Transcriptomic Analysis of Pediococcus pentosaceus Reveals Carbohydrate Metabolic Dynamics Under Lactic Acid Stress

Abstract

Stress physiology of lactic acid bacteria (LAB) is crucial to their ecological fitness and applicational implications. As a self-imposed stress, lactic acid is the major final metabolic product of LAB and its accumulation can be detrimental to bacterial cells. However, the relationship between LAB carbohydrate metabolism, the primary energy supplying bioactivities, and lactic acid stress responses is not fully understood. Pediococcus pentosaceus has been recognized as an important cell factory and demonstrated probiotic activities. This study investigated behavior of P. pentosaceus under lactic and acetic acid stresses, particularly with supplementations of metabolizable carbohydrates. Lactic and acetic acid retain similar growth stagnation effect, and both resulted in cell death in P. pentosaceus. All metabolizable carbohydrates improved bacterial survival compared to lactic acid control, while xylooligosaccharides (XOS) exerted the highest viability protective efficacy, 0.82 log CFU/mL higher population survived than other carbohydrates after 30 h of incubation. RNA-seq pipeline showcased the intensive global transcriptional responses of P. pentosaceus to lactic acid, which caused significant regulations (more than 2 Log2 fold) of 16.5% of total mRNA coding genes. Glucose mainly led to gene suppressions (83 genes) while XOS led to gene up-regulations (19 genes) under lactic acid stress. RT-qPCR study found that RNA polymerase-centered transcriptional regulation is the primary regulatory approach in evaluated culture conditions. The synergy between lactic acid stress and carbohydrate metabolism should be attentively contemplated in future studies and applications.

Age-specific composition of milk microbiota in Tibetan sheep and goats

“…Most species in the genus Pediococcus , identified in our study, act as probiotics with inhibitory effects against foodborne pathogens and antifungal properties (Kamiloğlu 2022 ). They contribute to regulating intestinal immune function, lowering cholesterol levels, and resisting tumors (Han et al 2021 ). Saccharopolyspora , a gram-positive bacterium, produces various active substances such as antibiotics, vitamins, enzymes, and algal growth factors (Veyisoglu et al 2022 ).…”

Isolation of Efficient Xylooligosaccharides-Fermenting Probiotic Lactic Acid Bacteria from Ethnic Pickled Bamboo Shoot Products

“…As far as our research is concerned, the utilization of XOSs by probiotic LAB has been extensively studied in terms of metabolic activity, enzyme activity, and transcriptomic analysis. The discovery of a coding region for xylanase and β-xylosidase was recorded in P. acitilactici [35], P. pentosaceus [36], Lp. plantarum, and Lv.…”