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Sample records for yeast extract hydrolysate

  1. 40 CFR 180.1246 - Yeast Extract Hydrolysate from Saccharomyces cerevisiae: exemption from the requirement of a...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Yeast Extract Hydrolysate from... PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1246 Yeast Extract Hydrolysate from... exemption from the requirement of a tolerance for residues of the biochemical pesticide Yeast...

  2. 40 CFR 180.1246 - Yeast Extract Hydrolysate from Saccharomyces cerevisiae: exemption from the requirement of a...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Yeast Extract Hydrolysate from... PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1246 Yeast Extract Hydrolysate from... exemption from the requirement of a tolerance for residues of the biochemical pesticide Yeast...

  3. 40 CFR 180.1246 - Yeast Extract Hydrolysate from Saccharomyces cerevisiae: exemption from the requirement of a...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Yeast Extract Hydrolysate from... PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1246 Yeast Extract Hydrolysate from... exemption from the requirement of a tolerance for residues of the biochemical pesticide Yeast...

  4. 40 CFR 180.1246 - Yeast Extract Hydrolysate from Saccharomyces cerevisiae: exemption from the requirement of a...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Yeast Extract Hydrolysate from... PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1246 Yeast Extract Hydrolysate from... exemption from the requirement of a tolerance for residues of the biochemical pesticide Yeast...

  5. 40 CFR 180.1246 - Yeast Extract Hydrolysate from Saccharomyces cerevisiae: exemption from the requirement of a...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Yeast Extract Hydrolysate from... PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1246 Yeast Extract Hydrolysate from... exemption from the requirement of a tolerance for residues of the biochemical pesticide Yeast...

  6. Membrane Extraction for Detoxification of Biomass Hydrolysates

    SciTech Connect

    Grzenia, D. L.; Schell, D. J.; Wickramasinghe, S. R.

    2012-05-01

    Membrane extraction was used for the removal of sulfuric acid, acetic acid, 5-hydroxymethyl furfural and furfural from corn stover hydrolyzed with dilute sulfuric acid. Microporous polypropylene hollow fiber membranes were used. The organic extractant consisted of 15% Alamine 336 in: octanol, a 50:50 mixture of oleyl alcohol:octanol or oleyl alcohol. Rapid removal of sulfuric acid, 5-hydroxymethyl and furfural was observed. The rate of acetic acid removal decreased as the pH of the hydrolysate increased. Regeneration of the organic extractant was achieved by back extraction into an aqueous phase containing NaOH and ethanol. A cleaning protocol consisting of flushing the hydrolysate compartment with NaOH and the organic phase compartment with pure organic phase enabled regeneration and reuse of the module. Ethanol yields from hydrolysates detoxified by membrane extraction using 15% Alamine 336 in oleyl alcohol were about 10% higher than those from hydrolysates detoxified using ammonium hydroxide treatment.

  7. Bioprocessing of bagasse hydrolysate for ethanol and xylitol production using thermotolerant yeast.

    PubMed

    Kumar, Sachin; Dheeran, Pratibha; Singh, Surendra P; Mishra, Indra M; Adhikari, Dilip K

    2015-01-01

    Fermentation of xylose-rich and glucose-rich bagasse hydrolysates, obtained from the two-stage acid hydrolysis was studied using the thermotolerant yeast Kluyveromyces sp. IIPE453. The yeast could grow on xylose-rich hydrolysate at 50 °C with the dry cell weight, cell mass yield and maximum specific growth rate of 5.35 g l(-1), 0.58 g g(-1) and 0.13 h(-1), respectively. The yeast was found to be very promising for ethanol as well as xylitol production from the sugars obtained from the lignocellulosic biomass. Batch fermentations of xylose-rich and glucose-rich hydrolysates yielded 0.61 g g(-1) xylitol and 0.43 g g(-1) ethanol in the broth, respectively based on the sugars present in the hydrolysate. Overall ethanol yield of 165 g (210 ml) and 183 g xylitol per kg of bagasse was obtained, when bagasse hydrolysate was used as a substrate. Utilization of both the glucose and xylose sugars makes the process most economical by producing both ethanol and xylitol based on biorefinery concept. On validating the experimental data of ethanol fermentation, the modified Luong kinetic model for product inhibition as well as inhibition due to inhibitory compounds present in hydrolysate, the model was found to be the best fit for ethanol formation from bagasse hydrolysate using Kluyveromyces sp. IIPE453. PMID:25090978

  8. Yeast strains for ethanol production from lignocellulosic hydrolysates during in situ detoxification.

    PubMed

    Tian, Shen; Zhou, Guixiong; Yan, Fei; Yu, Yong; Yang, Xiushan

    2009-01-01

    Yeast strains Y1, Y4 and Y7 demonstrated high conversion efficiencies for sugars and high abilities to tolerate or metabolize inhibitors in dilute-acid lignocellulosic hydrolysates. Strains Y1 and Y4 completely consumed the glucose within 24 h in dilute-acid lignocellulosic hydrolysate during in situ detoxification, and the maximum ethanol yields reached 0.49 g and 0.45 g ethanol/g glucose, equivalent to maximum theoretical values of 96% and 88.2%, respectively. Strain Y1 could metabolize xylose to xylitol with a yield of 0.64 g/g xylose, whereas Y4 was unable to utilize xylose as a substrate. Strain Y7 was able to consume sugars (glucose and xylose) within 72 h during hydrolysate in situ detoxification, producing a high ethanol yield (equivalent to 93.6% of the maximum theoretical value). Y1 and Y7 are the most efficient yeast strains yet reported for producing ethanol from non-detoxified dilute-acid lignocellulosic hydrolysates. These findings offer huge potential for improving the economics of bio-ethanol production from lignocellulosic hydrolysates. PMID:19393310

  9. Ethanol production using a soy hydrolysate-based medium or a yeast autolysate-based medium

    DOEpatents

    Ingram, Lonnie O.

    2000-01-01

    This invention presents a method for the production of ethanol that utilizes a soy hydrolysate-based nutrient medium or a yeast autolysate-based medium nutrient medium in conjunction with ethanologenic bacteria and a fermentable sugar for the cost-effective production of ethanol from lignocellulosic biomass. The invention offers several advantages over presently available media for use in ethanol production, including consistent quality, lack of toxins and wide availability.

  10. Production of bioactive protein hydrolysate using the yeasts isolated from soft chhurpi.

    PubMed

    Rai, Amit Kumar; Kumari, Reena; Sanjukta, Samurailatpam; Sahoo, Dinabandhu

    2016-11-01

    The aim of this work was to study the production of bioactive protein hydrolysates using yeasts isolated from chhurpi. For this, a total of 125 proteolytic yeasts were isolated and molecular identification was carried out by analysis of the restriction digestion pattern generated by digesting the PCR amplified internal transcribed spacer region and 5.8S rRNA gene (ITS1-5.8S-ITS2) using three endonucleases (HaeIII, CfoI and HinfI). The results obtained showed that different proteolytic yeasts were dominant in marketed products (Kluyveromyces marxianus and Issatchenkia orientalis) and samples from production centers (Trichosporon asahii, Saccharomyces cerevisiae and Exophiala dermatitidis). Proteolytic strains in individual groups showed their ability to hydrolyze milk protein and enhance antioxidant property. Among the isolates, fermentation using K. marxianus YMP45 and S. cerevisiae YAM14 resulted in higher antioxidant activity. This is the first report on application of yeast isolated from fermented food of North-East India for the production of bioactive protein hydrolysate. PMID:27494105

  11. Molecular mechanisms of yeast tolerance and in situ detoxification of lignocellulose hydrolysates.

    PubMed

    Liu, Z Lewis

    2011-05-01

    Pretreatment of lignocellulose biomass for biofuel production generates inhibitory compounds that interfere with microbial growth and subsequent fermentation. Remediation of the inhibitors by current physical, chemical, and biological abatement means is economically impractical, and overcoming the inhibitory effects of lignocellulose hydrolysate poses a significant technical challenge for lower-cost cellulosic ethanol production. Development of tolerant ethanologenic yeast strains has demonstrated the potential of in situ detoxification for numerous aldehyde inhibitors derived from lignocellulose biomass pretreatment and conversion. In the last decade, significant progress has been made in understanding mechanisms of yeast tolerance for tolerant strain development. Enriched genetic backgrounds, enhanced expression, interplays, and global integration of many key genes enable yeast tolerance. Reprogrammed pathways support yeast functions to withstand the inhibitor stress, detoxify the toxic compounds, maintain energy and redox balance, and complete active metabolism for ethanol fermentation. Complex gene interactions and regulatory networks as well as co-regulation are well recognized as involved in yeast adaptation and tolerance. This review presents our current knowledge on mechanisms of the inhibitor detoxification based on molecular studies and genomic-based approaches. Our improved understanding of yeast tolerance and in situ detoxification provide insight into phenotype-genotype relationships, dissection of tolerance mechanisms, and strategies for more tolerant strain development for biofuels applications. PMID:21380517

  12. Identification of furfural as a key toxin in lignocellulosic hydrolysates and evolution of a tolerant yeast strain.

    PubMed

    Heer, Dominik; Sauer, Uwe

    2008-11-01

    The production of fuel ethanol from low-cost lignocellulosic biomass currently suffers from several limitations. One of them is the presence of inhibitors in lignocellulosic hydrolysates that are released during pre-treatment. These compounds inhibit growth and hamper the production of ethanol, thereby affecting process economics. To delineate the effects of such complex mixtures, we conducted a chemical analysis of four different real-world lignocellulosic hydrolysates and determined their toxicological effect on yeast. By correlating the potential inhibitor abundance to the growth-inhibiting properties of the corresponding hydrolysates, we identified furfural as an important contributor to hydrolysate toxicity for yeast. Subsequently, we conducted a targeted evolution experiment to improve growth behaviour of the half industrial Saccharomyces cerevisiae strain TMB3400 in the hydrolysates. After about 300 generations, representative clones from these evolved populations exhibited significantly reduced lag phases in medium containing the single inhibitor furfural, but also in hydrolysate-supplemented medium. Furthermore, these strains were able to grow at concentrations of hydrolysates that effectively killed the parental strain and exhibited significantly improved bioconversion characteristics under industrially relevant conditions. The improved resistance of our evolved strains was based on their capacity to remain viable in a toxic environment during the prolonged, furfural induced lag phase. PMID:21261870

  13. Oil production by oleaginous yeasts using the hydrolysate from pretreatment of wheat straw with dilute sulfuric acid.

    PubMed

    Yu, Xiaochen; Zheng, Yubin; Dorgan, Kathleen M; Chen, Shulin

    2011-05-01

    This paper explores the use of the hydrolysate from the dilute sulfuric acid pretreatment of wheat straw for microbial oil production. The resulting hydrolysate was composed of pentoses (24.3g/L) and hexoses (4.9 g/L), along with some other degradation products, such as acetic acid, furfural, and hydroxymethylfurfural (HMF). Five oleaginous yeast strains, Cryptococcus curvatus, Rhodotorula glutinis, Rhodosporidium toruloides, Lipomyces starkeyi, and Yarrowia lipolytica, were evaluated by using this hydrolysate as substrates. The results showed that all of these strains could use the detoxified hydrolysate to produce lipids while except R. toruloides non-detoxified hydrolysate could also be used for the growth of all of the selective yeast strains. C. curvatus showed the highest lipid concentrations in medium on both the detoxified (4.2g/L) and non-detoxified (5.8 g/L) hydrolysates. And the inhibitory effect studies on C. curvatus indicated HMF had insignificant impacts at a concentration of up to 3g/L while furfural inhibited cell growth and lipid content by 72.0% and 62.0% at 1g/L, respectively. Our work demonstrates that lipid production is a promising alternative to utilize hemicellulosic sugars obtained during pretreatment of lignocellulosic materials. PMID:21463940

  14. 21 CFR 172.590 - Yeast-malt sprout extract.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Yeast-malt sprout extract. 172.590 Section 172.590... Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout extract, as described in this section, may... produced by partial hydrolysis of yeast extract (derived from Saccharomyces cereviseae,...

  15. 21 CFR 184.1983 - Bakers yeast extract.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Bakers yeast extract. 184.1983 Section 184.1983... Listing of Specific Substances Affirmed as GRAS § 184.1983 Bakers yeast extract. (a) Bakers yeast extract... a selected strain of yeast, Saccharomyces cerevisiae. It may be concentrated or dried. (b)...

  16. 21 CFR 172.590 - Yeast-malt sprout extract.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Yeast-malt sprout extract. 172.590 Section 172.590... CONSUMPTION Flavoring Agents and Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout... prescribed conditions: (a) The additive is produced by partial hydrolysis of yeast extract (derived...

  17. 21 CFR 184.1983 - Bakers yeast extract.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Bakers yeast extract. 184.1983 Section 184.1983... Listing of Specific Substances Affirmed as GRAS § 184.1983 Bakers yeast extract. (a) Bakers yeast extract... a selected strain of yeast, Saccharomyces cerevisiae. It may be concentrated or dried. (b)...

  18. 21 CFR 172.590 - Yeast-malt sprout extract.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Yeast-malt sprout extract. 172.590 Section 172.590... CONSUMPTION Flavoring Agents and Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout... prescribed conditions: (a) The additive is produced by partial hydrolysis of yeast extract (derived...

  19. 21 CFR 184.1983 - Bakers yeast extract.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Bakers yeast extract. 184.1983 Section 184.1983... Listing of Specific Substances Affirmed as GRAS § 184.1983 Bakers yeast extract. (a) Bakers yeast extract... a selected strain of yeast, Saccharomyces cerevisiae. It may be concentrated or dried. (b)...

  20. 21 CFR 172.590 - Yeast-malt sprout extract.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Yeast-malt sprout extract. 172.590 Section 172.590... CONSUMPTION Flavoring Agents and Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout... prescribed conditions: (a) The additive is produced by partial hydrolysis of yeast extract (derived...

  1. 21 CFR 172.590 - Yeast-malt sprout extract.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Yeast-malt sprout extract. 172.590 Section 172.590... CONSUMPTION Flavoring Agents and Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout... prescribed conditions: (a) The additive is produced by partial hydrolysis of yeast extract (derived...

  2. 21 CFR 184.1983 - Bakers yeast extract.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Bakers yeast extract. 184.1983 Section 184.1983... GRAS § 184.1983 Bakers yeast extract. (a) Bakers yeast extract is the food ingredient resulting from concentration of the solubles of mechanically ruptured cells of a selected strain of yeast,...

  3. 21 CFR 184.1983 - Bakers yeast extract.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Bakers yeast extract. 184.1983 Section 184.1983... Listing of Specific Substances Affirmed as GRAS § 184.1983 Bakers yeast extract. (a) Bakers yeast extract... a selected strain of yeast, Saccharomyces cerevisiae. It may be concentrated or dried. (b)...

  4. Detoxification of Eucheuma spinosum Hydrolysates with Activated Carbon for Ethanol Production by the Salt-Tolerant Yeast Candida tropicalis.

    PubMed

    Ra, Chae Hun; Jung, Jang Hyun; Sunwoo, In Young; Kang, Chang Han; Jeong, Gwi-Taek; Kim, Sung-Koo

    2015-06-01

    The objective of this study was to optimize the slurry contents and salt concentrations for ethanol production from hydrolysates of the seaweed Eucheuma spinosum. A monosaccharide concentration of 44.2 g/l as 49.6% conversion of total carbohydrate of 89.1 g/l was obtained from 120 g dw/l seaweed slurry. Monosaccharides from E. spinosum slurry were obtained by thermal acid hydrolysis and enzymatic hydrolysis. Addition of activated carbon at 2.5% (w/v) and the adsorption time of 2 min were used in subsequent adsorption treatments to prevent the inhibitory effect of HMF. The adsorption surface area of the activated carbon powder was 1,400-1,600 m(2)/g and showed selectivity to 5-hydroxymethyl furfural (HMF) from monosaccharides. Candida tropicalis KCTC 7212 was cultured in yeast extract, peptone, glucose, and high-salt medium, and exposed to 80, 90, 100, and 110 practical salinity unit (psu) salt concentrations in the lysates. The 100 psu salt concentration showed maximum cell growth and ethanol production. The ethanol fermentations with activated carbon treatment and use of C. tropicalis acclimated to a high salt concentration of 100 psu produced 17.9 g/l of ethanol with a yield (YEtOH) of 0.40 from E. spinosum seaweed. PMID:25649983

  5. Bactericidal effect of hydrolysable and condensed tannin extracts on Campylobacter jejuni in vitro.

    PubMed

    Anderson, Robin C; Vodovnik, Maša; Min, Byeng R; Pinchak, William E; Krueger, Nathan A; Harvey, Roger B; Nisbet, David J

    2012-07-01

    Strategies are sought to reduce intestinal colonisation of food-producing animals by Campylobacter jejuni, a leading bacterial cause of human foodborne illness worldwide. Presently, we tested the antimicrobial activity of hydrolysable-rich blackberry, cranberry and chestnut tannin extracts and condensed tannin-rich mimosa, quebracho and sorghum tannins (each at 100 mg/mL) against C. jejuni via disc diffusion assay in the presence of supplemental casamino acids. We found that when compared to non-tannin-treated controls, all tested tannins inhibited the growth of C. jejuni and that inhibition by the condensed tannin-rich mimosa and quebracho extracts was mitigated in nutrient-limited medium supplemented with casamino acids. When tested in broth culture, both chestnut and mimosa extracts inhibited growth of C. jejuni and this inhibition was much greater in nutrient-limited than in full-strength medium. Consistent with observations from the disc diffusion assay, the inhibitory activity of the condensed tannin-rich mimosa extracts but not the hydrolysable tannin-rich chestnut extracts was mitigated by casamino acid supplementation to the nutrient-limited medium, likely because the added amino acids saturated the binding potential of the condensed tannins. These results demonstrate the antimicrobial activity of various hydrolysable and condensed tannin-rich extracts against C. jejuni and reveal that condensed tannins may be less efficient than hydrolysable tannins in controlling C. jejuni in gut environments containing high concentrations of amino acids and soluble proteins. PMID:22528299

  6. Lipid Production from Hemicellulose and Holocellulose Hydrolysate of Palm Empty Fruit Bunches by Newly Isolated Oleaginous Yeasts.

    PubMed

    Tampitak, Srikanya; Louhasakul, Yasmi; Cheirsilp, Benjamas; Prasertsan, Poonsuk

    2015-07-01

    Palm empty fruit bunches (EFBs) are abundant lignocellulosic wastes from palm oil mills. They are potential sources of sugars which can be converted to microbial lipids by oleaginous yeasts. To produce sugars from EFB, two-step and one-step hydrolysis reactions were performed. In the first step, the use of diluted sulfuric acid (0.5 % w/v) hydrolyzed hemicelluloses and released mainly pentoses, and in the second step of hydrolysis of residual pulp using 2.5 % (w/v), sulfuric acid released more hexoses. The use of 2.5 % (w/v) sulfuric acid in one-step hydrolysis of holocelluloses released the highest amount of sugars (38.3 g/L), but it also produced high concentration of potential inhibitors (>1 g/L). Three oleaginous yeasts, Rhodotorula mucilaginosa, Kluyveromyces marxianus, and Candida tropicalis, were isolated and screened for their ability to convert EFB hydrolysates into lipids. These yeasts grew well and produced lipids from EFB hemicellulose and holocellulose hydrolysate after potential inhibitors were removed. This study shows that EFB can be used for lipid production. PMID:26026262

  7. Bactericidal effect of hydrolysable and condensed tannin extracts on Campylobacter jejuni in vitro

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Strategies are sought to reduce intestinal colonization of food-producing animals by Campylobacter jejuni, a leading bacterial cause of human foodborne illness worldwide. Presently, we tested the antimicrobial activity of hydrolysable-rich blackberry, cranberry, chestnut tannin extracts, and conden...

  8. Evaluation of yeast strains for production of fuel ethanol from biomass hydrolysates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Robust industrial yeast strains are needed for profitable production of fuel ethanol from mixed biomass waste. USDA, ARS, NCAUR, RPT has been evaluating ethanol-producing yeasts, including Saccharomyces cerevisiae, engineered GMAX Saccharomyces cerevisiae, irradiated Kluyveromyces marxianus, and Pi...

  9. Yeast hydrolysate as a low-cost additive to serum-free medium for the production of human thrombopoietin in suspension cultures of Chinese hamster ovary cells.

    PubMed

    Sung, Y H; Lim, S W; Chung, J Y; Lee, G M

    2004-02-01

    To enhance the performance of a serum-free medium (SFM) for human thrombopoietin (hTPO) production in suspension cultures of recombinant Chinese hamster ovary (rCHO) cells, several low-cost hydrolysates such as yeast hydrolysate (YH), soy hydrolysate, wheat gluten hydrolysate and rice hydrolysate were tested as medium additives. Among various hydrolysates tested, the positive effect of YH on hTPO production was most significant. When 5 g l(-1) YH was added to SFM, the maximum hTPO concentration in batch culture was 40.41 microg ml(-1), which is 11.5 times higher than that in SFM without YH supplementation. This enhanced hTPO production in YH-supplemented SFM was obtained by the combined effect of enhanced q(hTPO) (the specific rate of hTPO production). The supplementation of YH in SFM increased q(hTPO) by 294% and extended culture longevity by >2 days if the culture was terminated at a cell viability of 50%. Furthermore, cell viability throughout the culture using YH-supplemented SFM was higher than that using any other hydrolysate-supplemented SFM tested, thereby minimizing degradation of hTPO susceptible to proteolytic degradation. In addition, YH supplementation did not affect in vivo biological activity of hTPO. Taken together, the results obtained demonstrate the potential of YH as a medium additive for hTPO production in serum-free suspension cultures of rCHO cells. PMID:12856163

  10. Hydrolysate of lipid extracted microalgal biomass residue: An algal growth promoter and enhancer.

    PubMed

    Maurya, Rahulkumar; Paliwal, Chetan; Chokshi, Kaumeel; Pancha, Imran; Ghosh, Tonmoy; Satpati, Gour Gopal; Pal, Ruma; Ghosh, Arup; Mishra, Sandhya

    2016-05-01

    The present study demonstrates the utilization of the algal hydrolysate (AH) prepared from lipid extracted residual harmful bloom-forming cyanobacteria Lyngbya majuscula biomass, as a growth supplement for the cultivation of green microalgae Chlorella vulgaris. BG-11 replacements with AH in different proportions significantly affects the cell count, dry cell weight (DCW), biomass productivity (BP) and pigments concentration. Among all, 25% AH substitution in BG11 media was found to be optimum which enhanced DCW, BP and pigments content by 39.13%, 40.81% and 129.47%, respectively, compared to control. The lipid content (31.95%) was also significantly higher in the 25% AH replacement. The volumetric productivity of neutral lipids (ideal for biodiesel) and total protein content of the cells significantly increased in all AH substitutions. Thus, lipid extracted microalgal biomass residue (LMBR) hydrolysate can be a potential growth stimulating supplement for oleaginous microalgae C. vulgaris. PMID:26890794

  11. Recycling of lipid-extracted hydrolysate as nitrogen supplementation for production of thraustochytrid biomass.

    PubMed

    Lowrey, Joshua; Armenta, Roberto E; Brooks, Marianne S

    2016-08-01

    Efficient resource usage is important for cost-effective microalgae production, where the incorporation of waste streams and recycled water into the process has great potential. This study builds upon emerging research on nutrient recycling in thraustochytrid production, where waste streams are recovered after lipid extraction and recycled into future cultures. This research investigates the nitrogen flux of recycled hydrolysate derived from enzymatic lipid extraction of thraustochytrid biomass. Results indicated the proteinaceous content of the recycled hydrolysate can offset the need to supply fresh nitrogen in a secondary culture, without detrimental impact upon the produced biomass. The treatment employing the recycled hydrolysate with no nitrogen addition accumulated 14.86 g L(-1) of biomass in 141 h with 43.3 % (w/w) lipid content compared to the control which had 9.26 g L(-1) and 46.9 % (w/w), respectively. This improved nutrient efficiency and wastewater recovery represents considerable potential for enhanced resource efficiency of commercial thraustochytrid production. PMID:27155854

  12. Preparation of Yeast Hydrolysate Enriched in Cyclo-His-Pro (CHP) by Enzymatic Hydrolysis and Evaluation of Its Functionality

    PubMed Central

    Lee, Hyun Jung; Son, Heung Soo; Park, Chung; Suh, Hyung Joo

    2015-01-01

    In this study, we attempted to enrich cyclo-His-Pro (CHP) using enzymatic hydrolysis of yeast and to evaluate the functionality of yeast hydrolysate (YH)-enriched CHP. Flavourzyme offered a better performance in enhancing CHP content than other proteases. The CHP enrichment conditions were optimized as follows: addition of 1% Flavourzyme, 48-h incubation at 60°C, and pH 6.0. The CHP content significantly increased by 20-fold after ultra-filtration (UF). Maximal CHP translation was obtained after heating for 8 h at 50°C and pH 7.0. YH showed poor foaming capacity between pH 3.0 to 9.0. The emulsifying activities of YHs were slightly higher at near acidic pH. Increase in heating temperature and time resulted in decreased CHP content. The results indicate that YH is more heat stable after UF. Therefore, the CHP in YH after UF can be used as a food additive with physiological CHP activity and high heat stability. PMID:26770916

  13. Liquid-liquid extraction of fermentation inhibiting compounds in lignocellulose hydrolysate.

    PubMed

    Zautsen, R R M; Maugeri-Filho, F; Vaz-Rossell, C E; Straathof, A J J; van der Wielen, L A M; de Bont, J A M

    2009-04-01

    Several compounds that are formed or released during hydrolysis of lignocellulosic biomass inhibit the fermentation of the hydrolysate. The use of a liquid extractive agent is suggested as a method for removal of these fermentation inhibitors. The method can be applied before or during the fermentation. For a series of alkanes and alcohols, partition coefficients were measured at low concentrations of the inhibiting compounds furfural, hydroxymethyl furfural, vanillin, syringaldehyde, coniferyl aldehyde, acetic acid, as well as for ethanol as the fermentation product. Carbon dioxide production was measured during fermentation in the presence of each organic solvent to indicate its biocompatibility. The feasibility of extractive fermentation of hydrolysate was investigated by ethanolic glucose fermentation in synthetic medium containing several concentrations of furfural and vanillin and in the presence of decanol, oleyl alcohol and oleic acid. Volumetric ethanol productivity with 6 g/L vanillin in the medium increased twofold with 30% volume oleyl alcohol. Decanol showed interesting extractive properties for most fermentation inhibiting compounds, but it is not suitable for in situ application due to its poor biocompatibility. PMID:19062184

  14. Quality assessment of lager brewery yeast samples and strains using barley malt extracts with anti-yeast activity.

    PubMed

    van Nierop, Sandra N E; Axcell, Barry C; Cantrell, Ian C; Rautenbach, Marina

    2009-04-01

    Membrane active anti-yeast compounds, such as antimicrobial peptides and proteins, cause yeast membrane damage which is likely to affect yeast vitality and fermentation performance, parameters which are notoriously difficult to analyse. In this work the sensitivity of lager brewery yeast strains towards barley malt extracts with anti-yeast activity was assessed with an optimised assay. It was found that yeast, obtained directly from a brewery, was much more sensitive towards the malt extracts than the same yeast strain propagated in the laboratory. Sensitivity to the malt extracts increased during the course of a laboratory scale fermentation when inoculated with brewery yeast. As the assay was able to differentiate yeast samples with different histories, it shows promise as a yeast quality assay measuring the yeast's ability to withstand stress which can be equated to vitality. The assay was also able to differentiate between different lager yeast strains of Saccharomyces cerevisiae propagated in the laboratory when challenged with a number of malt extracts of varying anti-yeast activity. The assessment of yeast strains in the presence of malt extracts will lead to the identification of yeast strains with improved quality/vitality that can withstand malt-associated anti-yeast activity during brewery fermentations. PMID:19171262

  15. Antioxidant Properties of Fish Protein Hydrolysates Prepared from Cod Protein Hydrolysate by Bacillus sp.

    PubMed

    Godinho, I; Pires, C; Pedro, S; Teixeira, B; Mendes, R; Nunes, M L; Batista, I

    2016-03-01

    Fermentative protein hydrolysates (FPH) were prepared with a proteolytic bacterium, Bacillus strain exhibiting high proteolytic activity. Three FPH with 1, 2, and 4 % of cod protein hydrolysate (CPH) and 0.5 % of yeast extract in the culture were prepared. The yields achieved varied between 30 and 58 % based on protein content. A general decrease of leucine, isoleucine, valine, alanine, arginine, threonine, proline, and glutamic acid was observed. All FPHs showed higher reducing power and DPPH radical scavenging activity than CPH, but similar ABTS radical scavenging activity. However, FPHs exhibited lower Cu(+2)-chelating activity than CPH. The ACE inhibitory activity of FPHs was not improved relatively to that recorded in CPH. The fermentative process seems to have potential to obtaining hydrolysates with improved biological activities or even to produce protein hydrolysates from native fish proteins. PMID:26590847

  16. Screening of Yeasts for Selection of Potential Strains and Their Utilization for In Situ Microbial Detoxification (ISMD) of Sugarcane Bagasse Hemicellulosic Hydrolysate.

    PubMed

    Soares, Luma C S R; Chandel, Anuj K; Pagnocca, Fernando C; Gaikwad, Swapnil C; Rai, Mahendra; da Silva, Silvio S

    2016-06-01

    Many toxic compounds are produced and released in the hemicellulosic hydrolyzates during the acid pretreatment step, which are required for the disruption of the lignocelluloses matrix and sugars release. The conventional methods of detoxification i.e. overliming, activated charcoal, ion exchange or even membrane-based separations have the limitations in removal of these toxic inhibitors in fermentation process. Hence, it is imperative to explore biological methods to overcome the inhibitors by minimizing the filtration steps, sugar loss and chemical additions. In the present study we screened sixty-four strains of yeasts to select potential strains for detoxification of furfural, acetic acid, ferulic acid, 5-hydroxymethyl furfural (5-HMF) as carbon and energy source. Among these strains Pichia occidentalis M1, Y1'a, Y1'b and Y3' showed a significant decrease in the toxic compounds but we selected two best yeast strains i.e. P. occidentalis Y1'a and P. occidentalis M1 for the further experiments with an aim to remove the fermentation inhibitors. The yeasts P. occidentalis Y1'a and P. occidentalis M1 were grown aerobically in sugarcane bagasse hemicellulose hydrolysate under submerged cultivation. For each yeast, a 2(2) full factorial design was performed considering the variables-pH (4.0 or 5.0) and agitation rate (100 or 300 rpm), and the percentage removal of HMF, furfural, acetic acid and phenols from hemicellulosic hydrolysates were responsive variables. After 96 h of biological treatment, P. occidentalis M1 and P. occidentalis Y1'a showed 42.89 and 46.04 % cumulative removal of inhibitors, respectively. PMID:27570309

  17. Yeast hydrolysate supplementation increases field abundance and persistence of sexually mature sterile Queensland fruit fly, Bactrocera tryoni (Froggatt).

    PubMed

    Reynolds, O L; Orchard, B A; Collins, S R; Taylor, P W

    2014-04-01

    The sterile insect technique (SIT) is a non-chemical approach used to control major pests from several insect families, including Tephritidae, and entails the mass-release of sterile insects that reduce fertility of wild populations. For SIT to succeed, released sterile males must mature and compete with wild males to mate with wild females. To reach sexual maturity, the Queensland fruit fly, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae), must obtain adequate nutrition after adult emergence; however, in current SIT programs sterile B. tryoni receive a pre-release diet that lacks key nutrients required to sustain sexual development. The chief objective of this study was to determine whether pre-release yeast hydrolysate (YH) supplements affect the persistence and abundance of sexually mature sterile male B. tryoni under field conditions. Experiments were run in outdoor cages under conditions of low and high environmental stress that differed markedly in temperature and humidity, and in the field. Under low environmental stress conditions, survival of sterile B. tryoni was monitored in cages under three diet treatments: (i) sugar only, (ii) sugar plus YH or (iii) sugar plus YH for 48 h and sugar only thereafter. Under high environmental stress conditions survival of sterile B. tryoni was monitored in cages under four diet treatments: (i) white sugar only, (ii) brown sugar only, (iii) white sugar plus YH and (iv) brown sugar plus YH. In a replicated field study, we released colour-marked sterile B. tryoni from two diet regimes, YH-supplemented or YH-deprived, and monitored abundance of sexually mature males. In the low-stress cage study, there was no effect of diet, although overall females lived longer than males. In the high stress cage study, mortality was lower for YH-fed flies than YH-deprived flies and females lived longer than males. In the field, YH supplementation resulted in higher abundance of sexually mature sterile males, with 1.2 YH-fed flies

  18. Evaluation of xylitol production using corncob hemicellulosic hydrolysate by combining tetrabutylammonium hydroxide extraction with dilute acid hydrolysis.

    PubMed

    Jia, Honghua; Shao, Tingting; Zhong, Chao; Li, Hengxiang; Jiang, Min; Zhou, Hua; Wei, Ping

    2016-10-20

    In this paper, we produced hemicellulosic hydrolysate from corncob by tetrabutylammonium hydroxide (TBAH) extraction and dilute acid hydrolysis combined, further evaluating the feasibility of the resultant corncob hemicellulosic hydrolysate used in xylitol production by Candida tropicalis. Optimized conditions for corncob hemicellulose extraction by TBAH was obtained via response surface methodology: time of 90min, temperature of 60°C, liquid/solid ratio of 12 (v/w), and TBAH concentration of 55%, resulting in a hemicellulose extraction of 80.07% under these conditions. The FT-IR spectrum of the extracted corncob hemicellulose is consistent with that of birchwood hemicellulose and exhibits specific absorbance of hemicelluloses at 1380, 1168, 1050, and 900cm(-1). In addition, we found that C. tropicalis can ferment the resulting corncob hemicellulosic hydrolysate with pH adjustment and activated charcoal treatment leading to a high xylitol yield and productivity of 0.77g/g and 2.45g/(Lh), respectively. PMID:27474613

  19. Spent brewer's yeast extract as an ingredient in cooked hams.

    PubMed

    Pancrazio, Gaston; Cunha, Sara C; de Pinho, Paula Guedes; Loureiro, Mónica; Meireles, Sónia; Ferreira, Isabel M P L V O; Pinho, Olívia

    2016-11-01

    This work describes the effect of the incorporation of 1% spent yeast extract into cooked hams. Physical/chemical/sensorial characteristics and changes during 12 and 90days storage were evaluated on control and treated cooked hams processed for 1.5, 2.0, 2.5 or 3h. Spent yeast extract addition increased hardness, chewiness, ash, protein and free amino acid content. Similar volatile profiles were obtained, although there were some quantitative differences. No advantages were observed for increased cooking time. No significant differences were observed for physical and sensorial parameters of cooked hams with spent yeast extract at 12 and 90days post production, but His, aldehydes and esters increased at the end of storage. This behaviour was similar to that observed for control hams. The higher hardness of cooked ham with 1% yeast extract was due to the stronger gel formed during cooking and was maintained during storage. This additive acts as gel stabilizer for cooked ham production and could potentially improve other processing characteristics. PMID:27449232

  20. Production of (R)-3-hydroxybutyric acid by Burkholderia cepacia from wood extract hydrolysates

    PubMed Central

    2014-01-01

    (R)-hydroxyalkanoic acids (R-HAs) are valuable building blocks for the synthesis of fine chemicals and biopolymers because of the chiral center and the two active functional groups. Hydroxyalkanoic acids fermentation can revolutionize the polyhydroxyalkanoic acids (PHA) production by increasing efficiency and enhancing product utility. Modifying the fermentation conditions that promotes the in vivo depolymerization and secretion to fermentation broth in wild type bacteria is a novel and promising approach to produce R-HAs. Wood extract hydrolysate (WEH) was found to be a suitable substrate for R-3-hydroxybutyric acid (R-3-HB) production by Burkholderia cepacia. Using Paulownia elongate WEH as a feedstock, the R-3-HB concentration in fermentation broth reached as high as 14.2 g/L after 3 days of batch fermentation and the highest concentration of 16.8 g/L was obtained at day 9. Further investigation indicated that the composition of culture medium contributed to the enhanced R-3-HB production. PMID:24949263

  1. Extraction and analysis of soluble inositol polyphosphates from yeast.

    PubMed

    Azevedo, Cristina; Saiardi, Adolfo

    2006-01-01

    Soluble inositol polyphosphates are implicated in the regulation of many important cellular functions. This protocol to extract and separate inositol polyphosphates from Saccharomyces cerevisiae is divided into three steps: labeling of yeast, extraction of soluble inositol polyphosphates and chromatographic separation. Yeast cells are incubated with tritiated inositol, which is taken up and metabolized into different phosphorylated forms. Soluble inositol polyphosphates are then acid-extracted and fractionated by high-performance liquid chromatography. The radioactivity of each fraction is determined by scintillation counting. This highly sensitive and reproducible method allows the accurate detection of subtle changes in the inositol polyphosphate profile and takes less than 48 h. It can easily be applied to other systems and we have included two adaptations of the protocol, one optimized for mammalian cells and the other for Arabidopsis thaliana. PMID:17406485

  2. Lipid Production of Heterotrophic Chlorella sp. from Hydrolysate Mixtures of Lipid-Extracted Microalgal Biomass Residues and Molasses.

    PubMed

    Zheng, Hongli; Ma, Xiaochen; Gao, Zhen; Wan, Yiqin; Min, Min; Zhou, Wenguang; Li, Yun; Liu, Yuhuan; Huang, He; Chen, Paul; Ruan, Roger

    2015-10-01

    This study investigated the feasibility of lipid production of Chlorella sp. from waste materials. Lipid-extracted microalgal biomass residues (LMBRs) and molasses were hydrolyzed, and their hydrolysates were analyzed. Five different hydrolysate mixture ratios (w/w) of LMBRs/molasses (1/0, 1/1, 1/4, 1/9, and 0/1) were used to cultivate Chlorella sp. The results showed that carbohydrate and protein were the two main compounds in the LMBRs, and carbohydrate was the main compound in the molasses. The highest biomass concentration of 5.58 g/L, Y biomass/sugars of 0.59 g/g, lipid productivity of 335 mg/L/day, and Y lipids/sugars of 0.25 g/g were obtained at the hydrolysate mixture ratio of LMBRs/molasses of 1/4. High C/N ratio promoted the conversion of sugars into lipids. The lipids extracted from Chlorella sp. shared similar lipid profile of soybean oil and is therefore a potential viable biodiesel feedstock. These results showed that Chlorella sp. can utilize mixed sugars and amino acids from LMBRs and molasses to accumulate lipids efficiently, thus reducing the cost of microalgal biodiesel production and improving its economic viability. PMID:26234438

  3. Inhibition of spoiling yeasts of fruit juices through citrus extracts.

    PubMed

    Bevilacqua, Antonio; Speranza, Barbara; Campaniello, Daniela; Corbo, Maria Rosaria; Sinigaglia, Milena

    2013-10-01

    This article reports on the bioactivities of citrus extracts (citrus extract, lemon extract, and neroli) toward Saccharomyces cerevisiae, Zygosaccharomyces bailii, Zygosaccharomyces rouxii, Pichia membranifaciens, and Rhodotorula bacarum. The bioactivities of the extracts (from 10 to 100 ppm) were evaluated through a microdilution method; thereafter, citrus extracts (0 to 80 ppm) were tested in combination with either pH (3.0 to 5.0) or temperature (5 to 25°C). Finally, a confirmatory experiment was run in a commercial drink (referred to as red fruit juice) containing citrus extract (40 ppm) that was inoculated with either S. cerevisiae or Z. bailii (5 log CFU/ml) and stored at 4 and 25°C. Yeasts increased to 7 log CFU/ml (Z. bailii) or 8 log CFU/ml (S. cerevisiae) in the control at 25°C, but the citrus extract addition controlled yeast growth for at least 3 days; under refrigeration, the effect was significant for 10 days. PMID:24112576

  4. Components of yeast (Sacchromyces cervisiae) extract as defined media additives that support the growth and productivity of CHO cells.

    PubMed

    Spearman, Maureen; Chan, Sarah; Jung, Vince; Kowbel, Vanessa; Mendoza, Meg; Miranda, Vivian; Butler, Michael

    2016-09-10

    Yeast and plant hydrolysates are used as media supplements to support the growth and productivity of CHO cultures for biopharmaceutical production. Through fractionation of a yeast lysate and metabolic analysis of a fraction that had bioactivity equivalent to commercial yeast extract (YE), bioactive components were identified that promoted growth and productivity of two recombinant CHO cell lines (CHO-Luc and CHO-hFcEG2) equivalent to or greater than YE-supplemented media. Autolysis of the yeast lysate was not necessary for full activity, suggesting that the active components are present in untreated yeast cells. A bioactive fraction (3KF) of the yeast lysate was isolated from the permeate using a 3kDa molecular weight cut-off (MWCO) filter. Supplementation of this 3KF fraction into the base media supported growth of CHO-Luc cells over eight passages equivalent to YE-supplemented media. The 3KF fraction was fractionated further by a cation exchange spin column using a stepwise pH elution. Metabolomic analysis of a bioactive fraction isolated at high pH identified several arginine and lysine-containing peptides as well as two polyamines, spermine and spermidine, with 3.5× and 4.5× higher levels compared to a fraction showing no bioactivity. The addition of a mixture of polyamines and their precursors (putrescine, spermine, spermidine, ornithine and citrulline) as well as increasing the concentration of some of the components of the original base medium resulted in a chemically-defined (CD) formulation that produced an equivalent viable cell density (VCD) and productivity of the CHO-Luc cells as the YE-supplemented medium. The VCD of the CHO-hFcEG2 culture in the CD medium was 1.9× greater and with equivalent productivity to the YE-supplemented media. PMID:27165505

  5. Recycling microbial lipid production wastes to cultivate oleaginous yeasts.

    PubMed

    Yang, Xiaobing; Jin, Guojie; Gong, Zhiwei; Shen, Hongwei; Bai, Fengwu; Zhao, Zongbao Kent

    2015-01-01

    To reduce wastes and the costs of microbial lipid production, it is imperative to recycle resources, including spent cell mass, mineral nutrients and water. In the present study, lipid production by the oleaginous yeast Rhodosporidium toruloides was used as a model system to demonstrate resources recycling. It was found that the hydrolysates of spent cell mass were good media to support cell growth of various oleaginous yeasts. When serial repitching experiments were performed using 70g/L glucose and the hydrolysates alone as nutrients, it produced 16.6, 14.6 and 12.9g/L lipids, for three successive cycles, while lipid titre remained almost constant when spent water was also recycled. The cell mass hydrolysates could be used as equivalents to the mixture of yeast extract and peptone to support lipid production from corn stalk hydrolysates. Our results showed efficient recycling of lipid production wastes and should be helpful to advance microbial lipid technology. PMID:25459808

  6. Sequential recycling of enzymatic lipid-extracted hydrolysate in fermentations with a thraustochytrid.

    PubMed

    Lowrey, Joshua; Armenta, Roberto E; Brooks, Marianne S

    2016-06-01

    This study extends the findings of prior studies proposing and validating nutrient recycling for the heterotrophic microalgae, Thraustochytrium sp. (T18), grown in optimized fed-batch conditions. Sequential nutrient recycling of enzymatically-derived hydrolysate in fermentors succeeded at growing the tested thraustochytrid strain, with little evidence of inhibition or detrimental effects upon culture health. The average maximum biomass obtained in the recycled hydrolysate was 63.68±1.46gL(-1) in 90h the first recycle followed by 65.27±1.15gL(-1) in 90h in the subsequent recycle of the same material. These compared to 58.59gL(-1) and 64.92gL(-1) observed in fresh media in the same time. Lipid production was slightly impaired, however, with a maximum total fatty acid content of 62.2±0.30% in the recycled hydrolysate compared to 69.4% in fresh control media. PMID:26994462

  7. A new yeast producing beta-glucosidase and tolerant to lignocellulose hydrolysate inhibitors for cellulosic ethanol production using SSF

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conventional cellulose-to-ethanol conversion requires cellulose degradation in order to be utilized for growth and fermentation by common ethanologenic yeast. Cellulose is commonly enzymatically degraded into cellobiose by cellulase and subsequently cellobiose broken down into glucose by beta-glucos...

  8. Identifying inhibitory compounds in lignocellulosic biomass hydrolysates using an exometabolomics approach

    PubMed Central

    2014-01-01

    Background Inhibitors are formed that reduce the fermentation performance of fermenting yeast during the pretreatment process of lignocellulosic biomass. An exometabolomics approach was applied to systematically identify inhibitors in lignocellulosic biomass hydrolysates. Results We studied the composition and fermentability of 24 different biomass hydrolysates. To create diversity, the 24 hydrolysates were prepared from six different biomass types, namely sugar cane bagasse, corn stover, wheat straw, barley straw, willow wood chips and oak sawdust, and with four different pretreatment methods, i.e. dilute acid, mild alkaline, alkaline/peracetic acid and concentrated acid. Their composition and that of fermentation samples generated with these hydrolysates were analyzed with two GC-MS methods. Either ethyl acetate extraction or ethyl chloroformate derivatization was used before conducting GC-MS to prevent sugars are overloaded in the chromatograms, which obscure the detection of less abundant compounds. Using multivariate PLS-2CV and nPLS-2CV data analysis models, potential inhibitors were identified through establishing relationship between fermentability and composition of the hydrolysates. These identified compounds were tested for their effects on the growth of the model yeast, Saccharomyces. cerevisiae CEN.PK 113-7D, confirming that the majority of the identified compounds were indeed inhibitors. Conclusion Inhibitory compounds in lignocellulosic biomass hydrolysates were successfully identified using a non-targeted systematic approach: metabolomics. The identified inhibitors include both known ones, such as furfural, HMF and vanillin, and novel inhibitors, namely sorbic acid and phenylacetaldehyde. PMID:24655423

  9. Fractionation of Phenolic Compounds Extracted from Propolis and Their Activity in the Yeast Saccharomyces cerevisiae

    PubMed Central

    Petelinc, Tanja; Polak, Tomaž; Demšar, Lea; Jamnik, Polona

    2013-01-01

    We have here investigated the activities of Slovenian propolis extracts in the yeast Saccharomyces cerevisiae, and identified the phenolic compounds that appear to contribute to these activities. We correlated changes in intracellular oxidation and cellular metabolic energy in these yeasts with the individual fractions of the propolis extracts obtained following solid-phase extraction. The most effective fraction was further investigated according to its phenolic compounds. PMID:23409133

  10. Effects of Cyclo-His-Pro-enriched yeast hydrolysate on blood glucose levels and lipid metabolism in obese diabetic ob/ob mice

    PubMed Central

    Jung, Eun Young; Hong, Yang Hee; Park, Chung

    2016-01-01

    BACKGROUND/OBJECTIVES We examined the hypoglycemic and anti-hyperlipidemic effect of yeast hydrolysate (YH) enriched with Cyclo-His-Pro (CHP) in the C57BL/6J ob/ob mouse model. MATERIALS/METHODS Mice were separated into 4 groups (8 mice/group) on the basis of blood glucose and body weight: WT control, lean mice given vehicle; ob/ob control, ob/ob mice given vehicle; YH-1, ob/ob mice given 0.5 g/kg of YH; YH-2, ob/ob mice given 1 g/kg of YH. YH in saline or vehicle was administered orally in the same volume every day for 3 weeks. RESULTS Mice treated with YH (0.5 and 1 g/kg) for 3 weeks displayed a significant reduction in overall body weight gain and perirenal and epididymal adipose tissue weight compared to the ob/ob control group. Additionally, high-density lipoprotein (HDL) cholesterol, glucose, and atherogenic indexes were significantly decreased in the blood of YH-1 and YH-2 groups compared to the ob/ob control. In ob/ob mice, YH administration significantly improved glucose tolerance and blood insulin levels. These data indicate that YH treatment produces potent hypoglycemic and anti-hyperlipidemic effects by controlling body weight, fat mass, blood lipid, insulin levels, and glucose tolerance. CONCLUSION YH could potentially be used as a treatment option for diabetes and hyperlipidemia. The CHP-enriched YH may be a promising strategy in the development of hypoglycemic peptide nutraceuticals. PMID:27087898

  11. Enumeration and rapid identification of yeasts during extraction processes of extra virgin olive oil in Tuscany.

    PubMed

    Mari, Eleonora; Guerrini, Simona; Granchi, Lisa; Vincenzini, Massimo

    2016-06-01

    The aim of this study was to evaluate the occurrence of yeast populations during different olive oil extraction processes, carried out in three consecutive years in Tuscany (Italy), by analysing crushed pastes, kneaded pastes, oil from decanter and pomaces. The results showed yeast concentrations ranging between 10(3) and 10(5) CFU/g or per mL. Seventeen dominant yeast species were identified by random amplified polymorphic DNA with primer M13 and their identification was confirmed by restriction fragments length polymorphism of ribosomal internal transcribed spacer and sequencing rRNA genes. The isolation frequencies of each species in the collected samples pointed out that the occurrence of the various yeast species in olive oil extraction process was dependent not only on the yeasts contaminating the olives but also on the yeasts colonizing the plant for oil extraction. In fact, eleven dominant yeast species were detected from the washed olives, but only three of them were also found in oil samples at significant isolation frequency. On the contrary, the most abundant species in oil samples, Yamadazyma terventina, did not occur in washed olive samples. These findings suggest a phenomenon of contamination of the plant for oil extraction that selects some yeast species that could affect the quality of olive oil. PMID:27116959

  12. Yeast extract stimulates production of glycolipid biosurfactants, mannosylerythritol lipids, by Pseudozyma hubeiensis SY62.

    PubMed

    Konishi, Masaaki; Nagahama, Takahiko; Fukuoka, Tokuma; Morita, Tomotake; Imura, Tomohiro; Kitamoto, Dai; Hatada, Yuji

    2011-06-01

    We improved the culture conditions for a biosurfactant producing yeast, Pseudozyma hubeiensis SY62. We found that yeast extract greatly stimulates MEL production. Furthermore, we demonstrated a highly efficient production of MELs in the improved medium by fed-batch cultivation. The final concentration of MELs reached 129 ± 8.2g/l for one week. PMID:21393057

  13. Protein Hydrolysates as Hypoallergenic, Flavors and Palatants for Companion Animals

    NASA Astrophysics Data System (ADS)

    Nagodawithana, Tilak W.; Nelles, Lynn; Trivedi, Nayan B.

    Early civilizations have relied upon their good sense and experience to develop and improve their food quality. The discovery of soy sauce centuries ago can now be considered one of the earliest protein hydrolysates made by man to improve palatability of foods. Now, it is well known that such savory systems are not just sources for enjoyment but complex semiotic systems that direct the humans to satisfy the body's protein need for their sustenance. Recent developments have resulted in a wide range of cost effective savory flavorings, the best known of which are autolyzed yeast extracts and hydrolyzed vegetable proteins. New technologies have helped researchers to improve the savory characteristics of yeast extracts through the application of Maillard reaction and by generating specific flavor enhancers through the use of enzymes. An interesting parallel exists in the pet food industry, where a similar approach is taken in using animal protein hydrolysates to create palatability enhancers via Maillard reaction scheme. Protein hydrolysates are also utilized extensively as a source of nutrition to the elderly, young children and immuno-compromised patient population. These hydrolysates have an added advantage in having peptides small enough to avoid any chance of an allergenic reaction which sometimes occur with the consumption of larger sized peptides or proteins. Accordingly, protein hydrolysates are required to have an average molecular weight distribution in the range 800-1,500 Da to make them non-allergenic. The technical challenge for scientists involved in food and feed manufacture is to use an appropriate combination of enzymes within the existing economic constraints and other physical factors/limitations, such as heat, pH, and time, to create highly palatable, yet still nutritious and hypoallergenic food formulations.

  14. New cultive medium for bioconversion of C5 fraction from sugarcane bagasse using rice bran extract

    PubMed Central

    da Silva, Debora Danielle Virginio; Cândido, Elisangela de Jesus; de Arruda, Priscila Vaz; da Silva, Silvio Silvério; Felipe, Maria das Graças de Almeida

    2014-01-01

    The use of hemicellulosic hydrolysates in bioprocesses requires supplementation as to ensure the best fermentative performance of microorganisms. However, in light of conflicting data in the literature, it is necessary to establish an inexpensive and applicable medium for the development of bioprocesses. This paper evaluates the fermentative performance of Scheffersomyces (Pichia) stipitis and Candida guilliermondii growth in sugarcane bagasse hemicellulosic hydrolysate supplemented with different nitrogen sources including rice bran extract, an important by-product of agroindustry and source of vitamins and amino acids. Experiments were carried out with hydrolysate supplemented with rice bran extract and (NH4)2SO4; peptone and yeast extract; (NH4)2SO4, peptone and yeast extract and non-supplemented hydrolysate as a control. S. stipitis produced only ethanol, while C. guilliermondii produced xylitol as the main product and ethanol as by-product. Maximum ethanol production by S. stipitis was observed when sugarcane bagasse hemicellulosic hydrolysate was supplemented with (NH4)2SO4, peptone and yeast extract. Differently, the maximum xylitol formation by C. guilliermondii was obtained by employing hydrolysate supplemented with (NH4)2SO4 and rice bran extract. Together, these findings indicate that: a) for both yeasts (NH4)2SO4 was required as an inorganic nitrogen source to supplement sugarcane bagasse hydrolysate; b) for S. stipitis, sugarcane hemicellulosic hydrolysate must be supplemented with peptone and yeast extract as organic nitrogen source; and: c) for C. guilliermondii, it must be supplemented with rice bran extract. The present study designed a fermentation medium employing hemicellulosic hydrolysate and provides a basis for studies about value-added products as ethanol and xylitol from lignocellulosic materials. PMID:25763056

  15. Specific initiation by RNA polymerase I in a whole-cell extract from yeast.

    PubMed Central

    Schultz, M C; Choe, S Y; Reeder, R H

    1991-01-01

    A protocol is described for making a soluble whole-cell extract from yeast (Saccharomyces cerevisiae) that supports active and specific transcription initiation by RNA polymerases I, II, and III. Specific initiation by polymerase I decreases in high-density cultures, paralleling the decrease in abundance of the endogenous 35S rRNA precursor. This extract should be useful for studying the molecular mechanisms that regulate rRNA transcription in yeast. Images PMID:1992452

  16. A strain of Meyerozyma guilliermondii isolated from sugarcane juice is able to grow and ferment pentoses in synthetic and bagasse hydrolysate media.

    PubMed

    Martini, Cristina; Tauk-Tornisielo, Sâmia Maria; Codato, Carolina Brito; Bastos, Reinaldo Gaspar; Ceccato-Antonini, Sandra Regina

    2016-05-01

    The search for new microbial strains that are able to withstand inhibitors released from hemicellulosic hydrolysis and are also still able to convert sugars in ethanol/xylitol is highly desirable. A yeast strain isolated from sugarcane juice and identified as Meyerozyma guilliermondii was evaluated for the ability to grow and ferment pentoses in synthetic media and in sugarcane bagasse hydrolysate. The yeast grew in xylose, arabinose and glucose at the same rate at an initial medium pH of 5.5. At pH 4.5, the yeast grew more slowly in arabinose. There was no sugar exhaustion within 60 h. At higher xylose concentrations with a higher initial cell concentration, sugar was exhausted within 96 h at pH 4.5. An increase of 350 % in biomass was obtained in detoxified hydrolysates, whereas supplementation with 3 g/L yeast extract increased biomass production by approximately 40 %. Ethanol and xylitol were produced more significantly in supplemented hydrolysates regardless of detoxification. Xylose consumption was enhanced in supplemented hydrolysates and arabinose was consumed only when xylose and glucose were no longer available. Supplementation had a greater impact on ethanol yield and productivity than detoxification; however, the product yields obtained in the present study are still much lower when compared to other yeast species in bagasse hydrolysate. By the other hand, the fermentation of both xylose and arabinose and capability of withstanding inhibitors are important characteristics of the strain assayed. PMID:27038950

  17. Synergistic inhibition of lipid oxidation by pea protein hydrolysate coupled with licorice extract in a liposomal model system.

    PubMed

    Zhang, Xin; Xiong, Youling L; Chen, Jie; Zhou, Liuming

    2013-09-01

    Fourteen pea protein hydrolysates (PPHs) were prepared using different proteases and tested for antioxidant activity in a liposomal model system under oxidative stress (100 μM FeCl3/2 mM ascorbate). Almost all PPHs inhibited lipid oxidation, and those prepared from heated protein with Flavourzyme (Fla-PPH) or Protamex (Pro-PPH) were the most effective. Remarkable synergistic effects were observed on both Fla-PPH and Pro-PPH with licorice extract (LE). Electron microscopy revealed a self-assembled network that appeared to provide crucial protection of liposome against oxidation. The presence of LE enhanced the antioxidant potential by producing a more compact network apparently via PPH-LE complexation. Zeta-potential measurements suggested electrostatic interactions are important driving forces for the accumulation of active peptides at the liposome interface. Peptides rich in leucine, lysine, glutamic acid, glutamine, valine, or proline with a hydrophobic N-terminus, as identified by mass spectrometry, were implicated in the antioxidative protection. PMID:23924409

  18. Synergy of licorice extract and pea protein hydrolysate for oxidative stability of soybean oil-in-water emulsions.

    PubMed

    Zhang, Xin; Xiong, Youling L; Chen, Jie; Zhou, Lirong

    2014-08-13

    Previously developed radical-scavenging pea protein hydrolysates (PPHs) prepared with Flavourzyme (Fla-PPH) and Protamex (Pro-PPH) were used as cosurfactants with Tween 20 to produce soybean oil-in-water (O/W) emulsions, and the suppression of lipid oxidation was investigated. Both PPHs significantly retarded oxidation (P < 0.05) of the emulsions when stored at 37 °C for 14 days. Electron microscopy revealed an interfacial peptidyl membrane around oil droplets, which afforded steric restrictions to oxidation initiators. When licorice extract (LE) was also used in emulsion preparation, a remarkable synergistic oxidation inhibition was observed with both PPHs. LE adsorbed onto oil droplets either directly or through associating with PPH to produce a thick and compact interfacial membrane enabling the defense against oxygen species. Liquiritin apioside, neolicuroside, glabrene, and 18β-glycyrrhetic acid were the predominant phenolic derivatives partitioning at the interface and most likely the major contributors to the notable synergistic antioxidant activity when coupled with PPHs. PMID:25058384

  19. Vegemite Beer: yeast extract spreads as nutrient supplements to promote fermentation

    PubMed Central

    Kerr, Edward D.

    2016-01-01

    Vegemite is an iconic Australian food spread made from spent brewers’ yeast extract, which has been reported to be used as an ingredient in illegal home brewing. In this study, we tested the utility of Vegemite and the similar spread Marmite in promoting fermentation. We could not culture microorganisms from either Vegemite or Marmite, consistent with these food-grade spreads being essentially sterile. To test if the addition of Vegemite or Marmite could assist in fermentation when additional viable yeast was also present, solutions containing glucose and a range of concentrations of either Vegemite or Marmite were inoculated with brewers’ yeast. No fermentation occurred in any condition without addition of extra brewer’s yeast. Fermentation did not occur when yeast was inoculated into solutions containing only glucose, but progressed efficiently with when Vegemite or Marmite was also added. Gas Chromatography confirmed that ethanol was present at ∼3% v/v post-fermentation in all samples which contained glucose, Vegemite or Marmite, and brewers’ yeast. Trace amounts of methanol were also detected. Mass spectrometry proteomics identified abundant intracellular yeast proteins and barley proteins in Vegemite and Marmite, and abundant secreted yeast proteins from actively growing yeast in those samples to which extra brewers’ yeast had been added. We estimate that the real-world cost of home brewed “Vegemite Beer” would be very low. Our results show that Vegemite or other yeast extract spreads could provide cheap and readily available sources of nutrient supplementation to increase the efficiency of fermentation in home brewing or other settings. PMID:27602264

  20. Vegemite Beer: yeast extract spreads as nutrient supplements to promote fermentation.

    PubMed

    Kerr, Edward D; Schulz, Benjamin L

    2016-01-01

    Vegemite is an iconic Australian food spread made from spent brewers' yeast extract, which has been reported to be used as an ingredient in illegal home brewing. In this study, we tested the utility of Vegemite and the similar spread Marmite in promoting fermentation. We could not culture microorganisms from either Vegemite or Marmite, consistent with these food-grade spreads being essentially sterile. To test if the addition of Vegemite or Marmite could assist in fermentation when additional viable yeast was also present, solutions containing glucose and a range of concentrations of either Vegemite or Marmite were inoculated with brewers' yeast. No fermentation occurred in any condition without addition of extra brewer's yeast. Fermentation did not occur when yeast was inoculated into solutions containing only glucose, but progressed efficiently with when Vegemite or Marmite was also added. Gas Chromatography confirmed that ethanol was present at ∼3% v/v post-fermentation in all samples which contained glucose, Vegemite or Marmite, and brewers' yeast. Trace amounts of methanol were also detected. Mass spectrometry proteomics identified abundant intracellular yeast proteins and barley proteins in Vegemite and Marmite, and abundant secreted yeast proteins from actively growing yeast in those samples to which extra brewers' yeast had been added. We estimate that the real-world cost of home brewed "Vegemite Beer" would be very low. Our results show that Vegemite or other yeast extract spreads could provide cheap and readily available sources of nutrient supplementation to increase the efficiency of fermentation in home brewing or other settings. PMID:27602264

  1. Antibacterial and antioxidant properties of mixed linkage beta-oligosaccharides from extracted β-glucan hydrolysed by Penicillium occitanis EGL lichenase.

    PubMed

    Chaari, Fatma; Belghith-Fendri, Lilia; Zaouri-Ellouzi, Soumaya; Driss, Dorra; Blibech, Monia; Kallel, Fatma; Bouaziz, Fatma; Mehdi, Yosra; Ellouz-Chaabouni, Semia; Ghorbel, Raoudha

    2016-06-01

    The aim of this study was first to ascertain the chemical composition and the physicochemical properties of cereal extracted β-glucan from barley flour. Secondly, to assess the antioxidant properties and the antibacterial properties of extracted β-glucan hydrolysates. The proximate composition, FT-IR and scanning electron microscopy of extracted β-Glucan were studied. Hydrolysates from extracted β-glucan, obtained by lichenase EGL from Penicillium occitanis, were a mixed linkage beta-oligosaccharides (MLBO) of trisaccharides and tetrasaccharides. MLBO showed a DPPH radical scavenger with IC50 about 1.8 ± 0.01 mg/mL whereas the IC50 of extracted β-glucan was about 5 ± 0.01 mg/mL. MLBO showed a high antioxidative capacity (175 μmol/mL α-tocopherol equivalents) at 5 mg/mL. The antimicrobial activity was confirmed against all tested bacteria especially at 20 mg/mL of MLBO while no inhibition was observed for all the strains used after the addition of either EGL or extracted β-glucan. PMID:26165546

  2. Extraction of genomic DNA from yeasts for PCR-based applications.

    PubMed

    Lõoke, Marko; Kristjuhan, Kersti; Kristjuhan, Arnold

    2011-05-01

    We have developed a quick and low-cost genomic DNA extraction protocol from yeast cells for PCR-based applications. This method does not require any enzymes, hazardous chemicals, or extreme temperatures, and is especially powerful for simultaneous analysis of a large number of samples. DNA can be efficiently extracted from different yeast species (Kluyveromyces lactis, Hansenula polymorpha, Schizosaccharomyces pombe, Candida albicans, Pichia pastoris, and Saccharomyces cerevisiae). The protocol involves lysis of yeast colonies or cells from liquid culture in a lithium acetate (LiOAc)-SDS solution and subsequent precipitation of DNA with ethanol. Approximately 100 nanograms of total genomic DNA can be extracted from 1 × 10(7) cells. DNA extracted by this method is suitable for a variety of PCR-based applications (including colony PCR, real-time qPCR, and DNA sequencing) for amplification of DNA fragments of ≤ 3500 bp. PMID:21548894

  3. [Study of the Sporothrix schenkii (yeast forms) extract. Electrophoretic and immunoelectrophoretic analyses: characterization of enzymatic activities].

    PubMed

    Walbaum, S; Duriez, T; Dujardin, L; Biguet, J

    1978-07-28

    An extract from living yeast forms of S. schenckii was prepared. The yeasts originated from a shake culture in B.H.I. broth (Difco) incubated for 3 days at 35 degrees C in darkness; they were harvested, washed and disrupted with glass beads in a model MSK Braun mechanical cell homogenizer; a freezing-thawing was added to improve the extract. After electrophoretic separation in agarose gel, the extract's components were characterized by their enzymic activity; with this technique, 30 bands were revealed. These enzymic activities were also investigated on the antigenic fractions of the extract revealed by a rabbit hyperimmunserum: 16 among 22 immunoprecipitates are identified by their catalytic properties. Study of the earliest precipitating antibodies (appearing-order and enzymic caracterization) in rabbits just immunized completes this work. How to ameliorate the quality of the extract by culture and extraction conditions is also specified. PMID:692628

  4. Use of Non-Conventional Cell Disruption Method for Extraction of Proteins from Black Yeasts.

    PubMed

    Čolnik, Maja; Primožič, Mateja; Knez, Željko; Leitgeb, Maja

    2016-01-01

    The influence of pressure and treatment time on cells disruption of different black yeasts and on activities of extracted proteins using supercritical carbon dioxide process was studied. The cells of three different black yeasts Phaeotheca triangularis, Trimatostroma salinum, and Wallemia ichthyophaga were exposed to supercritical carbon dioxide (SC CO2) by varying pressure at fixed temperature (35°C). The black yeasts cell walls were disrupted, and the content of the cells was spilled into the liquid medium. The impact of SC CO2 conditions on secretion of enzymes and proteins from black yeast cells suspension was studied. The residual activity of the enzymes cellulase, β-glucosidase, α-amylase, and protease was studied by enzymatic assay. The viability of black yeast cells was determined by measuring the optical density of the cell suspension at 600 nm. The total protein concentration in the suspension was determined on UV-Vis spectrophotometer at 595 nm. The release of intracellular and extracellular products from black yeast cells was achieved. Also, the observation by an environmental scanning electron microscopy shows major morphological changes with SC CO2-treated cells. The advantages of the proposed method are in a simple use, which is also possible for heat-sensitive materials on one hand and on the other hand integration of the extraction of enzymes and their use in biocatalytical reactions. PMID:27148527

  5. Use of Non-Conventional Cell Disruption Method for Extraction of Proteins from Black Yeasts

    PubMed Central

    Čolnik, Maja; Primožič, Mateja; Knez, Željko; Leitgeb, Maja

    2016-01-01

    The influence of pressure and treatment time on cells disruption of different black yeasts and on activities of extracted proteins using supercritical carbon dioxide process was studied. The cells of three different black yeasts Phaeotheca triangularis, Trimatostroma salinum, and Wallemia ichthyophaga were exposed to supercritical carbon dioxide (SC CO2) by varying pressure at fixed temperature (35°C). The black yeasts cell walls were disrupted, and the content of the cells was spilled into the liquid medium. The impact of SC CO2 conditions on secretion of enzymes and proteins from black yeast cells suspension was studied. The residual activity of the enzymes cellulase, β-glucosidase, α-amylase, and protease was studied by enzymatic assay. The viability of black yeast cells was determined by measuring the optical density of the cell suspension at 600 nm. The total protein concentration in the suspension was determined on UV–Vis spectrophotometer at 595 nm. The release of intracellular and extracellular products from black yeast cells was achieved. Also, the observation by an environmental scanning electron microscopy shows major morphological changes with SC CO2-treated cells. The advantages of the proposed method are in a simple use, which is also possible for heat-sensitive materials on one hand and on the other hand integration of the extraction of enzymes and their use in biocatalytical reactions. PMID:27148527

  6. Gastrointestinal Maturation is Accelerated in Turkey Poults Supplemented with a Mannan-Oligosaccharide Yeast Extract (Alphamune)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alphamune™, a yeast extract antibiotic alternative, has been shown to stimulate the immune system, increase body weight in pigs, and reduce Salmonella colonization in chickens. The influence of Alphamune™ on gastrointestinal tract development has not been reported. Two trials were conducted to evalu...

  7. Effects of dietary yeast extract on turkey stress response and heterophil oxidative burst activity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effective nutritional approaches to counteract the negative effects of stress would both improve human health and provide food animal producers with useful alternatives to antibiotics. In this study, turkeys were fed a standard diet or the same diet supplemented with yeast extract (Alphamune™, YE), ...

  8. A single protocol for extraction of gDNA from bacteria and yeast.

    PubMed

    Vingataramin, Laurie; Frost, Eric H

    2015-03-01

    Guanidine thiocyanate breakage of microorganisms has been the standard initial step in genomic DNA (gDNA) extraction of microbial DNA for two decades, despite the requirement for pretreatments to extract DNA from microorganisms other than Gram-negative bacteria. We report a quick and low-cost gDNA extraction protocol called EtNa that is efficient for bacteria and yeast over a broad range of concentrations. EtNa is based on a hot alkaline ethanol lysis. The solution can be immediately centrifuged to yield a crude gDNA extract suitable for PCR, or it can be directly applied to a silica column for purification. PMID:25757544

  9. Feather keratin hydrolysates obtained from microbial keratinases: effect on hair fiber

    PubMed Central

    2013-01-01

    Background Hair is composed mainly of keratin protein and a small amount of lipid. Protein hydrolysates, in particular those with low molecular weight distribution have been known to protect hair against chemical and environmental damage. Many types of protein hydrolysates from plants and animals have been used in hair and personal care such as keratin hydrolysates obtained from nails, horns and wool. Most of these hydrolysates are obtained by chemical hydrolysis and hydrothermal methods, but recently hydrolyzed hair keratin, feather keratin peptides, and feather meal peptides have been obtained by enzymatic hydrolysis using Bacillus spp in submerged fermentation. Results Keratin peptides were obtained by enzymatic hydrolysis of keratinases using Bacillus subtilis AMR. The microorganism was grown on a feather medium, pH 8.0 (1% feathers) and supplemented with 0.01% of yeast extract, for 5 days, at 28°C with agitation. The supernatant containing the hydrolysates was colleted by centrifugation and ultra filtered in an AMICON system using nano–membranes (Millipore – YC05). The Proteins and peptides were analyzed using HPTLC and MALDI-TOF-MS. Commercial preparations of keratin hydrolysates were used as a comparative standard. After five days the feather had been degraded (90-95%) by the peptidases and keratinases of the microorganism. MALDI-TOF mass spectrometry showed multiple peaks that correspond to peptides in the range of 800 to 1079 Daltons and the commercial hydrolysate was in the range of 900 to 1400 Da. HPTLC showed lower molecular mass peptides and amino acids in the enzymatic hydrolysate when compared with the commercial hydrolysate . A mild shampoo and a rinse off conditioner were formulated with the enzymatic hydrolysate and applied to hair fibers to evaluate the hydration, with and without heat, using a Corneometer® CM 825. The hydration was more efficient with heat, suggesting a more complete incorporation of hydrolysates into the fibers

  10. Single-cell protein production from Jerusalem artichoke extract by a recently isolated marine yeast Cryptococcus aureus G7a and its nutritive analysis.

    PubMed

    Gao, Lingmei; Chi, Zhenming; Sheng, Jun; Ni, Xiumei; Wang, Lin

    2007-12-01

    After crude protein of the marine yeast strains maintained in this laboratory was estimated by the method of Kjehldahl, we found that the G7a strain which was identified to be a strain of Cryptococcus aureus according to the routine identification and molecular methods contained high level of protein and could grow on a wide range of carbon sources. The optimal medium for single-cell protein production was seawater containing 6.0 g of wet weight of Jerusalem artichoke extract per 100 ml of medium and 4.0 g of the hydrolysate of soybean meal per 100 ml of medium, while the optimal conditions for single-cell protein production were pH 5.0 and 28.0 degrees C. After fermentation for 56 h, 10.1 g of cell dry weight per liter of medium and 53.0 g of crude protein per 100 g of cell dry weight (5.4 g/l of medium) were achieved, leaving 0.05 g of reducing sugar per 100 ml of medium and 0.072 g of total sugar per 100 ml of medium total sugar in the fermented medium. The yeast strain only contained 2.1 g of nucleic acid per 100 g of cell dry weight, but its cells contained a large amount of C(16:0) (19.0%), C(18:0) (46.3%), and C(18:1) (33.3%) fatty acids and had a large amount of essential amino acids, especially lysine (12.6%) and leucine (9.1%), and vitamin C (2.2 mg per 100 g of cell dry weight). These results show that the new marine yeast strain was suitable for single-cell protein production. PMID:17929010

  11. Unveiling the potential of novel yeast protein extracts in white wines clarification and stabilization

    PubMed Central

    Fernandes, Joana P.; Neto, Rodrigo; Centeno, Filipe; De Fátima Teixeira, Maria; Gomes, Ana Catarina

    2015-01-01

    Fining agents derived from animal and mineral sources are widely used to clarify and stabilize white wines. Nevertheless, health and environmental problems are being raised, concerning the allergenic and environmental impact of some of those fining products. In this study, our aim is to validate the potential of yeast protein extracts, obtained from an alternative and safe source, naturally present in wine: oenological yeasts. Three untreated white wines were used in this work in order to evaluate the impact of these novel yeast protein extracts (YPE) in terms of the wine clarification and stabilization improvement. Two separated fining trials were thus conducted at laboratory scale and the yeast alternatives were compared with reference fining agents, obtained from mineral, animal and vegetable origins. Our results indicate that YPE were capable to promote (i) brilliance/color improvement, (ii) turbidity reduction (76–89% comparing with the untreated wines), and (iii) production of compact and homogeneous lees (44% smaller volume than obtained with bentonite). Additionally, after submitting wines to natural and forced oxidations, YPE treatments revealed (iv) different forms of colloidal stabilization, by presenting comparable or superior effects when particularly compared to casein. Altogether, this study reveals that YPE represent a promising alternative for white wine fining, since they are resultant from a natural and more sustainable origin, at present not regarded as potential allergenic according to Regulation (EC) No. 1169/2011. PMID:25853122

  12. Unveiling the potential of novel yeast protein extracts in white wines clarification and stabilization.

    PubMed

    Fernandes, Joana P; Neto, Rodrigo; Centeno, Filipe; De Fátima Teixeira, Maria; Gomes, Ana Catarina

    2015-01-01

    Fining agents derived from animal and mineral sources are widely used to clarify and stabilize white wines. Nevertheless, health and environmental problems are being raised, concerning the allergenic and environmental impact of some of those fining products. In this study, our aim is to validate the potential of yeast protein extracts, obtained from an alternative and safe source, naturally present in wine: oenological yeasts. Three untreated white wines were used in this work in order to evaluate the impact of these novel yeast protein extracts (YPE) in terms of the wine clarification and stabilization improvement. Two separated fining trials were thus conducted at laboratory scale and the yeast alternatives were compared with reference fining agents, obtained from mineral, animal and vegetable origins. Our results indicate that YPE were capable to promote (i) brilliance/color improvement, (ii) turbidity reduction (76-89% comparing with the untreated wines), and (iii) production of compact and homogeneous lees (44% smaller volume than obtained with bentonite). Additionally, after submitting wines to natural and forced oxidations, YPE treatments revealed (iv) different forms of colloidal stabilization, by presenting comparable or superior effects when particularly compared to casein. Altogether, this study reveals that YPE represent a promising alternative for white wine fining, since they are resultant from a natural and more sustainable origin, at present not regarded as potential allergenic according to Regulation (EC) No. 1169/2011. PMID:25853122

  13. Complex coacervation of collagen hydrolysate extracted from leather solid wastes and chitosan for controlled release of lavender oil.

    PubMed

    Ocak, Buğra

    2012-06-15

    In the world, approximately 600,000 metric tonnes of chromium-containing solid wastes are generated by the leather industry each year. Environmental concerns and escalating landfill costs are becoming increasingly serious problems to the leather industry and seeking solutions to these problems is a prime concern in much research today. In this study, solid collagen-based protein hydrolysate was isolated from chromium-tanned leather wastes and its chemical properties were determined. Microcapsules of collagen hydrolysate (CH) - chitosan (C) crosslinked with glutaraldehyde (GA) containing Lavender oil (LO) were prepared by complex coacervation method. The effects of various processing parameters, including the CH to C ratio, LO content, and GA, on the oil load (%), oil content (%), encapsulation efficiency (%) and release rate of LO from microcapsules were investigated. As the ratio of C present in the CH/C mixture and crosslinking density increased, the release rate of LO from microcapsules slowed down. Optical and scanning electron microscopy images illustrated that the LO microcapsules were spherical in shape. Fourier transform infrared spectroscopy (FTIR) studies confirmed that there was no significant interaction between CH/C complex and LO. PMID:22361107

  14. GC Preps: Fast and Easy Extraction of Stable Yeast Genomic DNA

    PubMed Central

    Blount, Benjamin A.; Driessen, Maureen R. M.; Ellis, Tom

    2016-01-01

    Existing yeast genomic DNA extraction methods are not ideally suited to extensive screening of colonies by PCR, due to being too lengthy, too laborious or yielding poor quality DNA and inconsistent results. We developed the GC prep method as a solution to this problem. Yeast cells from colonies or liquid cultures are lysed by vortex mixing with glass beads and then boiled in the presence of a metal chelating resin. In around 12 minutes, multiple samples can be processed to extract high yields of genomic DNA. These preparations perform as effectively in PCR screening as DNA purified by organic solvent methods, are stable for up to 1 year at room temperature and can be used as the template for PCR amplification of fragments of at least 8 kb. PMID:27240644

  15. Dextransucrase production using cashew apple juice as substrate: effect of phosphate and yeast extract addition.

    PubMed

    Chagas, Clarice M A; Honorato, Talita L; Pinto, Gustavo A S; Maia, Geraldo A; Rodrigues, Sueli

    2007-05-01

    Cashew apples are considered agriculture excess in the Brazilian Northeast because cashew trees are cultivated primarily with the aim of cashew nut production. In this work, the use of cashew apple juice as a substrate for Leuconostoc mesenteroides cultivation was investigated. The effect of yeast extract and phosphate addition was evaluated using factorial planning tools. Both phosphate and yeast extract addition were significant factors for biomass growth, but had no significant effect on maximum enzyme activity. The enzyme activities found in cashew apple juice assays were at least 3.5 times higher than the activity found in the synthetic medium. Assays with pH control (pH = 6.5) were also carried out. The pH-controlled fermentation enhanced biomass growth, but decreased the enzyme activity. Crude enzyme free of cells produced using cashew apple juice was stable for 16 h at 30 degrees C at a pH of 5.0. PMID:17323142

  16. GC Preps: Fast and Easy Extraction of Stable Yeast Genomic DNA.

    PubMed

    Blount, Benjamin A; Driessen, Maureen R M; Ellis, Tom

    2016-01-01

    Existing yeast genomic DNA extraction methods are not ideally suited to extensive screening of colonies by PCR, due to being too lengthy, too laborious or yielding poor quality DNA and inconsistent results. We developed the GC prep method as a solution to this problem. Yeast cells from colonies or liquid cultures are lysed by vortex mixing with glass beads and then boiled in the presence of a metal chelating resin. In around 12 minutes, multiple samples can be processed to extract high yields of genomic DNA. These preparations perform as effectively in PCR screening as DNA purified by organic solvent methods, are stable for up to 1 year at room temperature and can be used as the template for PCR amplification of fragments of at least 8 kb. PMID:27240644

  17. Treatment of rice straw hemicellulosic hydrolysates with advanced oxidative processes: a new and promising detoxification method to improve the bioconversion process

    PubMed Central

    2013-01-01

    Background The use of lignocellulosic constituents in biotechnological processes requires a selective separation of the main fractions (cellulose, hemicellulose and lignin). During diluted acid hydrolysis for hemicellulose extraction, several toxic compounds are formed by the degradation of sugars and lignin, which have ability to inhibit microbial metabolism. Thus, the use of a detoxification step represents an important aspect to be considered for the improvement of fermentation processes from hydrolysates. In this paper, we evaluated the application of Advanced Oxidative Processes (AOPs) for the detoxification of rice straw hemicellulosic hydrolysate with the goal of improving ethanol bioproduction by Pichia stipitis yeast. Aiming to reduce the toxicity of the hemicellulosic hydrolysate, different treatment conditions were analyzed. The treatments were carried out according to a Taguchi L16 orthogonal array to evaluate the influence of Fe+2, H2O2, UV, O3 and pH on the concentration of aromatic compounds and the fermentative process. Results The results showed that the AOPs were able to remove aromatic compounds (furan and phenolic compounds derived from lignin) without affecting the sugar concentration in the hydrolysate. Ozonation in alkaline medium (pH 8) in the presence of H2O2 (treatment A3) or UV radiation (treatment A5) were the most effective for hydrolysate detoxification and had a positive effect on increasing the yeast fermentability of rice straw hemicellulose hydrolysate. Under these conditions, the higher removal of total phenols (above 40%), low molecular weight phenolic compounds (above 95%) and furans (above 52%) were observed. In addition, the ethanol volumetric productivity by P. stipitis was increased in approximately twice in relation the untreated hydrolysate. Conclusion These results demonstrate that AOPs are a promising methods to reduce toxicity and improve the fermentability of lignocellulosic hydrolysates. PMID:23414668

  18. Methyl jasmonate and yeast extract stimulate mitragynine production in Mitragyna speciosa (Roxb.) Korth. shoot culture.

    PubMed

    Wungsintaweekul, Juraithip; Choo-Malee, Jutarat; Charoonratana, Tossaton; Keawpradub, Niwat

    2012-10-01

    Mitragynine is a pharmacologically-active terpenoid indole alkaloid found in Mitragyna speciosa leaves. Treatment with methyl jasmonate (10 μM) for 24 h and yeast extract (0.1 mg/ml) for 12 h were the optimum conditions of elicitation of mitragynine accumulation in a M. speciosa shoot culture. The former elicitor gave 0.11 mg mitragynine/g dry wt. Tryptophan decarboxylase and strictosidine synthase mRNA levels were enhanced in accordance with mitragynine accumulation. PMID:22714271

  19. Ultrasound assisted extraction of carbohydrates from microalgae as feedstock for yeast fermentation.

    PubMed

    Zhao, Guili; Chen, Xue; Wang, Lei; Zhou, Shixiao; Feng, Huixing; Chen, Wei Ning; Lau, Raymond

    2013-01-01

    Recently, carbohydrates biomass from microalgae is considered as a promising and inexpensive feedstock for biofeuls production by microorganism fermentation. The main obstacle of the process is microalgae pretreatment and carbohydrates extraction from algal cell. In this study, comparison of three pretreatment methods was performed and the results showed that ultrasonic assisted extraction (UAE) was very effective. The effects of four parameters (ultrasonic power, extraction time, flow rate and algal cell concentration, respectively) on extraction efficiency were also investigated. Additionally, in order to identify significant factors for glucose yield, combination of these four parameters was examined by using fractional factorial design (FFD) and the regression model was obtained. Meanwhile, the refined model was confirmed as a good fitting model via analysis of variance (ANOVA). After extraction, glucose obtained from microalgae was used as substrate for Rhodosporidium toruloides fermentation and yeast biomass was much higher than that of control culture. PMID:23196255

  20. Microbial dynamics during azo dye degradation in a UASB reactor supplied with yeast extract.

    PubMed

    Silva, S Q; Silva, D C; Lanna, M C S; Baeta, B E L; Aquino, S F

    2014-01-01

    The present work aimed to investigate the microbial dynamics during the anaerobic treatment of the azo dye blue HRFL in bench scale upflow anaerobic sludge bed (UASB) reactor operated at ambient temperature. Sludge samples were collected under distinct operational phases, when the reactor were stable (low variation of color removal), to assess the effect of glucose and yeast extract as source of carbon and redox mediators, respectively. Reactors performance was evaluated based on COD (chemical oxygen demand) and color removal. The microbial dynamics were investigated by PCR-DGGE (Polimerase Chain Reaction - Denaturing Gradient of Gel Electrophoresis) technique by comparing the 16S rDNA profiles among samples. The results suggest that the composition of microorganisms changed from the beginning to the end of the reactor operation, probably in response to the presence of azo dye and/or its degradation byproducts. Despite the highest efficiency of color removal was observed in the presence of 500 mg/L of yeast extract (up to 93%), there were no differences regarding the microbial profiles that could indicate a microbial selection by the yeast extract addition. On the other hand Methosarcina barkeri was detected only in the end of operation when the best efficiencies on color removal occurred. Nevertheless the biomass selection observed in the last stages of UASB operation is probably a result of the washout of the sludge in response of accumulation of aromatic amines which led to tolerant and very active biomass that contributed to high efficiencies on color removal. PMID:25763018

  1. Microbial dynamics during azo dye degradation in a UASB reactor supplied with yeast extract

    PubMed Central

    Silva, S.Q.; Silva, D.C.; Lanna, M.C.S.; Baeta, B.E.L.; Aquino, S.F.

    2014-01-01

    The present work aimed to investigate the microbial dynamics during the anaerobic treatment of the azo dye blue HRFL in bench scale upflow anaerobic sludge bed (UASB) reactor operated at ambient temperature. Sludge samples were collected under distinct operational phases, when the reactor were stable (low variation of color removal), to assess the effect of glucose and yeast extract as source of carbon and redox mediators, respectively. Reactors performance was evaluated based on COD (chemical oxygen demand) and color removal. The microbial dynamics were investigated by PCR-DGGE (Polimerase Chain Reaction - Denaturing Gradient of Gel Electrophoresis) technique by comparing the 16S rDNA profiles among samples. The results suggest that the composition of microorganisms changed from the beginning to the end of the reactor operation, probably in response to the presence of azo dye and/or its degradation byproducts. Despite the highest efficiency of color removal was observed in the presence of 500 mg/L of yeast extract (up to 93%), there were no differences regarding the microbial profiles that could indicate a microbial selection by the yeast extract addition. On the other hand Methosarcina barkeri was detected only in the end of operation when the best efficiencies on color removal occurred. Nevertheless the biomass selection observed in the last stages of UASB operation is probably a result of the washout of the sludge in response of accumulation of aromatic amines which led to tolerant and very active biomass that contributed to high efficiencies on color removal. PMID:25763018

  2. Inaccurate DNA Synthesis in Cell Extracts of Yeast Producing Active Human DNA Polymerase Iota

    PubMed Central

    Makarova, Alena V.; Grabow, Corinn; Gening, Leonid V.; Tarantul, Vyacheslav Z.; Tahirov, Tahir H.; Bessho, Tadayoshi; Pavlov, Youri I.

    2011-01-01

    Mammalian Pol ι has an unusual combination of properties: it is stimulated by Mn2+ ions, can bypass some DNA lesions and misincorporates “G” opposite template “T” more frequently than incorporates the correct “A.” We recently proposed a method of detection of Pol ι activity in animal cell extracts, based on primer extension opposite the template T with a high concentration of only two nucleotides, dGTP and dATP (incorporation of “G” versus “A” method of Gening, abbreviated as “misGvA”). We provide unambiguous proof of the “misGvA” approach concept and extend the applicability of the method for the studies of variants of Pol ι in the yeast model system with different cation cofactors. We produced human Pol ι in baker's yeast, which do not have a POLI ortholog. The “misGvA” activity is absent in cell extracts containing an empty vector, or producing catalytically dead Pol ι, or Pol ι lacking exon 2, but is robust in the strain producing wild-type Pol ι or its catalytic core, or protein with the active center L62I mutant. The signature pattern of primer extension products resulting from inaccurate DNA synthesis by extracts of cells producing either Pol ι or human Pol η is different. The DNA sequence of the template is critical for the detection of the infidelity of DNA synthesis attributed to DNA Pol ι. The primer/template and composition of the exogenous DNA precursor pool can be adapted to monitor replication fidelity in cell extracts expressing various error-prone Pols or mutator variants of accurate Pols. Finally, we demonstrate that the mutation rates in yeast strains producing human DNA Pols ι and η are not elevated over the control strain, despite highly inaccurate DNA synthesis by their extracts. PMID:21304950

  3. Detergent assisted lipid extraction from wet yeast biomass for biodiesel: A response surface methodology approach.

    PubMed

    Yellapu, Sravan Kumar; Bezawada, Jyothi; Kaur, Rajwinder; Kuttiraja, Mathiazhakan; Tyagi, Rajeshwar D

    2016-10-01

    The lipid extraction from the microbial biomass is a tedious and high cost dependent process. In the present study, detergent assisted lipids extraction from the culture of the yeast Yarrowia lipolytica SKY-7 was carried out. Response surface methodology (RSM) was used to investigate the effect of three principle parameters (N-LS concentration, time and temperature) on microbial lipid extraction efficiency % (w/w). The results obtained by statistical analysis showed that the quadratic model fits in all cases. Maximum lipid recovery of 95.3±0.3% w/w was obtained at the optimum level of process variables [N-LS concentration 24.42mg (equal to 48mgN-LS/g dry biomass), treatment time 8.8min and reaction temperature 30.2°C]. Whereas the conventional chloroform and methanol extraction to achieve total lipid recovery required 12h at 60°C. The study confirmed that oleaginous yeast biomass treatment with N-lauroyl sarcosine would be a promising approach for industrial scale microbial lipid recovery. PMID:27416517

  4. Understanding the intracellular effects of yeast extract on the enhancement of Fc-fusion protein production in Chinese hamster ovary cell culture.

    PubMed

    Hu, Dongdong; Sun, Yating; Liu, Xuping; Liu, Jintao; Zhang, Xintao; Zhao, Liang; Wang, Haibin; Tan, Wen-Song; Fan, Li

    2015-10-01

    Yeast extract (YE), as a non-animal source additive for mammalian cell culture medium, has been widely used for manufacturing of therapeutic proteins. In the present study, one particular YE was found to have significantly improved the specific productivity (q p) of Fc-fusion protein in recombinant Chinese hamster ovary (rCHO) cell culture. In order to elucidate the intracellular effects of YE on protein productivity, steps of the target protein synthesis process were investigated to unveil their variations caused by YE addition. Stepwise analysis on Fc-fusion protein synthesis process showed that YE enhanced Fc-fusion protein gene transcription with cell cycle arrest at G1 phase; mammalian target of rapamycin (mTOR) signaling pathway was activated to enhance the translation of Fc-fusion protein, and the block in post-translational steps of Fc-fusion protein was alleviated by YE addition as well. Our results revealed the responses of multiple protein production steps to the addition of YE and provided a practical guidance for the separation and application of active compounds from hydrolysates. PMID:26162671

  5. Mild alkali-pretreatment effectively extracts guaiacyl-rich lignin for high lignocellulose digestibility coupled with largely diminishing yeast fermentation inhibitors in Miscanthus.

    PubMed

    Li, Ming; Si, Shengli; Hao, Bo; Zha, Yi; Wan, Can; Hong, Shufen; Kang, Yongbo; Jia, Jun; Zhang, Jing; Li, Meng; Zhao, Chunqiao; Tu, Yuanyuan; Zhou, Shiguang; Peng, Liangcai

    2014-10-01

    In this study, various alkali-pretreated lignocellulose enzymatic hydrolyses were evaluated by using three standard pairs of Miscanthus accessions that showed three distinct monolignol (G, S, H) compositions. Mfl26 samples with elevated G-levels exhibited significantly increased hexose yields of up to 1.61-fold compared to paired samples derived from enzymatic hydrolysis, whereas Msa29 samples with high H-levels displayed increased hexose yields of only up to 1.32-fold. In contrast, Mfl30 samples with elevated S-levels showed reduced hexose yields compared to the paired sample of 0.89-0.98 folds at p<0.01. Notably, only the G-rich biomass samples exhibited complete enzymatic hydrolysis under 4% NaOH pretreatment. Furthermore, the G-rich samples showed more effective extraction of lignin-hemicellulose complexes than the S- and H-rich samples upon NaOH pretreatment, resulting in large removal of lignin inhibitors to yeast fermentation. Therefore, this study proposes an optimal approach for minor genetic lignin modification towards cost-effective biomass process in Miscanthus. PMID:25079210

  6. Ethanolic fermentation of pentoses in lignocellulose hydrolysates

    SciTech Connect

    Hahn-Haegerdal, B.; Linden, T.; Senac, T.; Skoog, K.

    1991-12-31

    In the fermentation of lignocellulose hydrolysates to ethanol, two major problems are encountered: the fermentation of the pentose sugar xylose, and the presence of microbial inhibitors. Xylose can be directly fermented with yeasts; such as Pachysolen tannophilus, Candida shehatae, and Pichia stipis, or by isomerization of xylose to xylulose with the enzyme glucose (xylose) isomerase, and subsequent fermentation with bakers yeast, Saccharomyces cerevisiae. The direct fermentation requires low, carefully controlled oxygenation, as well as the removal of inhibitors. Also, the xylose-fermenting yeasts have a limited ethanol tolerance. The combined isomerization and fermentation with XI and S. cerevisiae gives yields and productivities comparable to those obtained in hexose fermentations without oxygenation and removal of inhibitors. However, the enzyme is not very stable in a lignocellulose hydrolysate, and S. cerevisiae has a poorly developed pentose phosphate shunt. Different strategies involving strain adaptation, and protein and genetic engineering adopted to overcome these different obstacles, are discussed.

  7. A Yeast Metabolite Extraction Protocol Optimised for Time-Series Analyses

    PubMed Central

    Sasidharan, Kalesh; Soga, Tomoyoshi; Tomita, Masaru; Murray, Douglas B.

    2012-01-01

    There is an increasing call for the absolute quantification of time-resolved metabolite data. However, a number of technical issues exist, such as metabolites being modified/degraded either chemically or enzymatically during the extraction process. Additionally, capillary electrophoresis mass spectrometry (CE-MS) is incompatible with high salt concentrations often used in extraction protocols. In microbial systems, metabolite yield is influenced by the extraction protocol used and the cell disruption rate. Here we present a method that rapidly quenches metabolism using dry-ice ethanol bath and methanol N-ethylmaleimide solution (thus stabilising thiols), disrupts cells efficiently using bead-beating and avoids artefacts created by live-cell pelleting. Rapid sample processing minimised metabolite leaching. Cell weight, number and size distribution was used to calculate metabolites to an attomol/cell level. We apply this method to samples obtained from the respiratory oscillation that occurs when yeast are grown continuously. PMID:22952947

  8. Antiulcer and antiproliferative properties of spent brewer's yeast peptide extracts for incorporation into foods.

    PubMed

    Amorim, Maria M; Pereira, Joana O; Monteiro, Karin M; Ruiz, Ana L; Carvalho, João E; Pinheiro, Hélder; Pintado, Manuela

    2016-05-18

    The main objective was to study the antiulcer and antiproliferative potential of yeast peptide extract for further incorporation into functional foods. Peptide concentrates were obtained by hydrolysis of spent brewer's yeast proteins followed by a filtration process. In order to prove the possible protection of gastric mucosa, an animal model with ulcerative lesions caused by oral administration of absolute ethanol was used. The peptide fraction <3 kDa was able to reduce gastric injuries to significant levels (p < 0.001) and the effective dose (DE50) was 816 mg per kg bw. The cytoprotective effect appears to depend on a prostaglandin-mediated mechanism and also on a nonspecific mechanism. The antiproliferative activity of the extract in nine different human tumoral cell lines was tested. The results exhibited a promising antiproliferative activity against the cell line K-562 (leukemia). The results suggest that a new peptide extract can be used to develop new value-added functional food products, although further studies are required. PMID:27125503

  9. Effect of scenedesmus acuminatus green algae extracts on the development of Candida lipolytic yeast in gas condensate-containing media

    NASA Technical Reports Server (NTRS)

    Bilmes, B. I.; Kasymova, G. A.; Runov, V. I.; Karavayeva, N. N.

    1980-01-01

    Data are given of a comparative study of the growth and development as well as the characteristics of the biomass of the C. Lipolytica yeast according to the content of raw protein, protein, lipids, vitamins in the B group, and residual hydrocarbons during growth in media with de-aromatized gas-condensate FNZ as the carbon source with aqueous and alcohol extracts of S. acuminatus as the biostimulants. It is shown that the decoction and aqueous extract of green algae has the most intensive stimulating effect on the yeast growth. When a decoction of algae is added to the medium, the content of residual hydrocarbons in the biomass of C. lipolytica yeast is reduced by 4%; the quantity of protein, lipids, thamine and inositol with replacement of the yeast autolysate by the decoction of algae is altered little.

  10. Efficient fermentation of Pinus sp. acid hydrolysates by an ethanologenic strain of Escherichia coli

    SciTech Connect

    Barbosa, M.F.S. de; Ingram, L.O. ); Beck, M.J. ); Fein, J.E.; Potts, D. )

    1992-04-01

    Process conditions for the acid hydrolysis of pine hemicellulose and cellulose have been described which provide a biocompatible sugar solution. By using an improved strain of recombinant Escherichia coli, strain KO11, hydrolysates supplemented with yeast extract and tryptone nutrients were converted to ethanol with an efficiency of 85% to over 100% on the basis of monomer sugar content (approximately 72 g/liter) and with the production of 35 g of ethanol per liter in 48 h. In the process described, approximately 347 liters of ethanol could be produced per dry metric ton of lignocellulose.

  11. Purification and full characterisation of citreoviridin produced by Penicillium citreonigrum in yeast extract sucrose (YES) medium.

    PubMed

    da Rocha, Mariana Wagner; Resck, Inês Sabioni; Caldas, Eloisa Dutra

    2015-01-01

    The mycotoxin citreoviridin has been associated with the 'yellow rice' disease, which caused cardiac beriberi in Japan. In Brazil, the consumption of contaminated rice was suspected to be involved in a recent beriberi outbreak. In this work, citreoviridin was produced by Penicillium citreonigrum, cultivated in 500 ml yeast extract sucrose (YES) liquid medium for 8 days at 25ºC, and the toxin extracted with chloroform from the liquid medium and the mycelium. A total of 15.3 g of crude extract was obtained from 48 culture flasks, with an estimated citreoviridin contend of 5.54 g, 74.3% being present in the mycelia. Semi-preparative HPLC of the crude extract yielded 27.1% citreoviridin. The HPLC-purified citreoviridin fraction was fully characterised by UV/VIS, FT-IR, (1)H- and (13)C-NMR, LC-MS/MS and LC-MSD TOF, and purity confirmed by gravimetric analysis. Isocitreoviridin was also produced by P. citreonigrum, accounting for about 10% of the citreoviridin present in the crude extract, most transformed into citreoviridin after 10 months under freezing conditions protected from light. Citreoviridin was shown to be stable under the same conditions, although it can suffer isomerisation after a longer storage period. Isomerisation is a potential source of variability in toxicological studies and purity of the material should be checked before study initiation. PMID:25190053

  12. Recovery of spores of Clostridium botulinum in yeast extract agar and pork infusion agar after heat treatment.

    PubMed

    Odlaug, T E; Pflug, I J

    1977-10-01

    Yeast extract agar, pork infusion agar, and modifications of these media were used to recover heated Clostridium botulinum spores. The D- and z-values were determined. Two type A strains and one type B strain of C. botulinum were studied. In all cases the D-values were largest when the spores were recovered in yeast extract agar, compared to the D-values for spores recovered in pork infusion agar. The z-values for strains 62A and A16037 were largest when the spores were recovered in pork infusion agar. The addition of sodium bicarbonate and sodium thioglycolate to pork infusion agar resulted in D-values for C. botulinum 62A spores similar to those for the same spores recovered in yeast extract agar. The results suggest that sodium bicarbonate and sodium thioglycolate should be added to recovery media for heated C. botulinum spores to obtain maximum plate counts. PMID:335970

  13. [Effects of 33% grapefruit extract on the growth of the yeast--like fungi, dermatopytes and moulds].

    PubMed

    Krajewska-Kułak, E; Lukaszuk, C; Niczyporuk, W

    2001-01-01

    Grapefruit seed extract was discovered by Jacob Harich an american immunologist in 1980. Assessment of the influence of grapefruit extract on the yeast-like fungi strains--Candida albicans growth. Material used in this investigation was ATCC test Candida albicans strains no 10231, 200 of Candida albicans strains, 5 of Candida sp. strains isolated from patients with candidiasis symptoms from different ontocenosis and 12 of dermatophytes and moulds isolated from patients. The susceptibility of the Candida was determined by serial dilution method. It seems that 33% grapefruit extract exert a potent antifungal activity against the yeast like fungi strains and had low activity against dermatophytes and moulds. Further studies in vitro and in vivo on greater number of the yeast-like fungi strains and other fungi species are needed. PMID:16886437

  14. Photocatalytic activity of biogenic silver nanoparticles synthesized using yeast ( Saccharomyces cerevisiae) extract

    NASA Astrophysics Data System (ADS)

    Roy, Kaushik; Sarkar, C. K.; Ghosh, C. K.

    2015-11-01

    Synthesis of metallic and semiconductor nanoparticles through physical and chemical route is quiet common but biological synthesis procedures are gaining momentum due to their simplicity, cost-effectivity and eco-friendliness. Here, we report green synthesis of silver nanoparticles from aqueous solution of silver salts using yeast ( Saccharomyces cerevisiae) extract. The nanoparticles formation was gradually investigated by UV-Vis spectrometer. X-ray diffraction analysis was done to identify different phases of biosynthesized Ag nanoparticles. Transmission electron microscopy was performed to study the particle size and morphology of silver nanoparticles. Fourier transform infrared spectroscopy of the nanoparticles was performed to study the role of biomolecules capped on the surface of Ag nanoparticles during interaction. Photocatalytic activity of these biosynthesized nanoparticles was studied using an organic dye, methylene blue under solar irradiation and these nanoparticles showed efficacy in degrading the dye within a few hours of exposure.

  15. Effect of Yeast Extract and Vitamin B(12) on Ethanol Production from Cellulose by Clostridium thermocellum I-1-B.

    PubMed

    Sato, K; Goto, S; Yonemura, S; Sekine, K; Okuma, E; Takagi, Y; Hon-Nami, K; Saiki, T

    1992-02-01

    Addition to media of yeast extract, a vitamin mixture containing vitamin B(12), biotin, pyridoxamine, and p-aminobenzoic acid, or vitamin B(12) alone enhanced formation of ethanol but decreased lactate production in the fermentation of cellulose by Clostridium thermocellum I-1-B. A similar effect was not observed with C. thermocellum ATCC 27405 and JW20. PMID:16348657

  16. Effects of yeast extract and vitamin D on turkey mortality and cellulitis incidence in a transport stress model.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We evaluated yeast extract (YE) and vitamin D (VD) in turkeys treated with dexamethasone (Dex) at intervals designed to simulate transport stress during a 3 stage growout. YE but not VD decreased early mortality (P = 0.001) and mortality at wk 7 (P= 0.02) and wk 12 (P = 0.002) but not wk 16. Celluli...

  17. Yeast Extract: Sucrose Ratio Effects on Egg Load, Survival, and Mortality Caused by GF-120 in Western Cherry Fruit Fly

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extrinsic sources of nitrogen are needed by tephritid fruit flies for optimal nutrition. In this study, relationships between yeast extract diets containing 0, 0.109, 0.545, 1.09, 2.18, 3.27, and 5.45% nitrogen (N) and diet intake, survival, egg production, and responses to spinosad bait in western...

  18. Use of yeast cell wall extract as a tool to reduce the impact of necrotic enteritis in broilers.

    PubMed

    M'Sadeq, Shawkat A; Wu, Shu-Biao; Choct, Mingan; Forder, Rebecca; Swick, Robert A

    2015-05-01

    The use of a yeast cell wall extract derived from Saccharomyces cerevisiae (Actigen(®)) has been proposed as an alternative to in-feed antibiotics. This experiment was conducted to investigate the efficacy of yeast cell extract as an alternative to zinc bacitracin or salinomycin using a necrotic enteritis challenge model. A feeding study was conducted using 480-day-old male Ross 308 chicks assigned to 48 floor pens. A 2 × 4 factorial arrangement of treatments was employed. The factors were: challenge (- or +) and feed additive (control, zinc bacitracin at 100/50 mg/kg, yeast cell wall extract at 400/800/200 mg/kg, or salinomycin at 60 mg/kg in starter, grower, and finisher, respectively). Diets based on wheat, sorghum, soybean meal, meat and bone meal, and canola meal were formulated according to the Ross 308 nutrient specifications. Birds were challenged using a previously established protocol (attenuated Eimeria spp oocysts) on d 9 and 10(8) to 10(9) Clostridium perfringens (type A strain EHE-NE18) on d 14 and 15). Challenged and unchallenged birds were partitioned to avoid cross contamination. Challenged birds had lower weight gain, feed intake and livability compared to unchallenged birds on d 24 and d 35 (P < 0.05). Birds given zinc bacitracin, yeast cell wall extract, or salinomycin had improved weight gain and livability when compared to control birds given no additives. Challenge × additive interactions were observed for feed intake and weight gain on d 24 and d 35 (P < 0.01). The additives all had a greater positive impact on feed intake, weight gain, and livability in challenged than unchallenged birds. All challenged birds showed higher necrotic enteritis lesion scores in the small intestine sections when compared to unchallenged birds (P < 0.01). Birds fed yeast cell wall extract exhibited increased villus height, decreased crypt depth, and increased villus:crypt ratio when challenged. Yeast cell wall extract, zinc bacitracin, and salinomycin were

  19. Assessment of protease activity in hydrolysed extracts from SSF of hair waste by and indigenous consortium of microorganisms.

    PubMed

    Yazid, Noraziah Abu; Barrena, Raquel; Sánchez, Antoni

    2016-03-01

    Hair wastes from the tannery industry were assessed for its suitability as substrates for protease production by solid-state fermentation (SSF) using a pilot-batch mode operation and anaerobically digested sludge as co-substrate. Maximum protease activity (52,230±1601Ug(-1)DM) was observed at the 14th day of SSF. Single step purification resulted in 2 fold purification with 74% of recovery by ultrafiltration with 10kDa cut-off. The recovered enzyme was stable at a temperature of 30°C and pH 11; optimal conditions that were determined by a central composite full factorial experimental design. The enzyme activity was inhibited by phenylmethylsulfonyl fluoride, which indicates that it belongs to serine protease group. The remaining solid material after protease extraction could be easily stabilized to obtain a final good quality compost-like material as the final dynamic respiration index was lower than 1gO2kg(-1)OMh(-1). The lyophilized recovered enzymes were a good alternative in the process of cowhides dehairing with respect to the current chemical treatment, avoiding the production of solid wastes and highly polluted wastewaters. In conclusion, the entire process can be considered a low-cost sustainable technology for the dehairing process, closing the organic matter cycle in the form of value added product and a compost-like material from a waste. PMID:26856443

  20. In Vivo Hypocholesterolemic Effect of MARDI Fermented Red Yeast Rice Water Extract in High Cholesterol Diet Fed Mice

    PubMed Central

    Beh, Boon Kee; Kong, Joan; Ho, Wan Yong; Mohd Yusof, Hamidah; Hussin, Aminuddin bin; Jaganath, Indu Bala; Alitheen, Noorjahan Banu; Jamaluddin, Anisah

    2014-01-01

    Fermented red yeast rice has been traditionally consumed as medication in Asian cuisine. This study aimed to determine the in vivo hypocholesterolemic and antioxidant effects of fermented red yeast rice water extract produced using Malaysian Agricultural Research and Development Institute (MARDI) Monascus purpureus strains in mice fed with high cholesterol diet. Absence of monacolin-k, lower level of γ-aminobutyric acid (GABA), higher content of total amino acids, and antioxidant activities were detected in MARDI fermented red yeast rice water extract (MFRYR). In vivo MFRYR treatment on hypercholesterolemic mice recorded similar lipid lowering effect as commercial red yeast rice extract (CRYR) as it helps to reduce the elevated serum liver enzyme and increased the antioxidant levels in liver. This effect was also associated with the upregulation of apolipoproteins-E and inhibition of Von Willebrand factor expression. In summary, MFRYR enriched in antioxidant and amino acid without monacolin-k showed similar hypocholesterolemic effect as CRYR that was rich in monacolin-k and GABA. PMID:25031606

  1. In Vivo Hypocholesterolemic Effect of MARDI Fermented Red Yeast Rice Water Extract in High Cholesterol Diet Fed Mice.

    PubMed

    Yeap, Swee Keong; Beh, Boon Kee; Kong, Joan; Ho, Wan Yong; Mohd Yusof, Hamidah; Mohamad, Nurul Elyani; Hussin, Aminuddin Bin; Jaganath, Indu Bala; Alitheen, Noorjahan Banu; Jamaluddin, Anisah; Long, Kamariah

    2014-01-01

    Fermented red yeast rice has been traditionally consumed as medication in Asian cuisine. This study aimed to determine the in vivo hypocholesterolemic and antioxidant effects of fermented red yeast rice water extract produced using Malaysian Agricultural Research and Development Institute (MARDI) Monascus purpureus strains in mice fed with high cholesterol diet. Absence of monacolin-k, lower level of γ-aminobutyric acid (GABA), higher content of total amino acids, and antioxidant activities were detected in MARDI fermented red yeast rice water extract (MFRYR). In vivo MFRYR treatment on hypercholesterolemic mice recorded similar lipid lowering effect as commercial red yeast rice extract (CRYR) as it helps to reduce the elevated serum liver enzyme and increased the antioxidant levels in liver. This effect was also associated with the upregulation of apolipoproteins-E and inhibition of Von Willebrand factor expression. In summary, MFRYR enriched in antioxidant and amino acid without monacolin-k showed similar hypocholesterolemic effect as CRYR that was rich in monacolin-k and GABA. PMID:25031606

  2. Methyl jasmonate, yeast extract and sucrose stimulate phenolic acids accumulation in Eryngium planum L. shoot cultures.

    PubMed

    Kikowska, Małgorzata; Kędziora, Izabela; Krawczyk, Aldona; Thiem, Barbara

    2015-01-01

    Eryngium planum L. has been reported as a medicinal plant used in traditional medicine in Europe. The tissue cultures may be an alternative source of the biomass rich in desired bioactive compounds. The purpose of this study was to investigate the influence of the biotechnological techniques on the selected phenolic acids accumulation in the agitated shoot cultures of E. planum. Qualitative and quantitative analyses of those compounds in 50% aqueous - methanolic extracts from the biomass were conducted by applying the HPLC method. Methyl jasmonate (MeJA), yeast extract (YE) and sucrose (Suc) stimulated accumulation of the phenolic acids: rosmarinic (RA), chlorogenic (CGA) and caffeic (CA) in in vitro shoot cultures. Cultivation of shoots in liquid MS media supplemented with 1.0 mg L(-1) 6-benzyladenine and 0.1 mg L(-1) indole-3-acetic acid in the presence of 100 µM MeJA for 48h was an optimum condition of elicitation and resulted in approximately 4.5-fold increased content of RA + CGA + CA in plant material compared to the control (19.795 mg g(-1) DW, 4.36 mg g(-1) DW, respectively). The results provide the first evidence that the selected phenolic acids can be synthesized in elicited shoot cultures of flat sea holly in higher amount than in untreated shoots. PMID:25856557

  3. The optimized capsid gene of porcine circovirus type 2 expressed in yeast forms virus-like particles and elicits antibody responses in mice fed with recombinant yeast extracts.

    PubMed

    Bucarey, Sergio A; Noriega, Jorge; Reyes, Paulina; Tapia, Cecilia; Sáenz, Leonardo; Zuñiga, Alejandro; Tobar, Jaime A

    2009-09-25

    Porcine circovirus type 2 (PCV2)-associated diseases are considered to be the biggest problem for the worldwide swine industry. The PCV2 capsid protein (Cap) is an important antigen for development of vaccines. At present, most anti-PCV2 vaccines are produced as injectable formulations. Although effective, these vaccines have certain drawbacks, including stress with concomitant immunosuppresion, and involve laborious and time-consuming procedures. In this study, Saccharomyces cerevisiae was used as a vehicle to deliver PCV2 antigen in a preliminary attempt to develop an oral vaccine, and its immunogenic potential in mice was tested after oral gavage-mediated delivery. The cap gene with a yeast-optimized codon usage sequence (opt-cap) was chemically synthesized and cloned into Escherichia coli/Saccharomyces cerevisiae shuttle vector, pYES2, under the control of the Gal1 promoter. Intracellular expression of the Cap protein was confirmed by Western blot analysis and its antigenic properties were compared with those of baculovirus/insect cell-produced Cap protein derived from the native PCV2 cap gene. It was further demonstrated by electron micrography that the yeast-derived PCV2 Cap protein self-assembles into virus-like particles (VLPs) that are morphologically and antigenically similar to insect cell-derived VLPs. Feeding raw yeast extract containing Cap protein to mice elicited both serum- and fecal-specific antibodies against the antigen. These results show that it is feasible to use S. cerevisiae as a safe and simple system to produce PCV2 virus-like particles, and that oral yeast-mediated antigen delivery is an alternative strategy to efficiently induce anti-PCV2 antibodies in a mouse model, which is worthy of further investigation in swine. PMID:19664739

  4. Fractionation and characterization of brewers' spent grain protein hydrolysates.

    PubMed

    Celus, Inge; Brijs, Kristof; Delcour, Jan A

    2009-06-24

    Protein hydrolysates with a low and high degree of hydrolysis were enzymatically produced from brewers' spent grain (BSG), the insoluble residue of barley malt resulting from the manufacture of wort in the production of beer. To that end, BSG protein concentrate (BPC), prepared by alkaline extraction of BSG and subsequent acid precipitation, was enzymatically hydrolyzed with Alcalase during both 1.7 and 120 min. Because these hydrolysates contained many different peptides, fractionation of the hydrolysates with graded ammonium sulfate or ethanol precipitation was performed to obtain fractions homogeneous in terms of molecular weight (MW) and hydrophobicity. The emulsifying and foaming capacities of the resultant fractions were determined. MW distributions and surface hydrophobicities of fractions with protein contents exceeding 75% were investigated to determine relationships between technofunctional and physicochemical properties. It was found that the emulsifying and foaming properties are determined by different physicochemical properties of the proteins or peptides. Neither MW nor hydrophobicity alone determines the emulsifying and foaming properties of protein hydrolysates. BSG protein hydrolysates with good emulsifying properties contained less than 40% of fragments with MW exceeding 14 500. Moreover, these hydrolysates had a high surface hydrophobicity. BSG protein hydrolysates with good foaming properties contained less than 10% of material with MW lower than 1700. Hydrolysates with good foaming properties showed low surface hydrophobicities, except for protein hydrolysates with higher levels of protein fragments with MW exceeding 14 500 than of such fragments with MW in a 1700-14 500 range. PMID:19456139

  5. Simulation of the continuous fermentation of manioc hydrolysate

    SciTech Connect

    Bonomi, A.; Aboutboul, H.; Schmidell, W.

    1981-01-01

    The simulation of the continuous fermentation of manioc hydrolysate utilizing a yeast strain of Saccharomyces cerevisiae isolated from the commercial pressed yeast largely employed in Brazilian distilleries is described. The model used in the simulation is derived from batch experimental runs. In order to assess the economical competitiveness of the continuous fermentation, some additional concepts, such as cell recycle, and two fermentors connected in series with and without feed division of fresh substrate, are analyzed and compared.

  6. Preparation and characterization of yeast nuclear extracts for efficient RNA polymerase B (II)-dependent transcription in vitro.

    PubMed Central

    Verdier, J M; Stalder, R; Roberge, M; Amati, B; Sentenac, A; Gasser, S M

    1990-01-01

    We present a reproducible method for the preparation of nuclear extracts from the yeast Saccharomyces cerevisiae that support efficient RNA polymerase B (II)-dependent transcription. Extracts from both a crude nuclear fraction and Percoll-purified nuclei are highly active for site-specific initiation and transcription of a G-free cassette under the Adenovirus major late promoter. At optimal extract concentrations transcription is at least 5 times more efficient with the yeast extracts than with HeLa whole cell extracts. We show that the transcriptional activity is sensitive to alpha-amanitin and to depletion of factor(s) recognizing the TATA-box of the promoter. The in vitro reaction showed maximal activity after 45 min, was very sensitive to Cl-, but was not affected by high concentrations of potassium. We find that the efficiency of in vitro transcription in nuclear extracts is reproducibly high when spheroplasting is performed with a partially purified beta 1,3-glucanase (lyticase). Therefore a simplified method to isolate the lyticase from the supernatant of Oerskovia xanthineolytica is also presented. Images PMID:2263463

  7. Impact of Phosphate, Potassium, Yeast Extract, and Trace Metals on Chitosan and Metabolite Production by Mucor indicus.

    PubMed

    Safaei, Zahra; Karimi, Keikhosro; Zamani, Akram

    2016-01-01

    In this study the effects of phosphate, potassium, yeast extract, and trace metals on the growth of Mucor indicus and chitosan, chitin, and metabolite production by the fungus were investigated. Maximum yield of chitosan (0.32 g/g cell wall) was obtained in a phosphate-free medium. Reversely, cell growth and ethanol formation by the fungus were positively affected in the presence of phosphate. In a phosphate-free medium, the highest chitosan content (0.42 g/g cell wall) and cell growth (0.66 g/g sugar) were obtained at 2.5 g/L of KOH. Potassium concentration had no significant effect on ethanol and glycerol yields. The presence of trace metals significantly increased the chitosan yield at an optimal phosphate and potassium concentration (0.50 g/g cell wall). By contrast, production of ethanol by the fungus was negatively affected (0.33 g/g sugars). A remarkable increase in chitin and decrease in chitosan were observed in the absence of yeast extract and concentrations lower than 2 g/L. The maximum chitosan yield of 51% cell wall was obtained at 5 g/L of yeast extract when the medium contained no phosphate, 2.5 g/L KOH, and 1 mL/L trace metal solution. PMID:27589726

  8. Identification and quantitation of phosphorus metabolites in yeast neutral pH extracts by nuclear magnetic resonance spectroscopy.

    PubMed

    Teleman, A; Richard, P; Toivari, M; Penttilä, M

    1999-07-15

    (31)P NMR spectroscopy offers a possibility to obtain a survey of all low-molecular-weight phosphorylated compounds in yeast. The yeast cells have been extracted using chloroform into a neutral aqueous phase. The use of high fields and the neutral pH extracts, which are suitable for NMR analysis, results in well-resolved (31)P NMR spectra. Two-dimensional NMR experiments, such as proton-detected heteronuclear single quantum ((1)H-(31)P HSQC) and (31)P correlation spectroscopy ((31)P COSY), have been used to assign the resonances. In the phosphomonoester region many of the signals could be assigned to known metabolites in the glycolytic and pentose phosphate pathways, although some signals remain unidentified. Accumulation of ribulose 5-phosphate, xylulose 5-phosphate, and ribose 5-phosphate was observed in a strain lacking transketolase activity when grown in synthetic complete medium. No such accumulation occurred when the cells were grown in yeast-peptone-dextrose medium. Trimetaphosphate (intracellular concentration about 0.2 mM) was detected in both cold methanol-chloroform and perchloric acid extracts. PMID:10405295

  9. Development of a D-xylose fermenting and inhibitor tolerant industrial Saccharomyces cerevisiae strain with high performance in lignocellulose hydrolysates using metabolic and evolutionary engineering

    PubMed Central

    2013-01-01

    Background The production of bioethanol from lignocellulose hydrolysates requires a robust, D-xylose-fermenting and inhibitor-tolerant microorganism as catalyst. The purpose of the present work was to develop such a strain from a prime industrial yeast strain, Ethanol Red, used for bioethanol production. Results An expression cassette containing 13 genes including Clostridium phytofermentans XylA, encoding D-xylose isomerase (XI), and enzymes of the pentose phosphate pathway was inserted in two copies in the genome of Ethanol Red. Subsequent EMS mutagenesis, genome shuffling and selection in D-xylose-enriched lignocellulose hydrolysate, followed by multiple rounds of evolutionary engineering in complex medium with D-xylose, gradually established efficient D-xylose fermentation. The best-performing strain, GS1.11-26, showed a maximum specific D-xylose consumption rate of 1.1 g/g DW/h in synthetic medium, with complete attenuation of 35 g/L D-xylose in about 17 h. In separate hydrolysis and fermentation of lignocellulose hydrolysates of Arundo donax (giant reed), spruce and a wheat straw/hay mixture, the maximum specific D-xylose consumption rate was 0.36, 0.23 and 1.1 g/g DW inoculum/h, and the final ethanol titer was 4.2, 3.9 and 5.8% (v/v), respectively. In simultaneous saccharification and fermentation of Arundo hydrolysate, GS1.11-26 produced 32% more ethanol than the parent strain Ethanol Red, due to efficient D-xylose utilization. The high D-xylose fermentation capacity was stable after extended growth in glucose. Cell extracts of strain GS1.11-26 displayed 17-fold higher XI activity compared to the parent strain, but overexpression of XI alone was not enough to establish D-xylose fermentation. The high D-xylose consumption rate was due to synergistic interaction between the high XI activity and one or more mutations in the genome. The GS1.11-26 had a partial respiratory defect causing a reduced aerobic growth rate. Conclusions An industrial yeast strain for

  10. Yeast Extract and Silver Nitrate Induce the Expression of Phenylpropanoid Biosynthetic Genes and Induce the Accumulation of Rosmarinic Acid in Agastache rugosa Cell Culture.

    PubMed

    Park, Woo Tae; Arasu, Mariadhas Valan; Al-Dhabi, Naif Abdullah; Yeo, Sun Kyung; Jeon, Jin; Park, Jong Seok; Lee, Sook Young; Park, Sang Un

    2016-01-01

    The present study aimed to investigate the role of yeast extract and silver nitrate on the enhancement of phenylpropanoid pathway genes and accumulation of rosmarinic acid in Agastache rugosa cell cultures. The treatment of cell cultures with yeast extract (500 mg/L) and silver nitrate (30 mg/L) for varying times enhanced the expression of genes in the phenylpropanoid pathway and the production of rosmarinic acid. The results indicated that the expression of RAS and HPPR was proportional to the amount of yeast extract and silver nitrate. The transcript levels of HPPR under yeast extract treatment were 1.84-, 1.97-, and 2.86-fold higher than the control treatments after 3, 6, and 12 h, respectively, whereas PAL expression under silver nitrate treatment was 52.31-fold higher than in the non-treated controls after 24 h of elicitation. The concentration of rosmarinic acid was directly proportional to the concentration of the applied elicitors. Yeast extract supplementation documented the highest amount of rosmarinic acid at 4.98 mg/g, whereas silver nitrate addition resulted in a comparatively lower amount of rosmarinic acid at 0.65 mg/g. In conclusion, addition of yeast extract to the cell cultures enhanced the accumulation of rosmarinic acid, which was evidenced by the expression levels of the phenylpropanoid biosynthetic pathway genes in A. rugosa. PMID:27043507

  11. Discovery of plant extracts that greatly delay yeast chronological aging and have different effects on longevity-defining cellular processes.

    PubMed

    Lutchman, Vicky; Medkour, Younes; Samson, Eugenie; Arlia-Ciommo, Anthony; Dakik, Pamela; Cortes, Berly; Feldman, Rachel; Mohtashami, Sadaf; McAuley, Mélissa; Chancharoen, Marisa; Rukundo, Belise; Simard, Éric; Titorenko, Vladimir I

    2016-03-29

    We discovered six plant extracts that increase yeast chronological lifespan to a significantly greater extent than any of the presently known longevity-extending chemical compounds. One of these extracts is the most potent longevity-extending pharmacological intervention yet described. We show that each of the six plant extracts is a geroprotector which delays the onset and decreases the rate of yeast chronological aging by eliciting a hormetic stress response. We also show that each of these extracts has different effects on cellular processes that define longevity in organisms across phyla. These effects include the following: 1) increased mitochondrial respiration and membrane potential; 2) augmented or reduced concentrations of reactive oxygen species; 3) decreased oxidative damage to cellular proteins, membrane lipids, and mitochondrial and nuclear genomes; 4) enhanced cell resistance to oxidative and thermal stresses; and 5) accelerated degradation of neutral lipids deposited in lipid droplets. Our findings provide new insights into mechanisms through which chemicals extracted from certain plants can slow biological aging. PMID:26918729

  12. Discovery of plant extracts that greatly delay yeast chronological aging and have different effects on longevity-defining cellular processes

    PubMed Central

    Samson, Eugenie; Arlia-Ciommo, Anthony; Dakik, Pamela; Cortes, Berly; Feldman, Rachel; Mohtashami, Sadaf; McAuley, Mélissa; Chancharoen, Marisa; Rukundo, Belise; Simard, Éric; Titorenko, Vladimir I.

    2016-01-01

    We discovered six plant extracts that increase yeast chronological lifespan to a significantly greater extent than any of the presently known longevity-extending chemical compounds. One of these extracts is the most potent longevity-extending pharmacological intervention yet described. We show that each of the six plant extracts is a geroprotector which delays the onset and decreases the rate of yeast chronological aging by eliciting a hormetic stress response. We also show that each of these extracts has different effects on cellular processes that define longevity in organisms across phyla. These effects include the following: 1) increased mitochondrial respiration and membrane potential; 2) augmented or reduced concentrations of reactive oxygen species; 3) decreased oxidative damage to cellular proteins, membrane lipids, and mitochondrial and nuclear genomes; 4) enhanced cell resistance to oxidative and thermal stresses; and 5) accelerated degradation of neutral lipids deposited in lipid droplets. Our findings provide new insights into mechanisms through which chemicals extracted from certain plants can slow biological aging. PMID:26918729

  13. Interactions of grape tannins and wine polyphenols with a yeast protein extract, mannoproteins and β-glucan.

    PubMed

    Mekoue Nguela, J; Poncet-Legrand, C; Sieczkowski, N; Vernhet, A

    2016-11-01

    At present, there is a great interest in enology for yeast derived products to replace aging on lees in winemaking or as an alternative for wine fining. These are yeast protein extracts (YPE), cell walls and mannoproteins. Our aim was to further understand the mechanisms that drive interactions between these components and red wine polyphenols. To this end, interactions between grape skin tannins or wine polyphenols or tannins and a YPE, a mannoprotein fraction and a β-glucan were monitored by binding experiments, ITC and DLS. Depending on the tannin structure, a different affinity between the polyphenols and the YPE was observed, as well as differences in the stability of the aggregates. This was attributed to the mean degree of polymerization of tannins in the polyphenol fractions and to chemical changes that occur during winemaking. Much lower affinities were found between polyphenols and polysaccharides, with different behaviors between mannoproteins and β-glucans. PMID:27211695

  14. DNA synthesis in yeast cell-free extracts dependent on recombinant DNA plasmids purified from Escherichia coli.

    PubMed Central

    Jong, A Y; Scott, J F

    1985-01-01

    In our attempts to establish a cell-free DNA replication system for the yeast Saccharomyces cerevisiae, we have observed that recombinant DNA plasmids purified from Escherichia coli by a common procedure (lysozyme-detergent lysis and equilibrium banding in cesium chloride ethidium bromide gradients) often serve as templates for DNA synthesis by elongation enzymes. The templates could be elongated equally well by enzymes present in the yeast cell-free extracts, by the large proteolytic fragment of E. coli DNA polymerase I or by T4 DNA polymerase. The template activity of the purified plasmids was dependent on the presence of heterologous DNA segments in the bacterial vectors. The template activity could be diminished by treatment with alkali. We propose that the ability of recombinant plasmids isolated from bacterial hosts to serve as elongation templates may lead to erroneous conclusions when these plasmids are used as templates for in vitro replication or transcription reactions. Images PMID:3889851

  15. Improving the robustness of a low-cost insect cell medium for baculovirus biopesticides production, via hydrolysate streamlining using a tube bioreactor-based statistical optimization routine.

    PubMed

    Huynh, Hoai T; Chan, Leslie C L; Tran, Trinh T B; Nielsen, Lars K; Reid, Steven

    2012-01-01

    A critical component of an in vitro production process for baculovirus biopesticides is a growth medium that is efficacious, robust, and inexpensive. An in-house low-cost serum-free medium, VPM3, has been shown to be very promising in supporting Helicoverpa armigera nucleopolyhedrovirus (HaSNPV) production in H. zea insect cell suspension cultures, for use as a biopesticide against the Heliothine pest complex. However, VPM3 is composed of a significant number of undefined components, including five different protein hydrolysates, which introduce a challenging lot-to-lot variability to the production process. In this study, an intensive statistical optimization routine was employed to reduce the number of protein hydrolysates in VPM3 medium. Nearly 300 runs (including replicates) were conducted with great efficiency by using 50 mL TubeSpin® bioreactors to propagate insect cell suspension cultures. Fractional factorial experiments were first used to determine the most important of the five default protein hydrolysates, and to screen for seven potential substitutes for the default meat peptone, Primatone RL. Validation studies informed by the screening tests showed that promising alternative media could be formulated based on just two protein hydrolysates, in particular the YST-AMP (Yeast Extract and Amyl Meat Peptone) and YST-POT (Yeast Extract and Lucratone Potato Peptone) combinations. The YST-AMP (meat-based) and YST-POT (meat-free) variants of VPM3 were optimized using response surface methodology, and were shown to be just as good as the default VPM3 and the commercial Sf-900 II media in supporting baculovirus yields, hence providing a means toward a more reproducible and scalable production process for HaSNPV biopesticides. PMID:22323401

  16. Long-Term Fungal Inhibition by Pisum sativum Flour Hydrolysate during Storage of Wheat Flour Bread.

    PubMed

    Rizzello, Carlo Giuseppe; Lavecchia, Anna; Gramaglia, Valerio; Gobbetti, Marco

    2015-06-15

    In order to identify antifungal compounds from natural sources to be used as ingredients in the bakery industry, water/salt-soluble extracts (WSE) from different legume flour hydrolysates obtained by the use of a fungal protease were assayed against Penicillium roqueforti DPPMAF1. The agar diffusion assays allowed the selection of the pea (Pisum sativum) hydrolysate as the most active. As shown by the hyphal radial growth rate, the WSE had inhibitory activity towards several fungi isolated from bakeries. The MIC of the WSE was 9.0 mg/ml. Fungal inhibition was slightly affected by heating and variations in pH. The antifungal activity was attributed to three native proteins (pea defensins 1 and 2 and a nonspecific lipid transfer protein [nsLTP]) and a mixture of peptides released during hydrolysis. The three proteins have been reported previously as components of the defense system of the plant. Five peptides were purified from WSE and were identified as sequences encrypted in leginsulin A, vicilin, provicilin, and the nsLTP. To confirm antifungal activity, the peptides were chemically synthesized and tested. Freeze-dried WSE were used as ingredients in leavened baked goods. In particular, breads made by the addition of 1.6% (wt/wt) of the extract and fermented by baker's yeast or sourdough were characterized for their main chemical, structural, and sensory features, packed in polyethylene bags, stored at room temperature, and compared to controls prepared without pea hydrolysate. Artificially inoculated slices of a bread containing the WSE did not show contamination by fungi until at least 21 days of storage and behaved like the bread prepared with calcium propionate (0.3%, wt/wt). PMID:25862230

  17. Long-Term Fungal Inhibition by Pisum sativum Flour Hydrolysate during Storage of Wheat Flour Bread

    PubMed Central

    Lavecchia, Anna; Gramaglia, Valerio; Gobbetti, Marco

    2015-01-01

    In order to identify antifungal compounds from natural sources to be used as ingredients in the bakery industry, water/salt-soluble extracts (WSE) from different legume flour hydrolysates obtained by the use of a fungal protease were assayed against Penicillium roqueforti DPPMAF1. The agar diffusion assays allowed the selection of the pea (Pisum sativum) hydrolysate as the most active. As shown by the hyphal radial growth rate, the WSE had inhibitory activity towards several fungi isolated from bakeries. The MIC of the WSE was 9.0 mg/ml. Fungal inhibition was slightly affected by heating and variations in pH. The antifungal activity was attributed to three native proteins (pea defensins 1 and 2 and a nonspecific lipid transfer protein [nsLTP]) and a mixture of peptides released during hydrolysis. The three proteins have been reported previously as components of the defense system of the plant. Five peptides were purified from WSE and were identified as sequences encrypted in leginsulin A, vicilin, provicilin, and the nsLTP. To confirm antifungal activity, the peptides were chemically synthesized and tested. Freeze-dried WSE were used as ingredients in leavened baked goods. In particular, breads made by the addition of 1.6% (wt/wt) of the extract and fermented by baker's yeast or sourdough were characterized for their main chemical, structural, and sensory features, packed in polyethylene bags, stored at room temperature, and compared to controls prepared without pea hydrolysate. Artificially inoculated slices of a bread containing the WSE did not show contamination by fungi until at least 21 days of storage and behaved like the bread prepared with calcium propionate (0.3%, wt/wt). PMID:25862230

  18. Peat Hydrolysate Medium Optimization for Pullulan Production

    PubMed Central

    Boa, Jacques M.; LeDuy, Anh

    1984-01-01

    Peat hydrolysate, a diluted acid-autoclaved extract of peat, was used as a substrate for the production of the extracellular polysaccharide pullulan by three strains of Aureobasidium pullulans, 140B, 142, and 2552. It was found that the addition of (NH4)2SO4 and K2HPO4 as sources of nitrogen and phosphate, respectively, is not necessary for the polysaccharide production. The economically optimized culture medium for large-scale production of pullulan contains peat hydrolysate, 0.05% NaCl, 0.02% MgSO4, and 0.01% antifoam FG-10. The initial pH of peat hydrolysate medium is adjusted to its optimum value of 6.0 with Ca(OH)2. The total ingredient cost for the production of each kilogram of pullulan with optimized medium is only 1/10 of that with the nonoptimized medium. In this study, a zero cost for peat hydrolysate was assumed, since it is an effluent of the peat and peat processing industries. PMID:16346596

  19. Overcoming the toxicity effects of municipal wastewater sludge and biosolid extracts in the Yeast Estrogen Screen (YES) assay.

    PubMed

    Citulski, Joel; Farahbakhsh, Khosrow

    2012-04-01

    For nearly two decades, the Yeast Estrogen Screen (YES) has been used as a valuable tool for determining the total estrogenic potency of various environmental samples, including influent and effluent streams at municipal wastewater plants. However, applying the YES assay to wastewater sludges and stabilized biosolids has been problematic. This is due to co-extracted compounds from the solids either proving toxic to the yeast or masking the presence of estrogenic substances. The present research describes the development and validation of sample preparation steps that mitigate the toxicity effects of municipal wastewater sludge and biosolid samples in the YES assay, while allowing for reliable dose-dependent expression of estrogenic activity. A copper work-up for sulfur removal and chromatographic cleanup with silica and alumina were required in addition to solid-phase extraction to adequately remove interfering compounds. Sample stabilization methods such as autoclaving, lyophilization and formaldehyde treatment were found to be detrimental to the assay. Hence, heat-drying is recommended to prevent cytotoxicity and the degradation of estrogenic substances. PMID:22277884

  20. Asymmetric bioreduction of acetophenones by Baker's yeast and its cell-free extract encapsulated in sol-gel silica materials

    NASA Astrophysics Data System (ADS)

    Kato, Katsuya; Nakamura, Hitomi; Nakanishi, Kazuma

    2014-02-01

    Baker's yeast (BY) encapsulated in silica materials was synthesized using a yeast cell suspension and its cell-free extract during a sol-gel reaction of tetramethoxysilane with nitric acid as a catalyst. The synthesized samples were fully characterized using various methods, such as scanning electron microscopy, nitrogen adsorption-desorption, Fourier transform infrared spectroscopy, thermogravimetry, and differential thermal analysis. The BY cells were easily encapsulated inside silica-gel networks, and the ratio of the cells in the silica gel was approximately 75 wt%, which indicated that a large volume of BY was trapped with a small amount of silica. The enzyme activity (asymmetric reduction of prochiral ketones) of BY and its cell-free extract encapsulated in silica gel was investigated in detail. The activities and enantioselectivities of free and encapsulated BY were similar to those of acetophenone and its fluorine derivatives, which indicated that the conformation structure of BY enzymes inside silica-gel networks did not change. In addition, the encapsulated BY exhibited considerably better solvent (methanol) stability and recyclability compared to free BY solution. We expect that the development of BY encapsulated in sol-gel silica materials will significantly impact the industrial-scale advancement of high-efficiency and low-cost biocatalysts for the synthesis of valuable chiral alcohols.

  1. Malt-yeast extract-sucrose agar, a suitable medium for enumeration and isolation of fungi from silage.

    PubMed Central

    Skaar, I; Stenwig, H

    1996-01-01

    A general medium named malt-yeast extract-sucrose agar (MYSA) containing oxgall was designed. The medium was intended for the enumeration and isolation of molds and yeasts in routine examinations of animal feed stuffs. In this study MYSA was tested as a general medium for mycological examination of silage. The medium was compared with dichloran-rose bengal medium (DRBC) in an examination of more than 500 specimens of big bale grass silage. Selected characteristics of known fungal species commonly isolated from feeds were examined after growth on MYSA and DRBC and on malt extract agar, used as a noninhibitory control medium. MYSA suppressed bacterial growth, without affecting the growth of fungi common in feeds. The fungi growing on MYSA were easily recognized, and the medium seemed to slow radial growth of fungal colonies, which permitted, easy counting. The number of species found was higher on MYSA than on DRBC. When we compared MYSA with DRBC for mycological examination of grass silage samples, MYSA was found to be the medium of choice. PMID:8837416

  2. Sophorolipid production from biomass hydrolysates.

    PubMed

    Samad, Abdul; Zhang, Ji; Chen, Da; Liang, Yanna

    2015-02-01

    Although extensive research has been conducted on producing sophorolipids using Candida (Starmerella) bombicola from pure sugars and various oil sources, production of this biosurfactant has not been evaluated when cells are cultivated in lignocellulosic hydrolysates. Here, we report for the first time that C. bombicola is capable of producing sophorolipids on hydrolysates derived from sweet sorghum bagasse and corn fiber. Without oil supplementation, a sophorolipid concentration of 3.6 and 1.0 g/L was detected from cultures with bagasse and corn fiber hydrolysates, respectively. With the addition of soybean oil at 100 g/L, the yield of sophorolipids from these two hydrolysates in the same order was 84.6 and 15.6 g/L. Surprisingly, C. bombicola consumed all monomeric sugars and nonsugar compounds in the hydrolysates, and cultures with bagasse hydrolysates had higher yield of sophorolipids than those from a standard medium which contained pure glucose at the same concentration. PMID:25475889

  3. [Studies on the effects of carbon:nitrogen ratio, inoculum type and yeast extract addition on jasmonic acid production by Botryodiplodia theobromae Pat. strain RC1].

    PubMed

    Eng Sánchez, Felipe; Gutiérrez-Rojas, Mariano; Favela-Torres, Ernesto

    2008-09-30

    Jasmonic acid is a native plant growth regulator produced by algae, microorganisms and higher plants. This regulator is involved in the activation of defence mechanisms against pathogens and wounding in plants. Studies concerning the effects of carbon: nitrogen ratio (C/Nr: 17, 35 and 70), type of inoculum (spores or mycelium) and the yeast extract addition in the media on jasmonic acid production by Botryodiplodia theobromae were evaluated. Jasmonic acid production was stimulated at the carbon: nitrogen ratio of 17. Jasmonic acid productivity was higher in the media inoculated with mycelium and in the media with yeast extract 1.7 and 1.3 times, respectively. PMID:18785793

  4. Fermentative lactic acid production from coffee pulp hydrolysate using Bacillus coagulans at laboratory and pilot scales.

    PubMed

    Pleissner, Daniel; Neu, Anna-Katrin; Mehlmann, Kerstin; Schneider, Roland; Puerta-Quintero, Gloria Inés; Venus, Joachim

    2016-10-01

    In this study, the lignocellulosic residue coffee pulp was used as carbon source in fermentative l(+)-lactic acid production using Bacillus coagulans. After thermo-chemical treatment at 121°C for 30min in presence of 0.18molL(-1) H2SO4 and following an enzymatic digestion using Accellerase 1500 carbon-rich hydrolysates were obtained. Two different coffee pulp materials with comparable biomass composition were used, but sugar concentrations in hydrolysates showed variations. The primary sugars were (gL(-1)) glucose (20-30), xylose (15-25), sucrose (5-11) and arabinose (0.7-10). Fermentations were carried out at laboratory (2L) and pilot (50L) scales in presence of 10gL(-1) yeast extract. At pilot scale carbon utilization and lactic acid yield per gram of sugar consumed were 94.65% and 0.78gg(-1), respectively. The productivity was 4.02gL(-1)h(-1). Downstream processing resulted in a pure formulation containing 937gL(-1)l(+)-lactic acid with an optical purity of 99.7%. PMID:27359065

  5. Bio-Based Solvents for Green Extraction of Lipids from Oleaginous Yeast Biomass for Sustainable Aviation Biofuel.

    PubMed

    Breil, Cassandra; Meullemiestre, Alice; Vian, Maryline; Chemat, Farid

    2016-01-01

    Lipid-based oleaginous microorganisms are potential candidates and resources for the sustainable production of biofuels. This study was designed to evaluate the performance of several alternative bio-based solvents for extracting lipids from yeasts. We used experimental design and simulation with Hansen solubility simulations and the conductor-like screening model for realistic solvation (COSMO-RS) to simulate the solubilization of lipids in each of these solvents. Lipid extracts were analyzed by high performance thin-layer chromatography (HPTLC) to obtain the distribution of lipids classes and gas chromatography coupled with a flame ionization detector (GC/FID) to obtain fatty acid profiles. Our aim was to correlate simulation with experimentation for extraction and solvation of lipids with bio-based solvents in order to make a preliminary evaluation for the replacement of hexane to extract lipids from microorganisms. Differences between theory and practice were noted for several solvents, such as CPME, MeTHF and ethyl acetate, which appeared to be good candidates to replace hexane. PMID:26861274

  6. Bioflavour production from orange peel hydrolysate using immobilized Saccharomyces cerevisiae.

    PubMed

    Lalou, Sofia; Mantzouridou, Fani; Paraskevopoulou, Adamantini; Bugarski, Branko; Levic, Steva; Nedovic, Victor

    2013-11-01

    The rising trend of bioflavour synthesis by microorganisms is hindered by the high manufacturing costs, partially attributed to the cost of the starting material. To overcome this limitation, in the present study, dilute-acid hydrolysate of orange peel was employed as a low-cost, rich in fermentable sugars substrate for the production of flavour-active compounds by Saccharomyces cerevisiae. With this purpose, the use of immobilized cell technology to protect cells against the various inhibitory compounds present in the hydrolysate was evaluated with regard to yeast viability, carbon and nitrogen consumption and cell ability to produce flavour active compounds. For cell immobilization the encapsulation in Ca alginate beads was used. The results were compared with those obtained using free-cell system. Based on the data obtained immobilized cells showed better growth performance and increased ability for de novo synthesis of volatile esters of "fruity" aroma (phenylethyl acetate, ethyl hexanoate, octanoate, decanoate and dodecanoate) than those of free cells. The potential for in situ production of new formulations containing flavour-active compounds derive from yeast cells and also from essential oil of orange peel (limonene, α-terpineol) was demonstrated by the fact that bioflavour mixture was found to accumulate within the beads. Furthermore, the ability of the immobilized yeast to perform efficiently repeated batch fermentations of orange peel hydrolysate for bioflavour production was successfully maintained after six consecutive cycles of a total period of 240 h. PMID:23995224

  7. Selection and use of pectinolytic yeasts for improving clarification and phenolic extraction in winemaking.

    PubMed

    Belda, Ignacio; Conchillo, Lorena B; Ruiz, Javier; Navascués, Eva; Marquina, Domingo; Santos, Antonio

    2016-04-16

    Pectinase enzymes have shown a considerable influence in both, sensitive and technological properties of wines. They can help to improve clarification process, releasing more color and flavor compounds entrapped in grape skin, facilitating the liberation of phenolic compounds. This work aims to find yeasts that, because of their native pectinases, can be applied on combined fermentations with Saccharomyces cerevisiae obtaining significant benefits over single-inoculated traditional fermentations. 462 yeast strains isolated from wineries were identified and tested for several enzymatic activities of recognized interest for enology industry. Considering the 7 identified species, only Aureobasidium pullulans, Metschnikowia pulcherrima and Metschnikowia fructicola showed polygalacturonase activity. Because of its interest in winemaking, due to its reported incidence in wine flavor, the impact of M. pulcherrima as a source of pectinolytic enzymes was analyzed by measuring its influence in filterability, turbidity and the increase on color, anthocyanin and polyphenol content of wines fermented in combination with S. cerevisiae. Among the strains screened, M. pulcherrima NS-EM-34 was selected, due to its polygalacturonase activity, for further characterization in both, laboratory and semi-industrial scale assays. The kinetics concerning several metabolites of enological concern were followed during the entire fermentation process at microvinification scale. Improved results were obtained in the expected parameters when M. pulcherrima NS-EM-34 was used, in comparison to wines fermented with S. cerevisiae alone and combined with other pectinolytic and non-pectinolytic yeasts (A. pullulans and Lachancea thermotolerans, respectively), even working better than commercial enzymes preparations in most parameters. Additionally, M. pulcherrima NS-EM-34 was used at a semi-industrial scale combined with three different S. cerevisiae strains, confirming its potential application for

  8. Effects of algal hydrolysate as reaction medium on enzymatic hydrolysis of lignocelluloses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Algal biomass has been proposed as a source of lipids and sugars for biofuel productions. However, a substantial portion of potentially valuable algal material remains as a liquid hydrolysate after sugar and lipid extractions. This study examined the effects of an algal hydrolysate on the enzymatic...

  9. Ethanolic fermentation of lignocellulose hydrolysates

    SciTech Connect

    Hahn-Haegerdal, B.

    1996-12-31

    This minireview discusses various factors which require consideration for the ethanolic fermentation of lignocellulose hydrolysates. The production of an alternative transportation fuel requires pretreatment of the biomass and detoxification to enhance the fermentability. Recombinant DNA technology makes it possible to engineer new microorganisms for efficient ethanol production from all sugars present in the hydrolysates. 60 refs.

  10. The effect of a yeast extract feed additive on turkeys challenged with Escherichia coli and Listeria monocytogenes and subjected to transport stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is a need to develop nutritional methods for controlling pathogens in poultry production. A yeast extract supplement, Alphamune™ (YE) was added to the diet of turkeys which were exposed to E. coli and L. monocytogenes Scott A at 16 wks of age using coarse spray and feed inclusion. Positive c...

  11. Photodynamic inactivation of yeast and bacteria by extracts of Alternanthera brasiliana.

    PubMed

    Andreazza, Nathalia L; de Lourenco, Caroline C; Siqueira, Carlos A T; Sawaya, Alexandra C H F; Lapinski, Tadia F; Gasparetto, Adriana; Khouri, Sonia; Zamuner, Stella R; Munin, Egberto; Salvador, Marcos Jose

    2013-08-01

    This study was undertaken to evaluate the effect of Alternathera brasiliana (Amaranthaceae) extracts as photosensitizing agents in photodynamic antimicrobial therapies (PACT) against Staphylococcus aureus, Staphylococcus epidermidis and Candida dubliniensis. The crude hexane and ethanol extracts were obtained from A. brasiliana whole plant and showed absortion from 650 to 700 nm. Also, singlet molecular oxygen (1O2) production (type II photosensitization reaction) was examined, and the results show that 1,3-diphenylisobenzofuran photodegradation was greatly enhanced in the presence of the A. brasiliana extracts. One plate in each assay was irradiated while the other was not irradiated, the number of colony-forming units per milliliter (CFU/mL) was obtained, and data analyzed by the Tukey test. The chemical composition of the extracts was determined by chromatographic and spectrometric techniques; steroids, triterpenes, and flavonoids were identified. Laser irradiation alone at 685 nm using diode laser, output power of 35 mW, and energy of 28 J/cm2, or non-irradiated crude extracts in sub-inhibitory concentration did not reduce the number of CFU/mL significantly, whereas irradiated hexane and ethanol extracts, in sub-inhibitory concentrations, inhibited the growth of these microorganisms. The photoactivation of hexane and ethanol extracts of A. brasiliana, in sub-inhibitory concentrations, using red laser radiation at 685 nm had an antimicrobial effect. PMID:23547779

  12. Effects of bentonite and yeast extract as nutrient on decrease in hydraulic conductivity of porous media due to CaCO3 precipitation induced by Sporosarcina pasteurii.

    PubMed

    Eryürük, Kağan; Yang, Suyin; Suzuki, Daisuke; Sakaguchi, Iwao; Katayama, Arata

    2015-10-01

    The reduction mechanism of hydraulic conductivity was investigated in porous media treated with bentonite and CaCO3 precipitates induced by growing cells of Sporosarcina pasteurii (ATCC 11859). Bentonite, the bacterial cells, and a precipitation solution, composing of 0.5 M CaCl2 and 0.5 M urea with or without 2% weight/volume yeast extract allowing the bacterial growth were sequentially introduced into the continuous-flow columns containing glass beads between 0.05 and 3 mm in diameter. The treatments reduced the hydraulic conductivity of the columns from between 8.4 × 10(-1) and 4.1 × 10(-3) cm/s to between 9.9 × 10(-4) and 2.1 × 10(-6) cm/s as the lowest. With yeast extract, the conductivity continuously decreased during four days of the experiment, while became stable after two days without yeast extract. Introduction of the bacterial cells did not decrease the conductivity. The reduction in hydraulic conductivity was inversely correlated with the volume occupied by the depositions of bentonite and CaCO3 precipitates in column, showing the same efficiency but a larger effect of the CaCO3 precipitates with increasing volume by bacterial growth. The smaller glass beads resulted in larger volume of the depositions. Bentonite increased the deposition of CaCO3 precipitates. Analysis using the Kozeny-Carman equation suggested that without yeast extract, bentonite and the CaCO3 precipitates formed aggregates with glass beads, thus increasing their diameter and consequently decreasing the pore size in the column. With yeast extract, in addition to the aggregates, the individual CaCO3 precipitates formed separately from the aggregates reduced the hydraulic conductivity. PMID:25736267

  13. Simple method for the extraction and reversed-phase high-performance liquid chromatographic analysis of carotenoid pigments from red yeasts (Basidiomycota, Fungi).

    PubMed

    Weber, Roland W S; Anke, Heidrun; Davoli, Paolo

    2007-03-23

    A simple method for the extraction of carotenoid pigments from frozen wet cells of red yeasts (Basidiomycota) and their analysis by reversed-phase HPLC using a C(18) column and a water/acetone solvent system is described. Typical red yeast carotenoids belonging to an oxidative series from the monocyclic gamma-carotene to 2-hydroxytorularhodin and from the bicyclic beta-carotene to astaxanthin were separated. Pigment identity was confirmed by LC-atmospheric pressure chemical ionisation (APCI) mass spectrometry using similar chromatographic conditions. PMID:17266973

  14. Improvement of grape and wine phenolic content by foliar application to grapevine of three different elicitors: Methyl jasmonate, chitosan, and yeast extract.

    PubMed

    Portu, Javier; López, Rosa; Baroja, Elisa; Santamaría, Pilar; Garde-Cerdán, Teresa

    2016-06-15

    Phenolic compounds play a key role in grape and wine organoleptic properties, being therefore a key parameter in wine quality. Elicitor application constitutes an interesting field of research since it is indirectly involved in the accumulation of phenolic compounds. The aim of this study was to compare the effect of the application of three different elicitors on both grape and wine phenolic content. Methyl jasmonate, chitosan, and a commercial yeast extract were applied to the canopy at veraison and one week later. Results showed that foliar treatments carried out with methyl jasmonate and yeast extract achieved the best results, increasing grape and wine anthocyanin content when compared to the control. Moreover, the application of the yeast elicitor also enhanced grape stilbene content. In contrast, the chitosan treatment did not have a substantial impact on the phenolic compounds. The results of this study indicate that methyl jasmonate and yeast extract applications could be a simple practice to increase grape and wine phenolic content. PMID:26868568

  15. Improvement of Omega-3 Docosahexaenoic Acid Production by Marine Dinoflagellate Crypthecodinium cohnii Using Rapeseed Meal Hydrolysate and Waste Molasses as Feedstock

    PubMed Central

    Gong, Yangmin; Liu, Jiao; Jiang, Mulan; Liang, Zhuo; Jin, Hu; Hu, Xiaojia; Wan, Xia; Hu, Chuanjiong

    2015-01-01

    Rapeseed meal and waste molasses are two important agro-industrial by-products which are produced in large quantities. In this study, solid state fermentation and fungal autolysis were performed to produce rapeseed meal hydrolysate (RMH) using fungal strains of Aspergillus oryzae, Penicillium oxalicum and Neurospora crassa. The hydrolysate was used as fermentation feedstock for heterotrophic growth of microalga Crypthecodinium cohnii that produce docosahexaenoic acid (DHA). The addition of waste molasses as a supplementary carbon source greatly increased the biomass and DHA yield. In the batch fermentations using media composed of diluted RMH (7%) and 1-9% waste molasses, the highest biomass concentration and DHA yield reached 3.43 g/L and 8.72 mg/L, respectively. The algal biomass produced from RMH and molasses medium also had a high percentage of DHA (22-34%) in total fatty acids similar to that of commercial algal biomass. RMH was shown to be rich in nitrogen supply comparable to the commercial nitrogen feedstock like yeast extract. Using RMH as sole nitrogen source, waste molasses excelled other carbon sources and produced the highest concentration of biomass. This study suggests that DHA production of the marine dinoflagellate C. cohnii could be greatly improved by concomitantly using the cheap by-products rapeseed meal hydrolysate and molasses as alternative feedstock. PMID:25942565

  16. Improvement of Omega-3 Docosahexaenoic Acid Production by Marine Dinoflagellate Crypthecodinium cohnii Using Rapeseed Meal Hydrolysate and Waste Molasses as Feedstock.

    PubMed

    Gong, Yangmin; Liu, Jiao; Jiang, Mulan; Liang, Zhuo; Jin, Hu; Hu, Xiaojia; Wan, Xia; Hu, Chuanjiong

    2015-01-01

    Rapeseed meal and waste molasses are two important agro-industrial by-products which are produced in large quantities. In this study, solid state fermentation and fungal autolysis were performed to produce rapeseed meal hydrolysate (RMH) using fungal strains of Aspergillus oryzae, Penicillium oxalicum and Neurospora crassa. The hydrolysate was used as fermentation feedstock for heterotrophic growth of microalga Crypthecodinium cohnii that produce docosahexaenoic acid (DHA). The addition of waste molasses as a supplementary carbon source greatly increased the biomass and DHA yield. In the batch fermentations using media composed of diluted RMH (7%) and 1-9% waste molasses, the highest biomass concentration and DHA yield reached 3.43 g/L and 8.72 mg/L, respectively. The algal biomass produced from RMH and molasses medium also had a high percentage of DHA (22-34%) in total fatty acids similar to that of commercial algal biomass. RMH was shown to be rich in nitrogen supply comparable to the commercial nitrogen feedstock like yeast extract. Using RMH as sole nitrogen source, waste molasses excelled other carbon sources and produced the highest concentration of biomass. This study suggests that DHA production of the marine dinoflagellate C. cohnii could be greatly improved by concomitantly using the cheap by-products rapeseed meal hydrolysate and molasses as alternative feedstock. PMID:25942565

  17. Cellulase Production from Spent Lignocellulose Hydrolysates by Recombinant Aspergillus niger▿

    PubMed Central

    Alriksson, Björn; Rose, Shaunita H.; van Zyl, Willem H.; Sjöde, Anders; Nilvebrant, Nils-Olof; Jönsson, Leif J.

    2009-01-01

    A recombinant Aspergillus niger strain expressing the Hypocrea jecorina endoglucanase Cel7B was grown on spent hydrolysates (stillage) from sugarcane bagasse and spruce wood. The spent hydrolysates served as excellent growth media for the Cel7B-producing strain, A. niger D15[egI], which displayed higher endoglucanase activities in the spent hydrolysates than in standard medium with a comparable monosaccharide content (e.g., 2,100 nkat/ml in spent bagasse hydrolysate compared to 480 nkat/ml in standard glucose-based medium). In addition, A. niger D15[egI] was also able to consume or convert other lignocellulose-derived compounds, such as acetic acid, furan aldehydes, and phenolic compounds, which are recognized as inhibitors of yeast during ethanolic fermentation. The results indicate that enzymes can be produced from the stillage stream as a high-value coproduct in second-generation bioethanol plants in a way that also facilitates recirculation of process water. PMID:19251882

  18. Xylitol bioproduction in hemicellulosic hydrolysate obtained from sorghum forage biomass.

    PubMed

    Camargo, Danielle; Sene, Luciane; Variz, Daniela Inês Loreto Saraiva; Felipe, Maria das Graças de Almeida

    2015-04-01

    This study evaluated the biotechnological production of xylitol from sorghum forage biomass. The yeast Candida guilliermondii was cultivated in hemicellulosic hydrolysates obtained from biomass of three sorghum varieties (A, B, and C). First, the biomass was chemically characterized and subjected to dilute acid hydrolysis to obtain the hemicellulosic hydrolysates which were vacuum-concentrated and detoxified with activated charcoal. The hemicellulosic hydrolysates (initial pH 5.5) were supplemented with nutrients, and fermentations were conducted in 125-mL Erlenmeyer flasks containing 50 mL medium, under 200 rpm, at 30 °C for 96 h. Fermentations were evaluated by determining the parameters xylitol yield (Y P/S ) and productivity (QP), as well as the activities of the enzymes xylose reductase (XR) and xylitol dehydrogenase (XDH). There was no significant difference among the three varieties with respect to the contents of cellulose, hemicellulose, and lignin, although differences were found in the hydrolysate fermentability. Maximum xylitol yield and productivity values for variety A were 0.35 g/g and 0.16 g/L.h(-1), respectively. It was coincident with XR (0.25 U/mg prot) and XDH (0.17 U/mg prot) maximum activities. Lower values were obtained for varieties B and C, which were 0.25 and 0.17 g/g for yield and 0.12 and 0.063 g/L.h(-1) for productivity. PMID:25672324

  19. A new β-glucosidase producing yeast for lower-cost cellulosic ethanol production from xylose-extracted corncob residues by simultaneous saccharification and fermentation.

    PubMed

    Liu, Z Lewis; Weber, Scott A; Cotta, Michael A; Li, Shi-Zhong

    2012-01-01

    This study reports a new yeast strain of Clavispora NRRL Y-50464 that is able to utilize cellobiose as sole source of carbon and produce sufficient native β-glucosidase enzyme activity for cellulosic ethanol production using SSF. In addition, this yeast is tolerant to the major inhibitors derived from lignocellulosic biomass pre-treatment such as 2-furaldehyde (furfural) and 5-(hydroxymethyl)-2-furaldehyde (HMF), and converted furfural into furan methanol in less than 12h and HMF into furan-2,5-dimethanol within 24h in the presence of 15 mM each of furfural and HMF. Using xylose-extracted corncob residue as cellulosic feedstock, an ethanol production of 23 g/l was obtained using 25% solids loading at 37 °C by SSF without addition of exogenous β-glucosidase. Development of this yeast aids renewable biofuels development efforts for economic consolidated SSF bio-processing. PMID:22133603

  20. Extraction of ethanol with higher carboxylic acid solvents and their toxicity to yeast

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In a screening exercise for ethanol-selective extraction solvents, partitioning of ethanol and water from a 5 wt% aqueous solution into several C8 – C18 carboxylic acids was studied. Results for the acids are compared with those from alcohols of similar structure. In all cases studied, the acids exh...

  1. Effect of storage conditions on the stability and fermentability of enzymatic lignocellulosic hydrolysate.

    PubMed

    Jin, Mingjie; Bothfeld, William; Austin, Samantha; Sato, Trey K; La Reau, Alex; Li, Haibo; Foston, Marcus; Gunawan, Christa; LeDuc, Richard D; Quensen, John F; McGee, Mick; Uppugundla, Nirmal; Higbee, Alan; Ranatunga, Ruwan; Donald, Charles W; Bone, Gwen; Ragauskas, Arthur J; Tiedje, James M; Noguera, Daniel R; Dale, Bruce E; Zhang, Yaoping; Balan, Venkatesh

    2013-11-01

    To minimize the change of lignocellulosic hydrolysate composition during storage, the effects of storage conditions (temperature, pH and time) on the composition and fermentability of hydrolysate prepared from AFEX™ (Ammonia Fiber Expansion - a trademark of MBI, Lansing, MI) pretreated corn stover were investigated. Precipitates formed during hydrolysate storage increased with increasing storage pH and time. The precipitate amount was the least when hydrolysate was stored at 4 °C and pH 4.8, accounting for only 0.02% of the total hydrolysate weight after 3-month storage. No significant changes of NMR (Nuclear Magnetic Resonance) spectra and concentrations of sugars, minerals and heavy metals were observed after storage under this condition. When pH was adjusted higher before fermentation, precipitates also formed, consisting of mostly struvite (MgNH4PO4·6H2O) and brushite (CaHPO4·2H2O). Escherichia coli and Saccharomyces cerevisiae fermentation studies and yeast cell growth assays showed no significant difference in fermentability between fresh hydrolysate and stored hydrolysate. PMID:23999256

  2. Acetic acid removal from corn stover hydrolysate using ethyl acetate and the impact on Saccharomyces cerevisiae bioethanol fermentation.

    PubMed

    Aghazadeh, Mahdieh; Ladisch, Michael R; Engelberth, Abigail S

    2016-07-01

    Acetic acid is introduced into cellulose conversion processes as a consequence of composition of lignocellulose feedstocks, causing significant inhibition of adapted, genetically modified and wild-type S. cerevisiae in bioethanol fermentation. While adaptation or modification of yeast may reduce inhibition, the most effective approach is to remove the acetic acid prior to fermentation. This work addresses liquid-liquid extraction of acetic acid from biomass hydrolysate through a pathway that mitigates acetic acid inhibition while avoiding the negative effects of the extractant, which itself may exhibit inhibition. Candidate solvents were selected using simulation results from Aspen Plus™, based on their ability to extract acetic acid which was confirmed by experimentation. All solvents showed varying degrees of toxicity toward yeast, but the relative volatility of ethyl acetate enabled its use as simple vacuum evaporation could reduce small concentrations of aqueous ethyl acetate to minimally inhibitory levels. The toxicity threshold of ethyl acetate, in the presence of acetic acid, was found to be 10 g L(-1) . The fermentation was enhanced by extracting 90% of the acetic acid using ethyl acetate, followed by vacuum evaporation to remove 88% removal of residual ethyl acetate along with 10% of the broth. NRRL Y-1546 yeast was used to demonstrate a 13% increase in concentration, 14% in ethanol specific production rate, and 11% ethanol yield. This study demonstrated that extraction of acetic acid with ethyl acetate followed by evaporative removal of ethyl acetate from the raffinate phase has potential to significantly enhance ethanol fermentation in a corn stover bioethanol facility. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:929-937, 2016. PMID:27090191

  3. Kinetic considerations about the study of alcoholic fermentations in starch hydrolysate

    SciTech Connect

    Converti, A.; Perego, P.; Del Borghi, M.; Parisi, F.; Ferraiolo, G.

    1986-05-01

    Alcoholic fermentations of starch hydrolysate by two different yeast strains, Saccharomyces cerevisiae (var. Vinal) and Saccharomyces oviformis (IMAP 383), have been studied in batch runs. In order to evaluate the different inhibition phenomena due to both substrate and product, a new kinetic equation is suggested. 23 references.

  4. Budding yeast protein extraction and purification for the study of function, interactions, and post-translational modifications.

    PubMed

    Szymanski, Eva Paige; Kerscher, Oliver

    2013-01-01

    Homogenization by bead beating is a fast and efficient way to release DNA, RNA, proteins, and metabolites from budding yeast cells, which are notoriously hard to disrupt. Here we describe the use of a bead mill homogenizer for the extraction of proteins into buffers optimized to maintain the functions, interactions and post-translational modifications of proteins. Logarithmically growing cells expressing the protein of interest are grown in a liquid growth media of choice. The growth media may be supplemented with reagents to induce protein expression from inducible promoters (e.g. galactose), synchronize cell cycle stage (e.g. nocodazole), or inhibit proteasome function (e.g. MG132). Cells are then pelleted and resuspended in a suitable buffer containing protease and/or phosphatase inhibitors and are either processed immediately or frozen in liquid nitrogen for later use. Homogenization is accomplished by six cycles of 20 sec bead-beating (5.5 m/sec), each followed by one minute incubation on ice. The resulting homogenate is cleared by centrifugation and small particulates can be removed by filtration. The resulting cleared whole cell extract (WCE) is precipitated using 20% TCA for direct analysis of total proteins by SDS-PAGE followed by Western blotting. Extracts are also suitable for affinity purification of specific proteins, the detection of post-translational modifications, or the analysis of co-purifying proteins. As is the case for most protein purification protocols, some enzymes and proteins may require unique conditions or buffer compositions for their purification and others may be unstable or insoluble under the conditions stated. In the latter case, the protocol presented may provide a useful starting point to empirically determine the best bead-beating strategy for protein extraction and purification. We show the extraction and purification of an epitope-tagged SUMO E3 ligase, Siz1, a cell cycle regulated protein that becomes both sumoylated and

  5. Cyanobacterial biomass as carbohydrate and nutrient feedstock for bioethanol production by yeast fermentation

    PubMed Central

    2014-01-01

    Background Microbial bioconversion of photosynthetic biomass is a promising approach to the generation of biofuels and other bioproducts. However, rapid, high-yield, and simple processes are essential for successful applications. Here, biomass from the rapidly growing photosynthetic marine cyanobacterium Synechococcus sp. PCC 7002 was fermented using yeast into bioethanol. Results The cyanobacterium accumulated a total carbohydrate content of about 60% of cell dry weight when cultivated under nitrate limitation. The cyanobacterial cells were harvested by centrifugation and subjected to enzymatic hydrolysis using lysozyme and two alpha-glucanases. This enzymatic hydrolysate was fermented into ethanol by Saccharomyces cerevisiae without further treatment. All enzyme treatments and fermentations were carried out in the residual growth medium of the cyanobacteria with the only modification being that pH was adjusted to the optimal value. The highest ethanol yield and concentration obtained was 0.27 g ethanol per g cell dry weight and 30 g ethanol L-1, respectively. About 90% of the glucose in the biomass was converted to ethanol. The cyanobacterial hydrolysate was rapidly fermented (up to 20 g ethanol L-1 day-1) even in the absence of any other nutrient additions to the fermentation medium. Conclusions Cyanobacterial biomass was hydrolyzed using a simple enzymatic treatment and fermented into ethanol more rapidly and to higher concentrations than previously reported for similar approaches using cyanobacteria or microalgae. Importantly, as well as fermentable carbohydrates, the cyanobacterial hydrolysate contained additional nutrients that promoted fermentation. This hydrolysate is therefore a promising substitute for the relatively expensive nutrient additives (such as yeast extract) commonly used for Saccharomyces fermentations. PMID:24739806

  6. Detoxification of rice straw and olive tree pruning hemicellulosic hydrolysates employing Saccharomyces cerevisiae and its effect on the ethanol production by Pichia stipitis.

    PubMed

    Fonseca, Bruno Guedes; Puentes, Juan Gabriel; Mateo, Soledad; Sánchez, Sebastian; Moya, Alberto J; Roberto, Inês Conceição

    2013-10-01

    The aim of this work was to study the ability of Saccharomyces cerevisiae (baker's yeast) to metabolize a variety of aromatic compounds found in rice straw (RSHH) and olive tree pruning (OTHH) hemicellulosic hydrolysates, obtained by acid hydrolysis at different sugar and toxic compound concentrations. Initially, the hydrolysates were inoculated with S. cerevisiae (10 g L(-1)) and incubated at 30 °C under agitation at 200 rpm for 6 h. The results showed that this yeast was able to utilize phenolic and furan compounds in both hemicellulose hydrolysates. Next, the treated hydrolysates were inoculated with Pichia stipitis NRRL Y-7124 to evaluate the effect of biotransformation of aromatic compounds on ethanol production, and better fermentation results were obtained in this case compared to untreated ones. The untreated hemicellulose hydrolysates were not able to be fermented when they were incubated with Pichia stipitis. However, in RSHH treated hydrolysates, ethanol (Y(P/S)) and biomass (Y(X/S)) yields and volumetric ethanol productivity (Q(P)) were 0.17 g g(-1), 0.15 g g(-1) and 0.09 g L(-1) h(-1), respectively. The OTHH-treated hydrolysates showed less favorable results compared to RSHH, but the fermentation process was favored with regard to untreated hydrolysate. These results showed that the fermentation by P. stipitis in untreated hydrolysates was strongly inhibited by toxic compounds present in the media and that treatment with S. cerevisiae promoted a significant reduction in their toxicities. PMID:23992561

  7. Valorisation of side streams from wheat milling and confectionery industries for consolidated production and extraction of microbial lipids.

    PubMed

    Tsakona, Sofia; Skiadaresis, Argyrios G; Kopsahelis, Nikolaos; Chatzifragkou, Afroditi; Papanikolaou, Seraphim; Kookos, Ioannis K; Koutinas, Apostolis A

    2016-05-01

    Crude enzymes produced via solid state fermentation (SSF) using wheat milling by-products have been employed for both fermentation media production using flour-rich waste (FRW) streams and lysis of Rhodosporidium toruloides yeast cells. Filter sterilization of crude hydrolysates was more beneficial than heat sterilization regarding yeast growth and microbial oil production. The initial carbon to free amino nitrogen ratio of crude hydrolysates was optimised (80.2g/g) in fed-batch cultures of R. toruloides leading to a total dry weight of 61.2g/L with microbial oil content of 61.8% (w/w). Employing a feeding strategy where the glucose concentration was maintained in the range of 12.2-17.6g/L led to the highest productivity (0.32 g/L·h). The crude enzymes produced by SSF were utilised for yeast cell treatment leading to simultaneous release of around 80% of total lipids in the broth and production of a hydrolysate suitable as yeast extract replacement. PMID:26769508

  8. Evaluation of the inhibition of carbohydrate hydrolysing enzymes, antioxidant activity and polyphenolic content of extracts of ten African Ficus species (Moraceae) used traditionally to treat diabetes

    PubMed Central

    2013-01-01

    Background Some Ficus species have been used in traditional African medicine in the treatment of diabetes. The antidiabetic potential of certain species has been confirmed in vivo but the mechanism of activity remains uncertain. The aim of this study was to determine the activity and to investigate the mechanism of antidiabetic activity of ten selected Ficus species through inhibition of α-amylase and α-glucosidase activity, and the possible relationship between these activities, the total polyphenolic content and the antioxidant activity. Methods Dried acetone leaf extracts were reconstituted with appropriate solvents and used to determine total polyphenolic content antioxidant activity, α-amylase and α-glucosidase inhibitory activity. Results The crude acetone extract of F. lutea had the highest polyphenolic content (56.85 ± 1.82 mg GAE/g of dry material) and the strongest antioxidant activity with a TEAC value of 4.80 ± 0.90. The antioxidant activity of the acetone extracts of the Ficus species may not be ascribed to total polyphenolic content alone. The crude extract at a concentration of 0.5 mg/ml of F. lutea (64.3 ± 3.6%) had the best α-glucosidase (sucrase) inhibitory activity. The EC50 of F. lutea (290 ± 111 μg/ml) was not significantly different from that of F. sycomorus (217 ± 69 μg/ml). The α-amylase inhibitory activity of F. lutea (95.4 ± 1.2%) at a concentration of 1 mg/ml was the highest among the Ficus species screened. The EC50 for F. lutea (9.42 ± 2.01 μ g/ml), though the highest, was not significantly different (p < 0.05) from that of F. craterostoma and F. natalensis. It was apparent that the crude acetone extract of F. lutea is a partially non-competitive inhibitor of α-amylase and α-glucosidase. Based on correlation coefficients polyphenolics may be responsible for α-glucosidase activity but probably not for α-amylase activity. Conclusion Antidiabetic activity potential via inhibition

  9. Yeast cell wall extract induces disease resistance against bacterial and fungal pathogens in Arabidopsis thaliana and Brassica crop.

    PubMed

    Narusaka, Mari; Minami, Taichi; Iwabuchi, Chikako; Hamasaki, Takashi; Takasaki, Satoko; Kawamura, Kimito; Narusaka, Yoshihiro

    2015-01-01

    Housaku Monogatari (HM) is a plant activator prepared from a yeast cell wall extract. We examined the efficacy of HM application and observed that HM treatment increased the resistance of Arabidopsis thaliana and Brassica rapa leaves to bacterial and fungal infections. HM reduced the severity of bacterial leaf spot and anthracnose on A. thaliana and Brassica crop leaves with protective effects. In addition, gene expression analysis of A. thaliana plants after treatment with HM indicated increased expression of several plant defense-related genes. HM treatment appears to induce early activation of jasmonate/ethylene and late activation of salicylic acid (SA) pathways. Analysis using signaling mutants revealed that HM required SA accumulation and SA signaling to facilitate resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola and the fungal pathogen Colletotrichum higginsianum. In addition, HM-induced resistance conferred chitin-independent disease resistance to bacterial pathogens in A. thaliana. These results suggest that HM contains multiple microbe-associated molecular patterns that activate defense responses in plants. These findings suggest that the application of HM is a useful tool that may facilitate new disease control methods. PMID:25565273

  10. Yeast Cell Wall Extract Induces Disease Resistance against Bacterial and Fungal Pathogens in Arabidopsis thaliana and Brassica Crop

    PubMed Central

    Narusaka, Mari; Minami, Taichi; Iwabuchi, Chikako; Hamasaki, Takashi; Takasaki, Satoko; Kawamura, Kimito; Narusaka, Yoshihiro

    2015-01-01

    Housaku Monogatari (HM) is a plant activator prepared from a yeast cell wall extract. We examined the efficacy of HM application and observed that HM treatment increased the resistance of Arabidopsis thaliana and Brassica rapa leaves to bacterial and fungal infections. HM reduced the severity of bacterial leaf spot and anthracnose on A. thaliana and Brassica crop leaves with protective effects. In addition, gene expression analysis of A. thaliana plants after treatment with HM indicated increased expression of several plant defense-related genes. HM treatment appears to induce early activation of jasmonate/ethylene and late activation of salicylic acid (SA) pathways. Analysis using signaling mutants revealed that HM required SA accumulation and SA signaling to facilitate resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola and the fungal pathogen Colletotrichum higginsianum. In addition, HM-induced resistance conferred chitin-independent disease resistance to bacterial pathogens in A. thaliana. These results suggest that HM contains multiple microbe-associated molecular patterns that activate defense responses in plants. These findings suggest that the application of HM is a useful tool that may facilitate new disease control methods. PMID:25565273

  11. Yeast extract promotes decolorization of azo dyes by stimulating azoreductase activity in Shewanella sp. strain IFN4.

    PubMed

    Imran, Muhammad; Arshad, Muhammad; Negm, Fayek; Khalid, Azeem; Shaharoona, Baby; Hussain, Sabir; Mahmood Nadeem, Sajid; Crowley, David E

    2016-02-01

    Biological treatment of azo dyes commonly requires a combined anaerobic-aerobic process in which initial decolorization is achieved by reductive cleavage of azo bonds on the parent molecule. The present study was conducted to examine the relative importance of co-substrates for driving reductive decolorization of azo dyes by Shewanella sp. strain IFN4 using whole cells and enzyme assays. Results showed that the dye decolorization by strain IFN4 was faster in medium containing 1gL(-1) yeast extract (YE) as compared to nine other co-substrates. Moreover, only YE stimulated azoreductase activity (increased from 1.32 to 4.19U/mg protein). Increasing the level of YE up to 8gL(-)(1) resulted into 81% decolorization of the dye in 1h along with an increase in azoreductase activity up to 6.16U/mg protein. Among the components of YE, only riboflavin stimulated the decolorization process as well as enzyme activity. Moreover, strain IFN4 demonstrated flavin reductase activity, and a significant correlation (r(2)=0.98) between flavin reduction and dye reduction by this strain emphasized the involvement of flavin compounds in the decolorization process. The results of this study show that YE serves both as a source of reducing equivalents and an electron shuttle for catalyzing dye reduction. PMID:26454074

  12. Synthesis of yeast extract-stabilized Cu nanoclusters for sensitive fluorescent detection of sulfide ions in water.

    PubMed

    Jin, Lihua; Zhang, Zaihua; Tang, Anwen; Li, Cong; Shen, Yehua

    2016-05-15

    In this work, we have presented a novel strategy to utilize as-synthesized yeast extract-stabilized Cu nanoclusters (Cu NCs) for sensitive and selective detection of S(2-). The fluorescence intensity of Cu NCs was enhanced significantly in the presence of both Na2S2O8 and S(2-). By virtue of this specific response, a Cu NC-based fluorescent turn-on sensor was developed, which allows the detection of S(2-) in the range of 0.02-0.8 μM with a detection limit of 10nM. The enhancing mechanism was also discussed based on fluorescence decay, transmission electron microscopy (TEM) and dynamic light scattering (DLS) studies, indicating that S(2-) enhanced the Cu NCs emission mainly through sulfide-induced aggregation of Cu NCs. Furthermore, we demonstrated the usability of the present approach for the detection of S(2-) in water samples, which illustrates its great potential for the environmental monitoring and water quality inspection fields. PMID:26703988

  13. The evaluation of mixtures of yeast and potato extracts in growth media for biomass production of lactic cultures.

    PubMed

    Gaudreau, H; Renard, N; Champagne, C P; Van Horn, D

    2002-07-01

    The effectiveness of yeast extracts (YE) and potato extracts (PE) to promote growth of seven lactic cultures was evaluated by automated spectrophotometry (AS). Two aspects of the growth curve were analysed: (1) maximum biomass obtained (using ODmax) and (2) highest specific growth rate mu(max)) Eleven lots from the same PE-manufacturing process were examined for lot-to-lot variability. The ODmax values of three of the seven strains were significantly affected by lot source, but mu(max) was not significantly affected. The growth of bacteria was systematically lower in base medium containing 100% PE than in base medium containing 100% YE for both ODmax or mu(max) data, which could be related to the lower content in nitrogen-based compounds in PE. In AS assays, highest OD values for Lactobacillus casei EQ28, Lactobacillus rhamnosus R-011, Lactobacillus plantarum EQ12, and Streptococcus thermophilus R-083 were obtained with a mixture of PE and YE. Fermentations (2 L) were also carried out to determine the accuracy of AS to predict biomass levels obtained under fermentation trials. In these fermentations, replacement of 50% YE with PE was shown to enable good growth of S. thermophilus. With L. rhamnosus R-011, a high correlation (R2 = 0.95) was found between ODmax data obtained in the AS assays and that of the 2-L bioreactor when the same growth medium was used for both series of fermentations. However, AS was not as efficient when industrial media were used for the bioreactor assays. The relationship was still good for ODmax between AS data and that of the bioreactor data with L. rhamnosus R-011 in industrial LBS medium (R2 = 0.87), but was very poor with the S. thermophilus R-083 on Rosell #43 industrial medium (R2 = 0.33). Since PE cost 40% less than YE, there are strong economic advantages in considering such a partial replacement of YE by PE. PMID:12224561

  14. Efficient production of l-lactic acid from hydrolysate of Jerusalem artichoke with immobilized cells of Lactococcus lactis in fibrous bed bioreactors.

    PubMed

    Shi, Zhouming; Wei, Peilian; Zhu, Xiangcheng; Cai, Jin; Huang, Lei; Xu, Zhinan

    2012-10-10

    Hydrolysate of Jerusalem artichoke was applied for the production of l-lactic acid by immobilized Lactococcus lactis cells in a fibrous bed bioreactor system. Preliminary experiments had indicated that the high quality hydrolysate, which was derived from the 40 min acid treatment at 95 °C and pH 1.8, was sufficient to support the cell growth and synthesis of l-lactic acid. With the addition of 5 g/l yeast extract, the fermentative performance of free cell system was evidently improved. After the basal settlement of hydrolysate based fermentation, the batch mode and the fed-batch mode fermentation were carried out in the free cell system and the fibrous bed bioreactor system, respectively. In all cases the immobilized cells presented the superior ability to produce l-lactic acid. The comparison of batch mode and fed-batch mode also indicated that the growth-limiting feeding strategy could reduce the lag phase of fermentation process and enhance the production of l-lactic acid. The achieved maximum concentration of l-lactic acid was 142 g/l in the fed-batch mode. Subsequent repeated-batch fermentation of the fibrous bed bioreactor system had further exhibited the persistence and stability of this system for the high production of l-lactic acid in a long term. Our work suggested the great potential of the fibrous bed bioreactor system and hydrolysate of J. artichoke in the economical production of l-lactic acid at industrial scale. PMID:22975123

  15. Production of Defatted Palm Kernel Cake Protein Hydrolysate as a Valuable Source of Natural Antioxidants

    PubMed Central

    Zarei, Mohammad; Ebrahimpour, Afshin; Abdul-Hamid, Azizah; Anwar, Farooq; Saari, Nazamid

    2012-01-01

    The aim of this study was to produce a valuable protein hydrolysate from palm kernel cake (PKC) for the development of natural antioxidants. Extracted PKC protein was hydrolyzed using different proteases (alcalase, chymotrypsin, papain, pepsin, trypsin, flavourzyme, and bromelain). Subsequently, antioxidant activity and degree of hydrolysis (DH) of each hydrolysate were evaluated using DPPH• radical scavenging activity and O-phthaldialdehyde spectrophotometric assay, respectively. The results revealed a strong correlation between DH and radical scavenging activity of the hydrolysates, where among these, protein hydrolysates produced by papain after 38 h hydrolysis exhibited the highest DH (91 ± 0.1%) and DPPH• radical scavenging activity (73.5 ± 0.25%) compared to the other hydrolysates. In addition, fractionation of the most effective (potent) hydrolysate by reverse phase high performance liquid chromatography indicated a direct association between hydrophobicity and radical scavenging activity of the hydrolysates. Isoelectric focusing tests also revealed that protein hydrolysates with basic and neutral isoelectric point (pI) have the highest radical scavenging activity, although few fractions in the acidic range also exhibited good antioxidant potential. PMID:22942692

  16. Microwave, ultrasound, thermal treatments, and bead milling as intensification techniques for extraction of lipids from oleaginous Yarrowia lipolytica yeast for a biojetfuel application.

    PubMed

    Meullemiestre, Alice; Breil, Cassandra; Abert-Vian, Maryline; Chemat, Farid

    2016-07-01

    In the present work, two different ways of lipids extraction from Yarrowia lipolytica yeast were investigated in order to maximize the extraction yield. Firstly, various modern techniques of extraction including ultrasound, microwave, and bead milling were tested to intensify the efficiency of lipid recovery. Secondly, several pretreatments such as freezing/defrosting, cold drying, bead milling, and microwave prior two washing of mixture solvent of chloroform:methanol (1:2, v/v) were study to evaluate the impact on lipid recovery. All these treatments were compared to conventional maceration, in terms of lipids extraction yield and lipid composition analysis. The main result of this study is the large difference of lipid recovery among treatments and the alteration of lipids profile after microwave and ultrasound techniques. PMID:27017129

  17. Simultaneous saccharification and fermentation (SSF) using cellobiose fermenting yeast Brettanomyces custersii

    DOEpatents

    Spindler, D.D.; Grohmann, K.; Wyman, C.E.

    1992-03-31

    A process for producing ethanol from plant biomass includes forming a substrate from the biomass with the substrate including hydrolysates of cellulose and hemicellulose. A species of the yeast Brettanomyces custersii (CBS 5512), which has the ability to ferment both cellobiose and glucose to ethanol, is then selected and isolated. The substrate is inoculated with this yeast, and the inoculated substrate is then fermented under conditions favorable for cell viability and conversion of hydrolysates to ethanol. 2 figs.

  18. Simultaneous saccharification and fermentation (SSF) using cellobiose fermenting yeast Brettanomyces custersii

    SciTech Connect

    Spindler, Diane D.; Grohmann, Karel; Wyman, Charles E.

    1992-01-01

    A process for producing ethanol from plant biomass includes forming a substrate from the biomass with the substrate including hydrolysates of cellulose and hemicellulose. A species of the yeast Brettanomyces custersii (CBS 5512), which has the ability to ferment both cellobiose and glucose to ethanol, is then selected and isolated. The substrate is inoculated with this yeast, and the inoculated substrate is then fermented under conditions favorable for cell viability and conversion of hydrolysates to ethanol.

  19. Protein Hydrolysates/Peptides in Animal Nutrition

    NASA Astrophysics Data System (ADS)

    McCalla, Jeff; Waugh, Terry; Lohry, Eric

    The use of protein hydrolysates as an important nutrient for growth and maintenance has been increasing in animal nutrition. Although animal proteins and protein hydrolysates are widely used however, recently vegetable protein hydrolysates are gaining importance. This chapter reviews the use of protein hydrolysates developed by enzyme hydrolysis and by solid state fermentation process in animal nutrition especially for piglets and compares it with the standard products such as plasma and fishmeal.

  20. Comparative proteomic analysis of the response to silver ions and yeast extract in Salvia miltiorrhiza hairy root cultures.

    PubMed

    Wang, Yajun; Shen, Ye; Shen, Zhuo; Zhao, Le; Ning, Deli; Jiang, Chao; Zhao, Rong; Huang, Luqi

    2016-10-01

    Biotic and abiotic stresses can inhibit plant growth, resulting in losses of crop productivity. However, moderate adverse stress can promote the accumulation of valuable natural products in medicinal plants. Elucidating the underlying molecular mechanisms thus might help optimize the variety of available plant medicinal materials and improve their quality. In this study, Salvia miltiorrhiza hairy root cultures were employed as an in vitro model of the Chinese herb Danshen. A comparative proteomic analysis using 2-dimensional gel electrophoresis and MALDI-TOF-MS was performed. By comparing the gel images of groups exposed to the stress of yeast extract (YE) combined with Ag(+) and controls, 64 proteins were identified that showed significant changes in protein abundance for at least one time point after treatment. According to analysis based on the KEGG and related physiological experimental verification, it was found that YE and Ag(+) stress induced a burst of reactive oxygen species and activated the Ca(2+)/calmodulin signaling pathway. Expression of immune-suppressive proteins increased. Epidermal cells underwent programmed cell death. Energy metabolism was enhanced and carbon metabolism shifted to favor the production of secondary metabolites such as lignin, tanshinone and salvianolic acids. The tanshinone and salvianolic acids were deposited on the collapsed epidermal cells forming a physicochemical barrier. The defense proteins and these natural products together enhanced the stress resistance of the plants. Since higher levels of natural products represent good quality in medicinal materials, this study sheds new light on quality formation mechanisms of medicinal plants and will hopefully encourage further research on how the planting environment affects the efficacy of herbal medicines. PMID:27372730

  1. 21 CFR 102.22 - Protein hydrolysates.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Protein hydrolysates. 102.22 Section 102.22 Food... Nonstandardized Foods § 102.22 Protein hydrolysates. The common or usual name of a protein hydrolysate shall be specific to the ingredient and shall include the identity of the food source from which the protein...

  2. 21 CFR 102.22 - Protein hydrolysates.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Protein hydrolysates. 102.22 Section 102.22 Food... Nonstandardized Foods § 102.22 Protein hydrolysates. The common or usual name of a protein hydrolysate shall be specific to the ingredient and shall include the identity of the food source from which the protein...

  3. 21 CFR 102.22 - Protein hydrolysates.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Protein hydrolysates. 102.22 Section 102.22 Food... Nonstandardized Foods § 102.22 Protein hydrolysates. The common or usual name of a protein hydrolysate shall be specific to the ingredient and shall include the identity of the food source from which the protein...

  4. 21 CFR 102.22 - Protein hydrolysates.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Protein hydrolysates. 102.22 Section 102.22 Food... Nonstandardized Foods § 102.22 Protein hydrolysates. The common or usual name of a protein hydrolysate shall be specific to the ingredient and shall include the identity of the food source from which the protein...

  5. 21 CFR 102.22 - Protein hydrolysates.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Protein hydrolysates. 102.22 Section 102.22 Food... Nonstandardized Foods § 102.22 Protein hydrolysates. The common or usual name of a protein hydrolysate shall be specific to the ingredient and shall include the identity of the food source from which the protein...

  6. Carbon source utilization and inhibitor tolerance of 45 oleaginous yeast species

    PubMed Central

    Sitepu, Irnayuli; Selby, Tylan; Lin, Ting; Zhu, Shirley; Boundy-Mills, Kyria

    2014-01-01

    Conversion of lignocellulosic hydrolysates to lipids using oleaginous (high lipid) yeasts requires alignment of the hydrolysate composition with the characteristics of the yeast strain, including ability to utilize certain nutrients, ability to grow independently of costly nutrients such as vitamins, and ability to tolerate inhibitors. Some combination of these characteristics may be present in wild strains. In this study, 48 oleaginous yeast strains belonging to 45 species were tested for ability to utilize carbon sources associated with lignocellulosic hydrolysates, tolerate inhibitors, and grow in medium without supplemented vitamins. Some well-studied oleaginous yeast species, as well as some that have not been frequently utilized in research or industrial production, emerged as promising candidates for industrial use due to ability to utilize many carbon sources, including Cryptococcus aureus, Cryptococcus laurentii, Hanaella aff. zeae, Tremella encephala, and Trichosporon coremiiforme. Other species excelled in inhibitor tolerance, including Candida aff. tropicalis, Cyberlindnera jadinii, Metschnikowia pulcherrima Schwanniomyces occidentalis and Wickerhamomyces ciferii. No yeast tested could utilize all carbon sources and tolerate all inhibitors tested. These results indicate that yeast strains should be selected based on characteristics compatible with the composition of the targeted hydrolysate. Other factors to consider include the production of valuable co-products such as carotenoids, availability of genetic tools, biosafety level, and flocculation of the yeast strain. The data generated in this study will aid in aligning yeasts with compatible hydrolysates for conversion of carbohydrates to lipids to be used for biofuels and other oleochemicals. PMID:24818698

  7. Biohydrogen Production from Hydrolysates of Selected Tropical Biomass Wastes with Clostridium Butyricum.

    PubMed

    Dan Jiang; Fang, Zhen; Chin, Siew-Xian; Tian, Xiao-Fei; Su, Tong-Chao

    2016-01-01

    Biohydrogen production has received widespread attention from researchers in industry and academic fields. Response surface methodology (RSM) was applied to evaluate the effects of several key variables in anaerobic fermentation of glucose with Clostridium butyrium, and achieved the highest production rate and yield of hydrogen. Highest H2 yield of 2.02 mol H2/mol-glucose was achieved from 24 h bottle fermentation of glucose at 35 °C, while the composition of medium was (g/L): 15.66 glucose, 6.04 yeast extract, 4 tryptone, 3 K2HPO4, 3 KH2PO4, 0.05 L-cysteine, 0.05 MgSO4·7H2O, 0.1 MnSO4·H2O and 0.3 FeSO4·7H2O, which was very different from that for cell growth. Sugarcane bagasse and Jatropha hulls were selected as typical tropical biomass wastes to produce sugars via a two-step acid hydrolysis for hydrogen production. Under the optimized fermentation conditions, H2 yield (mol H2/mol-total reducing sugar) was 2.15 for glucose, 2.06 for bagasse hydrolysate and 1.95 for Jatropha hull hydrolysate in a 3L fermenter for 24 h at 35 °C, with H2 purity of 49.7-64.34%. The results provide useful information and basic data for practical use of tropical plant wastes to produce hydrogen. PMID:27251222

  8. Biohydrogen Production from Hydrolysates of Selected Tropical Biomass Wastes with Clostridium Butyricum

    NASA Astrophysics Data System (ADS)

    Dan Jiang; Fang, Zhen; Chin, Siew-Xian; Tian, Xiao-Fei; Su, Tong-Chao

    2016-06-01

    Biohydrogen production has received widespread attention from researchers in industry and academic fields. Response surface methodology (RSM) was applied to evaluate the effects of several key variables in anaerobic fermentation of glucose with Clostridium butyrium, and achieved the highest production rate and yield of hydrogen. Highest H2 yield of 2.02 mol H2/mol-glucose was achieved from 24 h bottle fermentation of glucose at 35 °C, while the composition of medium was (g/L): 15.66 glucose, 6.04 yeast extract, 4 tryptone, 3 K2HPO4, 3 KH2PO4, 0.05 L-cysteine, 0.05 MgSO4·7H2O, 0.1 MnSO4·H2O and 0.3 FeSO4·7H2O, which was very different from that for cell growth. Sugarcane bagasse and Jatropha hulls were selected as typical tropical biomass wastes to produce sugars via a two-step acid hydrolysis for hydrogen production. Under the optimized fermentation conditions, H2 yield (mol H2/mol-total reducing sugar) was 2.15 for glucose, 2.06 for bagasse hydrolysate and 1.95 for Jatropha hull hydrolysate in a 3L fermenter for 24 h at 35 °C, with H2 purity of 49.7–64.34%. The results provide useful information and basic data for practical use of tropical plant wastes to produce hydrogen.

  9. Biohydrogen Production from Hydrolysates of Selected Tropical Biomass Wastes with Clostridium Butyricum

    PubMed Central

    Dan Jiang; Fang, Zhen; Chin, Siew-xian; Tian, Xiao-fei; Su, Tong-chao

    2016-01-01

    Biohydrogen production has received widespread attention from researchers in industry and academic fields. Response surface methodology (RSM) was applied to evaluate the effects of several key variables in anaerobic fermentation of glucose with Clostridium butyrium, and achieved the highest production rate and yield of hydrogen. Highest H2 yield of 2.02 mol H2/mol-glucose was achieved from 24 h bottle fermentation of glucose at 35 °C, while the composition of medium was (g/L): 15.66 glucose, 6.04 yeast extract, 4 tryptone, 3 K2HPO4, 3 KH2PO4, 0.05 L-cysteine, 0.05 MgSO4·7H2O, 0.1 MnSO4·H2O and 0.3 FeSO4·7H2O, which was very different from that for cell growth. Sugarcane bagasse and Jatropha hulls were selected as typical tropical biomass wastes to produce sugars via a two-step acid hydrolysis for hydrogen production. Under the optimized fermentation conditions, H2 yield (mol H2/mol-total reducing sugar) was 2.15 for glucose, 2.06 for bagasse hydrolysate and 1.95 for Jatropha hull hydrolysate in a 3L fermenter for 24 h at 35 °C, with H2 purity of 49.7–64.34%. The results provide useful information and basic data for practical use of tropical plant wastes to produce hydrogen. PMID:27251222

  10. Influence of the propagation strategy for obtaining robust Saccharomyces cerevisiae cells that efficiently co-ferment xylose and glucose in lignocellulosic hydrolysates.

    PubMed

    Tomás-Pejó, Elia; Olsson, Lisbeth

    2015-11-01

    Development of xylose-fermenting yeast strains that are tolerant to the inhibitors present in lignocellulosic hydrolysates is crucial to achieve efficient bioethanol production processes. In this study, the importance of the propagation strategy for obtaining robust cells was studied. Addition of hydrolysate during propagation of the cells adapted them to the inhibitors, resulting in more tolerant cells with shorter lag phases and higher specific growth rates in minimal medium containing acetic acid and vanillin than unadapted cells. Addition of hydrolysate during propagation also resulted in cells with better fermentation capabilities. Cells propagated without hydrolysate were unable to consume xylose in wheat straw hydrolysate fermentations, whereas 40.3% and 97.7% of the xylose was consumed when 12% and 23% (v/v) hydrolysate, respectively, was added during propagation. Quantitative polymerase chain reaction revealed changes in gene expression, depending on the concentration of hydrolysate added during propagation. This study highlights the importance of using an appropriate propagation strategy for the optimum performance of yeast in fermentation of lignocellulosic hydrolysates. PMID:25989314

  11. Influence of the propagation strategy for obtaining robust Saccharomyces cerevisiae cells that efficiently co-ferment xylose and glucose in lignocellulosic hydrolysates

    PubMed Central

    Tomás-Pejó, Elia; Olsson, Lisbeth

    2015-01-01

    Development of xylose-fermenting yeast strains that are tolerant to the inhibitors present in lignocellulosic hydrolysates is crucial to achieve efficient bioethanol production processes. In this study, the importance of the propagation strategy for obtaining robust cells was studied. Addition of hydrolysate during propagation of the cells adapted them to the inhibitors, resulting in more tolerant cells with shorter lag phases and higher specific growth rates in minimal medium containing acetic acid and vanillin than unadapted cells. Addition of hydrolysate during propagation also resulted in cells with better fermentation capabilities. Cells propagated without hydrolysate were unable to consume xylose in wheat straw hydrolysate fermentations, whereas 40.3% and 97.7% of the xylose was consumed when 12% and 23% (v/v) hydrolysate, respectively, was added during propagation. Quantitative polymerase chain reaction revealed changes in gene expression, depending on the concentration of hydrolysate added during propagation. This study highlights the importance of using an appropriate propagation strategy for the optimum performance of yeast in fermentation of lignocellulosic hydrolysates. PMID:25989314

  12. Citric acid production from extract of Jerusalem artichoke tubers by the genetically engineered yeast Yarrowia lipolytica strain 30 and purification of citric acid.

    PubMed

    Wang, Ling-Fei; Wang, Zhi-Peng; Liu, Xiao-Yan; Chi, Zhen-Ming

    2013-11-01

    In this study, citric acid production from extract of Jerusalem artichoke tubers by the genetically engineered yeast Yarrowia lipolytica strain 30 was investigated. After the compositions of the extract of Jerusalem artichoke tubers for citric acid production were optimized, the results showed that natural components of extract of Jerusalem artichoke tubers without addition of any other components were suitable for citric acid production by the yeast strain. During 10 L fermentation using the extract containing 84.3 g L(-1) total sugars, 68.3 g L(-1) citric acid was produced and the yield of citric acid was 0.91 g g(-1) within 336 h. At the end of the fermentation, 9.2 g L(-1) of residual total sugar and 2.1 g L(-1) of reducing sugar were left in the fermented medium. At the same time, citric acid in the supernatant of the culture was purified. It was found that 67.2 % of the citric acid in the supernatant of the culture was recovered and purity of citric acid in the crystal was 96 %. PMID:23584740

  13. Formation of secretory vesicles in permeabilized cells: a salt extract from yeast membranes promotes budding of nascent secretory vesicles from the trans-Golgi network of endocrine cells.

    PubMed Central

    Ling, W L; Shields, D

    1996-01-01

    The mechanism of secretory-vesicle formation from the trans-Golgi network (TGN) of endocrine cells is poorly understood. To identify cytosolic activities that facilitate the formation and fission of nascent secretory vesicles, we treated permeabilized pituitary GH3 cells with high salt to remove endogenous budding factors. Using this cell preparation, secretory-vesicle budding from the TGN required addition of exogenous cytosol and energy. Mammalian cytosols (GH3 cells and bovine brain) promoted post-TGN vesicle formation. Most significantly, a salt extract of membranes from the yeast Saccharomyces cerevisiae, a cell lacking a regulated secretory pathway, stimulated secretory vesicle budding in the absence of mammalian cytosolic factors. These results demonstrate that the factors which promote secretory-vesicle release from the TGN are conserved between yeast and mammalian cells. PMID:8615761

  14. Biotechnological strategies to overcome inhibitors in lignocellulose hydrolysates for ethanol production: review.

    PubMed

    Parawira, W; Tekere, M

    2011-03-01

    One of the major challenges faced in commercial production of lignocellulosic bioethanol is the inhibitory compounds generated during the thermo-chemical pre-treatment step of biomass. These inhibitory compounds are toxic to fermenting micro-organisms. The ethanol yield and productivity obtained during fermentation of lignocellulosic hydrolysates is decreased due to the presence of inhibiting compounds, such as weak acids, furans and phenolic compounds formed or released during thermo-chemical pre-treatment step such as acid and steam explosion. This review describes the application and/or effect of biological detoxification (removal of inhibitors before fermentation) or use of bioreduction capability of fermenting yeasts on the fermentability of the hydrolysates. Inhibition of yeast fermentation by the inhibitor compounds in the lignocellulosic hydrolysates can be reduced by treatment with enzymes such as the lignolytic enzymes, for example, laccase and micro-organisms such as Trichoderma reesei, Coniochaeta ligniaria NRRL30616, Trametes versicolor, Pseudomonas putida Fu1, Candida guilliermondii, and Ureibacillus thermosphaericus. Microbial and enzymatic detoxifications of lignocellulosic hydrolysate are mild and more specific in their action. The efficiency of enzymatic process is quite comparable to other physical and chemical methods. Adaptation of the fermentation yeasts to the lignocellulosic hydrolysate prior to fermentation is suggested as an alternative approach to detoxification. Increases in fermentation rate and ethanol yield by adapted micro-organisms to acid pre-treated lignocellulosic hydrolysates have been reported in some studies. Another approach to alleviate the inhibition problem is to use genetic engineering to introduce increased tolerance by Saccharomyces cerevisiae, for example, by overexpressing genes encoding enzymes for resistance against specific inhibitors and altering co-factor balance. Cloning of the laccase gene followed by

  15. Debittering of Protein Hydrolysates by Lactobacillus LBL-4 Aminopeptidase

    PubMed Central

    Tchorbanov, Bozhidar; Marinova, Margarita; Grozeva, Lydia

    2011-01-01

    Yoghurt strain Lactobacillus LBL-4 cultivated for 8–10 h at pH ~6.0 was investigated as a considerable food-grade source of intracellular aminopeptidase. Cell-free extract manifesting >200 AP U/l was obtained from cells harvested from 1 L culture media. Subtilisin-induced hydrolysates of casein, soybean isolate, and Scenedesmus cell protein with degree of hydrolysis 20–22% incubated at 45°C for 10 h by 10 AP U/g peptides caused an enlarging of DH up to 40–42%, 46–48%, and 38–40% respectively. The DH increased rapidly during the first 4 h, but gel chromatography studies on BioGel P-2 showed significant changes occurred during 4–10 h of enzyme action when the DH increased gradually. After the digestion, the remained AP activity can be recovered by ultrafiltration (yield 40–50%). Scenedesmus protein hydrolysate with DH 20% was inoculated by Lactobacillus LBL-4 cells, and after 72 h cultivation the DH reached 32%. The protein hydrolysates (DH above 40%) obtained from casein and soybean isolate (high Q value) demonstrated a negligible bitterness while Scenedesmus protein hydrolysates (low Q value) after both treatments were free of bitterness. PMID:21876793

  16. System and method for conditioning a hardwood pulp liquid hydrolysate

    SciTech Connect

    Waite, Darrell M; Arnold, Richard; St. Pierre, James; Pendse, Hemant P; Ceckler, William H

    2013-12-17

    A system and method for hardwood pulp liquid hydrolysate conditioning includes a first evaporator receives a hardwood mix extract and outputting a quantity of vapor and extract. A hydrolysis unit receives the extract, hyrolyzes and outputs to a lignin separation device, which separates and recovers a quantity of lignin. A neutralization device receives extract from the lignin separation device and a neutralizing agent, producing a mixture of solid precipitate and a fifth extract. The solid precipitate is removed from the fifth extract. A second evaporator removes a quantity of acid from the fifth extract in a vapor form. This vapor may be recycled to improve total acid recovery or discarded. A desalination device receives the diluted extract, separates out some of the acid and salt and outputs a desalinated solution.

  17. System and method for conditioning a hardwood pulp liquid hydrolysate

    SciTech Connect

    Waite, Darrell; Arnold, Richard; St. Pierre, James; Pendse, Hemant P.; Ceckler, William H.

    2015-06-30

    A system and method for hardwood pulp liquid hydrolysate conditioning includes a first evaporator receives a hardwood mix extract and outputting a quantity of vapor and extract. A hydrolysis unit receives the extract, hydrolyzes and outputs to a lignin separation device, which separates and recovers a quantity of lignin. A neutralization device receives extract from the lignin separation device and a neutralizing agent, producing a mixture of solid precipitate and a fifth extract. The solid precipitate is removed from the fifth extract. A second evaporator removes a quantity of acid from the fifth extract in a vapor form. This vapor may be recycled to improve total acid recovery or discarded. A desalination device receives the diluted extract, separates out some of the acid and salt and outputs a desalinated solution.

  18. Benefits and Limitations of Protein Hydrolysates as Components of Serum-Free Media for Animal Cell Culture Applications

    NASA Astrophysics Data System (ADS)

    Lobo-Alfonso, Juliet; Price, Paul; Jayme, David

    Increased understanding of influential factors for the cultivation of animal cells, combined with heightened regulatory concern over potential transmission of adventitious contaminants associated with serum and other animal-derived components, has elevated interest in using protein hydrolysates as serum replacements or nutrient supplements. This paper reviews the chemistry and biology of various hydrolysates derived from animal, plant and microbial sources. It provides specific examples of a beneficial selection of plant and yeast hydrolysates as ingredients of serum-free nutrient formulations for bioproduction applications of cultured mammalian and insect cells. Strategies for customizing and optimizing nutrients for specialized applications and general benefits and limitations of protein hydrolysates for biopharmaceutical production are also discussed.

  19. A Four-Hour Yeast Bioassay for the Direct Measure of Estrogenic Activity in Wastewater without Sample Extraction, Concentration, or Sterilization

    PubMed Central

    Balsiger, Heather A.; de la Torre, Roberto; Lee, Wen-Yee; Cox, Marc B.

    2010-01-01

    The assay described here represents an improved yeast bioassay that provides a rapid yet sensitive screening method for EDCs with very little hands-on time and without the need for sample preparation. Traditional receptor-mediated reporter assays in yeast were performed twelve to twenty four hours after ligand addition, used colorimetric substrates, and, in many cases, required high, non-physiological concentrations of ligand. With the advent of new chemiluminescent substrates a ligand-induced signal can be detected within thirty minutes using high picomolar to low nanomolar concentrations of estrogen. As a result of the sensitivity (EC50 for estradiol is ~ 0.7 nM) and the very short assay time (2-4 hours) environmental water samples can typically be assayed directly without sterilization, extraction, and concentration. Thus, these assays represent rapid and sensitive approaches for determining the presence of contaminants in environmental samples. As proof of principle, we directly assayed wastewater influent and effluent taken from a wastewater treatment plant in the El Paso, TX area for the presence of estrogenic activity. The data obtained in the four-hour yeast bioassay directly correlated with GC-mass spectrometry analysis of these same water samples. PMID:20074779

  20. Effects of Ca(OH)(2) treatments ("overliming") on the composition and toxicity of bagasse hemicellulose hydrolysates.

    PubMed

    Martinez, A; Rodriguez, M E; York, S W; Preston, J F; Ingram, L O

    2000-09-01

    Hemicellulose syrups from dilute sulfuric acid hydrolysates of hemicellulose contain inhibitors that prevent efficient fermentation by yeast or bacteria. It is well known that the toxicity of these hydrolysate syrups can be ameliorated by optimized "overliming" with Ca(OH)(2). We have investigated the optimization of overliming treatments for sugar cane bagasse hydrolysates (primarily pentose sugars) using recombinant Escherichia coli LY01 as the biocatalyst. A comparison of composition before and after optimal overliming revealed a substantial reduction in furfural, hydroxymethylfurfural, and three unidentified high-performance liquid chromatography (HPLC) peaks. Organic acids (acetic, formic, levulinic) were not affected. Similar changes have been reported after overliming of spruce hemicellulose hydrolysates (Larsson et al., 1999). Our studies further demonstrated that the extent of furan reduction correlated with increasing fermentability. However, furan reduction was not the sole cause for reduced toxicity. After optimal overliming, bagasse hydrolysate was rapidly and efficiently fermented (>90% yield) by LY01. During these studies, titration, and conductivity were found to be in excellent agreement as methods to estimate sulfuric acid content. Titration was also found to provide an estimate of total organic acids in hydrolysate, which agreed well with the sum of acetic, levulinic, and formic acids obtained by HPLC. Titration of acids, measurement of pH before and after treatment, and furan analyses are proposed as relatively simple methods to monitor the reproducibility of hydrolysate preparations and the effectiveness of overliming treatments. PMID:10898862

  1. Effects of added chelated trace minerals, organic selenium, yeast culture, direct-fed microbials, and Yucca schidigera extract in horses: II. Nutrient excretion and potential environmental impact.

    PubMed

    Gordon, M E; Edwards, M S; Sweeney, C R; Jerina, M L

    2013-08-01

    The objective of this study was to test the hypothesis that an equine diet formulated with chelated trace minerals, organic selenium, yeast culture, direct-fed microbials (DFM) and Yucca schidigera extract would decrease excretion of nutrients that have potential for environmental impact. Horses were acclimated to 100% pelleted diets formulated with (ADD) and without (CTRL) the aforementioned additives. Chelated sources of Cu, Zn, Mn, and Co were included in the ADD diet at a 100% replacement rate of sulfate forms used in the CTRL diet. Additionally, the ADD diet included organic selenium yeast, DFM, and Yucca schidigera extract. Ten horses were fed the 2 experimental diets during two 42-d periods in a crossover design. Total fecal and urine collection occurred during the last 14 d of each period. Results indicate no significant differences between Cu, Zn, Mn, and Co concentrations excreted via urine (P > 0.05) due to dietary treatment. There was no difference between fecal Cu and Mn concentrations (P > 0.05) based on diet consumed. Mean fecal Zn and Co concentrations excreted by horses consuming ADD were greater than CTRL (P < 0.003). Differences due to diet were found for selenium fecal (P < 0.0001) and urine (P < 0.0001) excretions, with decreased concentrations found for horses consuming organic selenium yeast (ADD). In contrast, fecal K (%) was greater (P = 0.0421) for horses consuming ADD, whereas concentrations of fecal solids, total N, ammonia N, P, total ammonia, and fecal output did not differ between dietary treatments (P > 0.05). In feces stockpiled to simulate a crude composting method, no differences (P > 0.05) due to diet were detected for particle size, temperature, moisture, OM, total N, P, phosphate, K, moisture, potash, or ammonia N (P > 0.05). Although no difference (P = 0.2737) in feces stockpile temperature due to diet was found, temperature differences over time were documented (P < 0.0001). In conclusion, the addition of certain chelated

  2. Effects of Some Environmental Factors on Growth Characteristics of Candida utilis on Peat Hydrolysates.

    PubMed

    Chang, F H

    1985-01-01

    Samples of peat from Pine Island and Brookston bogs in Minnesota were hydrolyzed with various concentrations of HCl or H(2)SO(4) solutions, before or after debituminization (an extraction process used to remove waxy materials, bitumens, from peat), to produce peak hydrolysates as growth substrates for Candida utilis. Hydrolysates were neutralized with concentrated NaOH solution to pH 3.5, 4.5, 5.0, 5.5, 6.0, and 7.0. The precipitated humates were removed by filtration. The resulting peat hydrolysates were amended with reagent-grade K(2)HPO(4), K(2)SO(4), and MgSO(4), 200, 100, and 50 mg per liter of peat hydrolysate, respectively. The debituminized peat produced more total nitrogen (TN) and reducing substances (RS) than the nondebituminized peat. Peat hydrolysates produced by HCl solutions contained slightly higher RS and TN than those produced by H(2)SO(4) solutions; however, the latter were better growth substrates than the former. The yield coefficients in both H(2)SO(4) and HCl hydrolysates initially decreased at 12 to 24 h and then increased gradually over the remaining incubation period (24 to 96 h). As TN and RS were increased, an increase in cell density, biomass, and productivity was observed. In contrast, a decrease in specific growth rate occurred as the RS and TN were increased. The generation time of C. utilis was affected by the concentrations of RS and TN. A peak substrate yield coefficient was found at pH 5.0 in HCl hydrolysates and at pH 6.0 to 6.5 in H(2)SO(4) hydrolysates. Good linear correlation coefficients were found between RS and biomass of C. utilis. The coefficients of correlation increased as the TN level in hydrolysates was increased. PMID:16346708

  3. Effects of Some Environmental Factors on Growth Characteristics of Candida utilis on Peat Hydrolysates

    PubMed Central

    Chang, Fu-Hsian

    1985-01-01

    Samples of peat from Pine Island and Brookston bogs in Minnesota were hydrolyzed with various concentrations of HCl or H2SO4 solutions, before or after debituminization (an extraction process used to remove waxy materials, bitumens, from peat), to produce peak hydrolysates as growth substrates for Candida utilis. Hydrolysates were neutralized with concentrated NaOH solution to pH 3.5, 4.5, 5.0, 5.5, 6.0, and 7.0. The precipitated humates were removed by filtration. The resulting peat hydrolysates were amended with reagent-grade K2HPO4, K2SO4, and MgSO4, 200, 100, and 50 mg per liter of peat hydrolysate, respectively. The debituminized peat produced more total nitrogen (TN) and reducing substances (RS) than the nondebituminized peat. Peat hydrolysates produced by HCl solutions contained slightly higher RS and TN than those produced by H2SO4 solutions; however, the latter were better growth substrates than the former. The yield coefficients in both H2SO4 and HCl hydrolysates initially decreased at 12 to 24 h and then increased gradually over the remaining incubation period (24 to 96 h). As TN and RS were increased, an increase in cell density, biomass, and productivity was observed. In contrast, a decrease in specific growth rate occurred as the RS and TN were increased. The generation time of C. utilis was affected by the concentrations of RS and TN. A peak substrate yield coefficient was found at pH 5.0 in HCl hydrolysates and at pH 6.0 to 6.5 in H2SO4 hydrolysates. Good linear correlation coefficients were found between RS and biomass of C. utilis. The coefficients of correlation increased as the TN level in hydrolysates was increased. PMID:16346708

  4. Butyric acid fermentation from pretreated and hydrolysed wheat straw by an adapted Clostridium tyrobutyricum strain

    PubMed Central

    Baroi, G N; Baumann, I; Westermann, P; Gavala, H N

    2015-01-01

    Butyric acid is a valuable building-block for the production of chemicals and materials and nowadays it is produced exclusively from petroleum. The aim of this study was to develop a suitable and robust strain of Clostridium tyrobutyricum that produces butyric acid at a high yield and selectivity from lignocellulosic biomasses. Pretreated (by wet explosion) and enzymatically hydrolysed wheat straw (PHWS), rich in C6 and C5 sugars (71.6 and 55.4 g l−1 of glucose and xylose respectively), was used as substrate. After one year of serial selections, an adapted strain of C. tyrobutyricum was developed. The adapted strain was able to grow in 80% (v v−1) PHWS without addition of yeast extract compared with an initial tolerance to less than 10% PHWS and was able to ferment both glucose and xylose. It is noticeable that the adapted C. tyrobutyricum strain was characterized by a high yield and selectivity to butyric acid. Specifically, the butyric acid yield at 60–80% PHWS lie between 0.37 and 0.46 g g−1 of sugar, while the selectivity for butyric acid was as high as 0.9–1.0 g g−1 of acid. Moreover, the strain exhibited a robust response in regards to growth and product profile at pH 6 and 7. PMID:26230610

  5. Transcriptional activation of a geranylgeranyl diphosphate synthase gene, GGPPS2, isolated from Scoparia dulcis by treatment with methyl jasmonate and yeast extract.

    PubMed

    Yamamura, Y; Mizuguchi, Y; Taura, F; Kurosaki, F

    2014-10-01

    A cDNA clone, designated SdGGPPS2, was isolated from young seedlings of Scoparia dulcis. The putative amino acid sequence of the translate of the gene showed high homology with geranylgeranyl diphosphate synthase (GGPPS) from various plant sources, and the N-terminal residues exhibited the characteristics of chloroplast targeting sequence. An appreciable increase in the transcriptional level of SdGGPPS2 was observed by exposure of the leaf tissues of S. dulcis to methyl jasmonate, yeast extract or Ca(2+) ionophore A23187. In contrast, SdGGPPS1, a homologous GGPPS gene of the plant, showed no or only negligible change in the expression level upon treatment with these stimuli. The truncated protein heterologously expressed in Escherichia coli in which the putative targeting domain was deleted catalyzed the condensation of farnesyl diphosphate and isopentenyl diphosphate to liberate geranylgeranyl diphosphate. These results suggested that SdGGPPS2 plays physiological roles in methyl jasmonate and yeast extract-induced metabolism in the chloroplast of S. dulcis cells. PMID:25027024

  6. Ethanol production from xylose by enzymic isomerization and yeast fermentation

    SciTech Connect

    Chiang, L.C.; Hsiao, H.Y.; Ueng, P.P.; Chen, L.F.; Tsao, G.T.

    1981-01-01

    Repetitive enzymic isomerization of xylose followed by yeast fermentation of xylulose, and simultaneous enzymic isomerization and yeast fermentation were proven to be methods capable of converting xylose to ethanol. The fermentation product, ethanol, xylitol, or glycerol, has little inhibitory or deactivation effect on the activity of isomerase. In a comparison of the ability of yeasts to ferment xylulose to ethanol, Schizosaccharomyces pombe was found to be superior to industrial bakers' yeast. Under optimal conditions (pH 6, temperature 30/sup 0/C), a final ethanol concentration of 6.3 wt.% was obtained from simulated hemicellulose hydrolysate using a simultaneous fermentation process. The ethanol yield was over 80% of the theoretical value.

  7. Identification by mass spectrometry of two-dimensional gel electrophoresis-separated proteins extracted from lager brewing yeast.

    PubMed

    Joubert, R; Strub, J M; Zugmeyer, S; Kobi, D; Carte, N; Van Dorsselaer, A; Boucherie, H; Jaquet-Guffreund, L

    2001-08-01

    As two-dimensional (2-D) electrophoresis allows the separation of several hundred proteins in a single gel, this technique has become an important tool for proteome studies and for investigating the cellular physiology. In order to take advantage of information provided by the comparison of proteome pictures, the mass spectrometry technique is the way chosen for a rapid and an accurate identification of proteins of interest. Unfortunately, in the case of industrial yeasts, due to the high level of complexity of their genome, the whole DNA sequence is not yet available and all encoded protein sequences are still unknown. Nevertheless, this study presents here 30 lager brewing yeast proteins newly identified with matrix assisted laser desorption/ionization-time of flight (MALDI-TOF), tandem mass spectrometry (MS/MS) and database searching against the protein sequences of Saccharomyces cerevisiae. The identified proteins of the industrial strain correspond to proteins which do not comigrate with known proteins of S. cerevisiae separated on 2-D gels. This study presents an application of the MS technique for the identification of industrial yeast proteins which are only homologous to the corresponding S. cerevisiae proteins. PMID:11565791

  8. Improvement on the productivity of continuous tequila fermentation by Saccharomyces cerevisiae of Agave tequilana juice with supplementation of yeast extract and aeration.

    PubMed

    Hernández-Cortés, Guillermo; Valle-Rodríguez, Juan Octavio; Herrera-López, Enrique J; Díaz-Montaño, Dulce María; González-García, Yolanda; Escalona-Buendía, Héctor B; Córdova, Jesús

    2016-12-01

    Agave (Agave tequilana Weber var. azul) fermentations are traditionally carried out employing batch systems in the process of tequila manufacturing; nevertheless, continuous cultures could be an attractive technological alternative to increase productivity and efficiency of sugar to ethanol conversion. However, agave juice (used as a culture medium) has nutritional deficiencies that limit the implementation of yeast continuous fermentations, resulting in high residual sugars and low fermentative rates. In this work, fermentations of agave juice using Saccharomyces cerevisiae were put into operation to prove the necessity of supplementing yeast extract, in order to alleviate nutritional deficiencies of agave juice. Furthermore, continuous fermentations were performed at two different aeration flow rates, and feeding sterilized and non-sterilized media. The obtained fermented musts were subsequently distilled to obtain tequila and the preference level was compared against two commercial tequilas, according to a sensorial analysis. The supplementation of agave juice with air and yeast extract augmented the fermentative capacity of S. cerevisiae S1 and the ethanol productivities, compared to those continuous fermentations non supplemented. In fact, aeration improved ethanol production from 37 to 40 g L(-1), reducing sugars consumption from 73 to 88 g L(-1) and ethanol productivity from 3.0 to 3.2 g (Lh)(-1), for non-aerated and aerated (at 0.02 vvm) cultures, respectively. Supplementation of yeast extract allowed an increase in specific growth rate and dilution rates (0.12 h(-1), compared to 0.08 h(-1) of non-supplemented cultures), ethanol production (47 g L(-1)), reducing sugars consumption (93 g L(-1)) and ethanol productivity [5.6 g (Lh)(-1)] were reached. Additionally, the effect of feeding sterilized or non-sterilized medium to the continuous cultures was compared, finding no significant differences between both types of cultures. The overall effect

  9. Delipidation-based solid-phase extraction pretreatment technique for plasma broad-coverage metabolomic profiling to reveal the potential pathogenesis of yeast-induced fever in rats.

    PubMed

    Zhang, Zhixin; Qin, Lingling; Guo, Mingxing; Gao, Shanshan; Zhang, Qingqing; Wang, Qing; Lu, Zhiwei; Zhao, Huizhen; Liu, Yuehong; Wang, Meiling; Fu, Shuang; Bai, Xu; Gao, Xiaoyan

    2016-07-01

    During the process of metabolomics profiling by using ultra high performance liquid chromatography coupled with time-of flight mass spectrometry, blood sample pretreatment is a crucial step for biomarker discovery. Herein, in order to prevent the potential loss of metabolites and ion suppression phenomena caused by the proteins and phospholipids contained in blood fluids, a delipidation-based solid-phase extraction pretreatment technique for plasma broad-coverage metabolomic profiling was performed. This technique can be summarized as a single extraction, a single elution of solid-phase extraction plate, followed by four times measuring with electrospray ionization in positive and negative ion mode, respectively. This approach significantly increased the number of features detected in plasma, and 1572 features in positive mode and 1352 features in negative mode were detected, respectively. Besides, the stability and repeatability of the approach were greatly improved. For these advantages, the approach was employed to elucidate the potential pathogenesis of yeast-induced fever in rats. The biomarkers associated with the pathogenesis of fever were shown to be related to amino acids metabolism and lipid metabolism. The delipidation-based solid-phase extraction pretreatment approach can provide a useful tool to reveal the pathological mechanisms of such systemic pathological process. PMID:27173137

  10. Yeast Infections

    MedlinePlus

    ... antibiotics, it can multiply and cause an infection. Yeast infections affect different parts of the body in different ways: Thrush is a yeast infection that causes white patches in your mouth Candida ...

  11. Antioxidant and antihypertensive activity of gelatin hydrolysate from Nile tilapia skin.

    PubMed

    Choonpicharn, Sadabpong; Jaturasitha, Sanchai; Rakariyatham, Nuansri; Suree, Nuttee; Niamsup, Hataichanoke

    2015-05-01

    Fish skin, a by-product from fish processing industries, still contains a significant amount of protein-rich material. Gelatin was extracted from Nile tilapia skin with the yield 20.77 ± 0.80 % wet weight. Gelatin was then separately hydrolyzed by proteases, including bromelain, papain, trypsin, flavourzyme, alcalase and neutrase. Low molecular weight gelatin hydrolysate (<10 kDa) has a great potential as an antioxidant agent. Flavourzyme hydrolysate has potent activity on ABTS radical scavenging (1,413.61 ± 88.74 μg trolox/mg protein) and also inhibits the oxidation of linoleic acid at a high level (59.74 ± 16.57 % inhibition). The greatest reducing power is in alcalase hydrolysate (4.951 ± 1.577 mM trolox/mg protein). While, bromelain hydrolysate has the highest ferrous ion chelating activity (86.895 ± 0.061 %). Evaluation of the angiotensin-I-converting enzyme's inhibitory activity indicates that all hydrolysates have great potency as an antihypertensive agent. All studied tilapia skin gelatin hydrolysates contain potent antioxidant and anti-hypertensive effects. PMID:25892821

  12. Gentamicin-Containing Peptone-Yeast Extract Medium for Cocultivation of Hartmannella vermiformis ATCC 50256 and Virulent Strains of Legionella pneumophila

    PubMed Central

    Wadowsky, R. M.; Wang, L.; Laus, S.; Dowling, J. N.; Kuchta, J. M.; States, S. J.; Yee, R. B.

    1995-01-01

    We evaluated the use of peptone-yeast extract (PY) medium, different strains of Hartmannella vermiformis, and gentamicin in a coculture system to improve the discrimination of virulent and avirulent strains of Legionella pneumophila. H. vermiformis ATCC 50256 was unique among four strains of H. vermiformis, in that it multiplied equally well in Medium 1034 and PY medium (Medium 1034 without fetal calf serum, folic acid, hemin, and yeast nucleic acid and with a 50% reduction of peptone). However, both a virulent strain of L. pneumophila and its avirulent derivative strain multiplied in cocultures when PY medium was used. The multiplication of this avirulent strain was greatly reduced by incorporating gentamicin (1 (mu)g/ml) into the cocultivation system. Five virulent-avirulent sets of L. pneumophila strains were then tested for multiplication in cocultures with H. vermiformis ATCC 50256 and the gentamicin-containing PY medium. Only the virulent strains multiplied. The modified cocultivation system can discriminate between virulent and avirulent strains of L. pneumophila. PMID:16535197

  13. Could yeast infections impair recovery from mental illness? A case study using micronutrients and olive leaf extract for the treatment of ADHD and depression.

    PubMed

    Rucklidge, Julia J

    2013-01-01

    Micronutrients are increasingly used to treat psychiatric disorders including attention-deficit/hyperactivity disorder (ADHD), mood disorders, stress, and anxiety. However, a number of factors influence optimal response and absorption of nutrients, including the health of the gut, particularly the presence of yeast infections, such as Candida. As part of a wider investigation into the impact of micronutrients on psychiatric symptoms, many participants who experienced a yeast infection during their treatment showed a diminished response to the micronutrients. One case was followed systematically over a period of 3 y with documentation of deterioration in psychiatric symptoms (ADHD and mood) when infected with Candida and then symptom improvement following successful treatment of the infection with olive leaf extract (OLE) and probiotics. This case outlines that micronutrient treatment might be severely compromised by infections such as Candida and may highlight the importance of gut health when treating psychiatric disorders with nutrients. Given the role that inflammation can play in absorption of nutrients, it was hypothesized that the infection was impairing absorption of the micronutrients. PMID:23784606

  14. Hydrolysed formula and risk of allergic or autoimmune disease: systematic review and meta-analysis

    PubMed Central

    Ierodiakonou, Despo; Khan, Tasnia; Chivinge, Jennifer; Robinson, Zoe; Geoghegan, Natalie; Jarrold, Katharine; Afxentiou, Thalia; Reeves, Tim; Cunha, Sergio; Trivella, Marialena; Garcia-Larsen, Vanessa; Leonardi-Bee, Jo

    2016-01-01

    Objective To determine whether feeding infants with hydrolysed formula reduces their risk of allergic or autoimmune disease. Design Systematic review and meta-analysis, as part of a series of systematic reviews commissioned by the UK Food Standards Agency to inform guidelines on infant feeding. Two authors selected studies by consensus, independently extracted data, and assessed the quality of included studies using the Cochrane risk of bias tool. Data sources Medline, Embase, Web of Science, CENTRAL, and LILACS searched between January 1946 and April 2015. Eligibility criteria for selecting studies Prospective intervention trials of hydrolysed cows’ milk formula compared with another hydrolysed formula, human breast milk, or a standard cows’ milk formula, which reported on allergic or autoimmune disease or allergic sensitisation. Results 37 eligible intervention trials of hydrolysed formula were identified, including over 19 000 participants. There was evidence of conflict of interest and high or unclear risk of bias in most studies of allergic outcomes and evidence of publication bias for studies of eczema and wheeze. Overall there was no consistent evidence that partially or extensively hydrolysed formulas reduce risk of allergic or autoimmune outcomes in infants at high pre-existing risk of these outcomes. Odds ratios for eczema at age 0-4, compared with standard cows’ milk formula, were 0.84 (95% confidence interval 0.67 to 1.07; I2=30%) for partially hydrolysed formula; 0.55 (0.28 to 1.09; I2=74%) for extensively hydrolysed casein based formula; and 1.12 (0.88 to 1.42; I2=0%) for extensively hydrolysed whey based formula. There was no evidence to support the health claim approved by the US Food and Drug Administration that a partially hydrolysed formula could reduce the risk of eczema nor the conclusion of the Cochrane review that hydrolysed formula could prevent allergy to cows’ milk. Conclusion These findings do not support current guidelines

  15. Co-fermentation of glucose, xylose and/or cellobiose by yeast

    SciTech Connect

    Jeffries, Thomas W.; Willis, Laura B.; Long, Tanya M.; Su, Yi-Kai

    2013-09-10

    Provided herein are methods of using yeast cells to produce ethanol by contacting a mixture comprising xylose with a Spathaspora yeast cell under conditions suitable to allow the yeast to ferment at least a portion of the xylose to ethanol. The methods allow for efficient ethanol production from hydrolysates derived from lignocellulosic material and sugar mixtures including at least xylose and glucose or xylose, glucose and cellobiose.

  16. Radiation hydrolysate of tuna cooking juice with enhanced antioxidant properties

    NASA Astrophysics Data System (ADS)

    Choi, Jong-il; Sung, Nak-Yun; Lee, Ju-Woon

    2012-08-01

    Tuna protein hydrolysates are of increasing interest because of their potential application as a source of bioactive peptides. Large amounts of tuna cooking juice with proteins and extracts are produced during the process of tuna canning, and these cooking juice wastes cause environmental problems. Therefore, in this study, cooking juice proteins were hydrolyzed by irradiation for their utilization as functional additives. The degree of hydrolysis of tuna cooking juice protein increased from 0% to 15.1% at the absorbed doses of 50 kGy. To investigate the antioxidant activity of the hydrolysate, it was performed the ferric reducing antioxidant power (FRAP) assay, and the lipid peroxidation inhibitory and superoxide radical scavenging activities were measured. The FRAP values increased from 1470 μM to 1930 μM and IC50 on superoxide anion was decreased from 3.91 μg/mL to 1.29 μg/mL at 50 kGy. All of the antioxidant activities were increased in the hydrolysate, suggesting that radiation hydrolysis, which is a simple process that does not require an additive catalysts or an inactivation step, is a promising method for food and environmental industries.

  17. A yeast bioassay for direct measurement of thyroid hormone disrupting effects in water without sample extraction, concentration, or sterilization.

    PubMed

    Li, Jian; Ren, Shujuan; Han, Shaolun; Li, Na

    2014-04-01

    The present study introduces an improved yeast bioassay for rapid yet sensitive evaluation of thyroid hormone disruption at the level of thyroid receptor (TR) in environmental water samples. This assay does not require water sample preparation and thus requires very little hands-on time. Based on different β-galactosidase substrates, two modified bioassays, a colorimetric bioassay and a chemiluminescent bioassay, were developed. The compounds tested included the known thyroid hormone 3,3',5-triiodo-l-thyronine (T3), the specific TR antagonist amiodarone hydrochloride (AH) and phthalate esters (PAEs), which potentially disrupt thyroid hormone signaling. The EC50 values for T3 were similar to those previously obtained using a 96-well plate bioassay. TR antagonism by AH was studied in the presence of 2.5 × 10(-7)M T3, and the concentration producing 20% of the maximum effect (RIC20) for AH was 3.1 × 10(-7)M and 7.8 × 10(-9)M for the colorimetric bioassay and chemiluminescent bioassay, respectively. None of the tested PAEs induced β-galactosidase expression, but diethylhexyl phthalate, benzyl butyl phthalate and dibutyl phthalate demonstrated TR antagonism. Furthermore, water samples collected from Guanting reservoir in Beijing were evaluated. Although TR agonism was not observed, antagonism was detected in all water samples and is expressed as AH equivalents. The toxicology equivalent quantity values obtained by the chemiluminescent bioassay ranged from 21.2 ± 1.6 to 313.9 ± 28.8 μg L(-1) AH, and similar values were obtained for the colorimetric bioassay. The present study shows that the modified yeast bioassay can be used as a valuable tool for quantification of thyroid hormone disrupting effects in environmental water samples. PMID:24355165

  18. Inhibitor degradation and lipid accumulation potentials of oleaginous yeast Trichosporon cutaneum using lignocellulose feedstock.

    PubMed

    Wang, Juan; Gao, Qiuqiang; Zhang, Huizhan; Bao, Jie

    2016-10-01

    Oleaginous yeast Trichosporon cutaneum is robust to high levels of lignocellulose derived inhibitor compounds with considerable lipid accumulation capacity. The potential of lipid accumulation of T. cutaneum ACCC 20271 was investigated using corn stover hydrolysates with varying sugar and inhibitor concentrations. Biodiesel was synthesized using the extracted lipid and the product satisfied the ASTM standards. Among the typical inhibitors, T. cutaneum ACCC 20271 is relatively sensitive to furfural and 4-hydroxybenzaldehyde, but strongly tolerant to high titers of formic acid, acetic acid, levulinic acid, HMF, vanillin, and syringaldehyde. It is capable of complete degradation of formic acid, acetic acid, vanillin and 4-hydroxybenzaldehyde. Finally, the inhibitor degradation pathways of T. cutaneum ACCC 20271 were constructed based on the newly sequenced whole genome information and the experimental results. The study provided the first insight to the inhibitor degradation of T. cutaneum and demonstrated the potentials of lipid production from lignocellulose. PMID:27441826

  19. Actinopyga lecanora Hydrolysates as Natural Antibacterial Agents

    PubMed Central

    Ghanbari, Raheleh; Ebrahimpour, Afshin; Abdul-Hamid, Azizah; Ismail, Amin; Saari, Nazamid

    2012-01-01

    Actinopyga lecanora, a type of sea cucumber commonly known as stone fish with relatively high protein content, was explored as raw material for bioactive peptides production. Six proteolytic enzymes, namely alcalase, papain, pepsin, trypsin, bromelain and flavourzyme were used to hydrolyze A. lecanora at different times and their respective degrees of hydrolysis (DH) were calculated. Subsequently, antibacterial activity of the A. lecanora hydrolysates, against some common pathogenic Gram positive bacteria (Bacillus subtilis and Staphylococcus aureus) and Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Pseudomonas sp.) were evaluated. Papain hydrolysis showed the highest DH value (89.44%), followed by alcalase hydrolysis (83.35%). Bromelain hydrolysate after one and seven hours of hydrolysis exhibited the highest antibacterial activities against Pseudomonas sp., P. aeruginosa and E. coli at 51.85%, 30.07% and 30.45%, respectively compared to the other hydrolysates. Protein hydrolysate generated by papain after 8 h hydrolysis showed maximum antibacterial activity against S. aureus at 20.19%. The potent hydrolysates were further fractionated using RP-HPLC and antibacterial activity of the collected fractions from each hydrolysate were evaluated, wherein among them only three fractions from the bromelain hydrolysates exhibited inhibitory activities against Pseudomonas sp., P. aeruginosa and E. coli at 24%, 25.5% and 27.1%, respectively and one fraction of papain hydrolysate showed antibacterial activity of 33.1% against S. aureus. The evaluation of the relationship between DH and antibacterial activities of papain and bromelain hydrolysates revealed a meaningful correlation of four and six order functions. PMID:23222684

  20. Emulsion properties of casein and whey protein hydrolysates and the relation with other hydrolysate characteristics.

    PubMed

    van der Ven, C; Gruppen, H; de Bont, D B; Voragen, A G

    2001-10-01

    Casein and whey protein were hydrolyzed using 11 different commercially available enzyme preparations. Emulsion-forming ability and emulsion stability of the digests were measured as well as biochemical properties with the objective to study the relations between hydrolysate characteristics and emulsion properties. All whey protein hydrolysates formed emulsions with bimodal droplet size distributions, signifying poor emulsion-forming ability. Emulsion-forming ability of some casein hydrolysates was comparable to that of intact casein. Emulsion instability was caused by creaming and coalescence. Creaming occurred mainly in whey hydrolysate emulsions and in casein hydrolysate emulsions containing large emulsion droplets. Coalescence was dominant in casein emulsions with a broad particle size distribution. Emulsion instability due to coalescence was related to apparent molecular weight distribution of hydrolysates; a relative high amount of peptides larger than 2 kDa positively influences emulsion stability. PMID:11600059

  1. Bioethanol potentials of corn cob hydrolysed using cellulases of Aspergillus niger and Penicillium decumbens

    PubMed Central

    Saliu, Bolanle Kudirat; Sani, Alhassan

    2012-01-01

    Corn cob is a major component of agricultural and domestic waste in many parts of the world. It is composed mainly of cellulose which can be converted to energy in form of bioethanol as an efficient and effective means of waste management. Production of cellulolytic enzymes were induced in the fungi Aspergillus niger and Penicillium decumbens by growing them in mineral salt medium containing alkali pre-treated and untreated corn cobs. The cellulases were characterized and partially purified. Alkali pre-treated corn cobs were hydrolysed with the partially purified cellulases and the product of hydrolysis was fermented using the yeast saccharomyces cerevisae to ethanol. Cellulases of A. niger produced higher endoglucanase and exoglucanase activity (0.1698 IU ml-1 and 0.0461 FPU ml-1) compared to that produced by P. decumbens (0.1111 IU ml-1 and 0.153 FPU ml-1). Alkali pre-treated corn cob hydrolysed by cellulases of A. niger yielded 7.63 mg ml-1 sugar which produced 2.67 % (v/v) ethanol on fermentation. Ethanol yield of the hydrolysates of corn cob by cellulases of P. decumbens was much lower at 0.56 % (v/v). Alkali pre-treated corn cob, hydrolysed with cellulases of A. niger is established as suitable feedstock for bioethanol production.

  2. Lipid production by Cryptococcus curvatus on hydrolysates derived from corn fiber and sweet sorghum bagasse following dilute acid pretreatment.

    PubMed

    Liang, Yanna; Jarosz, Kimberly; Wardlow, Ashley T; Zhang, Ji; Cui, Yi

    2014-08-01

    Corn fiber and sweet sorghum bagasse (SSB) are both pre-processed lignocellulosic materials that can be used to produce liquid biofuels. Pretreatment using dilute sulfuric acid at a severity factor of 1.06 and 1.02 released 83.2 and 86.5 % of theoretically available sugars out of corn fiber and SSB, respectively. The resulting hydrolysates derived from pretreatment of SSB at SF of 1.02 supported growth of Cryptococcus curvatus well. In 6 days, the dry cell density reached 10.8 g/l with a lipid content of 40 % (w/w). Hydrolysates from corn fiber, however, did not lead to any significant cell growth even with addition of nutrients. In addition to consuming glucose, xylose, and arabinose, C. curvatus also utilized formic acid, acetic acid, 4-hydroxymethylfurfural, and levulinic acid for growth. Thus, C. curvatus appeared to be an excellent yeast strain for producing lipids from hydrolysates developed from lignocellulosic feedstocks. PMID:24928546

  3. Influence of autochthonous lactic acid bacteria and enzymatic yeast extracts on the microbiological, biochemical and sensorial properties of Lben generic products.

    PubMed

    Mangia, Nicoletta P; Garau, Giovanni; Murgia, Marco A; Bennani, Abdelmajid; Deiana, Pietrino

    2014-05-01

    In this study we identified Lactococcus lactis subsp. lactis, Lc. lactis subsp. lactis biovar diacetylactis, Kluyveromices lactis and Saccharomyces cerevisiae as the dominant microorganisms of traditional Moroccan acid-alcoholic fermented milk named Lben. The low pH (3·8±0·3), lactose (16·8±3·4 mg/l) and lactic acid (8·16±0·6 mg/l) content indicated that a strong fermentation occurred in the traditional product which was also characterised by the substantial presence of ethanol and typical volatile carbonyl compounds (i.e., acetoin, diacetyl and acetaldehyde). Microbiological analyses of experimental Lben manufactured with selected strains (isolated from the traditional product) of Lc. lactis subsp. lactis and Lc. lactis subsp. lactis biovar. diacetylactis alone (batch A) and in combination with enzymatic extract of a K. lactis strain (batch B) indicated a good effectiveness of the starters employed (∼1010 CFU/g of lactococci after 8 h of incubation) and a significant effect of the yeast enzyme extract on lactococci viability. Despite slight changes in the physicochemical characteristics of the two Lben during the 15 d storage period, volatile compounds (i.e. ethanol, acetaldehyde, diacetyl and acetoin) were consistently higher in batch B. Moreover, sensorial analysis performed after 15 d of storage, highlighted higher odour and flavour intensity, vegetable odour and viscosity in batch B while batch A displayed higher astringency. PMID:24642233

  4. Mutations in the membrane anchor of yeast cytochrome c1 compensate for the absence of Oxa1p and generate carbonate-extractable forms of cytochrome c1.

    PubMed Central

    Hamel, P; Lemaire, C; Bonnefoy, N; Brivet-Chevillotte, P; Dujardin, G

    1998-01-01

    Oxa1p is a mitochondrial inner membrane protein that is mainly required for the insertion/assembly of complex IV and ATP synthase and is functionally conserved in yeasts, humans, and plants. We have isolated several independent suppressors that compensate for the absence of Oxa1p. Molecular cloning and sequencing reveal that the suppressor mutations (CYT1-1 to -6) correspond to amino acid substitutions that are all located in the membrane anchor of cytochrome c1 and decrease the hydrophobicity of this anchor. Cytochrome c1 is a catalytic subunit of complex III, but the CYT1-1 mutation does not seem to affect the electron transfer activity. The double-mutant cyt1-1,164, which has a drastically reduced electron transfer activity, still retains the suppressor activity. Altogether, these results suggest that the suppressor function of cytochrome c1 is independent of its electron transfer activity. In addition to the membrane-bound cytochrome c1, carbonate-extractable forms accumulate in all the suppressor strains. We propose that these carbonate-extractable forms of cytochrome c1 are responsible for the suppressor function by preventing the degradation of the respiratory complex subunits that occur in the absence of Oxa1p. PMID:9755193

  5. Applications of Protein Hydrolysates in Biotechnology

    NASA Astrophysics Data System (ADS)

    Pasupuleti, Vijai K.; Holmes, Chris; Demain, Arnold L.

    By definition, protein hydrolysates are the products that are obtained after the hydrolysis of proteins and this can be achieved by enzymes, acid or alkali. This broad definition encompasses all the products of protein hydrolysis - peptides, amino acids and minerals present in the protein and acid/alkali used to adjust pH (Pasupuleti 2006). Protein hydrolysates contain variable side chains depending on the enzymes used. These side chains could be carboxyl, amino, imidazole, sulfhydryl, etc. and they may exert specific physiological roles in animal, microbial, insect and plant cells. This introductory chapter reviews the applications of protein hydrolysates in biotechnology. The word biotechnology is so broad and for the purpose of this book, we define it as a set of technologies such as cell culture technology, bioprocessing technology that includes fermentations, genetic engineering technology, microbiology, and so on. This chapter provides introduction and leads to other chapters on manufacturing and applications of protein hydrolysates in biotechnology.

  6. Biofunctional Properties of Enzymatic Squid Meat Hydrolysate

    PubMed Central

    Choi, Joon Hyuk; Kim, Kyung-Tae; Kim, Sang Moo

    2015-01-01

    Squid is one of the most important commercial fishes in the world and is mainly utilized or consumed as sliced raw fish or as processed products. The biofunctional activities of enzymatic squid meat hydrolysate were determined to develop value-added products. Enzymatic squid hydrolysate manufactured by Alcalase effectively quenched 1,1-diphenyl-2-picrylhydrazyl radical, hydroxyl radical, and hydrogen peroxide radical with IC50 values of 311, 3,410, and 111.5 μg/mL, respectively. Angiotensin I-converting enzyme inhibitory activity of squid hydrolysate was strong with an IC50 value of 145.1 μg/mL, while tyrosinase inhibitory activity with an IC50 value of 4.72 mg/mL was moderately low. Overall, squid meat hydrolysate can be used in food or cosmetic industries as a bioactive ingredient and possibly be used in the manufacture of seasoning, bread, noodle, or cosmetics. PMID:25866752

  7. Hydrolysates of lignocellulosic materials for biohydrogen production.

    PubMed

    Chen, Rong; Wang, Yong-Zhong; Liao, Qiang; Zhu, Xun; Xu, Teng-Fei

    2013-05-01

    Lignocellulosic materials are commonly used in bio-H2 production for the sustainable energy resource development as they are abundant, cheap, renewable and highly biodegradable. In the process of the bio-H2 production, the pretreated lignocellulosic materials are firstly converted to monosaccharides by enzymolysis and then to H2 by fermentation. Since the structures of lignocellulosic materials are rather complex, the hydrolysates vary with the used materials. Even using the same lignocellulosic materials, the hydrolysates also change with different pretreatment methods. It has been shown that the appropriate hydrolysate compositions can dramatically improve the biological activities and bio-H2 production performances. Over the past decades, hydrolysis with respect to different lignocellulosic materials and pretreatments has been widely investigated. Besides, effects of the hydrolysates on the biohydrogen yields have also been examined. In this review, recent studies on hydrolysis as well as their effects on the biohydrogen production performance are summarized. PMID:23710634

  8. Contribution of PRS3, RPB4 and ZWF1 to the resistance of industrial Saccharomyces cerevisiae CCUG53310 and PE-2 strains to lignocellulosic hydrolysate-derived inhibitors.

    PubMed

    Cunha, Joana T; Aguiar, Tatiana Q; Romaní, Aloia; Oliveira, Carla; Domingues, Lucília

    2015-09-01

    PRS3, RPB4 and ZWF1 were previously identified as key genes for yeast tolerance to lignocellulose-derived inhibitors. To better understand their contribution to yeast resistance to the multiple stresses occurring during lignocellulosic hydrolysate fermentations, we overexpressed these genes in two industrial Saccharomyces cerevisiae strains, CCUG53310 and PE-2, and evaluated their impact on the fermentation of Eucalyptus globulus wood and corn cob hydrolysates. PRS3 overexpression improved the fermentation rate (up to 32%) and productivity (up to 48%) in different hydrolysates. ZWF1 and RPB4 overexpression did not improve the fermentation performance, but their increased expression in the presence of acetic acid, furfural and hydroxymethylfurfural was found to contribute to yeast adaptation to these inhibitors. This study expands our understanding about the molecular mechanisms involved in industrial yeast tolerance to the stresses occurring during lignocellulosic bioethanol production and highlights the importance of selecting appropriate strain backgrounds/hydrolysates combinations when addressing further improvement of these processes. PMID:25974617

  9. Effects and mechanism of cerebroprotein hydrolysate on learning and memory ability in mice.

    PubMed

    An, L; Han, X; Li, H; Ma, Y; Shi, L; Xu, G; Yuan, G; Sun, J; Zhao, N; Sheng, Y; Wang, M; Du, P

    2016-01-01

    Cerebroprotein hydrolysate is an extract from porcine brain tissue that acts on the central nervous system in various ways to protect neurons and improve memory, attention, and vigilance. This study examined the effect and mechanism of cerebroprotein hydrolysate on learning and memory in mice with scopolamine-induced impairment. Mice were given an intraperitoneal injection of scopolamine hydrobromide to establish a murine model of learning and memory impairment. After 35 successive days of cerebroprotein hydrolysate treatment, their behaviors were observed in the Morris water maze and step-down test. Superoxide dismutase (SOD), Na(+)-K(+)-ATPase, and acetylcholinesterase (AChE) activity, and malondialdehyde (MDA), γ-aminobutyric acid (GABA), and glutamic acid (Glu) levels in the brain tissue of the mice were determined, and pathological changes in the hippocampus were examined. The results of the water-maze test showed that cerebroprotein hydrolysate shortened the escape latency and increased the number of platform crossings. In the step-down test, cerebroprotein hydrolysate treatment prolonged the step-down latency and reduced the number of errors; cerebroprotein hydrolysate increased the activity of SOD, Na(+)-K(+)-ATPase, and AChE, reduced the levels of MDA, decreased the Glu/GABA ratio in brain tissue, and reduced pathological changes in the hippocampus. The results indicate that cerebroprotein hydrolysate can improve learning and memory in mice with scopolamine-induced impairment. This effect may be associated with its ability to reduce injury caused by free radicals, improve acetylcholine function, and modulate the Glu/GABA learning and memory regulation system, reducing excitotoxicity caused by Glu. PMID:27525868

  10. Selective media for detecting and enumerating foodborne yeasts.

    PubMed

    Beuchat, L R

    1993-06-25

    No one medium is satisfactory for detecting, isolating and enumerating all yeasts in all foods. Antibiotic-supplemented media such as dichloran rose Bengal chloramphenicol agar, tryptone glucose yeast extract chloramphenicol agar, oxytetracycline glucose yeast extract agar and rose Bengal chloramphenicol agar are superior to acidified potato dextrose agar and other acidified media for enumeration of the vast majority of spoilage yeasts. Dichloran glycerol (18%) agar performs well for enumerating moderately xerotolerant yeasts. Malt extract yeast extract glucose (up to 60%) can be used for detecting and enumerating moderate and extreme xerophiles. These media also support the growth of moulds. Lysine agar, Schwarz differential agar and Lin's wild yeast differential agar are used by the brewing industry to differentiate wild yeasts from brewer's strains. Lysine agar is selective for apiculate yeasts and ethanol sulfite yeast extract agar is selective for Saccharomyces. Both have application in wineries. Modified molybdate agar can be used to selectively isolate yeasts from tropical fruits. Preservative-resistant yeasts can be detected on malt acetic agar. The recommended incubation temperature is 25 degrees C, but incubation time between plating and counting colonies ranges from 5 days for determination of general populations of yeasts to 10 days for more for xerotolerant yeasts. There is need for new and improved media for selectively isolating various groups, genera, species and strains of yeasts capable of growing only under specific environmental conditions in specific types of foods and beverages. PMID:8357752

  11. Effects of added chelated trace minerals, organic selenium, yeast culture, direct-fed microbials, and Yucca schidigera extract in horses. Part I: Blood nutrient concentration and digestibility.

    PubMed

    Gordon, M E; Edwards, M S; Sweeney, C R; Jerina, M L

    2013-08-01

    The objective of this study was to test the hypothesis that feed additives such as chelated minerals, organic Se, yeast culture, direct-fed microbials, and Yucca schidigera extract would improve nutrient digestibility when included in an equine diet. Horses (Quarter Horse geldings 4.5 to 16 yr of age; mean BW 522 kg ± 46 kg) were acclimated to 100% pelleted diets formulated with (ADD) and without (CTRL) commercially available sources of the aforementioned additives followed by a 14-d collection period of feces and urine. Chelated sources of Cu, Zn, Mn and Co were utilized versus sulfated forms, at a 100% replacement rate. No significant differences among apparent the digestibility of DM, ADF, or NDF (P= 0.665, P = 0.866, P = 0.747, respectively) were detected between dietary treatments. Likewise, no differences in apparent digestibility of Cu (P = 0.724), Zn (P = 0.256), Mn (P = 0.888), Co (P = 0.71), or Se (P = 0.588) were observed. No differences were observed in serum Cu, Mn, or Co concentrations between ADD and CTRL at acclimation or collection time points (P > 0.05). While no difference in serum Zn concentrations were observed between ADD and CTRL groups at acclimation (P > 0.05), they were statistically higher at the collection time period for horses consuming CTRL (P < 0.0001). Whole blood Se concentration was greater in the CTRL group versus the ADD group both at acclimation (P = 0.041) and collection (P = 0.005) time periods. In reference to time, serum Cu concentrations increased (P = 0.012) for animals consuming CTRL, but not ADD (P > 0.05). Serum Zn concentrations of horses consuming both ADD (P = 0.021) and CTRL (P < 0.0001) increased over time from acclimation to collection time points. No time differences (P > 0.05) were observed in serum Mn concentrations. Serum Co concentrations increased over time in horses consuming both ADD (P = 0.001) and CTRL (P = 0.021). From acclimation to collection, whole blood Se concentration increased for horses

  12. Improvement of D-Ribose Production from Corn Starch Hydrolysate by a Transketolase-Deficient Strain Bacillus subtilis UJS0717

    PubMed Central

    Wei, Zhuan; Zhou, Jue; Sun, WenJing; Cui, FengJie; Xu, QinHua; Liu, ChangFeng

    2015-01-01

    D-Ribose is a five-carbon sugar and generally used as an energy source to improve athletic performance and the ability. The culture conditions for maximum D-ribose production performance from cheap raw material corn starch hydrolysate were improved by using one-factor-at-a-time experiments and a three-level Box-Behnken factorial design. The optimal fermentation parameters were obtained as 36°C culture temperature, 10% inoculum volume, and 7.0 initial pH. The mathematical model was then developed to show the effect of each medium composition and their interactions on the production of D-ribose and estimated that the optimized D-ribose production performance with the concentration of 62.13 g/L, yield of 0.40 g/g, and volumetric productivity of 0.86 g/L·h could be obtained when the medium compositions were set as 157 g/L glucose, 21 g/L corn steep liquor, 3.2 g/L (NH4)2SO4, 1 g/L yeast extract, 0.05 g/L MnSO4·H2O, and 20 g/L CaCO3. These findings indicated the D-ribose production performance was significantly improved compared to that under original conditions. PMID:26759810

  13. Improvement of D-Ribose Production from Corn Starch Hydrolysate by a Transketolase-Deficient Strain Bacillus subtilis UJS0717.

    PubMed

    Wei, Zhuan; Zhou, Jue; Sun, WenJing; Cui, FengJie; Xu, QinHua; Liu, ChangFeng

    2015-01-01

    D-Ribose is a five-carbon sugar and generally used as an energy source to improve athletic performance and the ability. The culture conditions for maximum D-ribose production performance from cheap raw material corn starch hydrolysate were improved by using one-factor-at-a-time experiments and a three-level Box-Behnken factorial design. The optimal fermentation parameters were obtained as 36°C culture temperature, 10% inoculum volume, and 7.0 initial pH. The mathematical model was then developed to show the effect of each medium composition and their interactions on the production of D-ribose and estimated that the optimized D-ribose production performance with the concentration of 62.13 g/L, yield of 0.40 g/g, and volumetric productivity of 0.86 g/L·h could be obtained when the medium compositions were set as 157 g/L glucose, 21 g/L corn steep liquor, 3.2 g/L (NH4)2SO4, 1 g/L yeast extract, 0.05 g/L MnSO4·H2O, and 20 g/L CaCO3. These findings indicated the D-ribose production performance was significantly improved compared to that under original conditions. PMID:26759810

  14. Development of an enzymatic fish hydrolysate and its use in instant soup bases.

    PubMed

    Gálvez, A; Morales de Léon, J; Bourges Rodríguez, H

    1985-12-01

    The successful conservation of fish products, at low costs, is a subject of special interest in the developing countries. Conscious of this fact, our group has been studying several fish conservation methods, such as autolysis with high salt concentrations, and has obtained a sauce of high nutritive value and long shelf life. Nevertheless, the reaction process takes from four to six months. In the study herein reported, the hydrolysis was accelerated and controlled by using the following enzymes: papain, HT proteolytic, and Brew (N) zyme. The hydrolysate was then mixed with cereals to prepare instant soups. As results indicated, the best hydrolysate was obtained with Brew (N) zyme at 50 degrees C and 8.30 hours. This hydrolysate contains 93.0 g/100 g crude protein with a protein efficiency ratio (PER) and a net protein utilization (NPU) of 60% that of casein's NPU as well as a content of 0.8% ether extract. The lowest-cost mixtures with the highest nutritive value were: hydrolysate-wheat-soymeal, and hydrolysate-rice-soymeal, with 38.3 and 29.7 protein per 100 g of mixture, respectively, and a NPU of 79.0 and 79.8% in relation to casein, respectively. The soups prepared had a satisfactory acceptance rating. There were no significant differences in flavor and aroma at a confidence level of 95%. The cost per gram of protein is about US$ 0.22 per kg. PMID:3842931

  15. Xylitol production from wheat straw hemicellulosic hydrolysate: hydrolysate detoxification and carbon source used for inoculum preparation

    PubMed Central

    Canilha, Larissa; Carvalho, Walter; Felipe, Maria das Graças Almeida; de Almeida e Silva, João Batista

    2008-01-01

    Wheat straw hemicellulosic hydrolysate was used for xylitol bioproduction. The use of a xylose-containing medium to grow the inoculum did not favor the production of xylitol in the hydrolysate, which was submitted to a previous detoxification treatment with 2.5% activated charcoal for optimized removal of inhibitory compounds. PMID:24031226

  16. Measurement of the inhibitory potential and detoxification of biomass pretreatment hydrolysate for ethanol production

    SciTech Connect

    Rivard, C.J.; Engel, R.E.; Nagle, N.J.

    1996-12-31

    The Microtox assay represents a rapid, accurate, and reproducible method for determining general microbial toxicity. This assay was used to evaluate the relative toxicity of a variety of hydrolysate samples derived from dilute-acid and alkaline biomass pretreatment. Toxicity is elicited from biomass degradation products, such as furfural, hydroxymethyl furfural, and acetic acid, generated during pretreatment. Microtox results indicate that the pretreatment samples examined ranged from 9 to 71 toxicity units (TU). Correlations of TU and sample absorbance at several wavelengths were evaluated for all sample series. Sample TU values best agreed with absorbance at 230 nm, but the unsatisfactory fit suggests that absorbance should not be used as an absolute measure of sample toxicity. Microtox data for pretreatment hydrolysate samples were correlated with the inhibition experienced by the ethanologenic yeast, Saccharomyces cerevisiae strain D{sub 5}A, during the simultaneous saccharification and fermentation (SSF) process of pretreated biomass. None of the alkaline pretreatment conditions produced inhibition during SSF. However, the acid pretreatment conditions did produce a wide range of inhibitory and noninhibitory hydrolysates. In general, fermentation was inhibited for acid-pretreated hydrolysate samples with values exceeding 45 TU. Preliminary studies that focused on reducing hydrolysate sample toxicity (detoxification) indicate that adding perlite and zeolite had little effect. However, the use of charcoal, a universal flocculent, or ion-exchange resins significantly reduced sample toxicity, holding promise for the efficient bioconversion of pretreated biomass to ethanol. Moreover, the developed toxicity measurement assay can quickly monitor the quality of the pretreatment process. In this way, biomass conversion operation processes can be reliably controlled at the pilot and commercial scales. 4 refs., 4 figs., 3 tabs.

  17. Xuezhikang, Extract of Red Yeast Rice, Improved Abnormal Hemorheology, Suppressed Caveolin-1 and Increased eNOS Expression in Atherosclerotic Rats

    PubMed Central

    Yang, Ya-Bing; Liu, Mei-Lin

    2013-01-01

    Background Xuezhikang is the extract of red yeast rice, which has been widely used for the management of atherosclerotic disease, but the molecular basis of its antiatherosclerotic effects has not yet been fully identified. Here we investigated the changes of eNOS in vascular endothelia and RBCs, eNOS regulatory factor Caveolin-1 in endothelia, and hemorheological parameters in atherosclerotic rats to explore the protective effects of Xuezhikang. Methodology/Principal Findings Wistar rats were divided into 4 groups (n = 12/group) group C, controls; group M, high-cholesterol diet (HCD) induced atherosclerotic models; group X, HCD+Xuezhikang; and group L, HCD +Lovastatin. In group X, Xuezhikang inhibited oxidative stress, down-regulated caveolin-1 in aorta wall (P<0.05), up-regulated eNOS expression in vascular endothelia and erythrocytes (P<0.05), increased NOx (nitrite and nitrate) in plasma and cGMP in erythrocyte plasma and aorta wall (P<0.05), increased erythrocyte deformation index (EDI), and decreased whole blood viscosity and plasma viscosity (P<0.05), with the improvement of arterial pathology. Conclusions/Significance Xuezhikang up-regulated eNOS expression in vascular endothelia and RBCs, increased plasma NOx and improved abnormal hemorheology in high cholesterol diet induced atherosclerotic rats. The elevated eNOS/NO and improved hemorheology may be beneficial to atherosclerotic disease. PMID:23675421

  18. An economic approach to efficient isotope labeling in insect cells using homemade 15N-, 13C- and 2H-labeled yeast extracts.

    PubMed

    Opitz, Christian; Isogai, Shin; Grzesiek, Stephan

    2015-07-01

    Heterologous expression of proteins in insect cells is frequently used for crystallographic structural studies due to the high yields even for challenging proteins requiring the eukaryotic protein processing capabilities of the host. However for NMR studies, the need for isotope labeling poses extreme challenges in eukaryotic hosts. Here, we describe a robust method to achieve uniform protein (15)N and (13)C labeling of up to 90 % in baculovirus-infected insect cells. The approach is based on the production of labeled yeast extract, which is subsequently supplemented to insect cell growth media. The method also allows deuteration at levels of >60 % without decrease in expression yield. The economic implementation of the labeling procedures into a standard structural biology laboratory environment is described in a step-by-step protocol. Applications are demonstrated for a variety of NMR experiments using the Abelson kinase domain, GFP, and the beta-1 adrenergic receptor as examples. Deuterated expression of the latter provides spectra of very high quality of a eukaryotic G-protein coupled receptor. PMID:26070442

  19. Comparing the sugar profiles and primary structures of alkali-extracted water-soluble polysaccharides in cell wall between the yeast and mycelial phases from Tremella fuciformis.

    PubMed

    Zhu, Hanyu; Yuan, Yuan; Liu, Juan; Zheng, Liesheng; Chen, Liguo; Ma, Aimin

    2016-05-01

    To gain insights into dimorphism, cell wall polysaccharides from Tremella fuciformis strains were obtained from alkali-extracted water-soluble fractions PTF-M38 (from the mycelial form), PTF-Y3 and PTF-Y8 (from the yeast form) of T. fuciformis strains were used to gain some insights into dimorphism study. Their chemical properties and structural features were investigated using gel permeation chromatography, gas chromatography, UV and IR spectrophotometry and Congo red binding reactions. The results indicated that the backbones of PTF-M38, PTF-Y3 and PTF-Y8 were configured with α-linkages with average molecular weights of 1.24, 1.08, and 1.19 kDa, respectively. PTF-M38 was mainly composed of xylose, mannose, glucose, and galactose in a ratio of 1:1.47:0.48:0.34, while PTF-Y3 and PTF-Y8 were mainly composed of xylose, mannose and glucose in a ratio of 1:1.65:4.06 and 1:1.21:0.44, respectively. The sugar profiles of PTF-M38, PTF-Y3 and PTF-Y8 were also established for further comparison. These profiles showed that all three polysaccharides contained the same sugars but in different ratios, and the carbon sources (xylose, mannose, glucose, and galactose) affected the sugar ratios within the polysaccharides. PMID:27095457

  20. Vasorelaxant Effect of 5'-Methylthioadenosine Obtained from Candida utilis Yeast Extract through the Suppression of Intracellular Ca(2+) Concentration in Isolated Rat Aorta.

    PubMed

    Kumrungsee, Thanutchaporn; Akiyama, Sayaka; Saiki, Tomomi; Omae, Masato; Hamasawa, Kazuhiro; Matsui, Toshiro

    2016-05-01

    Our study is the first to demonstrate the vasorelaxant effect of Candida utilis yeast extract on rat aorta (EC50 of 7.2 ± 3.2 mg/mL). Among five identified compounds, 5'-methylthioadenosine (MTA) exhibited comparable vasorelaxant effect (EC50 of 190 ± 40 μM) with adenosine, a known vasodilator, on 1 μM phenylephrine (PE)-contracted Sprague-Dawley rat aortic rings. MTA induced vasorelaxation in an endothelium-independent manner and independent of the adenosine receptors. MTA reduced a CaCl2-induced vasocontraction stimulated by 1 μM PE, whereas the effect was abolished in a 60 mM KCl-induced vasocontraction. This indicates that MTA was not involved in the suppression of extracellular Ca(2+) influx. MTA significantly (P < 0.01) attenuated the PE-induced activation of calmodulin-dependent kinase II (CaMK II) in aortic rings and inhibited the phosphorylation of L-type Ca(2+) channel (VDCC). In conclusion, the underlying mechanism(s) of MTA-induced vasorelaxation involves the inhibition of Ca(2+)/CaMK II/VDCC phosphorylation pathway, resulting in the suppression of intracellular Ca(2+) concentration in aortic rings. PMID:27066696

  1. Long-Term n-Caproic Acid Production from Yeast-Fermentation Beer in an Anaerobic Bioreactor with Continuous Product Extraction.

    PubMed

    Ge, Shijian; Usack, Joseph G; Spirito, Catherine M; Angenent, Largus T

    2015-07-01

    Multifunctional reactor microbiomes can elongate short-chain carboxylic acids (SCCAs) to medium-chain carboxylic acids (MCCAs), such as n-caproic acid. However, it is unclear whether this microbiome biotechnology platform is stable enough during long operating periods to consistently produce MCCAs. During a period of 550 days, we improved the operating conditions of an anaerobic bioreactor for the conversion of complex yeast-fermentation beer from the corn kernel-to-ethanol industry into primarily n-caproic acid. We incorporated and improved in-line, membrane liquid-liquid extraction to prevent inhibition due to undissociated MCCAs at a pH of 5.5 and circumvented the addition of methanogenic inhibitors. The microbiome accomplished several functions, including hydrolysis and acidogenesis of complex organic compounds and sugars into SCCAs, subsequent chain elongation with undistilled ethanol in beer, and hydrogenotrophic methanogenesis. The methane yield was 2.40 ± 0.52% based on COD and was limited by the availability of carbon dioxide. We achieved an average n-caproate production rate of 3.38 ± 0.42 g L(-1) d(-1) (7.52 ± 0.94 g COD L(-1) d(-1)) with an n-caproate yield of 70.3 ± 8.81% and an n-caproate/ethanol ratio of 1.19 ± 0.15 based on COD for a period of ∼55 days. The maximum production rate was achieved by increasing the organic loading rates in tandem with elevating the capacity of the extraction system and a change in the complex feedstock batch. PMID:25941741

  2. Protein enrichment of an Opuntia ficus-indica cladode hydrolysate by cultivation of Candida utilis and Kluyveromyces marxianus

    PubMed Central

    Akanni, Gabriel B; du Preez, James C; Steyn, Laurinda; Kilian, Stephanus G

    2015-01-01

    BACKGROUND The cladodes of Opuntia ficus-indica (prickly pear cactus) have a low protein content; for use as a balanced feed, supplementation with other protein sources is therefore desirable. We investigated protein enrichment by cultivation of the yeasts Candida utilis and Kluyveromyces marxianus in an enzymatic hydrolysate of the cladode biomass. RESULTS Dilute acid pretreatment and enzymatic hydrolysis of sun-dried cladodes resulted in a hydrolysate containing (per litre) 45.5 g glucose, 6.3 g xylose, 9.1 g galactose, 10.8 g arabinose and 9.6 g fructose. Even though K. marxianus had a much higher growth rate and utilized l-arabinose and d-galactose more completely than C. utilis, its biomass yield coefficient was lower due to ethanol and ethyl acetate production despite aerobic cultivation. Yeast cultivation more than doubled the protein content of the hydrolysate, with an essential amino acid profile superior to sorghum and millet grains. CONCLUSIONS This K. marxianus strain was weakly Crabtree positive. Despite its low biomass yield, its performance compared well with C. utilis. This is the first report showing that the protein content and quality of O. ficus-indica cladode biomass could substantially be improved by yeast cultivation, including a comparative evaluation of C. utilis and K. marxianus. © 2014 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:25371280

  3. Characterisation of cysteine proteinases responsible for digestive proteolysis in guts of larval western corn rootworm (Diabrotica virgifera) by expression in the yeast Pichia pastoris.

    PubMed

    Bown, David P; Wilkinson, Hillary S; Jongsma, Maarten A; Gatehouse, John A

    2004-04-01

    Cysteine proteinases are the major class of enzymes responsible for digestive proteolysis in western corn rootworm (Diabrotica virgifera), a serious pest of maize. A larval gut extract hydrolysed typical cathepsin substrates, such as Z-phe-arg-AMC and Z-arg-arg-AMC, and hydrolysis was inhibited by Z-phe-tyr-DMK, specific for cathepsin L. A cDNA library representing larval gut tissue mRNA contained cysteine proteinase-encoding clones at high frequency. Sequence analysis of 11 cysteine proteinase cDNAs showed that 9 encoded cathepsin L-like enzymes, and 2 encoded cathepsin B-like enzymes. Three enzymes (two cathepsin L-like, DvRS5 and DvRS30, and one cathepsin B-like, DvRS40) were expressed as recombinant proteins in culture supernatants of the yeast Pichia pastoris. The cathepsin L-like enzymes were active proteinases, whereas the cathepsin B-like enzyme was inactive until treated with bovine trypsin. The amino acid residue in the S2 binding pocket, the major determinant of substrate specificity in cathepsin cysteine proteinases, predicted that the two cathepsin L-like enzymes, DvRS5 and DvRS30, should differ in substrate specificity, with the latter resembling cathepsin B in hydrolysing substrates with a positively charged residue at P2. This prediction was confirmed; DvRS5 only hydrolysed Z-phe-arg-AMC and not Z-arg-arg-AMC, whereas DvRS30 hydrolysed both substrates. The enzymes showed similar proteolytic activity towards peptide substrates. PMID:15041015

  4. Direct conversion of inulin and extract of tubers of Jerusalem artichoke into single cell oil by co-cultures of Rhodotorula mucilaginosa TJY15a and immobilized inulinase-producing yeast cells.

    PubMed

    Zhao, Chun-Hai; Chi, Zhe; Zhang, Fang; Guo, Feng-Jun; Li, Mei; Song, Wei-Bo; Chi, Zhen-Ming

    2011-05-01

    In this study, it was found that the immobilized inulinase-producing cells of Pichia guilliermondii M-30 could produce 169.3 U/ml of inulinase activity while the free cells of the same yeast strain only produced 124.3 U/ml of inulinase activity within 48 h. When the immobilized inulinase-producing yeast cells were co-cultivated with the free cells of Rhodotorula mucilaginosa TJY15a, R. mucilaginosa TJY15a could accumulate 53.2% oil from inulin in its cells and cell dry weight reached 12.2g/l. Under the similar conditions, R. mucilaginosa TJY15a could accumulate 55.4% (w/w) oil from the extract of Jerusalem artichoke tubers in its cells and cell dry weight reached 12.8 g/l within 48 h. When the co-cultures were grown in 2l fermentor, R. mucilaginosa TJY15a could accumulate 56.6% (w/w) oil from the extract of Jerusalem artichoke tubers in its cells and cell dry weight reached 19.6g/l within 48 h. Over 90.0% of the fatty acids from the yeast strain TJY15a grown in the extract of Jerusalem artichoke tubers was C(16:0), C(18:1) and C(18:2), especially C(18:1) (50.6%). PMID:21411313

  5. Beta-glucan-depleted, glycopeptide-rich extracts from Brewer's and Baker's yeast (Saccharomyces cerevisiae) lower interferon-gamma production by stimulated human blood cells in vitro.

    PubMed

    Williams, Roderick; Dias, Daniel A; Jayasinghe, Nirupama; Roessner, Ute; Bennett, Louise E

    2016-04-15

    Regulation of the human immune system requires controlled pro- and anti-inflammatory responses for host defence against infection and disease states. Yeasts (Saccharomyces cerevisiae), as used in brewing and baking, are mostly known for ability to stimulate the human immune-system predominantly reflecting the pro-inflammatory cell wall β-glucans. However, in this study, using food-compatible processing methods, glycopeptide-enriched and β-glucan-depleted products were each prepared from Brewer's and Baker's yeasts, which suppressed production of interferon-γ (IFN-γ) in human whole blood cell assay, signifying that anti-inflammatory factors are also present in yeast. Anti-inflammatory bioactivities of products prepared from Brewer's and Baker's yeast were compared with the commercial yeast product, Epicor®. While unfractionated Epicor was inactive, the C18 resin-binding fractions of Brewer's and Baker's yeast products and Epicor dose-dependently lowered IFN-γ, demonstrating that Epicor also contained both pro-inflammatory (β-glucans) and anti-inflammatory components. Anti-inflammatory activity was attributed to C18 resin-binding species glyco-peptides in Epicor and experimental yeast products. This study demonstrated that pro- and anti-inflammatory factors could be resolved and enriched in yeasts by suitable processing, with potential to improve specific activities. PMID:26617014

  6. A new beta-glucosidase producing yeast for lower-cost cellulosic ethanol production from xylose-extracted corncob residues by simultaneous saccharification and fermentation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conventional cellulose-to-ethanol conversion by simultaneous saccharification and fermentation (SSF)requires enzymatic saccharification using both cellulase and ß-glucosidase allowing cellulose utilization by common ethanologenic yeast. Here we report a new yeast strain of Clavispora NRRL Y-50464 th...

  7. Counting Yeast.

    ERIC Educational Resources Information Center

    Bealer, Jonathan; Welton, Briana

    1998-01-01

    Describes changes to a traditional study of population in yeast colonies. Changes to the procedures include: (1) only one culture per student team; (2) cultures are inoculated only once; and (3) the same tube is sampled daily. (DDR)

  8. Preparation and characterisation of protein hydrolysates from Indian defatted rice bran meal.

    PubMed

    Bandyopadhyay, Kakali; Misra, Gautam; Ghosh, Santinath

    2008-01-01

    Rice bran meal is a very good source of protein along with other micronutrients. Rice bran meal has been utilized to produce protein isolates and respective protein hydrolysates for potential application in various food products. De-oiled rice bran meal, available from Indian rice bran oil extraction plants, was initially screened by passing through an 80-mesh sieve (yield about 70%). A fraction (yield-30%) rich in fibre and silica was initially discarded from the meal. The protein content of the through fraction increased from 20.8% to 24.1% whereas silica content reduced from 3.1% to 0.4%. Rice bran protein isolate (RPI) was prepared by alkaline extraction followed by acidic precipitation at isoelectric point. This protein isolate was hydrolysed by papain at pH 8.0 and at 37 degrees C for 10, 20, 30, 45 and 60 minutes. The peptides produced by partial hydrolysis had been evaluated by determining protein solubility, emulsion activity index (EAI), emulsion stability index (ESI), foam capacity and foam stability (FS). All protein hydrolysates showed better functional properties than the original protein isolate. These improved functional properties of rice bran protein hydrolysates would make it useful for various application especially in food, pharmaceutical and related industries. PMID:18075222

  9. Methane production from acid hydrolysates of Agave tequilana bagasse: evaluation of hydrolysis conditions and methane yield.

    PubMed

    Arreola-Vargas, Jorge; Ojeda-Castillo, Valeria; Snell-Castro, Raúl; Corona-González, Rosa Isela; Alatriste-Mondragón, Felipe; Méndez-Acosta, Hugo O

    2015-04-01

    Evaluation of diluted acid hydrolysis for sugar extraction from cooked and uncooked Agave tequilana bagasse and feasibility of using the hydrolysates as substrate for methane production, with and without nutrient addition, in anaerobic sequencing batch reactors (AnSBR) were studied. Results showed that the hydrolysis over the cooked bagasse was more effective for sugar extraction at the studied conditions. Total sugars concentration in the cooked and uncooked bagasse hydrolysates were 27.9 g/L and 18.7 g/L, respectively. However, 5-hydroxymethylfurfural was detected in the cooked bagasse hydrolysate, and therefore, the uncooked bagasse hydrolysate was selected as substrate for methane production. Interestingly, results showed that the AnSBR operated without nutrient addition obtained a constant methane production (0.26 L CH4/g COD), whereas the AnSBR operated with nutrient addition presented a gradual methane suppression. Molecular analyses suggested that methane suppression in the experiment with nutrient addition was due to a negative effect over the archaeal/bacterial ratio. PMID:25647030

  10. Effect of proteolysis on the sialic acid content and bifidogenic activity of ovomucin hydrolysates.

    PubMed

    Sun, Xiaohong; Gänzle, Michael; Field, Catherine J; Wu, Jianping

    2016-12-01

    Ovomucin, accounting for ∼3.5% of egg white proteins, contains 2.6-7.4% of sialic acid; sialic acid is suggested to play important roles in host-recognition, cognition and memory development. However, ovomucin's limited water solubility might restrict its future applications. The objective of the study was to examine the effect of proteolysis of ovomucin on the sialic acid content and bifidogenic activity of ovomucin hydrolysates. Ovomucin extract was hydrolyzed by 14 proteases with yields and DHs ranging from 42.6% (flavourzyme) to 97.4% (protease N), and 2.4% (flavourzyme) to 46.3% (pronase), respectively. Ovomucin hydrolyzed by pronase and protex 26L showed molecular weight (Mw) distributions less than 40kDa while others larger than 200kDa. Allergenicity of ovomucin hydrolysates was significantly reduced (P<0.05) in comparison to ovomucin extract. The content of sialic acid in hydrolysates ranged from 0.1% (protex 26L) to 3.7% (pronase). Ovomucin hydrolysates did not generally support growth of Bifidobacterium spp. in vitro. PMID:27374509

  11. Oyster (Crassostrea gigas) Hydrolysates Produced on a Plant Scale Have Antitumor Activity and Immunostimulating Effects in BALB/c Mice

    PubMed Central

    Wang, Yu-Kai; He, Hai-Lun; Wang, Guo-Fan; Wu, Hao; Zhou, Bai-Cheng; Chen, Xiu-Lan; Zhang, Yu-Zhong

    2010-01-01

    Oyster extracts have been reported to have many bioactive peptides. But the function of oyster peptides produced by proteolysis is still unknown. In this study, the oligopeptide-enriched hydrolysates from oyster (Crassostrea gigas) were produced using the protease from Bacillus sp. SM98011 at laboratory level, and scaled up to pilot (100 L) and plant (1,000 L) levels with the same conditions. And the antitumor activity and immunostimulating effects of the oyster hydrolysates in BALB/c mice were investigated. The growth of transplantable sarcoma-S180 was obviously inhibited in a dose-dependent manner in BALB/c mice given the oyster hydrolysates. Mice receiving 0.25, 0.5 and 1 mg/g of body weight by oral gavage had 6.8%, 30.6% and 48% less tumor growth, respectively. Concurrently, the weight coefficients of the thymus and the spleen, the activity of natural killer (NK) cells, the spleen proliferation of lymphocytes and the phagocytic rate of macrophages in S180-bearing mice significantly increased after administration of the oyster hydrolysates. These results demonstrated that oyster hydrolysates produced strong immunostimulating effects in mice, which might result in its antitumor activity. The antitumor and immunostimulating effects of oyster hydrolysates prepared in this study reveal its potential for tumor therapy and as a dietary supplement with immunostimulatory activity. PMID:20390104

  12. Flow cytometric detection of wild yeast in lager breweries.

    PubMed

    Jespersen, L; Lassen, S; Jakobsen, M

    1993-02-01

    A flow cytometric method for detection of wild yeast infections in breweries is reported. It is based on selective enrichment in Malt extract Yeast extract Glucose Peptone broth (MYGP) at 37 degrees C and in MYGP with 200 ppm CuSO4 at 25 degrees C, staining with a fluorochrome precursor and flow cytometry. In experiments with several types of wild yeast isolated from breweries and two different strains of lager yeast it has been possible to detect one wild yeast per 10(6) culture yeast after 48-72 h of incubation and, in some cases, after 24 h. PMID:8466805

  13. Xylulokinase Overexpression in Two Strains of Saccharomyces cerevisiae Also Expressing Xylose Reductase and Xylitol Dehydrogenase and Its Effect on Fermentation of Xylose and Lignocellulosic Hydrolysate

    PubMed Central

    Johansson, Björn; Christensson, Camilla; Hobley, Timothy; Hahn-Hägerdal, Bärbel

    2001-01-01

    Fermentation of the pentose sugar xylose to ethanol in lignocellulosic biomass would make bioethanol production economically more competitive. Saccharomyces cerevisiae, an efficient ethanol producer, can utilize xylose only when expressing the heterologous genes XYL1 (xylose reductase) and XYL2 (xylitol dehydrogenase). Xylose reductase and xylitol dehydrogenase convert xylose to its isomer xylulose. The gene XKS1 encodes the xylulose-phosphorylating enzyme xylulokinase. In this study, we determined the effect of XKS1 overexpression on two different S. cerevisiae host strains, H158 and CEN.PK, also expressing XYL1 and XYL2. H158 has been previously used as a host strain for the construction of recombinant xylose-utilizing S. cerevisiae strains. CEN.PK is a new strain specifically developed to serve as a host strain for the development of metabolic engineering strategies. Fermentation was carried out in defined and complex media containing a hexose and pentose sugar mixture or a birch wood lignocellulosic hydrolysate. XKS1 overexpression increased the ethanol yield by a factor of 2 and reduced the xylitol yield by 70 to 100% and the final acetate concentrations by 50 to 100%. However, XKS1 overexpression reduced the total xylose consumption by half for CEN.PK and to as little as one-fifth for H158. Yeast extract and peptone partly restored sugar consumption in hydrolysate medium. CEN.PK consumed more xylose but produced more xylitol than H158 and thus gave lower ethanol yields on consumed xylose. The results demonstrate that strain background and modulation of XKS1 expression are important for generating an efficient xylose-fermenting recombinant strain of S. cerevisiae. PMID:11526030

  14. Electricity generation from rapeseed straw hydrolysates using microbial fuel cells.

    PubMed

    Jablonska, Milena A; Rybarczyk, Maria K; Lieder, Marek

    2016-05-01

    Rapeseed straw is an attractive fuel material for microbial fuel cells (MFCs) due to its high content of carbohydrates (more than 60% carbohydrates). This study has demonstrated that reducing sugars can be efficiently extracted from raw rapeseed straw by combination of hydrothermal pretreatment and enzymatic hydrolysis followed by utilization as a fuel in two-chamber MFCs for electrical power generation. The most efficient method of saccharification of this lignocellulosic biomass (17%) turned out hydrothermal pretreatment followed by enzymatic hydrolysis. Electricity was produced using hydrolysate concentrations up to 150mg/dm(3). The power density reached 54mW/m(2), while CEs ranged from 60% to 10%, corresponding to the initial reducing sugar concentrations of 10-150mg/dm(3). The COD degradation rates based on charge calculation increased from 0.445gCOD/m(2)/d for the hydrolysate obtained with the microwave treatment to 0.602gCOD/m(2)/d for the most efficient combination of hydrothermal treatment followed by enzymatic hydrolysis. PMID:26930033

  15. Identification of oleaginous yeast strains able to accumulate high intracellular lipids when cultivated in alkaline pretreated corn stover

    PubMed Central

    Sitepu, Irnayuli R.; Jin, Mingjie; Fernandez, J. Enrique; da Costa Sousa, Leonardo; Balan, Venkatesh; Boundy-Mills, Kyria L.

    2015-01-01

    Microbial oil is a potential alternative to food/plant-derived biodiesel fuel. Our previous screening studies identified a wide range of oleaginous yeast species, using a defined laboratory medium known to stimulate lipid accumulation. In this study, the ability of these yeasts to grow and accumulate lipids was further investigated in synthetic hydrolysate (SynH) and authentic ammonia fiber expansion (AFEX™)-pretreated corn stover hydrolysate (ACSH). Most yeast strains tested were able to accumulate lipids in SynH, but only a few were able to grow and accumulate lipids in ACSH medium. Cryptococcus humicola UCDFST 10-1004 was able to accumulate as high as 15.5 g/L lipids, out of a total of 36 g/L cellular biomass when grown in ACSH, with a cellular lipid content of 40% of cell dry weight. This lipid production is among the highest reported values for oleaginous yeasts grown in authentic hydrolysate. Pre-culturing in SynH media with xylose as sole carbon source enabled yeasts to assimilate both glucose and xylose more efficiently in the subsequent hydrolysate medium. This study demonstrates that ACSH is a suitable medium for certain oleaginous yeasts to convert lignocellullosic sugars to triacylglycerols for production of biodiesel and other valuable oleochemicals. PMID:25052467

  16. Yeast Droplets

    NASA Astrophysics Data System (ADS)

    Nguyen, Baochi; Upadhyaya, Arpita; van Oudenaarden, Alexander; Brenner, Michael

    2002-11-01

    It is well known that the Young's law and surface tension govern the shape of liquid droplets on solid surfaces. Here we address through experiments and theory the shape of growing aggregates of yeast on agar substrates, and assess whether these ideas still hold. Experiments are carried out on Baker's yeast, with different levels of expressions of an adhesive protein governing cell-cell and cell-substrate adhesion. Changing either the agar concentration or the expression of this protein modifies the local contact angle of a yeast droplet. When the colony is small, the shape is a spherical cap with the contact angle obeying Young's law. However, above a critical volume this structure is unstable, and the droplet becomes nonspherical. We present a theoretical model where this instability is caused by bulk elastic effects. The model predicts that the transition depends on both volume and contact angle, in a manner quantitatively consistent with our experiments.

  17. Physicochemical and bitterness properties of enzymatic pea protein hydrolysates.

    PubMed

    Humiski, L M; Aluko, R E

    2007-10-01

    The effects of different proteolytic treatments on the physiochemical and bitterness properties of pea protein hydrolysates were investigated. A commercial pea protein isolate was digested using each of 5 different proteases to produce protein hydrolysates with varying properties. After 4 h of enzyme digestion, samples were clarified by centrifugation followed by desalting of the supernatant with a 1000 Da membrane; the retentates were then freeze-dried. Alcalase and Flavourzymetrade mark produced protein hydrolysates with significantly higher (P < 0.05) degree of hydrolysis when compared to the other proteases. Flavourzyme, papain, and alcalase produced hydrolysates that contained the highest levels of aromatic amino acids, while trypsin hydrolysate had the highest levels of lysine and arginine. Papain hydrolysate contained high molecular weight peptides (10 to 178 kDa) while hydrolysates from the other 4 proteases contained predominantly low molecular weight peptides (hydrolysate was significantly (P < 0.05) the highest while alcalase and trypsin hydrolysates were the lowest. Inhibition of angiotensin converting enzyme (ACE) activity was significantly higher (P < 0.05) for papain hydrolysate while Flavourzyme hydrolysate had the least inhibitory activity. Sensory analysis showed that the alcalase hydrolysate was the most bitter while papain and alpha-chymotrypsin hydrolysates were the least. Among the 5 enzymes used in this study, papain and alpha-chymotrypsin appear to be the most desirable for producing high quality pea protein hydrolysates because of the low bitterness scores combined with a high level of angiotensin converting enzyme inhibition and moderate free radical scavenging activity. PMID:17995627

  18. Oil Production from Yarrowia lipolytica Po1g Using Rice Bran Hydrolysate

    PubMed Central

    Tsigie, Yeshitila Asteraye; Wang, Chun-Yuan; Kasim, Novy S.; Diem, Quy-Do; Huynh, Lien-Huong; Ho, Quoc-Phong; Truong, Chi-Thanh; Ju, Yi-Hsu

    2012-01-01

    The purpose of this study was to produce microbial oil from Yarrowia lipolytica Po1g grown in defatted rice bran hydrolysate. After removing oil from rice bran by Soxhlet extraction, the bran is subjected to acid hydrolysis with various sulfuric acid concentrations (1–4% v/v), reaction times (1–8 h), and reaction temperatures (60–120°C). The optimal conditions for maximum total sugar production from the hydrolysate were found to be 3% sulfuric acid at 90°C for 6 h. Glucose was the predominant sugar (43.20 ± 0.28 g/L) followed by xylose (4.93 ± 0.03 g/L) and arabinose (2.09 ± 0.01 g/L). The hydrolysate was subsequently detoxified by neutralization to reduce the amount of inhibitors such as 5-hydroxymethylfurfural (HMF) and furfural to increase its potential as a medium for culturing Y. lipolytica Po1g. Dry cell mass and lipid content of Y. lipolytica Po1g grown in detoxified defatted rice bran hydrolysate (DRBH) under optimum conditions were 10.75 g/L and 48.02%, respectively. PMID:22496604

  19. Effect of hydrolysable tannins on intestinal morphology, proliferation and apoptosis in entire male pigs.

    PubMed

    Bilić-Šobot, Diana; Kubale, Valentina; Škrlep, Martin; Čandek-Potokar, Marjeta; Prevolnik Povše, Maja; Fazarinc, Gregor; Škorjanc, Dejan

    2016-10-01

    This study aimed to evaluate the effect of hydrolysable tannin supplementation on morphology, cell proliferation and apoptosis in the intestine and liver of fattening boars. A total of 24 boars (Landrace × Large white) were assigned to four treatment groups: Control (fed commercial feed mixture) and three experimental groups fed the same diet supplemented with 1%, 2% and 3% of hydrolysable tannin-rich extract. Animals were housed individually with ad libitum access to feed and then slaughtered at 193 d of age and 122 ± 10 kg body weight. Diets supplemented with hydrolysable tannin affected the morphometric traits of the duodenum mucosa as reflected in increased villus height, villus perimeter and mucosal thickness. No effect was observed on other parts of the small intestine. In the large intestine, tannin supplementation reduced mitosis (in the caecum and descending colon) and apoptosis (in the caecum, ascending and descending colon). No detrimental effect of tannin supplementation on liver tissue was observed. The present findings suggest that supplementing boars with hydrolysable tannins at concentrations tested in this experiment has no unfavourable effects on intestinal morphology. On the contrary, it may alter cell debris production in the large intestine and thus reduce intestinal skatole production. PMID:27434497

  20. Oil production from Yarrowia lipolytica Po1g using rice bran hydrolysate.

    PubMed

    Tsigie, Yeshitila Asteraye; Wang, Chun-Yuan; Kasim, Novy S; Diem, Quy-Do; Huynh, Lien-Huong; Ho, Quoc-Phong; Truong, Chi-Thanh; Ju, Yi-Hsu

    2012-01-01

    The purpose of this study was to produce microbial oil from Yarrowia lipolytica Po1g grown in defatted rice bran hydrolysate. After removing oil from rice bran by Soxhlet extraction, the bran is subjected to acid hydrolysis with various sulfuric acid concentrations (1-4% v/v), reaction times (1-8 h), and reaction temperatures (60-120°C). The optimal conditions for maximum total sugar production from the hydrolysate were found to be 3% sulfuric acid at 90°C for 6 h. Glucose was the predominant sugar (43.20 ± 0.28 g/L) followed by xylose (4.93 ± 0.03 g/L) and arabinose (2.09 ± 0.01 g/L). The hydrolysate was subsequently detoxified by neutralization to reduce the amount of inhibitors such as 5-hydroxymethylfurfural (HMF) and furfural to increase its potential as a medium for culturing Y. lipolytica Po1g. Dry cell mass and lipid content of Y. lipolytica Po1g grown in detoxified defatted rice bran hydrolysate (DRBH) under optimum conditions were 10.75 g/L and 48.02%, respectively. PMID:22496604

  1. Evaluation of cotton stalk hydrolysate for xylitol production.

    PubMed

    Sapcı, Burcu; Akpinar, Ozlem; Bolukbasi, Ufuk; Yilmaz, Levent

    2016-07-01

    Cotton stalk is a widely distributed and abundant lignocellulosic waste found in Turkey. Because of its rich xylose content, it can be a promising source for the production of xylitol. Xylitol can be produced by chemical or biotechnological methods. Because the biotechnological method is a simple process with great substrate specificity and low energy requirements, it is more of an economic alternative for the xylitol production. This study aimed to use cotton stalk for the production of xylitol with Candida tropicalis Kuen 1022. For this purpose, the combined effects of different oxygen concentration, inoculum level and substrate concentration were investigated to obtain high xylitol yield and volumetric xylitol production rate. Candida tropicalis Kuen 1022 afforded different concentrations of xylitol depending on xylose concentration, inoculum level, and oxygen concentration. The optimum xylose, yeast concentration, and airflow rate for cotton stalk hydrolysate were found as 10.41 g L(-1), 0.99 g L(-1), and 1.02 vvm, respectively, and under these conditions, xylitol yield and volumetric xylitol production rate were obtained as 36% and 0.06 g L(-1) hr(-1), respectively. The results of this study show that cotton stalk can serve as a potential renewable source for the production of xylitol. PMID:26444685

  2. Quantification of astaxanthin in shrimp waste hydrolysate by HPLC.

    PubMed

    López-Cervantes, J; Sánchez-Machado, D I; Gutiérrez-Coronado, M A; Ríos-Vázquez, N J

    2006-10-01

    In the present study, a simple and rapid reversed-phase HPLC method for the determination of astaxanthin in shrimp waste hydrolysate has been developed and validated. The analytical procedure involves the direct extraction of astaxanthin from the lipid fraction with methanol. The analytical column, SS Exil ODS, was operated at 25C. The mobile phase consisted of a mixture of water:methanol:dichloromethane:acetonitrile (4.5:28:22:45.5 v/v/v/v) at a flow rate of 1.0 mL/min. Detection and identification were performed using a photodiode array detector (lambda(detection) = 476 nm). The proposed HPLC method showed adequate linearity, repeatability and accuracy. PMID:16802328

  3. Hot water extraction and steam explosion as pretreatments for ethanol production from spruce bark.

    PubMed

    Kemppainen, Katariina; Inkinen, Jenni; Uusitalo, Jaana; Nakari-Setälä, Tiina; Siika-aho, Matti

    2012-08-01

    Spruce bark is a source of interesting polyphenolic compounds and also a potential but little studied feedstock for sugar route biorefinery processes. Enzymatic hydrolysis and fermentation of spruce bark sugars to ethanol were studied after three different pretreatments: steam explosion (SE), hot water extraction (HWE) at 80 °C, and sequential hot water extraction and steam explosion (HWE+SE), and the recovery of different components was determined during the pretreatments. The best steam explosion conditions were 5 min at 190 °C without acid catalyst based on the efficiency of enzymatic hydrolysis of the material. However, when pectinase was included in the enzyme mixture, the hydrolysis rate and yield of HWE bark was as good as that of SE and HWE+SE barks. Ethanol was produced efficiently with the yeast Saccharomyces cerevisiae from the pretreated and hydrolysed materials suggesting the suitability of spruce bark to various lignocellulosic ethanol process concepts. PMID:22613888

  4. Role of glucose signaling in yeast metabolism

    SciTech Connect

    Dam, K. van

    1996-10-05

    The conversion of glucose to ethanol and carbon dioxide by yeast was the first biochemical pathway to be studied in detail. The initial observation that this process is catalyzed by an extract of yeast led to the discovery of enzymes and coenzymes and laid the foundation for modern biochemistry. In this article, knowledge concerning the relation between uptake of and signaling by glucose in the yeast Saccharomyces cerevisiae is reviewed and compared to the analogous process in prokaryotes. It is concluded that (much) more fundamental knowledge concerning these processes is required before rational redesign of metabolic fluxes from glucose in yeast can be achieved.

  5. Co-utilization of corn stover hydrolysates and biodiesel-derived glycerol by Cryptococcus curvatus for lipid production.

    PubMed

    Gong, Zhiwei; Zhou, Wenting; Shen, Hongwei; Zhao, Zongbao K; Yang, Zhonghua; Yan, Jiabao; Zhao, Mi

    2016-11-01

    In the present study, synergistic effects were observed when glycerol was co-fermented with glucose and xylose for lipid production by the oleaginous yeast Cryptococcus curvatus. Glycerol was assimilated simultaneously with sugars at the beginning of the culture without adaption time. Furthermore, better lipid production results, i.e., lipid yield and lipid productivity of 18.0g/100g and 0.13g/L/h, respectively, were achieved when cells were cultured in blends of corn stover hydrolysates and biodiesel-derived glycerol than those in the hydrolysates alone. The lipid samples had fatty acid compositional profiles similar to those of vegetable oils, suggesting their potential for biodiesel production. This co-utilization strategy provides an extremely simple solution to advance lipid production from both lignocelluloses and biodiesel-derived glycerol in one step. PMID:27529520

  6. Genome-wide screening of Saccharomyces cerevisiae genes required to foster tolerance towards industrial wheat straw hydrolysates.

    PubMed

    Pereira, Francisco B; Teixeira, Miguel C; Mira, Nuno P; Sá-Correia, Isabel; Domingues, Lucília

    2014-12-01

    The presence of toxic compounds derived from biomass pre-treatment in fermentation media represents an important drawback in second-generation bio-ethanol production technology and overcoming this inhibitory effect is one of the fundamental challenges to its industrial production. The aim of this study was to systematically identify, in industrial medium and at a genomic scale, the Saccharomyces cerevisiae genes required for simultaneous and maximal tolerance to key inhibitors of lignocellulosic fermentations. Based on the screening of EUROSCARF haploid mutant collection, 242 and 216 determinants of tolerance to inhibitory compounds present in industrial wheat straw hydrolysate (WSH) and in inhibitor-supplemented synthetic hydrolysate were identified, respectively. Genes associated to vitamin metabolism, mitochondrial and peroxisomal functions, ribosome biogenesis and microtubule biogenesis and dynamics are among the newly found determinants of WSH resistance. Moreover, PRS3, VMA8, ERG2, RAV1 and RPB4 were confirmed as key genes on yeast tolerance and fermentation of industrial WSH. PMID:25287021

  7. Economical production of poly(ε-l-lysine) and poly(l-diaminopropionic acid) using cane molasses and hydrolysate of streptomyces cells by Streptomyces albulus PD-1.

    PubMed

    Xia, Jun; Xu, Zhaoxian; Xu, Hong; Liang, Jinfeng; Li, Sha; Feng, Xiaohai

    2014-07-01

    Poly(ε-L-lysine) (ε-PL) and poly(L-diaminopropionic acid) (PDAP) co-production by Streptomyces albulus PD-1 from cane molasses and hydrolysate of strepyomyces cells (HSC) was investigated for the first time in this study. The optimal initial total sugar concentration of the cane molasses pretreated with sulfuric acid was determined to be 20 g L(-1), and HSC could substitute for yeast extract for ε-PL and PDAP co-production. When fed-batch fermentation was performed in 1t fermentor with pretreated cane molasses and HSC, 20.6 ± 0.5 g L(-1) of ε-PL and 5.2 ± 0.6 g L(-1) of PDAP were obtained. The amount of strepyomyces cells obtained in one fed-batch fermentation is sufficient to prepare the HSC to satisfy the demand of subsequent fermentations, thus the self-cycling of organic nitrogen source becomes available. These results suggest that the low-cost cane molasses and HSC can be used for the economical production of ε-PL and PDAP by S. albulus PD-1. PMID:24861999

  8. Iron-Binding Capacity of Defatted Rice Bran Hydrolysate and Bioavailability of Iron in Caco-2 Cells.

    PubMed

    Foong, Lian-Chee; Imam, Mustapha Umar; Ismail, Maznah

    2015-10-21

    The present study was aimed at utilizing defatted rice bran (DRB) protein as an iron-binding peptide to enhance iron uptake in humans. DRB samples were treated with Alcalase and Flavourzyme, and the total extractable peptides were determined. Furthermore, the iron-binding capacities of the DRB protein hydrolysates were determined, whereas iron bioavailability studies were conducted using an in vitro digestion and absorption model (Caco-2 cells). The results showed that the DRB protein hydrolysates produced by combined Alcalase and Flavourzyme hydrolysis had the best iron-binding capacity (83%) after 90 min of hydrolysis. The optimal hydrolysis time to produce the best iron-uptake in Caco-2 cells was found to be 180 min. The results suggested that DRB protein hydrolysates have potent iron-binding capacities and may enhance the bioavailability of iron, hence their suitability for use as iron-fortified supplements. PMID:26435326

  9. Comparative Composition and Antioxidant Activity of Peptide Fractions Obtained by Ultrafiltration of Egg Yolk Protein Enzymatic Hydrolysates

    PubMed Central

    Chay Pak Ting, Bertrand P.; Mine, Yoshinori; Juneja, Lekh R.; Okubo, Tsutomu; Gauthier, Sylvie F.; Pouliot, Yves

    2011-01-01

    The objective of the study was to compare the antioxidant activity of two distinct hydrolysates and their peptide fractions prepared by ultrafiltration (UF) using membranes with molecular weight cut-off of 5 and 1 kDa. The hydrolysates were a delipidated egg yolk protein concentrate (EYP) intensively hydrolyzed with a combination of two bacterial proteases, and a phosphoproteins (PPP) extract partially hydrolyzed with trypsin. Antioxidant activity, as determined by the oxygen radical absorbance capacity (ORAC) assay, was low for EYP and PPP hydrolysates with values of 613.1 and 489.2 μM TE·g−1 protein, respectively. UF-fractionation of EYP hydrolysate increased slightly the antioxidant activity in permeate fractions (720.5–867.8 μM TE·g−1 protein). However, ORAC values were increased by more than 3-fold in UF-fractions prepared from PPP hydrolysate, which were enriched in peptides with molecular weight lower than 5 kDa. These UF-fractions were characterized by their lower N/P atomic ratio and higher phosphorus content compared to the same UF-fractions obtained from EYP-TH. They also contained high amounts of His, Met, Leu, and Phe, which are recognized as antioxidant amino acids, but also high content in Lys and Arg which both represent target amino acids of trypsin used for the hydrolysis of PPP. PMID:24957729

  10. Detoxification of lignocellulosic hydrolysates using sodium borohydride.

    PubMed

    Cavka, Adnan; Jönsson, Leif J

    2013-05-01

    Addition of sodium borohydride to a lignocellulose hydrolysate of Norway spruce affected the fermentability when cellulosic ethanol was produced using Saccharomyces cerevisiae. Treatment of the hydrolysate with borohydride improved the ethanol yield on consumed sugar from 0.09 to 0.31 g/g, the balanced ethanol yield from 0.02 to 0.30 g/g, and the ethanol productivity from 0.05 to 0.57 g/(L×h). Treatment of a sugarcane bagasse hydrolysate gave similar results, and the experiments indicate that sodium borohydride is suitable for chemical in situ detoxification. The model inhibitors coniferyl aldehyde, p-benzoquinone, 2,6-dimethoxybenzoquinone, and furfural were efficiently reduced by treatment with sodium borohydride, even under mild reaction conditions (20 °C and pH 6.0). While addition of sodium dithionite to pretreatment liquid from spruce improved enzymatic hydrolysis of cellulose, addition of sodium borohydride did not. This result indicates that the strong hydrophilicity resulting from sulfonation of inhibitors by dithionite treatment was particularly important for alleviating enzyme inhibition. PMID:23567704