Whey after acid protein precipitation was used as substrate for PHB production in orbital shaker using Alcaligenes latus. Statistical analysis determined the most appropriate hydroxide for pH neutralization of whey after protein precipitation among NH4OH, KOH and NaOH 10% w/v. The results were compared to those of commercial lactose. A scale-up test in a 4 L bioreactor was done at 35 degrees C, 750 rpm, 7 L/min air flow, and 6.5 pH. The PHB was characterized through Fourier Transform Infrared Spectroscopy, thermogravimetry and differential scanning calorimetry. NH4OH provided the best results for productivity (p), 0.11 g/L. h, and for polymer yield, (YP/S), 1.08 g/g. The bioreactor experiment resulted in lower p and YP/ S. PHB showed maximum degradation temperature (291 degrees C), melting temperature (169 degrees C), and chemical properties similar to those of standard PHB. The use of whey as a substrate for PHB production did not affect significantly the final product quality. (C) 2016 Elsevier Ltd. All rights reserved.