Nisin-permeabilized microbial cell catalysts
AssigneeDanmarks Tekniske Universitet
InventorsPeter Ruhdal Jensen, Christian Solem, Jianming Liu, Robin Dorau, Qi Wang, Ge Zhao
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Abstract
A method and use of nisin-permeabilized microbial cells as whole-cell catalysts for reducing the amount of a target substrate in a sample to one of more product are provided. Specifically, a method of reducing the amount of lactose in a dairy sample using nisin-permeabilized lactic acid bacterial cell catalysts, which have been permeabilized by incubating with a nisin producing microbial cell and/or culture medium derived thereof. Further provided is a nisin producing microbial cell, derived from parent strain Lactococcus lactis subsp. lactis bv. diacetylactis SD96 (NCBI accession No. SRX6686433).
Claims16
A method for producing tagatose from isomerization of galactose in a sample, said method comprising the steps of:
- a) providing microbial cells comprising an intracellular arabinose isomerase EC 5.3.1.4 enzyme for catalyzing conversion of said galactose into tagatose,
- b) incubating said microbial cells with nisin as permeabilizing agent, wherein nisin is present in a concentration of 2-250 μg nisin per mg cells,
- c) optionally harvesting permeabilized cells obtained in step (b),
- d) incubating permeabilized cells obtained in step (b) or harvested cells obtained in step (c) with said sample comprising said galactose;
- wherein said microbial cells are susceptible to nisin-permeabilization, and wherein the galactose can transit through nisin pores of the permeabilized cells.
A whole-cell catalyst comprising nisin-permeabilized microbial cells;
- wherein the nisin-permeabilized cells comprise an intracellular arabinose isomerase EC 5.3.1.4 enzyme for catalyzing conversion of galactose into tagatose;
- wherein the microbial cells were permeabilized with nisin at a concentration of 2-250 μg nisin per mg cells;
- and further wherein the nisin-permeabilized cells are in a frozen or dried state.
A composition comprising (i) nisin-permeabilised microbial cells comprising an intracellular arabinose isomerase EC 5.3.1.4 enzyme and (ii) galactose and tagatose;
- wherein the microbial cells were permeabilized with nisin at a concentration of 2-250 μg nisin per mg cells.
Dependencies are inferred from the claim text.