The influence of carbon sources and mononucleotides on the production of extracellular alkaline phosphatase by bacillus intermedium

The biosynthesis of extracellular alkaline phosphatase in the streptomycin-resistant strainsBacillus intermedius S3-19 and S7 in the presence in the medium of 5’-nucleoside monophosphates and different sources of carbon—glucose, sodium pyruvate, sodium lactate, or glycerol—was studied. It was established that, in the presence of mononucleotides, the content of extracellular alkaline phosphatase in both strains increased; the maximal effect was caused by 5’-AMP at a concentration of 20μg/ml. In medium with a low orthophosphate content, where active biosynthesis of alkaline phosphatase occurred, 1% glucose and 0.5% pyruvate stimulated this process 2.5–4 times, and 2% sodium lactate and sodium pyruvate, on the contrary, inhibited it by 20–40%. Analysis of the dynamics of growth and accumulation of extracellular phosphatase in the presence of different sources of carbon in the medium gives evidence of an interrelationship between the biosynthesis of alkaline phosphatase and carbon metabolism inBacillus intermedius.     

The dynamic nature of the activities of the wood ant Formica aquilonia foraging to static food resources within a laboratory habitat

ABSTRACT. A laboratory colony of the wood ant Formica aquilonia (Yarrow) was maintained under strictly controlled feeding regimens. The number of foragers at a particular site is related to the previous provisioning of the colony and the familiarity and accessibility of the resource to foragers. Under a standard regimen a predictable number of ants forage to a known site and display a typical pattern of daily activity. This pattern is examined under stable and changing circumstances. Following food-deprivation individuals increase their foray-frequency and carry larger volumes of sugar solution per foray. On days of critical food-deficit supernumerary workers are recruited. How foragers are directed to a novel food source in unfamiliar territory is examined. Following-behaviour is not involved, neither it appears are pheromones.     

Methods in phenological mapping

Summary Phenological maps of flowering provide useful information about both spatial and temporal patterns of pollen emission, and their use could bring a substantial improvement of aerobiological forecasts. This paper presents a method for preparing flowering maps by computer on the basis of phenological data and topography. Data drawn from topographic maps are processed with the aid of an empirical model, based on the relationships between phenology and environment, for obtaining a phenological delay matrix. From this matrix it is possible to derive automatically various kinds of maps (chronological, synoptical and differential). An application is described, relating to the blooming patterns of a set of wild plants in a mountainous area of Northern Italy.     

Keratinolytic activity of Kocuria rosea

A strain of Kocuria rosea able to secrete keratin-hydrolysing proteinases (keratinases) in submerged batch cultures with finely milled feathers as carbon and nitrogen sources was studied. The highest production of keratinases was obtained when feathers were used as the only fermentation substrate (17 U/mg). Considerably lower activity was present in cultures containing glucose and others nutrient supplements. The optimum temperature and pH for keratinolytic activity was 40 °C and 10, respectively. Gelatin-sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE) electrophoresis analysis showed that Kocuria rosea grown on feathers secreted at least two alkaline extracellular proteases with apparent molecular weights of 90.2 and >200 kDa, respectively. These proteolytic activities appear sequentially during microbial growth. Keratinolytic activity was strongly inhibited by phenylmethanesulphonyl fluoride (PMSF), chymostatin and crystalline soybean trypsin inhibitor, indicating the presence of serine proteases. Proteolytic enzymes derived from the biodegradation of feathers by this microorganism could be a useful biotechnological tool in the leather, food and cosmetic industries.     

Sensitivity of macroecological patterns of South American parrots to differences in data sources

A criticism of macroecological studies has been their extensive use of secondary data sources. In this note we evaluate how different data sources affect macroecological patterns for the parrots of South America. We mapped extents of parrot occurrence based on four sources of range maps. We compared basic statistics for geographical range size distribution (mean, variance and skew) and calculated correlations between geographical range size estimates and grid cell species richness estimates. Finally, results from multiple regression analyses of species richness against six environmental variables were also compared. We found that patterns were very robust to the data source, with only relatively slight quantitative differences. Our results reinforce the notion that patterns emerging from macroecological analyses are robust to variations in data sources and cannot be merely artefacts resulting from low data quality, notably poorly defined mapping and conflicting taxonomy.