Cheese whey permeate, a processed by-product of the dairy industry, was utilized as the sole carbon source for the production of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) from Bacillus megaterium. In the present study, propionic acid was co-fed as an internal plasticizer to synthesize PHBV co-polymer. Cultivation parameters such as time, propionic acid, C/N ratio were optimized by investigating several parameters that affect the production of PHBV. The maximum PHBV content of 86.6% and the highest PHBV yield of 3.64 g/L were achieved at 72 h, 0.1% propionic acid content, and C/N ratio of 15. The presence of PHBV in the extracted sample was confirmed by gas chromatography–mass spectroscopy (GC–MS) and Fourier transform-infrared spectroscopy analysis, and further, the morphology was studied by scanning electron microscopy analysis. Mechanical characterization revealed that PHBV has a tensile strength of 4.41 MPa, which was higher than polyhydroxybutyrate with 3.37 MPa. The PHBV biopolymer was observed to be thermally stable between 100–400 °C. The melting point, crystallization temperature and glass transition temperature of PHBV were measured to be 116.60 °C, 108.92 °C and 87.88 °C respectively. The synthesized PHBV nanoparticles had an average diameter of 343.3 nm, and the zeta potential was found to be—21.3 mV.

乳清工业的加工副产物干酪乳清渗透液被用作唯一的碳源，用于由巨大芽孢杆菌生产聚（3-羟基丁酸酯-co-3-羟基戊酸酯）（PHBV）。在本研究中，丙酸作为一种内部增塑剂被共同喂入以合成PHBV共聚物。通过研究影响PHBV生产的几个参数，优化了诸如时间，丙酸，C / N比等培养参数。在72 h时，最大PHBV含量为86.6％，最高PHBV产量为3.64 g / L，丙酸含量为0.1％，C / N比为15。通过气相色谱法确认了萃取样品中PHBV的存在-质谱（GC-MS）和傅里叶变换红外光谱分析，此外，通过扫描电子显微镜分析对形态进行了研究。力学特性表明，PHBV的拉伸强度为4.41 MPa，高于聚羟基丁酸酯的3.37 MPa。观察到PHBV生物聚合物在100–400°C之间具有热稳定性。PHBV的熔点，结晶温度和玻璃化转变温度分别为116.60°C，108.92°C和87.88°C。合成的PHBV纳米颗粒具有343.3nm的平均直径，并且发现ζ电位为-21.3mV。