Über die Beeinflussung niederer Erdphycomyceten durch Flechten

Zusammenfassung Aus dem spärlichen Boden unter Flechten ließen sich nur in sehr seltenen Fällen vereinzelte niedere Erdphycomyceten herausködern.Bei Zusatz von zerkleinerten Flechten zu Aufschwemmungen von Erdboden mit bekanntem Phycomycetengehalt wurden die hinzugegebenen mit bekanntem Phycomycetengehalt wurden die hinzugegebenen Köder in sehr viel geringerem Maße besiedelt als ohne Flechtenzusatz.Eine besondere Empfindlichkeit bestimmter Pilzarten gegen die von den Flechten ausgehende Wirkung konnte nicht ermittelt werden.Herrn Professor Dr.A. Rippel zum 70. Geburtstag.     

Structure/function relationships in methylotrophic yeasts

Abstract This symposium marks the 15th anniversary of the discovery of microbodies in methylotrophic yeasts. In the intervening years much has been learned about the structure, function and biogenesis of these organelles and these advances are described. As our endeavours continued, unexpected results have confused commonly held views. This was for instance the case when microbody-minus mutants of yeasts became available which showed that some microbody matrix enzymes may be functional when present in the cytosol while others are not. At the molecular level, our understanding of structure/function relationships is also expanding. Examples are structural elements which relate to protein topogenesis and function of enzymes in different cell compartments. Other, perhaps more unusual, adaptations have also been encountered; some involve protein-protein interactions or even modified cofactors which possibly have helped methylotrophic yeasts to establish and/or maintain themselves in natural ecosystems.     

Human beta-defensin-2.

Human beta-defensin-2 (HBD-2) is a cysteine-rich cationic low molecular weight antimicrobial peptide recently discovered in psoriatic lesional skin. It is produced by a number of epithelial cells and exhibits potent antimicrobial activity against Gram-negative bacteria and Candida, but not Gram-positive Staphylococcus aureus. HBD-2 represents the first human defensin that is produced following stimulation of epithelial cells by contact with microorganisms such as Pseudomonas aeruginosa or cytokines such as TNF-alpha and IL-1 beta. The HBD-2 gene and protein are locally expressed in keratinocytes associated with inflammatory skin lesions such as psoriasis as well as in the infected lung epithelia of patients with cystic fibrosis. It is intriguing to speculate that HBD-2 is a dynamic component of the local epithelial defense system of the skin and respiratory tract having a role to protect surfaces from infection, and providing a possible reason why skin and lung infections with Gram-negative bacteria are rather rare.