Characterization of Candida sp. NY7122, a novel pentose-fermenting soil yeast

Abstract

Yeasts that ferment both hexose and pentose are important for cost-effective ethanol production. We found that the soil yeast strain NY7122 isolated from a blueberry field in Tsukuba (East Japan) could ferment both hexose and pentose (D-xylose and L-arabinose). NY7122 was closely related to Candida subhashii on the basis of the results of molecular identification using the sequence in the D1/D2 domains of 26S rDNA and 5.8S-internal transcribed spacer region. NY7122 produced at least 7.40 and 3.86 g l⁻¹ ethanol from 20 g l⁻¹ D-xylose and L-arabinose within 24 h. NY7122 could produce ethanol from pentose and hexose sugars at 37°C. The highest ethanol productivity of NY7122 was achieved under a low pH condition (pH 3.5). Fermentation of mixed sugars (50 g l⁻¹ glucose, 20 g l⁻¹ D-xylose, and 10 g l⁻¹ L-arabinose) resulted in a maximum ethanol concentration of 27.3 g l⁻¹ for the NY7122 strain versus 25.1 g l⁻¹ for Scheffersomyces stipitis. This is the first study to report that Candida sp. NY7122 from a soil environment could produce ethanol from both D-xylose and L-arabinose.

The production of arabitol by a novel plant yeast isolate Candida parapsilosis 27RL-4

“…Praphailong et al [18] and McGinnis et al [21], in evaluating studies, reported that it can sometimes provide an incomplete or incorrect identification, but C. parapsilosis was also recognized correctly. It should be noted that there are several differences between the metabolic profile obtained using Regional Laboratory of Renewable Energy, Institute ofof substrate at 30 and 37°C, respectively, with yields in the range 0.3-0.53 g g -1 [9]. The results obtained for the isolate C. parapsilosis 27RL-4 are generally similar to observations made on the capabilities of other Candida strains.…”

“…The use of this method with positive results has been reported in screening of pentose-fermenting yeasts [9], and xylitol and D-arabitol producing strains [16,17]. It is worth noting that in the three reports mentioned, the percentages of effective yeast strains were 1.5, 2.12, and 2.6%, respectively, while in the present work it was 1%.…”

“…Watanabe et al [9] selected strain NY7122, related to Candida subhashii, which was able to produce L-arabitol and ethanol from L-arabinose. Kumdam et al [4] determined that Debaryomyces nepalensis, isolated from rotten apple, produced arabitol in batch cultures with a yield of 0.26 g g -1 .…”

Preliminary Analysis of Sugar Supplementation on Alcoholic Fermentation by <i>Meyerozyma guilliermondii</i>

“…Preliminary studies on the production of alcohol from these alternative carbon sources would aid in the supply chain, emulating countries like Brazil and America who generate bioethanol from their excess sugar cane and corn resources [7]. For that reason, research into the consumption and fermentation of pentose sugars would be a logical step in the production of ethanol from alternative organic stock [8]. As research is turning to the exploration of unconventional organic substrates for ethanol production, known limits of S. cerevisiae in alcoholic fermentation are being stretched [9], [10].…”

Isolation and characterization of yeasts capable of efficient utilization of hemicellulosic hydrolyzate as the carbon source

“…All sugars present in lignocellulosic material, including D-glucose, D-mannose, D-galactose, D-xylose, and L-arabinose, must be fermented for cost-effective ethanol production. Therefore, a critical feature of any industrial producer of ethanol from lignocellulose is its ability to effectively ferment pentose sugars (Watanabe et al, 2012).…”