Department of Microbiology and Molecular Genetics, University of the Punjab, Lahore, Pakistan.
Department of Zoology, University of Lahore, Sargodha, Pakistan.
J Basic Microbiol. 2018 Mar;58(3):247-254. doi: 10.1002/jobm.201700276. Epub 2018 Jan 4.
Mixed bacterial cultures are increasingly being used in the production of polyhydroxyalkanoates (PHAs), as they have the potential to be more cost effective than axenic pure cultures. The purpose of this study was to use pure cultures in combination to identify their potential of PHA production. In this work we used volatile fatty acids (VFAs) and glucose as carbon source to check the ability of selected strains ST2 (Pseudomonas sp.) and CS8 (Bacillus sp.) as co-culture. The production of PHA in pure co-cultures of bacteria was therefore investigated in order to understand the effect of combining cultures on PHA production parameters and material properties. Bacteria could use the feed in better way when mixed as compared to individual strain. In undertaking this analysis, model volatile fatty acids (i.e., acetic and propionic acids) were used alone and in combination with glucose as feedstock. The production by Pseudomonas was 34% while 24% by Bacillus. However when combined and mixed feed (glucose + propionic acid) was used, 35% PHA produced. Overall, it was found that the ability of the pure cultures to produce PHA was low but when selected cultures were mixed, their ability to produce PHA was enhanced. Copolymers were obtained instead of homopolymers with improved properties. This suggests that industrial wastewater rich in volatile fatty acids and carbohydrates can be a good carbon source for PHA production with variable properties.
混合细菌培养物越来越多地用于聚羟基烷酸（PHA）的生产，因为它们具有比纯培养物更具成本效益的潜力。本研究的目的是使用纯培养物组合来确定它们生产 PHA 的潜力。在这项工作中，我们使用挥发性脂肪酸（VFAs）和葡萄糖作为碳源，以检查选定菌株 ST2（假单胞菌）和 CS8（芽孢杆菌）作为共培养物的 PHA 生产能力。因此，研究了细菌纯共培养物中 PHA 的生产情况，以了解组合培养对 PHA 生产参数和材料性能的影响。与单独的菌株相比，混合细菌可以更好地利用饲料。在进行这项分析时，使用了模型挥发性脂肪酸（即乙酸和丙酸）单独以及与葡萄糖一起作为原料。假单胞菌的产量为 34%，而芽孢杆菌的产量为 24%。然而，当使用混合饲料（葡萄糖+丙酸）时，PHA 的产量为 35%。总的来说，发现纯培养物生产 PHA 的能力较低，但当选择的培养物混合时，它们生产 PHA 的能力增强。获得了共聚物而不是具有改进性能的均聚物。这表明富含挥发性脂肪酸和碳水化合物的工业废水可以作为具有可变特性的 PHA 生产的良好碳源。
