Jung Hee Ju, Kim Su Hyun, Cho Do Hyun, Kim Byung Chan, Bhatia Shashi Kant, Lee Jongbok, Jeon Jong-Min, Yoon Jeong-Jun, Yang Yung-Hun
Department of Biological Engineering, College of Engineering, Konkuk University, Seoul 05029, Republic of Korea.
Institute for Ubiquitous Information Technology and Applications, Konkuk University, Seoul 05029, Republic of Korea.
Polymers (Basel). 2022 Dec 10;14(24):5407. doi: 10.3390/polym14245407.
Polyhydroxybutyrate (PHB) is a biodegradable bioplastic with potential applications as an alternative to petroleum-based plastics. However, efficient PHB production remains difficult. The main cost of PHB production is attributed to carbon sources; hence, finding inexpensive sources is important. Galactose is a possible substrate for polyhydroxyalkanoate production as it is abundant in marine environments. Marine bacteria that produce PHB from galactose could be an effective resource that can be used for efficient PHB production. In this study, to identify a galactose utilizing PHB producer, we examined 16 Halomonas strains. We demonstrated that Halomonas cerina (Halomonas sp. YK44) has the highest growth and PHB production using a culture media containing 2% galactose, final 4% NaCl, and 0.1% yeast extract. These culture conditions yielded 8.98 g/L PHB (78.1% PHB content (w/w)). When galactose-containing red algae (Eucheuma spinosum) hydrolysates were used as a carbon source, 5.2 g/L PHB was produced with 1.425% galactose after treatment with activated carbon. Since high salt conditions can be used to avoid sterilization, we examined whether Halomonas sp. YK44 could produce PHB in non-sterilized conditions. Culture media in these conditions yielded 72.41% PHB content. Thus, Halomonas sp. YK44 is robust against contamination, allowing for long-term culture and economical PHB production.
聚羟基丁酸酯（PHB）是一种可生物降解的生物塑料，具有作为石油基塑料替代品的潜在应用价值。然而，高效生产PHB仍然困难重重。PHB生产的主要成本归因于碳源；因此，寻找廉价的碳源很重要。半乳糖是聚羟基链烷酸酯生产的一种可能底物，因为它在海洋环境中含量丰富。能从半乳糖生产PHB的海洋细菌可能是一种可用于高效生产PHB的有效资源。在本研究中，为了鉴定利用半乳糖生产PHB的菌株，我们检测了16株嗜盐单胞菌菌株。我们证明，在含有2%半乳糖、最终4%氯化钠和0.1%酵母提取物的培养基中，嗜盐栖居菌（嗜盐单胞菌属YK44）具有最高的生长速率和PHB产量。这些培养条件下产生了8.98 g/L的PHB（PHB含量为78.1%（w/w））。当使用含半乳糖的红藻（刺麒麟菜）水解产物作为碳源时，经活性炭处理后，含1.425%半乳糖的培养基产生了5.2 g/L的PHB。由于高盐条件可用于避免灭菌，我们检测了嗜盐单胞菌属YK44在非灭菌条件下是否能生产PHB。在这些条件下的培养基产生了72.41%的PHB含量。因此，嗜盐单胞菌属YK44对污染具有较强的抵抗力，能够进行长期培养并实现经济的PHB生产。
