Sphaerobacter thermophilus synthesizes an ω-transaminase (ω-TA) that allows the production of enantiomerically pure β-amino acids. To obtain ω-TA variants with a higher activity and more favorable properties for industrial use, we modified critical amino acid residues either in the catalytic center or in a previously proposed signature motif critical for aromatic β-amino acid ω-TAs. Seventeen different variants of this enzyme were generated and their activity was examined with four β-amino acids and one γ-amino acid, and compared with the wildtype's activity.
View Article and Find Full Text PDFEnantioselective transamination of amino acids is a great challenge in biotechnology as suitable enzymes with wide substrate spectrum are rare. Here, we present a new transaminase from (VboTA, ω-transaminase) which is specific for β-amino acids. The amino acid sequence of VboTA is similar to an ω-transaminase from , for which a crystal-structure is available.
View Article and Find Full Text PDFGlobal climate change is predicted to alter drought-precipitation patterns, which will likely affect soil microbial communities and their functions, ultimately shifting microbially-mediated biogeochemical cycles. The present study aims to investigate the simultaneous variation of microbial community compositions and functions in response to drought and following rewetting events, using a soil metaproteomics approach. For this, an established field experiment located in an Austrian forest with two levels (moderate and severe stress) of precipitation manipulation was evaluated.
View Article and Find Full Text PDFLichens are recognized by macroscopic structures formed by a heterotrophic fungus, the mycobiont, which hosts internal autotrophic photosynthetic algal and/or cyanobacterial partners, referred to as the photobiont. We analyzed the structure and functionality of the entire lung lichen Lobaria pulmonaria L. Hoffm.
View Article and Find Full Text PDFThe marine isolate Bacillus pumilus SBUG 1800 is able to lyse living cells of Arthrobacter citreus on solid media as well as pasteurized A. citreus cells in liquid mineral salt medium. The cultivation of B.
View Article and Find Full Text PDFSymbioses represent a frequent and successful lifestyle on earth and lichens are one of their classic examples. Recently, bacterial communities were identified as stable, specific and structurally integrated partners of the lichen symbiosis, but their role has remained largely elusive in comparison to the well-known functions of the fungal and algal partners. We have explored the metabolic potentials of the microbiome using the lung lichen Lobaria pulmonaria as the model.
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