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Isak S. Pretorius - One of the best experts on this subject based on the ideXlab platform.

  • Expression of 2 Lipomyces kononenkoaeα‐Amylase Genes in Selected Whisky Yeast Strains
    Journal of Food Science, 2006
    Co-Authors: K. La Grange-nel, R.r. Cordero Otero, P. Van Rensburg, Annél Smit, Marius G. Lambrechts, Q. Willemse, Isak S. Pretorius
    Abstract:

    : Nineteen whisky yeasts were evaluated according to their fermentation performance and ability to produce a palatable spirit. Four of these strains were selected and, together with a commercial wine yeast strain (control), were transformed with integration plasmids containing the LKA1 and LKA2 α-amylase genes from the yeast Lipomyces kononenkoae. Fermentation trials with starch-containing media indicated that the transformants produced between 47% and 66% of the theoretical ethanol yield. This study has resulted in progress toward the development of whisky yeast that could ultimately be used in a process during which production of amylases, hydrolysis of starch, and fermentation of resulting sugars to grain whisky occur in a single step.

  • expression of 2 Lipomyces kononenkoaeα amylase genes in selected whisky yeast strains
    Journal of Food Science, 2006
    Co-Authors: K La Grangenel, P. Van Rensburg, Isak S. Pretorius, Annél Smit, Marius G. Lambrechts, Q. Willemse, R Cordero R Otero
    Abstract:

    : Nineteen whisky yeasts were evaluated according to their fermentation performance and ability to produce a palatable spirit. Four of these strains were selected and, together with a commercial wine yeast strain (control), were transformed with integration plasmids containing the LKA1 and LKA2 α-amylase genes from the yeast Lipomyces kononenkoae. Fermentation trials with starch-containing media indicated that the transformants produced between 47% and 66% of the theoretical ethanol yield. This study has resulted in progress toward the development of whisky yeast that could ultimately be used in a process during which production of amylases, hydrolysis of starch, and fermentation of resulting sugars to grain whisky occur in a single step.

  • Amylolytic enzymes from the yeast Lipomyces kononenkoae
    2005
    Co-Authors: Nivetha Ramachandran, Isak S. Pretorius, Ricardo R. Cordero Otero
    Abstract:

    The Lipomyces kononenkoae α-amylases LKA1 and LKA2 belong to the glycoside hydrolase family 13 and exhibit specificity towards α-1,4 and α-1,6 linkages in starch and related substrates. LKA1 exhibits specificity towards α- 1,4 and α-1,6 linkages and large amounts of reducing sugars are liberated from highly branched amylopectin and glycogen and linear amylose. LKA2, on the other hand, shows high reactivity towards lintner starch, dextrin and amylase, although only small amounts of reducing sugars are liberated from branched substrates, such as amylopectin and glycogen. These enzymes share the four conserved segments of the catalytic domain found in other members of the family, but have some major variant amino acids within these segments. In addition, LKA1 consists of an N-terminal starch-binding domain (SBD). This is the only α-amylase known to possess this N-terminal domain and it exhibits homology to the N-terminal SBD of Rhizopus oryzae glucoamylase. It shares no homology with the C-terminal starch-binding domains present in the cyclodextrin glucanotransferases, glucoamylases or α-amylases. The evolutionary tree based on the sequence alignment of SBDs reveals that the N-terminal SBDs are separated from the C-terminal SBDs.

  • Different genetic backgrounds influence the secretory expression of the LKA1-encoded Lipomyces kononenkoae α-amylase in industrial strains of Saccharomyces cerevisiae
    Biotechnology Letters, 2002
    Co-Authors: S. B. Gundllapalli. Moses, R.r. Cordero Otero, D. C. La Grange, P. Van Rensburg, Isak S. Pretorius
    Abstract:

    A haploid laboratory strain and four industrial (baking, brewing, wine, ATCC) strains of Saccharomyces cerevisiae were transformed with the Lipomyces kononenkoae α-amylase-encoding gene (LKA1). These transformants displayed significant differences in terms of the level of secretory expression of LKA1 under control of the PGK1 promoter and terminator, as well as their ability to produce and secrete the LKA1-encoded rawstarch-degrading α-amylase and to ferment starch. These results demonstrate the importance of the selection of appropriate host strains for yeast development pursuant to starch conversion into commercially important commodities via consolidated bioprocessing.

Ulrika Rova - One of the best experts on this subject based on the ideXlab platform.

  • single cell oil producing yeasts Lipomyces starkeyi and rhodosporidium toruloides selection of extraction strategies and biodiesel property prediction
    Energies, 2015
    Co-Authors: Nemailla Bonturi, Leonidas Matsakas, Robert Nilsson, Paul Christakopoulos, Everson Alves Miranda, Kris A Berglund, Ulrika Rova
    Abstract:

    Abstract: Single cell oils (SCOs) are considered potential raw material for the production of biodiesel. Rhodosporidium sp. and Lipomyces sp. are good candidates for SCO production. Lipid extractability differs according to yeast species and literature on the most suitable method for each oleaginous yeast species is scarce. This work aimed to investigate the efficiency of the most cited strategies for extracting lipids from intact and pretreated cells of Rhodosporidium toruloides and Lipomyces starkeyi . Lipid extractions were conducted using hexane or combinations of chloroform and methanol. The Folch method resulted in the highest lipid yields for both yeasts (42% for R. toruloides and 48% for L. starkeyi ). Also, this method eliminates the cell pretreatment step. The Bligh and Dyer method underestimated the lipid content in the tested strains (25% for R. toruloides and 34% for L. starkeyi ). Lipid extractability increased after acid pretreatment for the Pedersen, hexane, and Bligh and Dyer methods. For

  • Single Cell Oil Producing Yeasts Lipomyces starkeyi and Rhodosporidium toruloides : Selection of Extraction Strategies and Biodiesel Property Prediction
    Energies, 2015
    Co-Authors: Nemailla Bonturi, Leonidas Matsakas, Robert Nilsson, Paul Christakopoulos, Everson Alves Miranda, Kris A Berglund, Ulrika Rova
    Abstract:

    Single cell oils (SCOs) are considered potential raw material for the production of biodiesel. Rhodosporidium sp. and Lipomyces sp. are good candidates for SCO production. Lipid extractability differs according to yeast species and literature on the most suitable method for each oleaginous yeast species is scarce. This work aimed to investigate the efficiency of the most cited strategies for extracting lipids from intact and pretreated cells of Rhodosporidium toruloides and Lipomyces starkeyi . Lipid extractions were conducted using hexane or combinations of chloroform and methanol. The Folch method resulted in the highest lipid yields for both yeasts (42% for R. toruloides and 48% for L. starkeyi ). Also, this method eliminates the cell pretreatment step. The Bligh and Dyer method underestimated the lipid content in the tested strains (25% for R. toruloides and 34% for L. starkeyi ). Lipid extractability increased after acid pretreatment for the Pedersen, hexane, and Bligh and Dyer methods. For R. toruloides unexpected fatty acid methyl esters (FAME) composition were found for some lipid extraction strategies tested. Therefore, this work provides useful information for analytical and process development aiming at biodiesel production from the SCO of these two yeast species.

Nemailla Bonturi - One of the best experts on this subject based on the ideXlab platform.

  • single cell oil producing yeasts Lipomyces starkeyi and rhodosporidium toruloides selection of extraction strategies and biodiesel property prediction
    Energies, 2015
    Co-Authors: Nemailla Bonturi, Leonidas Matsakas, Robert Nilsson, Paul Christakopoulos, Everson Alves Miranda, Kris A Berglund, Ulrika Rova
    Abstract:

    Abstract: Single cell oils (SCOs) are considered potential raw material for the production of biodiesel. Rhodosporidium sp. and Lipomyces sp. are good candidates for SCO production. Lipid extractability differs according to yeast species and literature on the most suitable method for each oleaginous yeast species is scarce. This work aimed to investigate the efficiency of the most cited strategies for extracting lipids from intact and pretreated cells of Rhodosporidium toruloides and Lipomyces starkeyi . Lipid extractions were conducted using hexane or combinations of chloroform and methanol. The Folch method resulted in the highest lipid yields for both yeasts (42% for R. toruloides and 48% for L. starkeyi ). Also, this method eliminates the cell pretreatment step. The Bligh and Dyer method underestimated the lipid content in the tested strains (25% for R. toruloides and 34% for L. starkeyi ). Lipid extractability increased after acid pretreatment for the Pedersen, hexane, and Bligh and Dyer methods. For

  • Single Cell Oil Producing Yeasts Lipomyces starkeyi and Rhodosporidium toruloides : Selection of Extraction Strategies and Biodiesel Property Prediction
    Energies, 2015
    Co-Authors: Nemailla Bonturi, Leonidas Matsakas, Robert Nilsson, Paul Christakopoulos, Everson Alves Miranda, Kris A Berglund, Ulrika Rova
    Abstract:

    Single cell oils (SCOs) are considered potential raw material for the production of biodiesel. Rhodosporidium sp. and Lipomyces sp. are good candidates for SCO production. Lipid extractability differs according to yeast species and literature on the most suitable method for each oleaginous yeast species is scarce. This work aimed to investigate the efficiency of the most cited strategies for extracting lipids from intact and pretreated cells of Rhodosporidium toruloides and Lipomyces starkeyi . Lipid extractions were conducted using hexane or combinations of chloroform and methanol. The Folch method resulted in the highest lipid yields for both yeasts (42% for R. toruloides and 48% for L. starkeyi ). Also, this method eliminates the cell pretreatment step. The Bligh and Dyer method underestimated the lipid content in the tested strains (25% for R. toruloides and 34% for L. starkeyi ). Lipid extractability increased after acid pretreatment for the Pedersen, hexane, and Bligh and Dyer methods. For R. toruloides unexpected fatty acid methyl esters (FAME) composition were found for some lipid extraction strategies tested. Therefore, this work provides useful information for analytical and process development aiming at biodiesel production from the SCO of these two yeast species.

Everson Alves Miranda - One of the best experts on this subject based on the ideXlab platform.

  • single cell oil producing yeasts Lipomyces starkeyi and rhodosporidium toruloides selection of extraction strategies and biodiesel property prediction
    Energies, 2015
    Co-Authors: Nemailla Bonturi, Leonidas Matsakas, Robert Nilsson, Paul Christakopoulos, Everson Alves Miranda, Kris A Berglund, Ulrika Rova
    Abstract:

    Abstract: Single cell oils (SCOs) are considered potential raw material for the production of biodiesel. Rhodosporidium sp. and Lipomyces sp. are good candidates for SCO production. Lipid extractability differs according to yeast species and literature on the most suitable method for each oleaginous yeast species is scarce. This work aimed to investigate the efficiency of the most cited strategies for extracting lipids from intact and pretreated cells of Rhodosporidium toruloides and Lipomyces starkeyi . Lipid extractions were conducted using hexane or combinations of chloroform and methanol. The Folch method resulted in the highest lipid yields for both yeasts (42% for R. toruloides and 48% for L. starkeyi ). Also, this method eliminates the cell pretreatment step. The Bligh and Dyer method underestimated the lipid content in the tested strains (25% for R. toruloides and 34% for L. starkeyi ). Lipid extractability increased after acid pretreatment for the Pedersen, hexane, and Bligh and Dyer methods. For

  • Single Cell Oil Producing Yeasts Lipomyces starkeyi and Rhodosporidium toruloides : Selection of Extraction Strategies and Biodiesel Property Prediction
    Energies, 2015
    Co-Authors: Nemailla Bonturi, Leonidas Matsakas, Robert Nilsson, Paul Christakopoulos, Everson Alves Miranda, Kris A Berglund, Ulrika Rova
    Abstract:

    Single cell oils (SCOs) are considered potential raw material for the production of biodiesel. Rhodosporidium sp. and Lipomyces sp. are good candidates for SCO production. Lipid extractability differs according to yeast species and literature on the most suitable method for each oleaginous yeast species is scarce. This work aimed to investigate the efficiency of the most cited strategies for extracting lipids from intact and pretreated cells of Rhodosporidium toruloides and Lipomyces starkeyi . Lipid extractions were conducted using hexane or combinations of chloroform and methanol. The Folch method resulted in the highest lipid yields for both yeasts (42% for R. toruloides and 48% for L. starkeyi ). Also, this method eliminates the cell pretreatment step. The Bligh and Dyer method underestimated the lipid content in the tested strains (25% for R. toruloides and 34% for L. starkeyi ). Lipid extractability increased after acid pretreatment for the Pedersen, hexane, and Bligh and Dyer methods. For R. toruloides unexpected fatty acid methyl esters (FAME) composition were found for some lipid extraction strategies tested. Therefore, this work provides useful information for analytical and process development aiming at biodiesel production from the SCO of these two yeast species.

Paul Christakopoulos - One of the best experts on this subject based on the ideXlab platform.

  • single cell oil producing yeasts Lipomyces starkeyi and rhodosporidium toruloides selection of extraction strategies and biodiesel property prediction
    Energies, 2015
    Co-Authors: Nemailla Bonturi, Leonidas Matsakas, Robert Nilsson, Paul Christakopoulos, Everson Alves Miranda, Kris A Berglund, Ulrika Rova
    Abstract:

    Abstract: Single cell oils (SCOs) are considered potential raw material for the production of biodiesel. Rhodosporidium sp. and Lipomyces sp. are good candidates for SCO production. Lipid extractability differs according to yeast species and literature on the most suitable method for each oleaginous yeast species is scarce. This work aimed to investigate the efficiency of the most cited strategies for extracting lipids from intact and pretreated cells of Rhodosporidium toruloides and Lipomyces starkeyi . Lipid extractions were conducted using hexane or combinations of chloroform and methanol. The Folch method resulted in the highest lipid yields for both yeasts (42% for R. toruloides and 48% for L. starkeyi ). Also, this method eliminates the cell pretreatment step. The Bligh and Dyer method underestimated the lipid content in the tested strains (25% for R. toruloides and 34% for L. starkeyi ). Lipid extractability increased after acid pretreatment for the Pedersen, hexane, and Bligh and Dyer methods. For

  • Single Cell Oil Producing Yeasts Lipomyces starkeyi and Rhodosporidium toruloides : Selection of Extraction Strategies and Biodiesel Property Prediction
    Energies, 2015
    Co-Authors: Nemailla Bonturi, Leonidas Matsakas, Robert Nilsson, Paul Christakopoulos, Everson Alves Miranda, Kris A Berglund, Ulrika Rova
    Abstract:

    Single cell oils (SCOs) are considered potential raw material for the production of biodiesel. Rhodosporidium sp. and Lipomyces sp. are good candidates for SCO production. Lipid extractability differs according to yeast species and literature on the most suitable method for each oleaginous yeast species is scarce. This work aimed to investigate the efficiency of the most cited strategies for extracting lipids from intact and pretreated cells of Rhodosporidium toruloides and Lipomyces starkeyi . Lipid extractions were conducted using hexane or combinations of chloroform and methanol. The Folch method resulted in the highest lipid yields for both yeasts (42% for R. toruloides and 48% for L. starkeyi ). Also, this method eliminates the cell pretreatment step. The Bligh and Dyer method underestimated the lipid content in the tested strains (25% for R. toruloides and 34% for L. starkeyi ). Lipid extractability increased after acid pretreatment for the Pedersen, hexane, and Bligh and Dyer methods. For R. toruloides unexpected fatty acid methyl esters (FAME) composition were found for some lipid extraction strategies tested. Therefore, this work provides useful information for analytical and process development aiming at biodiesel production from the SCO of these two yeast species.