1887

Abstract

The ability of () to grow on lactose strongly depends on the formation of an extracellular glycoside hydrolase (GH) family 35 -galactosidase, encoded by the gene. Previous studies, using batch or transfer cultures of pregrown cells, had shown that is induced by lactose and -galactose, but to a lesser extent by galactitol. To test whether the induction level is influenced by the different growth rates attainable on these carbon sources, expression was compared in carbon-limited chemostat cultivations at defined dilution (=specific growth) rates. The data showed that expression by lactose, -galactose and galactitol positively correlated with the dilution rate, and that galactitol and -galactose induced the highest activities of -galactosidase at comparable growth rates. To know more about the actual inducer for -galactosidase formation, its expression in strains impaired in the first steps of the two -galactose-degrading pathways was compared. Induction by -galactose and galactitol was still found in strains deleted in the galactokinase-encoding gene , which is responsible for the first step of the Leloir pathway of -galactose catabolism. However, in a strain deleted in the aldose/-xylose reductase gene , which performs the reduction of -galactose to galactitol in a recently identified second pathway, induction by -galactose, but not by galactitol, was impaired. On the other hand, induction by -galactose and galactitol was not affected in an -arabinitol 4-dehydrogenase ()-deleted strain which is impaired in the subsequent step of galactitol degradation. These results indicate that galactitol is the actual inducer of Bga1 formation during growth on -galactose in .

Loading

Article metrics loading...

/content/journal/micro/10.1099/mic.0.2006/001602-0
2007-02-01
2020-07-09
Loading full text...

Full text loading...

/deliver/fulltext/micro/153/2/507.html?itemId=/content/journal/micro/10.1099/mic.0.2006/001602-0&mimeType=html&fmt=ahah

References

  1. Boon M. A., Janssen A. E., van't Riet K.. 2000; Effect of temperature and enzyme origin on the enzymatic synthesis of oligosaccharides. Enzyme Microb Technol26:271–281[CrossRef]
    [Google Scholar]
  2. Cardinali G., Vollenbroich V., Jeon M. S., Hollenberg C. P., de Graaf A. A.. 1997; Constitutive expression in gal7 mutants of Kluyveromyces lactis is due to internal production of galactose as an inducer of the Gal/Lac regulon. Mol Cell Biol17:1722–1730
    [Google Scholar]
  3. Coutinho P. M., Henrissat B.. 1999; Carbohydrate-active enzymes: an integrated database approach. In Recent Advances in Carbohydrate Bioengineering pp3–12 Edited by Gilbert H. J., Davies G., Henrissat B., Svensson B.. Cambridge: Royal Society of Chemistry;
    [Google Scholar]
  4. de Vries R. P., van den Broeck H. C., Dekkers E., Manzanares P., Visser J., de Graaff L. H.. 1999a; Differential expression of three α -galactosidase genes and a single β -galactosidase gene from Aspergillus niger . Appl Environ Microbiol65:2453–2460
    [Google Scholar]
  5. de Vries R. P., Visser J., de Graaff L. H.. 1999b; CreA modulates the XlnR-induced expression on xylose of Aspergillus niger genes involved in xylan degradation. Res Microbiol150:281–285[CrossRef]
    [Google Scholar]
  6. de Vries R. P., Jansen J., Aguilar G., Parenicova L., Joosten V., Wulfert F., Benen J. A., Visser J.. 2002; Expression profiling of pectinolytic genes from Aspergillus niger . FEBS Lett530:41–47[CrossRef]
    [Google Scholar]
  7. Druzhinina I. S., Schmoll M., Seiboth B., Kubicek C. P.. 2006; Global carbon utilization profiles of wild-type, mutant, and transformant strains of Hypocrea jecorina . Appl Environ Microbiol72:2126–2133[CrossRef]
    [Google Scholar]
  8. Fantes P. A., Roberts C. F.. 1973; β -Galactosidase activity and lactose utilization in Aspergillus nidulans . J Gen Microbiol77:417–486[CrossRef]
    [Google Scholar]
  9. Fekete E., Karaffa L., Sandor E., Seiboth B., Biro S., Szentirmai A., Kubicek C. P.. 2002; Regulation of formation of the intracellular β -galactosidase activity of Aspergillus nidulans . Arch Microbiol179:7–14[CrossRef]
    [Google Scholar]
  10. Fekete E., Karaffa L., Sandor E., Banyai I., Seiboth B., Gyemant G., Sepsi A., Szentirmai A., Kubicek C. P.. 2004; The alternative d-galactose degrading pathway of aspergillus nidulans proceeds via l-sorbose. Arch Microbiol181:35–44[CrossRef]
    [Google Scholar]
  11. Frey P. A.. 1996; The Leloir pathway: a mechanistic imperative for three enzymes to change the stereochemical configuration of a single carbon in galactose. FASEB J10:461–470
    [Google Scholar]
  12. Gekas V., Lopez-Leiva M.. 1985; Hydrolysis of lactose: a literature review. Process Biochem20:2–12
    [Google Scholar]
  13. Holsinger V. H., Kligerman A. E.. 1991; Application of lactase in dairy foods and other foods containing lactose. Food Technol45:92–95
    [Google Scholar]
  14. Ilyés H., Fekete E., Karaffa L., Szentirmai A., Kubicek C. P., Fekete É., Sándor E.. 2004; CreA-mediated carbon catabolite repression of β -galactosidase formation in Aspergillus nidulans is growth rate dependent. FEMS Microbiol Lett235:147–151
    [Google Scholar]
  15. Karaffa L., Fekete E., Gamauf C., Szentirmai A., Kubicek C. P., Seiboth B.. 2006; d-Galactose induces cellulase gene expression in Hypocrea jecorina at low growth rates. Microbiology152:1507–1514[CrossRef]
    [Google Scholar]
  16. Kristufek D., Hodits R., Kubicek C. P.. 1994; Coinduction of α -l-arabinofuranosidase and α -d-galactosidase formation in Trichoderma reesei RUT C-30. FEMS Microbiol Lett115:259–264
    [Google Scholar]
  17. Mathieu M., Felenbok B.. 1994; The Aspergillus nidulans CREA protein mediates glucose repression of the ethanol regulon at various levels through competition with the ALCR-specific transactivator. EMBO J13:4022–4027
    [Google Scholar]
  18. Nakayama T., Amachi T.. 1999; β -Galactosidase, enzymology. In Encyclopedia of Bioprocess Technology – Fermentation, Biocatalysis, and Bioseparation pp1291–1305 Edited by Flickinger M. C., Drew S. W.. New York: Wiley;
    [Google Scholar]
  19. Nikolaev I. V., Vinetski Y. P.. 1998; l-Arabinose induces synthesis of secreted β -galactosidase in the filamentous fungus Penicillium canescens . Biochemistry63:1294–1298
    [Google Scholar]
  20. Pail M., Peterbauer T., Seiboth B., Hametner C., Druzhinina I., Kubicek C. P.. 2004; The metabolic role and evolution of l-arabinitol 4-dehydrogenase of Hypocrea jecorina . Eur J Biochem271:1864–1872[CrossRef]
    [Google Scholar]
  21. Pakula T. M., Salonen K., Uusitalo J., Penttilä M.. 2005; The effect of specific growth rate on protein synthesis and secretion in the filamentous fungus Trichoderma reesei . Microbiology151:135–143[CrossRef]
    [Google Scholar]
  22. Penttilä M., Limon C., Nevalainen H.. 2004; Molecular biology of Trichoderma and biotechnological applications. In Handbook of Fungal Biotechnology pp413–427 Edited by Arora D. K.. New York: Marcel Dekker;
    [Google Scholar]
  23. Persson I., Tjerneld F., Hahn-Hägerdal B.. 1991; Fungal cellulolytic enzyme production: a review. Process Biochem26:65–74[CrossRef]
    [Google Scholar]
  24. Seiboth B., Hartl L., Pail M., Fekete E., Karaffa L., Kubicek C. P.. 2004; The galactokinase of Hypocrea jecorina is essential for cellulase induction by lactose but dispensable for growth on d-galactose. Mol Microbiol51:1015–1025[CrossRef]
    [Google Scholar]
  25. Seiboth B., Hartl L., Salovuori N., Lanthaler K., Robson G. D., Vehmaanperä J., Penttilä M. E., Kubicek C. P.. 2005; Role of the bga1 -encoded extracellular β -galactosidase of Hypocrea jecorina in cellulase induction by lactose. Appl Environ Microbiol71:851–857[CrossRef]
    [Google Scholar]
  26. Strauss J., Mach R. L., Zeilinger S., Hartler G., Wolschek M., Kubicek C. P., Stöffler G.. 1995; Cre1, the carbon catabolite repressor protein from Trichoderma reesei . FEBS Lett376:103–107[CrossRef]
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/mic.0.2006/001602-0
Loading
/content/journal/micro/10.1099/mic.0.2006/001602-0
Loading

Data & Media loading...

Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error