Effect of nitrogen sources on the levels of aldose reductase and xylitol dehydrogenase activities in the xylose-fermenting yeast Candida tenuis

Kern, Martin; Nidetzky, Bernd; Kulbe, Klaus D.; Haltrich, Dietmar

doi:10.1016/s0922-338x(97)86767-0

Cited by 17 publications

(3 citation statements)

References 23 publications

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“…In these trials, three parameters were kept constant: medium contained 2.5% (w/v) yeast extract, pH was 5.5 and aeration was by shaking at 250 rpm. Yeast extract has been shown to be a good nitrogen source, increasing aldose (xylose) reductase activity, thus enhancing the metabolism rate of xylose [ 15 ]. An aeration rate of 250 rpm improved significantly the assimilation and metabolism rate of xylitol presumably by providing more cofactor NAD, thus shortening the fermentation time to enrich L-arabinose.…”

Section: Methodsmentioning

confidence: 99%

A novel method to prepare L-Arabinose from xylose mother liquor by yeast-mediated biopurification

Cheng

Wang

et al. 2011

Microb Cell Fact

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BackgroundL-arabinose is an important intermediate for anti-virus drug synthesis and has also been used in food additives for diets-controlling in recent years. Commercial production of L-arabinose is a complex progress consisting of acid hydrolysis of gum arabic, followed by multiple procedures of purification, thus making high production cost. Therefore, there is a biotechnological and commercial interest in the development of new cost-effective and high-performance methods for obtaining high purity grade L-arabinose.ResultsAn alternative, economical method for purifying L-arabinose from xylose mother liquor was developed in this study. After screening 306 yeast strains, a strain of Pichia anomala Y161 was selected as it could effectively metabolize other sugars but not L-arabinose. Fermentation in a medium containing xylose mother liquor permitted enrichment of L-arabinose by a significant depletion of other sugars. Biochemical analysis of this yeast strain confirmed that its poor capacity for utilizing L-arabinose was due to low activities of the enzymes required for the metabolism of this sugar. Response surface methodology was employed for optimization the fermentation conditions in shake flask cultures. The optimum conditions were: 75 h fermentation time, at 32.5°C, in a medium containing 21% (v/v) xylose mother liquor. Under these conditions, the highest purity of L-arabinose reached was 86.1% of total sugar, facilitating recovery of white crystalline L-arabinose from the fermentation medium by simple methods.ConclusionYeast-mediated biopurification provides a dynamic method to prepare high purity of L-arabinose from the feedstock solution xylose mother liqour, with cost-effective and high-performance properties.

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Section: Methodsmentioning

confidence: 99%

A novel method to prepare L-Arabinose from xylose mother liquor by yeast-mediated biopurification

Cheng

Wang

et al. 2011

Microb Cell Fact

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“…In scientiWc literature, there is no suYcient information regarding to the inXuence of xylose concentration connected to medium pH over the enzymes of xylose metabolism, although some eVorts have been made in last years in order to elucidate the importance of other variables over this metabolism, for example: the eVect of oxygen transfer rates in Debaryomyces hansenii [7]; the induction of aldose reductase and XD activities from C. guilliermondii on mixed sugars [5], the eVect of nitrogen sources on the levels of aldose reductase and XD activities in C. tenuis [17] and the eVect of acetic acid present in bagasse hydrolysate on the activity of XR and XD in C. guilliermondii [18]. However, none of those researchers mentioned about the behavior of another important enzyme, G6PD, belonging to the PPP, the main source of NADPH, the XR cofactor.…”

Section: Biomass and Xylitol Productionmentioning

confidence: 99%

The behavior of key enzymes of xylose metabolism on the xylitol production by Candida guilliermondii grown in hemicellulosic hydrolysate

Gurpilhares

Hasmann

Pessoa

et al. 2008

J Ind Microbiol Biotechnol

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A variety of raw materials have been used in fermentation process. This study shows the use of rice straw hemicellulosic hydrolysate, as the only source of nutrient, to produce high added-value products. In the present work, the activity of the enzymes xylose reductase (XR); xylitol dehydrogenase (XD); and glucose-6-phosphate dehydrogenase (G6PD) during cultivation of Candida guilliermondii on rice straw hemicellulosic hydrolysate was measured and correlated with xylitol production under different pH values (around 4.5 and 7.5) and initial xylose concentration (around 30 and 70 g l(-1)). Independent of the pH value and xylose concentration evaluated, the title of XD remained constant. On the other hand, the volumetric activity of G6PD increased whereas the level of XR decreased when the initial xylose concentration was increased from 30 to 70 g l(-1). The highest values of xylitol productivity (Q (P) approximately 0.40 g l(-1)) and yield factor (Y (P/S) approximately 0.60 g g(-1)) were reached at highest G6PD/XR ratio and lowest XR/XD ratio. These results suggest that NADPH concentrations influence the formation of xylitol more than the activity ratios of the enzymes XR and XD. Thus, an optimal rate between G6PD and XR must be reached in order to optimize the xylitol production.

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“…A high final concentration of xylitol is achieved in the fermentation broth to potentially reduce the cost of downstream product recovery. Effects of the nitrogen sources on the fermentation are reported, as in studies with other yeasts, nitrogen sources have been found to influence production of biomass and xylitol . A fed‐batch production strategy demonstrated previously for a sorbose fermentation, is shown to greatly enhance xylitol productivity relative to a batch fermentation.…”

Section: Introductionmentioning

confidence: 86%

Repeated fed‐batch production of xylitol by Candida magnoliaeTISTR 5663

Sirisansaneeyakul

Wannawilai

Chisti

2012

J of Chemical Tech & Biotech

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Effect of nitrogen sources on the levels of aldose reductase and xylitol dehydrogenase activities in the xylose-fermenting yeast Candida tenuis

Cited by 17 publications

References 23 publications

A novel method to prepare L-Arabinose from xylose mother liquor by yeast-mediated biopurification

A novel method to prepare L-Arabinose from xylose mother liquor by yeast-mediated biopurification

The behavior of key enzymes of xylose metabolism on the xylitol production by Candida guilliermondii grown in hemicellulosic hydrolysate

Repeated fed‐batch production of xylitol by Candida magnoliaeTISTR 5663

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