Introducing the Atacama Desert

This brief introduction is intended to orientate the reader with respect to the principal environmental and historical features of the Atacama Desert, the oldest and continuously driest non-polar temperate desert on Earth. Exploration of its microbiology is relatively recent but both fundamental and applied research activities have grown dramatically in recent years reflecting the substantial interest in its microbial diversity, ecology, biogeochemistry, natural product potential and Mars-analogue properties of this unique and invigorating environment.     

Introducing the biogeographic species pool

The species pool concept has played a central role in the development of ecological theory for at least 60 yr. Surprisingly, there is little consensus as to how one should define the species pool, and consequently, no systematic approach exists. Because the definition of the species pool is essential to infer the processes that shape ecological communities, there is a strong incentive to develop an ecologically realistic definition of the species pool based on repeatable and transparent analytical approaches. Recently, several methodological tools have become available to summarize repeated patterns in the geographic distribution of species, phylogenetic clades and taxonomically broad lineages. Here, we present three analytical approaches that can be used to define what we term ‘the biogeographic species pool’: distance‐based clustering analysis, network modularity analysis, and assemblage dispersion fields. The biogeographic species pool defines the pool of potential community members in a broad sense and represents a first step towards a standardized definition of the species pool for the purpose of comparative ecological, evolutionary and biogeographic studies.     

Introducing transglycosylation activity in a liquefying alpha-amylase.

By mutating Ala-289 by Phe or Tyr in the Bacillus stearothermophilus alpha-amylase, we induced this enzyme to perform alcoholytic reactions, a function not present in the wild-type enzyme. This residue was selected from homology analysis with neopullulanase, where the residue has been implicated in the control of transglycosylation [Kuriki et al. (1996) J. Biol. Chem. 271, 17321-173291. We made some inferences about the importance of electrostatic and geometrical modifications in the active site environment of the amylase to explain the behavior of the modified enzyme.