Most plants obtain nitrogen through nitrogen-fixing bacteria and microbial decomposition of plant and animal material. Many vascular plants are able to form close symbiotic associations with endophytic fungi. Metarhizium is a common plant endophyte found in a large number of ecosystems. This abundant soil fungus is also a pathogen to a large number of insects, which are a source of nitrogen. It is possible that the endophytic capability and insect pathogenicity of Metarhizium are coupled to provide an active method of nitrogen transfer to plant hosts via fungal mycelia. We used soil microcosms to test the ability of M. robertsii to translocate insect-derived nitrogen to plants. Insects were injected with (15)N-labeled nitrogen, and we tracked the incorporation of (15)N into amino acids in two plant species, haricot bean (Phaseolus vulgaris) and switchgrass (Panicum virgatum), in the presence of M. robertsii. These findings are evidence that active nitrogen acquisition by plants in this tripartite interaction may play a larger role in soil nitrogen cycling than previously thought.

Metarhizium robertsii is a common soil fungus that occupies a specialized ecological niche as an endophyte and an insect pathogen. Previously, we showed that the endophytic capability and insect pathogenicity of Metarhizium are coupled to provide an active method of insect-derived nitrogen transfer to a host plant via fungal mycelia. We speculated that in exchange for this insect-derived nitrogen, the plant would provide photosynthate to the fungus. By using 13CO2, we show the incorporation of 13C into photosynthate and the subsequent translocation of 13C into fungal-specific carbohydrates (trehalose and chitin) in the root/endophyte complex. We determined the amount of 13C present in root-associated fungal biomass over a 21-day period by extracting fungal carbohydrates and analysing their composition using nuclear magnetic resonance (NMR) spectroscopy. These findings are evidence that the host plant is providing photosynthate to the fungus, likely in exchange for insect-derived nitrogen in a tripartite, and symbiotic, interaction.

A system of entrapping proteinaceous material in water-in-silicone oil emulsions using silicone surfactants is described. Although contact between cyclic and linear silicones and proteins is well-known to facilitate protein/enzyme denaturation, the additional presence of silicones bearing a few hydrophilic groups (silicone surfactants) in these W/O systems dramatically lowers the degree of protein denaturation. Spectrophotometric activity assays of R-chymotrypsin and lysozyme performed using a UV/visible spectrophotometer revealed that the enzymes entrapped within these emulsion systems retain activity that is equal to, or in some cases greater than, that of controls. The results suggest that these emulsions are a viable means by which to store proteinaceous materials.

We have successfully prepared an elastomeric material exhibiting excellent temperature-controlled self-healing characteristics.

Inspired by Nature, biocatalysis and biotechnology have quickly become burgeoning fields in silicon chemistry. From cell cultures to isolated enzymes researchers are exploring the use of biological systems to affect chemical transformations at or near silicon atoms. This review will examine the history of biotechnology as it pertains to organosilicon compounds (i.e., compounds with one or more Si-C bonds) and provide some insights into future directions for the field.