Phenotypic and genomic analysis of inulin consumption by Lactiplantibacillus plantarum strains from Sichuan pickle.

AIMS: To investigate the capability, properties, and molecular mechanism of inulin fermentation by lactic acid bacteria (LAB) from Sichuan pickle. METHODS AND RESULTS: A total of 79 LAB strains were purified from 30 aged Sichuan pickle brine samples, and only 21 Lactiplantibacillus plantarum strains (26.58%, 21/79) derived from 15 samples grew well through utilizing inulin as a carbon source. The fermentation tests through using long-chain inulin (lc-inulin) as a carbon source showed that only 6 L. plantarum strains grew well, while other 15 strains could only utilize short-chain oligofructose (FOS), and thin-layer chromatography analysis evidenced a strain specificity of inulin consumption patterns. Lactiplantibacillus plantarum YT041 is a vigorous inulin fermenter, and whole genome sequencing data revealed that sacPTS1 and fosRABCDXE operons might be associated with the fermentation of FOS and lc-inulin, respectively. CONCLUSIONS: The phenotype of inulin consumption is commonly present in LAB from Sichuan pickle, which is strain-specific and largely depends on their specific ecological niche and degree of polymerization.

Global genome and comparative transcriptomic analysis reveal the inulin consumption strategy of Lactiplantibacillus plantarum QS7T.

Sichuan pickle is a natural combination of probiotics and dietary fibers, in which a strain Lactiplantibacillus plantarum QS7T was found to be capable of efficiently metabolizing inulin. However, the underlying molecular mechanism of inulin consumption by the strain QS7T is unclear. Therefore, this study firstly investigated the metabolic characteristics of inulin in the strain QS7T, and the results showed it could grow very well on the medium containing inulin as a carbon source (maximum OD600 nm, 1.891 ± 0.028) and degrade both short-chain oligofructose and long-chain fructan components through thin layer chromatography analysis. Genomic sequencing and analysis revealed a high percentage of functional genes associated with carbohydrate transport and metabolism, particularly glycoside hydrolase (GH) genes responsible for hydrolysing carbohydrates, within the genome of the strain QS7T. Furthermore, comparative transcriptomic analysis of L. plantarum QS7T in response to inulin or glucose indicated that functional genes associated with inulin consumption including several genes encoding PTS sugar transporters and two predicted GH32 family genes encoding beta-fructofuranosidase and beta-fructosidase were significantly up-regulated by inulin compared to the gene expression on glucose. In conclusion, we obtained a mechanistic understanding of interplay between probiotic L. plantarum QS7T derived from Sichuan pickle and natural dietary fiber, inulin; totally two operons including a sacPTS1 operon responsible for metabolizing short-chain oligofructose primarily in the cytoplasm and a fos operon responsible for extracellularly degrading all moderate and long-chain fructan components linked to inulin consumption by L. plantarum QS7T.

Warming delays the phenological sequences of an autumn-flowering invader.

Phenology can play an important role in driving plant invasions; however, little is known about how climate warming, nitrogen (N) deposition, and invasion stages influence the phenological sequences of autumn-flowering invaders in a subtropical climate. Accordingly, we conducted an experiment to address the effects of experimental warming, N-addition, and community types on the first inflorescence buds, flowering, seed-setting, and dieback of invasive Solidago canadensis. Warming delayed the onset of first inflorescence buds, flowering, seed-setting, and dieback; N-addition did not influence these four phenophases; community types influenced the onset of first seed-setting but not the other phenological phases. Seed-setting was more sensitive to experimental manipulations than the other phenophases. The onset of first inflorescence buds, flowering, and seed-setting was marginally or significantly correlated with ramet height but not ramet numbers. Our results suggest that future climate warming might delay the phenological sequences of autumn-flowering invaders and some phenophases can shift with invasion stages.

Dissecting Solidago canadensis-soil feedback in its real invasion.

The importance of plant-soil feedback (PSF) has long been recognized, but the current knowledge on PSF patterns and the related mechanisms mainly stems from laboratory experiments. We aimed at addressing PSF effects on community performance and their determinants using an invasive forb Solidago canadensis. To do so, we surveyed 81 pairs of invaded versus uninvaded plots, collected soil samples from these pairwise plots, and performed an experiment with microcosm plant communities. The magnitudes of conditioning soil abiotic properties and soil biotic properties by S. canadensis were similar, but the direction was opposite; altered abiotic and biotic properties influenced the production of subsequent S. canadensis communities and its abundance similarly. These processes shaped neutral S. canadensis-soil feedback effects at the community level. Additionally, the relative dominance of S. canadensis increased with its ability of competitive suppression in the absence and presence of S. canadensis-soil feedbacks, and S. canadensis-induced decreases in native plant species did not alter soil properties directly. These findings provide a basis for understanding PSF effects and the related mechanisms in the field conditions and also highlight the importance of considering PSFs holistically.

Altered neurotransmitter levels with post-traumatic stress disorder.

AIM: The aim of this study was to observe the changes in the monoamine neurotransmitter levels of patients with post-traumatic stress disorder (PTSD) and explore whether the neurotransmitter level is correlated with the severity of PTSD. MATERIAL AND METHODS: A total of 15 PTSD patients without any physical injuries were enrolled into the study. Another 15 cases of pre-restoration patients were recruited as controls who experienced traumatic events but did not experience PTSD or had a Posttraumatic stress disorder Check List-Civilian version (PCL-C) score lower than 12 points. The levels of plasma monoamine neurotransmitters, including norepinephrine, 5-hydroxytryptamine, and dopamine, were tested using enzyme-linked immunosorbent assays. RESULTS: No significant differences were found between the monoamine neurotransmitter levels of the PTSD and the control groups (p > 0.05). A correlation study confirmed that the monoamine neurotransmitter levels and the PCL-C scores of the PTSD group were not significantly correlated (p > 0.05). CONCLUSION: No neurotransmitter changes are seen in PTSD caused by simple mental trauma, and the PCL-C scores do not associate with PTSD.