Suggestions by Calvin about a role of inorganic pyrophosphate (PPi) in early photosynthesis and by Lipmann that PPi may have been the original energy‐rich phosphate donor in biological energy conversion, were followed in the mid‐1960s by experimental results with isolated chromatophore membranes from the purple photosynthetic bacterium Rhodospirillum rubrum. PPi was shown to be hydrolysed in an uncoupler stimulated reaction by a membrane‐bound inorganic pyrophosphatase (PPase), to be formed at the expense of light energy in photophosphorylation and to be utilized as an energy donor for various energy‐requiring reactions, as a first known alternative to ATP. This direct link between PPi and photosynthesis led to increasing attention concerning the role of PPi in both early and present biological energy transfer. In the 1970s, the PPase was shown to be a proton pump and to be present also in higher plants. In the 1990s, sequences of H+‐PPase genes were obtained from plants, protists, bacteria and archaea and two classes of H+‐PPases differing in K+ sensitivity were established. Over 200 H+‐PPase sequences have now been determined. Recent biochemical and biophysical results have led to new progress and questions regarding the H+‐PPase family, as well as the families of soluble PPases and the inorganic polyphosphatases, which hydrolyse inorganic linear high‐molecular‐weight polyphosphates (HMW‐polyP). Here we will focus attention on the H+‐PPases, their evolution and putative active site motifs, response to monovalent cations, genetic regulation and some very recent results, based on new methods for obtaining large quantities of purified protein, about their tertiary and quaternary structures. IUBMB Life, 59: 76‐83, 2007

Bats are emblematic hosts of caves. These small flying mammals deserve special attention because their presence has a great economic and ecological impact; they introduce organic matter, the guano, in the ecosystem they live in. Indeed, “guano” (a Quechua word meaning “fertilizer”) is the accumulation of their fecal matter (excreta); its deposition can reach several meters. The composition of guano is influenced by the bat’s food. In addition to its role within the caves, the bat guano is exploited for various purposes; it is used as an effective fertilizer for the cultivation of plants because of having exceptionally high content of nitrogen, phosphate, and potassium and also for the improvement of detergents and other products of great value for humans. The bat guano hosts various classes of microorganisms (viruses, bacteria, algae, fungi, and protists), which are adapted to the cave environment. Since guano is highly acidic, these microorganisms can be considered as extremophiles. They produce functional organic compounds in extreme conditions that could be of interest not only in the drug industry but also in different biotechnological areas. Here, we review already available information on the ecological and economic effects of bats and their guano. We report their food preferences, foraging behaviors, and environmental impacts. Information on these aspects may be useful in finding a solution about protection and preservation of bat populations.

Summary: Costa Rica is at the centre of the Mesoamerican biodiversity hotspot. Little is known about cyanobacteria from this region so far. Here, four isolates of the order Stigonematales (section V) were characterized in a polyphasic approach. All strains were isolated from geothermal sites and hot springs of Costa Rica. However, one of them, identified as Westiellopsis sp. Ar73, did not grow at more than 40°C. Based on its identical 16S rRNA to several previously isolated Westiellopsis sp. and Fischerella muscicola strains, a ubiquitous distribution throughout tropical and subtropical regions can be implied. In contrast, the isolates MV9, MV11 and RV14 grew well up to 50–55°C. Based on morphologic, ultrastructural, molecular and physiologic data, MV9, MV11 and RV14 were identified to belong to the genus Fischerella . Two distinct intergenic transcribed spacer (ITS) types, with or without tRNA genes, were detected for all Stigonematales analysed here, indicating ITS polymorphism as a characteristic feature of heterocystous cyanobacteria. In phylogenetic trees, these Fischerella spp. formed a new and distinct clade within the wider lineage of thermophilic Fischerella ( Mastigocladus cf. laminosus ), which might represent a geographic lineage. Thus, geographic isolation may be an underestimated aspect of microbial evolution. The strains presented here are suitable as new models to study this group of cyanobacteria.