Chuksina T A, Fatkulin A A, Sorokina N P, Smykov I T, Kuraeva E V, Masagnaya E S, Smagina K A, Shkurnikov M Yu
Department of Biology and Biotechnology, HSE University, Moscow, 101000 Russian Federation.
V.M. Gorbatov Federal Research Center for Food Systems, Moscow, 109316 Russian Federation.
Acta Naturae. 2024 Jul-Sep;16(3):102-109. doi: 10.32607/actanaturae.27468.
Fermented dairy products are produced using starter cultures. They ferment milk to create products with a certain texture, aroma, and taste. However, the lactic acid bacteria used in this production are prone to bacteriophage infection. We examined the genomes of two newly discovered bacteriophage species that were isolated from cheese whey during the cheesemaking process. We have determined the species and the lytic spectrum of these bacteriophages. Phages vL_20A and vL_296 were isolated using lactococcal indicator cultures. They have unique lytic spectra: of the 21 possible identified host bacteria, only four are shared amongst them. The vL_20A and vL_296 genomes comprise linear double-stranded DNA lengths with 21,909 and 22,667 nucleotide pairs, respectively. (ANI 93.3 and 92.6, respectively) is the closest to the phages vL_20A and vL_296. The analysis of the CRISPR spacers in the genomes of starter cultures did not reveal any phage-specific vL_20A or vL_296 among them. This study highlights the biodiversity of phages, their widespread presence in dairy products, and their virulence. However, the virulence of phages is balanced by the presence of a significant number of bacterial strains with different sensitivities to phages in the starter cultures due to the bacterial immune system.
发酵乳制品是使用发酵剂生产的。它们发酵牛奶以制造出具有特定质地、香气和味道的产品。然而，这种生产过程中使用的乳酸菌容易受到噬菌体感染。我们检查了在奶酪制作过程中从奶酪乳清中分离出的两种新发现的噬菌体物种的基因组。我们已经确定了这些噬菌体的种类和裂解谱。噬菌体vL_20A和vL_296是使用乳球菌指示培养物分离出来的。它们具有独特的裂解谱：在21种可能鉴定出的宿主细菌中，它们仅共有4种。vL_20A和vL_296基因组分别由长度为21,909和22,667个核苷酸对的线性双链DNA组成。（平均核苷酸一致性分别为93.3和92.6）与噬菌体vL_20A和vL_296最为接近。对发酵剂培养物基因组中的CRISPR间隔序列的分析未发现其中有任何噬菌体特异性的vL_20A或vL_296。这项研究突出了噬菌体的生物多样性、它们在乳制品中的广泛存在以及它们的毒性。然而，由于细菌免疫系统，发酵剂培养物中存在大量对噬菌体具有不同敏感性的细菌菌株，这平衡了噬菌体的毒性。
