School of Food Science and Engineering, Wuhan Polytechnic University, Wuhan 430000, China.
School of Life Science and Technology, Wuhan Polytechnic University, Wuhan 430000, China.
J Food Prot. 2023 Sep;86(9):100125. doi: 10.1016/j.jfp.2023.100125. Epub 2023 Jul 3.
In order to explore the application prospects of phages for controlling bacterial contamination, a lytic phage Pf17397_F_PD1 (Later abbreviated as PD1) was isolated from fish guts using Pseudomonas fluorescens ATCC 17397 as the host bacterium. The phage displayed short latency (18 min), long lysis period (212 min), and high lysis volume (1.47 × 10 PFU/each cell). It displayed wide temperature (30-70°C) and pH (4-11) tolerance. Genomic comparison revealed a maximum sequence identity of 48.65% between phage PD1 and other identified phages, indicating that PD1 was a new phage. The phage PD1 significantly inhibited the growth of P. fluorescens in milk and grass carp at 4°C and 25°C. Compared to the negative control, bacterial levels in milk stored at 25°C for 48 h were reduced by 2.71 log CFU/mL and 2.84 log CFU/mL at the multiplicity of infection (MOI) of 100 and 1,000, respectively. In contrast, when grass carp were stored at 25°C for 24 h, the bacterial load was reduced by 1.28 log CFU/g and 2.64 log CFU/g compared to the control (MOI of 100 and 1,000). When the phage was applied for preservation of grass carp blocks, total volatile salt nitrogen (TVB-N) values of phage-treated samples increased by 6.8 mg/100 g and 7.5 mg/100 g at MOI of 100 and 1,000, respectively, after 7 days of storage, which was significantly lower than that of the control group (15.83 mg/100 g). This study showed that phage PD1 was a good natural biological antimicrobial agent against P. fluorescens ATCC 17397.
为了探索噬菌体在控制细菌污染方面的应用前景，本研究采用荧光假单胞菌 ATCC 17397 作为宿主菌，从鱼肠道中分离出一种裂解性噬菌体 Pf17397_F_PD1（简称 PD1）。该噬菌体潜伏期短（18 min）、裂解期长（212 min）、裂解体积大（1.47×10 PFU/个细胞）。它对温度（30-70°C）和 pH（4-11）具有广泛的耐受性。基因组比较显示，噬菌体 PD1 与其他已鉴定的噬菌体之间的最大序列同一性为 48.65%，表明 PD1 是一种新的噬菌体。噬菌体 PD1 能显著抑制牛奶和草鱼中荧光假单胞菌在 4°C 和 25°C 下的生长。与阴性对照组相比，在 MOI 为 100 和 1000 时，在 25°C 下储存 48 h 的牛奶中，细菌水平分别降低了 2.71 log CFU/mL 和 2.84 log CFU/mL。相比之下，当草鱼在 25°C 下储存 24 h 时，与对照组相比（MOI 为 100 和 1000），细菌负荷分别降低了 1.28 log CFU/g 和 2.64 log CFU/g。当噬菌体用于草鱼块保鲜时，噬菌体处理样品的总挥发性盐氮（TVB-N）值在 MOI 为 100 和 1000 时分别增加了 6.8 mg/100 g 和 7.5 mg/100 g，在储存 7 天后，显著低于对照组（15.83 mg/100 g）。本研究表明，噬菌体 PD1 是一种针对 ATCC 17397 荧光假单胞菌的良好天然生物抗菌剂。
