2 2 azino di

Carboxymethyl cellulose, birch wood xylan, 2,2′-azino-di-[3-ethylbenzothiazoline-6-sulphonic acid] (ABTS), dinitrosalicylic acid, sodium-potassium tartrate, bovine serum albumin (BSA), manganese sulphate, copper sulphate, tyrosine, leucine, cellobiose, avicel, xylose, tryptophan, aspartate, glutamate, hydrogen peroxide, and media components were products of Sigma-Aldrich (St Louis, MO, USA). Corn cob was purchased from a local market. The corn cob was sun-dried and powdered into fine particles which was utilized as carbon source in the basal media. Further processing on the powdered corn cob was carried out using standard sieve to an average size of 1 mm. All other chemicals used were of analytical grade.

Horse heart cytochrome c (Cyt-c, ≥95% purity), 2,2′-azino-di-(3-ethylbenzthiazoline sulfonic acid) (ABTS, ≥95% purity), hydrogen peroxide (99% purity) and hydroxylammonium chloride (99% purity) were obtained from Sigma-Aldrich^® (St. Louis, MO, USA). Methoxy PEG N-hydroxysuccinimide ester (mPEG-NHS, 5 kDa) with high purity was acquired from Nanocs^® (New York, NY, USA). The aqueous buffer used in the PEGylation reaction was potassium phosphate buffer (100 mM). All other reagents were of analytical grade. The water used was double-distilled, passed through a reverse osmosis system and was further treated with Direct-Q^® 8 UV remote water purification system (Merck^®, São Paulo, Brazil).