Showing papers on "Arabitol published in 2018"
TL;DR: Arabitol yield increased with increasing C/N ratio and a high I/O-N, suggesting higher yield at stationary phase of low pH, and catabolite repression was observed, with the following order of consumption: glucose > fructose > galactose > xylose > arabinose.
Abstract: Arabitol is a low-calorie sugar alcohol with anti-cariogenic properties. Enzymatic hydrolysate of soybean flour is a new renewable biorefinery feedstock containing hexose, pentose, and organic nitrogen sources. Arabitol production by Debaryomyces hansenii using soybean flour hydrolysate was investigated. Effects of medium composition, operating conditions, and culture stage (growing or stationary phase) were studied. Production was also compared at different culture volumes to understand the effect of dissolved oxygen concentration (DO). Main factors examined for medium composition effects were the carbon to nitrogen concentration ratio (C/N), inorganic (ammonium) to organic nitrogen ratio (I/O-N), and sugar composition. Arabitol yield increased with increasing C/N ratio and a high I/O-N (0.8–1.0), suggesting higher yield at stationary phase of low pH (3.5–4.5). Catabolite repression was observed, with the following order of consumption: glucose > fructose > galactose > xylose > arabinose. Arabitol production also favored hexoses and, among hexoses, glucose. DO condition was of critical importance to arabitol production and cell metabolism. The yeast consumed pentoses (xylose and arabinose) only at more favorable DO conditions. Finally, arabitol was produced in fermentors using mixed hydrolysates of soy flour and hulls. The process gave an arabitol yield of 54%, volumetric productivity of 0.90 g/L-h, and specific productivity of 0.031 g/g-h.
27 citations
TL;DR: In this article, a few-step approach for valorizing wheat bran into arabitol and xylitol via a few step approach is presented. But it does not address the problem of high energy consumption.
Abstract: Wheat bran is a lignocellulosic waste of milling industry. It contains hemicelluloses, which can be valorized into arabitol and xylitol via a few-step approach. It begins with extraction and hydrol...
20 citations
TL;DR: Results show that the formation of volatile and nonvolatile metabolites of S. fibuligera KJJ81 can be significantly affected by both the carbon sources and the cultivation time.
Abstract: Saccharomycopsis fibuligera KJJ81 isolated from nuruk is an amylolytic yeast that is widely used as a microbial starter in various fermented foods. Volatile and nonvolatile metabolites of S. fibuligera KJJ81 were investigated according to different carbon sources and cultivation times using a nontargeted metabolomic approach. Partial-least-squares discriminant analysis was applied to determine the major metabolites, which were found to be closely related to the clustering and discrimination of S. fibuligera KJJ81 samples. Some volatile metabolites derived from phenylalanine, such as 2-phenylethanol, 2-phenylethyl acetate, and ethyl phenylacetate, were predominantly found in cultivation medium containing glucose (YPD medium). In addition, the level of 2-phenylethanol increased continuously with the cultivation time. In terms of nonvolatile metabolites, carbohydrates (mannose, arabitol, and mannitol), fatty acids (palmitic acid and stearic acid), organic acids (oxalic acid and succinic acid), and amino acids (isoleucine, serine, alanine, glutamic acid, glycine, proline, phenylalanine, and threonine) were the main contributors to S. fibuligera KJJ81 samples cultivated in YPD medium according to cultivation time. These results show that the formation of volatile and nonvolatile metabolites of S. fibuligera KJJ81 can be significantly affected by both the carbon sources and the cultivation time.
17 citations
TL;DR: In this article, a strain designated GLp was constructed by inserting the bovine lactic acid dehydrogenase gene (LDHb) concomitantly with the interruption of the gene encoding pyruvate decarboxylase (PDC).
Abstract: Lactic acid is the monomer unit of the bioplastic poly-lactic acid (PLA). One candidate organism for lactic acid production is Pichia pastoris, a yeast widely used for heterologous protein production. Nevertheless, this yeast has a poor fermentative capability that can be modulated by controlling oxygen levels. In a previous study, lactate dehydrogenase (LDH) activity was introduced into P. pastoris, enabling this yeast to produce lactic acid. The present study aimed to increase the flow of pyruvate towards the production of lactic acid in P. pastoris. To this end, a strain designated GLp was constructed by inserting the bovine lactic acid dehydrogenase gene (LDHb) concomitantly with the interruption of the gene encoding pyruvate decarboxylase (PDC). Aerobic fermentation, followed by micro-aerophilic culture two-phase fermentations, showed that the GLp strain achieved a lactic acid yield of 0.65 g/g. The distribution of fermentation products demonstrated that the acetate titer was reduced by 20% in the GLp strain with a concomitant increase in arabitol production: arabitol increased from 0.025 g/g to 0.174 g/g when compared to the GS115 strain. Taken together, the results show a significant potential for P. pastoris in producing lactic acid. Moreover, for the first time, physiological data regarding co-product formation have indicated the redox balance limitations of this yeast.
14 citations
TL;DR: Wang et al. as discussed by the authors investigated the fungal spore tracers in fine particles (PM2.5), including mannitol and arabitol at an urban site in a Chinese megacity.
11 citations
TL;DR: The constitutively high mannitol content in Y. lipolytica cells was hypothesized to be a part of the core mechanism of stress resistance in this yeast species.
Abstract: Alterations in the concentrations of cell cytosol carbohydrates of polyextremophilic yeasts Yarrowia lipolytica under stresses of diverse nature were observed. Under pH stress, mannitol was the main storage carbohydrate (up to 89% of the total cytosol carbohydrates), while arabitol, glucose, and inositol were present in insignificant amounts (3 to 6%). Experiments with inhibition of de novo mannitol synthesis by bis(p-nitrophenyl) disulfide revealed that the cytoprotective effect of mannitol was most noticeable in the cells grown under acidic conditions (pH 4.0), while the role of catalase and superoxide dismutase, the enzymes of the first line of antioxidant protection, increased under alkaline conditions (pH 9.0). The constitutively high mannitol content in Y. lipolytica cells was hypothesized to be a part of the core mechanism of stress resistance in this yeast species.
9 citations
TL;DR: Findings indicate beneficial effects of endogenous polyols in improving shelf life of encapsulated mycelium and this may spur the successful development of microbial biocontrol agents in the future.
Abstract: Successful commercialization of microbial biocontrol agents, such as Metarhizium spp., is often constrained by poor drying survival and shelf life. Here, we hypothesized that culture age would influence endogenous arabitol, erythritol, mannitol and trehalose contents in M. brunneum mycelium and that elevated levels of these compounds would improve drying survival and shelf life of encapsulated mycelium coupled with enhanced fungal virulence against T. molitor larvae. We found that culture age significantly influenced endogenous arabitol and mannitol contents in mycelium with highest concentrations of 0.6 ± 0.2 and 2.1 ± 0.2 µg/mg after 72 h, respectively. Drying survival of encapsulated mycelium was independent of culture age and polyol content with 41.1 ± 4.4 to 55.0 ± 6.2%. Best shelf life was determined for biomass harvested after 72 h at all investigated storage temperatures with maximum values of 59.5 ± 3.3% at 5 °C followed by 54.5 ± 1.6% at 18 °C and 19.4 ± 1.3% at 25 °C after 6 months. Finally, high fungal virulence against T. molitor larvae of 83.3 ± 7.6 to 98.0 ± 1.8% was maintained during storage of encapsulated mycelium for 12 months with larval mortalities being independent of culture age and polyol content. In conclusion, our findings indicate beneficial effects of endogenous polyols in improving shelf life of encapsulated mycelium and this may spur the successful development of microbial biocontrol agents in the future.
9 citations
TL;DR: Investigation of metabolites produced during fungal development on maize and their correlation with aflatoxin levels found several polar metabolites were important for dose classification and several metabolites were interconnected with the TCA cycle.
Abstract: Aflatoxin contamination is associated with the development of aflatoxigenic fungi such as Aspergillus flavus and A. parasiticus on food grains. This study was aimed at investigating metabolites produced during fungal development on maize and their correlation with aflatoxin levels. Maize cobs were harvested at R3 (milk), R4 (dough), and R5 (dent) stages of maturity. Individual kernels were inoculated in petri dishes with four doses of fungal spores. Fungal colonisation, metabolite profile, and aflatoxin levels were examined. Grain colonisation decreased with kernel maturity: milk-, dough-, and dent-stage kernels by approximately 100%, 60%, and 30% respectively. Aflatoxin levels increased with dose at dough and dent stages. Polar metabolites including alanine, proline, serine, valine, inositol, iso-leucine, sucrose, fructose, trehalose, turanose, mannitol, glycerol, arabitol, inositol, myo-inositol, and some intermediates of the tricarboxylic acid cycle (TCA—also known as citric acid or Krebs cycle) were important for dose classification. Important non-polar metabolites included arachidic, palmitic, stearic, 3,4-xylylic, and margaric acids. Aflatoxin levels correlated with levels of several polar metabolites. The strongest positive and negative correlations were with arabitol (R = 0.48) and turanose and (R = −0.53), respectively. Several metabolites were interconnected with the TCA; interconnections of the metabolites with the TCA cycle varied depending upon the grain maturity.
9 citations
TL;DR: Comparative composition of lipids and cytosol soluble carbohydrates at different ambient pH values was studied for two obligately alkaliphilic fungi and for two alkalitolerant ones to indicate importance of trehalose and arabitol for alkalphily.
Abstract: Comparative composition of lipids and cytosol soluble carbohydrates at different ambient pH values was studied for two obligately alkaliphilic fungi (Sodiomyces magadii and S. alkalinus) and for two alkalitolerant ones (Acrostalagmus luteoalbus and Chordomyces antarcticus). The differences and common patterns were revealed in responses to pH stress for the fungi with different types of adaptation to ambient pH. While trehalose was one of the major cytosol carbohydrates in alkaliphilic fungi under optimal growth conditions (pH 10.2), pH decrease to 7.0 resulted in doubling its content. In alkalitolerant fungi trehalose was a minor component and its level did not change significantly at different pH. In alkalitolerant fungi, arabitol and mannitol were the major carbohydrate components, with their highest ratio observed under alkaline conditions and the lowest one, under neutral and acidic conditions. In alkaliphiles, significant levels of arabitol were revealed only under alkaline conditions, which indicated importance of trehalose and arabitol for alkaliphily. Decreased pH resulted in the doubling of the proportion of phosphatidic acids among the membrane lipids, which was accompanied by a decrease in the fractions of phosphatidylcholines and sterols. Alkalitolerant fungi also exhibited a decrease in sterol level at decreased pH, but against the background of increased proportion of one of phospholipids. Decreased unsaturation degree in the fatty acids of the major phospholipids was a common response to decreased ambient pH.
9 citations
TL;DR: Genome shuffling was performed in Candida parapsilosis DSM 70125, an efficient producer of arabitol, to obtain fusants with improvedArabitol production ability and showed that the ploidy of the new strains did not change.
Abstract: Arabitol is used in the food industry as a low-calorie sweetener. It is produced by yeasts during the biotransformation process of l-arabinose. Genome shuffling was performed in Candida parapsilosis DSM 70125, an efficient producer of arabitol, to obtain fusants with improved arabitol production ability. Four mutants from the parental library were used for the first round of genome shuffling. The best fusants, GSI-1 and GSI-10A, were subjected to a second round of genome shuffling. Finally, two fusants, GSII-3 and GSII-16, produced concentrations of arabitol that were 50% higher than that of the wild-type strain during selection culture. Under the optimal conditions established for C. parapsilosis, the two fusants produced 11.83 and 11.75 g/L of arabitol and were approximately 15–16% more efficient than the wild-type strain. Flow cytometry analysis showed that the ploidy of the new strains did not change.
7 citations
TL;DR: The proposed reversed phase ion-pair chromatographic method, based on the on-line complexation of sugar alcohols with molybdate ion, was successfully applied to measure sugarcohols in health drinks, eyedrops and mouthwashes.
TL;DR: 50 yeasts belonging to 24 ascomycetous species were screened for the ability to grow and produce arabitol in presence of 80 g/L lactose or glycerol, indicating that production is not growth associated and revealed some major parameters affecting production, such as the pH and the C:N ratio, that will be the target of following studies aiming at process optimization.
Abstract: Arabitol is a sugar alcohol, stereoisomer to xylitol, which is enlisted among the main target for biorefineries. It can serve as low calorie sweetener and as building block in the enantiopure synthesis of immunosuppressive glycolipids, herbicides, and drugs. Several studies described the fermentative production of arabitol by osmophilic yeasts, cultured with high concentrations of D-glucose. The utilization of cheaper carbon sources, such as glycerol or lactose, is of great interest for biorefinery implementation, but information on exploitation to arabitol production is still scarce. In the present study 50 yeasts belonging to 24 ascomycetous species were screened for the ability to grow and produce arabitol in presence of 80 g/L lactose or glycerol. Production from lactose was generally unsuccessful, the best producer being Kluyveromyces lactis WC 1401 with 0.94 g/L in 160 h. Production from glycerol was promising, with Zygosaccharomyces rouxii WC 1206, Pichia guilliermondii CBS 566, Hansenula anomala WC 1501, and Candida freyschussii ATCC 18737 yielding 3 to 4.5 g/L arabitol, with conversion yield (YP/S) ranging from 11 to 21.7%. Batch growth with high initial glycerol amount (160 g/L) resulted in higher production, with H. anomala WC 1501 yielding 10.0 g/L arabitol (YP/S = 12%) in 160 h. Preliminary bioreactor fermentations with H. anomala WC 1501 indicated that production is not growth associated and revealed some major parameters affecting production, such as the pH and the C:N ratio, that will be the target of following studies aiming at process optimization. Cultivation under controlled oxygenation (DOT = 20%) and pH (≥ 3.0) resulted in improvement in the performance of H. anomala WC 1501, yielding 16.1 g/L arabitol. Cultivation in a medium with high C:N ratio, lacking inorganic nitrogen yielded 17.1 g/L arabitol. Therefore, this strain was selected for the development of a fed-batch process, aiming to improve the efficiency of the biomass, generated in the growth phase, and increasing the production in the stationary phase.
Patent•
26 Jan 2018
TL;DR: In this article, a method for rapidly determining arabitol and mannitol in aerosol is proposed, which comprises the following steps: 1) preprocessing a sample: ultrasonically extracting arabalt and man nitol from an aerosol sample by using ultrapure water, and filtering the obtained solution; 2) determining the sample: taking a liquid chromatogram with the chromatographic column being an anion exchange column, and carrying out mass spectrometry multiple reaction monitoring analysis by using a mass analyzer: selecting and simultaneously detecting a plurality of parent
Abstract: The invention relates to the technical field of atmospheric chemical analysis test, and especially discloses a method for rapidly determining arabitol and mannitol in aerosol. The method comprises thefollowing steps: 1, preprocessing a sample: ultrasonically extracting arabitol and mannitol from an aerosol sample by using ultrapure water, and filtering the obtained solution; 2, determining the sample: taking a liquid chromatogram with the chromatographic column being an anion exchange column, and carrying out mass spectrometry multiple reaction monitoring analysis by using a mass analyzer: selecting and simultaneously detecting a plurality of parent ion pairs and daughter ion pairs, allowing the parent ions with the mass-to-charge ratio being 151.0 and 181.0 to undergo first-level mass spectrometry and enter a bumping chamber, and allowing ions of chips broken by the bumping chamber, with the mass-to-charge ratio being 71.0, 59.0 and 89.1, to undergo second-level mass spectrometry, wherein the same parent and daughter ion pairs have same compound parameters; and 3, processing data: qualitatively detecting the arabitol and the mannitol, and respectively quantifying the arabitol andthe mannitol with 151.0-71.0 and 181.0-89.1 ion pairs with highest abundance. The method has the advantages of fast detection speed and low cost.