Dept. of Bio and Nano Technology, Guru Jambheshwar University of Science & Technology, Hisar 125001, India.
Dept. of Microbiology, Central University of Haryana, Mahendergarh 123031, India.
Int J Biol Macromol. 2023 Apr 1;233:123575. doi: 10.1016/j.ijbiomac.2023.123575. Epub 2023 Feb 9.
Polyhydroxybutyrate (PHB) has significant potential for replacing non-biodegradable traditional plastic, which is responsible for several global environmental issues. The main problem with switching to bio-based alternatives for petrochemical plastics is the large price gap on the market. To overcome this problem, the present research was focused on the utilization of inexpensive substrates i.e. agricultural residues for cost-effective PHB production by endospore-forming bacteria Bacillus badius MTCC 13004. For efficient PHB production, Box-Behnken Design (BBD) was selected for media optimization and to observe the interactive effects of four variables i.e. pH, Na acetate, Banana peel, and mustard cake. PHB yield of 2.11 g/L was attained under optimized conditions compared to non-optimized conditions (0.72 g/L). FTIR spectra analysis of PHB extracted from Bacillus badius was found to be similar to commercial PHB. NMR data was also matched with the chemical shift signals CH, CH, and CH of PHB. The melting temperature (Tm) and glass transition temperature (Tg) of PHB from Bacillus badius was found to be 165.14 and 2.68 °C, respectively. Further, PCR protocol was also designed to amplify key enzymes of the PHB synthesis pathway i.e. PHB synthase (phb C gene).
聚羟基丁酸酯（PHB）在替代不可生物降解的传统塑料方面具有重要潜力，这些传统塑料是造成全球许多环境问题的主要原因。将石化塑料转向基于生物的替代品的主要问题是市场上的价格差距很大。为了解决这个问题，本研究集中于利用廉价的基质，即农业废弃物，通过芽孢形成细菌枯草芽孢杆菌 MTCC 13004 生产具有成本效益的 PHB。为了实现高效的 PHB 生产，选择了 Box-Behnken 设计（BBD）来优化培养基，并观察四个变量（即 pH、Na 乙酸盐、香蕉皮和芥菜饼）的交互作用。与非优化条件（0.72 g/L）相比，在优化条件下获得了 2.11 g/L 的 PHB 产量。从枯草芽孢杆菌提取的 PHB 的傅里叶变换红外光谱（FTIR）分析结果与商业 PHB 相似。NMR 数据也与 PHB 的 CH、CH 和 CH 的化学位移信号相匹配。从枯草芽孢杆菌获得的 PHB 的熔点（Tm）和玻璃化转变温度（Tg）分别为 165.14°C 和 2.68°C。此外，还设计了 PCR 方案来扩增 PHB 合成途径的关键酶，即 PHB 合酶（phbC 基因）。
