Mohd Zahari Mior Ahmad Khushairi, Ariffin Hidayah, Mokhtar Mohd Noriznan, Salihon Jailani, Shirai Yoshihito, Hassan Mohd Ali
Department of Process and Food Engineering, Faculty of Engineering, Universiti Putra Malaysia, Serdang, Selangor, Malaysia.
J Biomed Biotechnol. 2012;2012:125865. doi: 10.1155/2012/125865. Epub 2012 Oct 14.
Factors influencing poly(3-hydroxybutyrate) P(3HB) production by Cupriavidus necator CCUG52238(T) utilizing oil palm frond (OPF) juice were clarified in this study. Effects of initial medium pH, agitation speed, and ammonium sulfate (NH(4))(2)SO(4) concentration on the production of P(3HB) were investigated in shake flasks experiments using OPF juice as the sole carbon source. The highest P(3HB) content was recorded at pH 7.0, agitation speed of 220 rpm, and (NH(4))(2)SO(4) concentration at 0.5 g/L. By culturing the wild-type strain of C. necator under the aforementioned conditions, the cell dry weight (CDW) and P(3HB) content obtained were 9.31 ± 0.13 g/L and 45 ± 1.5 wt.%, respectively. This accounted for 40% increment of P(3HB) content compared to the nonoptimized condition. In the meanwhile, the effect of dissolved oxygen tension (DOT) on P(3HB) production was investigated in a 2-L bioreactor. Highest CDW (11.37 g/L) and P(3HB) content (44 wt.%) were achieved when DOT level was set at 30%. P(3HB) produced from OPF juice had a tensile strength of 40 MPa and elongation at break of 8% demonstrated that P(3HB) produced from renewable and cheap carbon source is comparable to those produced from commercial substrate.
本研究阐明了影响食酸戴尔福特菌CCUG52238(T)利用油棕叶(OPF)汁生产聚(3-羟基丁酸酯)[P(3HB)]的因素。在摇瓶实验中,以OPF汁作为唯一碳源,研究了初始培养基pH值、搅拌速度和硫酸铵[(NH₄)₂SO₄]浓度对P(3HB)产量的影响。在pH值为7.0、搅拌速度为220 rpm和(NH₄)₂SO₄浓度为0.5 g/L时,P(3HB)含量最高。在上述条件下培养食酸戴尔福特菌野生型菌株,获得的细胞干重(CDW)和P(3HB)含量分别为9.31±0.13 g/L和45±1.5 wt.%。与未优化条件相比,这使得P(3HB)含量增加了40%。同时在2-L生物反应器中研究了溶解氧张力(DOT)对P(3HB)产量的影响。当DOT水平设定为30%时,获得了最高的CDW(11.37 g/L)和P(3HB)含量(44 wt.%)。由OPF汁生产的P(3HB)的拉伸强度为40 MPa,断裂伸长率为8%,这表明由可再生和廉价碳源生产的P(3HB)与由商业底物生产的P(3HB)相当。