Don A. Cowan

TL;DR: Biochemical assays confirmed EstBL esterase activity and revealed a preference for short-chain p-nitrophenyl and β-naphthyl esters with no activity against β-lactam substrates, which indicated that EstBL adopts the α/β fold, which is common to all esterases.

Abstract: Many studies, mostly in temperate regions of the northern hemisphere, have demonstrated that agricultural practices affect the composition and diversity of soil microbial communities. However, very little is known about the impact of agriculture on the microbial communities in other regions of the world, most particularly on the African continent. In this study, we used MiSeq amplicon sequencing of bacterial 16S rRNA genes and fungal ITS regions to characterise microbial communities in agricultural and natural grassland soils located in the Mpumalanga Province of South Africa. Nine soil chemical parameters were also measured to evaluate the effects of edaphic factors on microbial community diversity. Bacterial and fungal communities were significantly richer and more diverse in natural grassland than in agricultural soils. Microbial taxonomic composition was also significantly different between the two habitat types. The phylum Acidobacteria was significantly more abundant in natural grassland than in agricultural soils, while Actinobacteria and the family Nectriaceae showed the opposite pattern. Soil pH and phosphorus significantly influenced bacterial communities, whereas phosphorus and calcium influenced fungal communities. These findings may be interpreted as a negative impact of land-use change on soil microbial diversity and composition.

TL;DR: A highly novel Paracoccus infecting virus (Shpa) is described which together with NgoΦ6 and vB_PmaS_IMEP1 is one of only three phages known to infect ParacOCcus species but does not show similarity to these phages.

TL;DR: The microbial diversity of lithobionts, the factors that influence colonization, and the roles played by these communities in the Antarctic soil ecosystem are described and the application of “omics-based approaches” is advocated that can reveal both the functional capacities and adaptive potentials of complex microbial communities.

TL;DR: The esterase-catalysed transesterification of N-carbobenzoxy-l-tyrosinep-nitrophenol ester (Z-Tyrp-NPE) with methanol was studied with water: meethanol cosolvent and with dry ethyl acetate as solvent, accounting for a 50-fold greater quantity of product formed per experiment in ethylacetate.