerevisiae, Candida shehata, Candida kefyr, Candida albicans, Candida steatulytica, and Candida tropicalis. This growth inhibition occurred to a greater extent under ultraviolet irradiation than without it. There are other compounds in Echinacea that are suspected to be phototoxic to microbes, but this has yet to be demonstrated (16). 

In yeast and mycelial fungi, xylose is metabolized via coupled oxidation-reduction reactions . Xylose reductase is the enzyme involved in the reduction of xylose to xylitol. Sequential enzymatic events, through the oxidation of xylitol to xylulose, lead to the utilization of xylose. Many yeast species utilize xylose readily, but the ethanol production capability is very limited. Only a few yeast species effectively produce ethanol from xylose these include Pachysolen tan-nophilus, Candida shihatae and Pichia stipitis [80]. The production of ethanol from xylose by these three yeast strains has been studied extensively in recent years. Recently, genetically engineered yeast strains have been constructed for more effective conversion of xylose to ethanol. 

Although many facultatively fermentative yeasts utilize xylose as the carbon source for growth, the ability of these yeasts to produce ethanol from xylose is limited. Yeast strains that utilize xylose often produce xylitol from xylose extra-cellularly as a normal metabolic activity. However, only a few can produce significant quantities of ethanol. The prominent strains that produce ethanol from xylose include Pachysolen tannophilus, Candida shihatae and Pichia stipitis. However, the efficient production of ethanol from xylose is limited by the regulation of dissolved oxygen as well as by the imbalance of cofactors in the metabolic pathway during xylose utilization. In recent years, much effort has been put into improving yeast strains in order to produce ethanol from xylose more efficiently. 

In 1929 Kinoshita [107] identified itaconic acid as the major metaboHc product of A. itaconicus. Later research showed that A. terreus is a better biocatalyst for itaconic acid accumulation. A number of yeast strains belonging to Candida and Rhodotorula [108] can also accumulate a limited amount of itaconic acid. Patents on the industrial production of itaconic acid using Aspergilli as the biocatalyst from molasses were issued in 1961. The currently preferred industrial process uses improved strains of A. terreus as the biocatalyst. The most often studied itaconic acid producers are A. terreus NRRL 265 and A. terreus NRRL 1960. 

The yeast strains Candida moUschiana 35 [5] and 35M5N [6], Candida entomophila... 

In 1991, Vasserot et al. isolated a yeast strain Candida ntolischiana 35) which produced an extracellular (3-glucosidase with a wide substrate spectrum and that could function at low pH value [3]. This enzyme was successfully studied for its potential to liberate aroma-rich terpenes. Microbial p-glucosidases can be used industrially in one of two ways. Either purified enzyme or intact cells could be immobilized or free in solution. Candida species are generally not well-suited for direct use in these industrial processes, because they fail to grow under the conditions of use. For this reason, the alternative approach of using the enzyme is more desirable. However, in order to permitt the process to be economically feasible, increased quantities of... 

Studies on Candida infection support the concept that neutrophils can be induced to release either pro- or anti-inflammatory cytokines, depending upon antigenic stimulus. Thus, mouse PMN cultured with a nonhealer C. albicans strain produce IL-10, while an attenuated yeast strain induces IL-12 [74,80]. In similar fashion, PMN isolated from mice genetically resistant to Trypanosoma cruzi were reported to produce IL-12 p40 and IFN-y, in contrast to cells from susceptible animals [73]. As described above, a subset of PMN from noninfected... 

In another study with wild strains isolated from raw milk, four different E. faecalis strains were shown to express ACE-inhibitory aetivity (IC50 values 34-59 mg/ml) in fermented milk (Muguerza et al., 2006). Quiros et al. (2007) identified several peptides in milk fermented with E. faecalis CECT 5727, and two of them, Leu-His-Leu-Pro-Leu-Pro [p-casein f(133-138)] and Leu-Val-Tyr-Pro-Phe-Pro-Gly-Pro-Ile-Pro-Asn-Ser-Leu-Pro-Gln-Asn-Ile-Pro-Pro [p-casein f(58-76)], showed IC50 values as low as 5 pM. ACE-inhibitory activity has been documented also in some yeast species, namely, S. cerevisiae and Candida parapsilosis (Hamme, Sannier, Piot, Didelot, Bordenave-Juchereau, 2009 Kuwabara et al., 1995). Eighteen yeast strains produced fermented milk with ACE-inhibitory values ranging from 8.7% to 88.2%. The... 

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