N cycle in burnt and unburnt soils under different vegetation covers in the Mediterranean region

The Mediterranean area is a fragile semi-arid ecosystem, characterized by a high level of biodiversity. Due to its climatic conditions, fires are frequent. Fires strongly impact the microbial community of the soil and the biogeochemical cycles of the ecosystem. Although the N cycle is crucial, limited data is available about the effects of fires on the microbial community involved in this cycle in these types of environments. The aim of this research was to evaluate the effects that fire has on the amount of microbial populations involved in the different steps of the N cycle in soils under different vegetation cover. To achieve this, surface soils were ollected from unburnt and burnt soil of four plant species (holm oak, pine, black locust, and herbs) from inside the Vesuvius National Park that are typical of the Mediterranean maquis. The soils were analyzed for their main abiotic proprieties (pH, water content, concentrations of organic C, total C, total N, NH4+, NO2–, and NO3–). They were also analyzed for their amount of total DNA (DNA yield), eubacterial DNA (16S rDNA), N2-fixer, ammonia oxidizer, archaea ammonia oxidizer, and denitrifier DNA. The largest amount of microbial populations involved in the N cycle of the unburnt soil was observed in the holm oak soil. Fires slightly affected the soil abiotic properties and the DNA yield of the unburnt soil, but significantly increased the amount of eubacteria, nitrifiers, and denitrifiers. The conditions of the pine and holm oak soil encouraged a faster recovery of the amount of microbial populations involved in the N cycle

Oral lactobacillus species in systemic sclerosis

In systemic sclerosis (SSc), the gastrointestinal tract (GIT) plays a central role in the patient’s quality of life. The microbiome populates the GIT, where a relationship between the Lactobacillus and gastrointestinal motility has been suggested. In this study, the analysis of oral Lactobacillus species in SSc patients and healthy subjects using culture-independent molecular techniques, together with a review of the literature on microbiota and lactobacilli in SSc, has been carried out. Twenty-nine SSc female patients (mean age 62) and twenty-three female healthy subjects (HS, mean age 57.6) were enrolled and underwent tongue and gum swab sampling. Quantitative PCR was conducted in triplicate using Lactobacillus specific primers rpoB1, rpoB1o and rpoB2 for the RNA-polymerase β subunit gene. Our data show significantly (p = 0.0211) lower LactobacillusspprpoB sequences on the tongue of patients with SSc compared to HS. The mean value of the amount of Lactobacillus ssprpoB gene on the gumsofSSc patients was minor compared to HS. A significant difference between tongue and gums (p = 0.0421) was found in HS but not in SSc patients. In conclusion, our results show a lower presence of Lactobacillus in the oral cavity of SSc patients. This strengthens the hypothesis that Lactobacillus may have both a protective and therapeutic role in SSc patients

Rational Design of a Plasmid Origin That Replicates Efficiently in Both Gram-Positive and Gram-Negative Bacteria

Background: Most plasmids replicate only within a particular genus or family