Department of Microbiology, CBSH, OUAT, Bhubaneswar, Odisha, 751003, India.
School of Science, Gujurat State Fertilizer and Chemical University, Fertilizer Nagar, Vigyan Bhavan, Vadodara, Gujurat, 391750, India.
Antonie Van Leeuwenhoek. 2023 Jun;116(6):521-529. doi: 10.1007/s10482-023-01825-0. Epub 2023 Apr 7.
PHAs (polyhydroxyalkanoates) are the bio-polyester synthesized by different aerobic and anaerobic bacteria as energy storage granule. However, its synthesis by anaerobes or facultative anaerobes is an imperative part of their physiology via assimilating broad range of substrates than aerobes. Thus, three Gram positive facultative anaerobic PHAs producers viz., Enterococcus sp. FM3, Actinomyces sp. CM4 and Bacillus sp. FM5 were selected. Among them, Bacillus sp. FM5 showed higher cell biomass production in MSM (mineral salt medium) comprised of glucose & peptone as carbon & nitrogen source at pH 9, temperature 37 °C, inoculum 10% and incubation period 72 h. Under optimized condition, Bacillus sp. FM5 produced 0.89 and 1.5 g l of PHAs through submerged and solid-state fermentation in anoxic condition. In-silico analysis confirmed the facultative anaerobic PHAs producing bacteria as Bacillus cereus FM5. IR spectra of PHAs illustrated a strong absorption peak at 1718.50 cm representing carbonyl ester (C=O) functional group of PHB (polyhydroxybutyrate), belonging to the family PHAs. It is the first report demonstrating PHAs production by Bacillus cereus FM5 in anoxic condition through different bioprocess technology, which may pave the way in the arena of further biopolymer research.
聚羟基脂肪酸酯（PHAs）是不同需氧菌和厌氧菌合成的生物聚酯，作为能量储存颗粒。然而，与需氧菌相比，它们通过同化更广泛的基质来合成，这是其生理学的重要组成部分。因此，选择了三种革兰氏阳性兼性厌氧菌 PHA 生产者，即肠球菌 FM3、放线菌 CM4 和芽孢杆菌 FM5。其中，芽孢杆菌 FM5 在包含葡萄糖和蛋白胨作为碳源和氮源的 MSM（无机盐培养基）中，在 pH 9、温度 37°C、接种量 10%和培养时间 72 h 的条件下，显示出更高的细胞生物量生产。在优化条件下，芽孢杆菌 FM5 在缺氧条件下通过浸没式和固态发酵分别产生了 0.89 和 1.5 g/L 的 PHAs。计算机分析证实，兼性厌氧菌 PHA 产生菌为 FM5 蜡样芽孢杆菌。PHAs 的 IR 光谱在 1718.50 cm 处显示出一个强吸收峰，代表 PHB（聚羟基丁酸酯）的羰基酯（C=O）官能团，属于 PHAs 家族。这是首次报道 FM5 蜡样芽孢杆菌在缺氧条件下通过不同生物工艺技术生产 PHAs，这可能为进一步的生物聚合物研究开辟道路。
