A nanoparticle composition, including: a nanoparticle; at least one polymer; and at least one protein; wherein: manufacturing the nanoparticle composition includes: combining a nanoparticle solution comprising the nanoparticle and a solvent with the at least one polymer in a first container to create a first solution; and combining the first solution with the at least one protein in a second container; the nanoparticle is selected from a group comprising boron nitride, silica, graphene, cellulose, carbon, latex, silver, and gold; the at least one polymer is selected from a group comprising polyethylene glycol, polyvinyl alcohol, silanes, paraxylene, and phenol formaldehyde; and the at least one protein is selected from a group comprising proteinases, kinases, proteases, laccases, and peroxidases.

Provided is a new CueO mutant with improved activity compared with wild-type CueO. The protein according to one or more embodiments of the present invention contains an amino acid sequence [1] or [2] and has laccase activity: [1] an amino acid sequence containing at least a region of positions 29-516 in SEQ ID NO: 14 with mutations (a) and (b): (a) a substitution of D360 with an amino acid other than D; and (b) one or more selected from a substitution of G304 with an amino acid other than G, a substitution of D373 with an amino acid other than D, and a substitution of Q374 with an amino acid other than Q; or [2] an amino acid sequence 90% or more identical to the sequence [1], and having residues corresponding to positions 360, 304, 373, and 374 of SEQ ID NO: 14 identical to those of the sequence [1].

A method for enhancing the degradation performance of lignin-degrading bacteria Erwinia sp. QL-Z3 and a culture medium for culturing the bacteria. The rate of degradation of an Erwinia sp. QL-Z3 strain to lignin is optimized from 14.23% before optimization to 25.01%. Under the conditions that the initial pH value of the culture medium is 8, the nitrogen source is NH.sub.4NO.sub.3, and the addition amount of lignin is 3 g/L, the activity of an LiP enzyme can be optimized to 371.00 U/L, which is 3.53 times that before optimization. When the initial pH value of the culture medium is 9.5, the nitrogen source is NH.sub.4NO.sub.3, and the concentration of lignin is 2.5 g/L, the activity of MnP and Lac enzymes can be optimized to 839.50 U/L and 219.00 U/L, respectively, which are 3.18 and 2.84 times that before optimization.

The present invention relates to an improved method of producing products comprising a target protein (TP) capable of crystallising under salting-in conditions by crystallisation of the TP. The invention makes use of at least two different TP-containing protein feeds which are mixed to prepare a supersaturated protein solution in which TP is crystallized. One of the protein feeds must have a pH of at least the pH providing the maximum crystallisation yield of the TP (pH.sub.MCY,TP) plus 0.1 and one of the protein feeds must have a pH of at most pH.sub.MCY,TP minus 0.1.