Plant seed oil-bodies as an immobilization matrix for a recombinant xylanase from the rumen fungus Neocallimastix patriciarum

Canola seed oil-bodies were investigated as a production vehicle and immobilization matrix for xylanases. A recombinant xynC gene from Neocallimastix patriciarum encoding a xylanase (XynC) was fused to an oleosin coding sequence suitable for targeting the xylanase to the oil-body membrane. This fusion gene was introduced into Brassica napus using Agrobacterium-mediated transformation. Transgenic Canola plants were obtained expressing xylanase which was targeted to the oil-bodies of seeds as shown by analysis with XynC-specific antibodies. Oil-bodies extracted from transgenic seeds exhibited xylanase activity, indicating the immobilization of XynC on the surface of oil bodies and the functioning of the xylanase as a fusion protein. The immobilized XynC retained its optimal temperature, K_m value and specificity. However, it exhibited reduced sensitivity to pH. Furthermore, it was shown that the enzyme immobilized on oil-bodies could be recycled by flotation several times without loss of activity.     

Nanodiamonds as an effective adsorbent for immobilization of extracellular peroxidases from luminous fungus Neonothopanus nambi to construct a phenol detection system

Modified nanodiamonds (MNDs) produced by detonation synthesis can be used as an effective adsorbent to immobilize extracellular peroxidases of the luminous basidiomycete Neonothopanus nambi. The enzymes are firmly immobilized on MND particles and exhibit catalytic activity. The indicator system (the MND–enzyme complex) reused many times retains its ability to catalyze reaction of co-oxidation of phenol and 4-aminoantipirine in the presence of hydrogen peroxide and remains functionally active during long-term storage (for 1?month or longer) in aqueous suspensions at 4?°C. MNDs and enzymes of higher fungi can be effectively used to construct new reusable indicator systems for analytical applications such as monitoring contamination of aquatic environments by phenolic compounds.