9 research outputs found
Bioprospecting reveals class III ω-transaminases converting bulky ketones and environmentally relevant polyamines
Amination of bulky ketones, particularly in (R) configuration, is an attractive chemical conversion; however, known ω-transaminases (ω-TAs) show insufficient levels of performance. By applying two screening methods, we discovered 10 amine transaminases from the class III ω-TA family that were 38% to 76% identical to homologues. We present examples of such enzymes preferring bulky ketones over keto acids and aldehydes with stringent (S) selectivity. We also report representatives from the class III ω-TAs capable of converting (R) and (S) amines and bulky ketones and one that can convert amines with longer alkyl substituents. The preference for bulky ketones was associated with the presence of a hairpin region proximal to the conserved Arg414 and residues conforming and close to it. The outward orientation of Arg414 additionally favored the conversion of (R) amines. This configuration was also found to favor the utilization of putrescine as an amine donor, so that class III ω-TAs with Arg414 in outward orientation may participate in vivo in the catabolism of putrescine. The positioning of the conserved Ser231 also contributes to the preference for amines with longer alkyl substituents. Optimal temperatures for activity ranged from 45 to 65°C, and a few enzymes retained ≥50% of their activity in water-soluble solvents (up to 50% [vol/vol]). Hence, our results will pave the way to design, in the future, new class III ω-TAs converting bulky ketones and (R) amines for the production of high-value products and to screen for those converting putrescine
Pressure adaptation is linked to thermal adaptation in salt-saturated marine habitats
The present study provides a deeper view of protein
functionality as a function of temperature, salt and
pressure in deep-sea habitats. A set of eight different
enzymes from five distinct deep-sea (3040–4908 m
depth), moderately warm (14.0–16.5°C) biotopes,
characterized by a wide range of salinities (39–348
practical salinity units), were investigated for this
purpose. An enzyme from a ‘superficial’ marine
hydrothermal habitat (65°C) was isolated and characterized
for comparative purposes. We report here the
first experimental evidence suggesting that in saltsaturated
deep-sea habitats, the adaptation to high
pressure is linked to high thermal resistance (P
value = 0.0036). Salinity might therefore increase the
temperature window for enzyme activity, and possibly
microbial growth, in deep-sea habitats. As an
example, Lake Medee, the largest hypersaline deepsea
anoxic lake of the Eastern Mediterranean Sea,
where the water temperature is never higher than
16°C, was shown to contain halopiezophilic-like
enzymes that are most active at 70°C and with denaturing
temperatures of 71.4°C. The determination of
the crystal structures of five proteins revealed
unknown molecular mechanisms involved in protein
adaptation to poly-extremes as well as distinct active
site architectures and substrate preferences relative
to other structurally characterized enzymes.European Community project MAMBA (FP7-KBBE-2008-226977). This grant BIO2011-25012 from the Spanish Ministry of Economy and Competitiveness (formerly MICINN). European Commission for ‘MicroB3’ grant (FP7-OCEAN.2011-2 (contract Nr
287589)). Government of Canada through Genome Canada
and the Ontario Genomics Institute (grant 2009-OGI-ABC-1405) and
U.S. National Institutes of Health (grants GM074942 and GM094585). Midwest Center for Structural Genomics).http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1462-2920hb2016Biochemistr
Entwicklung eines Rhodobacter-basierten Systems zur Synthese wirtsfremder Proteine und Phospholipide
The biotechnological potential of marine bacteria in the novel lineage of Pseudomonas pertucinogena
Marine habitats represent a prolific source for molecules of biotechnological interest. In particular, marine bacteria have attracted attention and were successfully exploited for industrial applications. Recently, a group of Pseudomonas species isolated from extreme habitats or living in association with algae or sponges were clustered in the newly established Pseudomonas pertucinogena lineage. Remarkably for the predominantly terrestrial genus Pseudomonas, more than half (9) of currently 16 species within this lineage were isolated from marine or saline habitats. Unlike other Pseudomonas species, they seem to have in common a highly specialized metabolism. Furthermore, the marine members apparently possess the capacity to produce biomolecules of biotechnological interest (e.g. dehalogenases, polyester hydrolases, transaminases). Here, we summarize the knowledge regarding the enzymatic endowment of the marine Pseudomonas pertucinogena bacteria and report on a genomic analysis focusing on the presence of genes encoding esterases, dehalogenases, transaminases and secondary metabolites including carbon storage compounds
Marine Biosurfactants: Biosynthesis, Structural Diversity and Biotechnological Applications
Biosurfactants are amphiphilic secondary metabolites produced by microorganisms. Marine bacteria have recently emerged as a rich source for these natural products which exhibit surface-active properties, making them useful for diverse applications such as detergents, wetting and foaming agents, solubilisers, emulsifiers and dispersants. Although precise structural data are often lacking, the already available information deduced from biochemical analyses and genome sequences of marine microbes indicates a high structural diversity including a broad spectrum of fatty acid derivatives, lipoamino acids, lipopeptides and glycolipids. This review aims to summarise biosyntheses and structures with an emphasis on low molecular weight biosurfactants produced by marine microorganisms and describes various biotechnological applications with special emphasis on their role in the bioremediation of oil-contaminated environments. Furthermore, novel exploitation strategies are suggested in an attempt to extend the existing biosurfactant portfoli
First Insights into the Genome Sequence of Pseudomonas oleovorans DSM 1045
The Gram-negative proteobacterium Pseudomonas oleovorans DSM 1045 is considered a promising source for enzymes of biotechnological interest, e.g., hydrolases and transaminases. Here, we present a draft sequence of its 4.86-Mb genome, enabling the identification of novel biocatalysts