Insufficient potassium and sulfur supply threaten the productivity of perennial forage grasses in smallholder farms on tropical sandy soils

Plant and Soil - Perennial forage grass production has the potential to improve smallholder livelihoods in the tropics. However, nutrient management is often challenging, especially on infertile...     

Correction to: Experimental evidence of minimal effects on octocoral hosts caused by the introduced ophiuroid Ophiothela mirabilis

Coral Reefs - A correction to this paper has been published: https://doi.org/10.1007/s00338-021-02110-0     

The contribution of corals to reef structural complexity in Kāne‘ohe Bay

Coral Reefs - The structural complexity of coral reefs provides important ecosystem functions, such as wave attenuation for coastal protection, surfaces for coral growth, and habitat for other...     

Streptomonospora litoralis sp. nov., a halophilic thiopeptides producer isolated from sand collected at Cuxhaven beach

Antonie van Leeuwenhoek - Strain M2T was isolated from the beach of Cuxhaven, Wadden Sea, Germany, in course of a program to attain new producers of bioactive natural products. Strain M2T produces...     

Variation in the ratio of curli and phosphoethanolamine cellulose associated with biofilm architecture and properties

Bacterial biofilms are communities of bacteria entangled in a self‐produced extracellular matrix (ECM). Escherichia coli direct the assembly of two insoluble biopolymers, curli amyloid fibers, and phosphoethanolamine (pEtN) cellulose, to build remarkable biofilm architectures. Intense curiosity surrounds how bacteria harness these amyloid‐polysaccharide composites to build biofilms, and how these biopolymers function to benefit bacterial communities. Defining ECM composition involving insoluble polymeric assemblies poses unique challenges to analysis and, thus, to comparing strains with quantitative ECM molecular correlates. In this work, we present results from a sum‐of‐the‐parts ¹³C solid‐state nuclear magnetic resonance (NMR) analysis to define the curli‐to‐pEtN cellulose ratio in the isolated ECM of the E. coli laboratory K12 strain, AR3110. We compare and contrast the compositional analysis and comprehensive biofilm phenotypes for AR3110 and a well‐studied clinical isolate, UTI89. The ECM isolated from AR3110 contains approximately twice the amount of pEtN cellulose relative to curli content as UTI89, revealing plasticity in matrix assembly principles among strains. The two parent strains and a panel of relevant gene mutants were investigated in three biofilm models, examining: (a) macrocolonies on agar, (b) pellicles at the liquid‐air interface, and (c) biomass accumulation on plastic. We describe the influence of curli, cellulose, and the pEtN modification on biofilm phenotypes with power in the direct comparison of these strains. The results suggest that curli more strongly influence adhesion, while pEtN cellulose drives cohesion. Their individual and combined influence depends on both the biofilm modality (agar, pellicle, or plastic‐associated) and the strain itself.