The adaptation of lichen symbiosis to desert saline-alkali stress depends more on their symbiotic algae.

Soil salinization is a major environmental threat to the entire terrestrial ecosystem. Lichens arose from the symbiosis of fungi and algae or cyanobacteria. They have a high tolerance to various extreme environments, including adaptation to saline-alkali habitats. Thus, lichens are pioneer species on saline-alkali soil. However, the separate resilience of the two symbiotic partners under saline-alkali conditions remains insufficiently understood. In this study, two representative symbiotic algae, Diplosphaera chodatii and Trebouxia jamesii, were studied for their physiological response to the saline-alkali stress by adjusting different concentrations of NaHCO3, together with their respective symbiotic fungi Endocarpon pusillum (terricolous lichen) and Umbilicaria muhlenbergii (saxicolous lichen). The results indicate that cell growth rate and biomass in all four cultures decreased in alkali-alkaline substrate, while cellular activities and ultrastructure were affected to a distinct extent. Compared with the symbiotic fungi, the algae were found to be more active in coordinating oxidative stress and lipid peroxidation damage under the saline-alkali stress. The antioxidant system of the alga was especially shown as a key adaptive trait and it provides an important strategy for species survival and persistence in arid saline-alkali desert. The specific survival ability of the lichen symbiosis relies on the stress resilience advantages of the symbiotic partners in combination. Our study provided new insights into understanding the adaptation of lichen symbiosis to desert saline-alkali soil, and the potential of lichen symbiotic algae in the future desert ecological restoration.

Rapid identification of Brucella sepsis/osteomyelitis in a 6-year old febrile patient with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry directly from positive blood culture: a case report.

BACKGROUND: Brucella is high-consequence pathogen and one of the most common seen laboratory- acquired infection pathogens. Quick and accurate detection of the pathogen will be of great important to reducing laboratory- acquired infection. Traditional biomedical reaction based method is time consumption, and mass spectrometry based method greatly reduces time consumption in pathogen identification. In the case presented here, we shared our experience in identification of Brucella directly from positive blood culture with mass spectrometry based method. CASE PRESENTATION: The patient is a 6-year boy with a history of three weeks fever accompanied with sweating and a pain at right patella. The patient also has a history of thalassemia and blood transfusion was performed previously admitted to our hospital. Two bottles of marrow culture and one bottle of blood culture were positive, and direct mass spectrometry from positive culture material revealed Brucella infection within 1 h. CONCLUSION: Clinical characters and laboratory findings of the patient presented here might help clinician in non-endemic region to made suspected brucellosis diagnose. Our experience in rapid identification of Brucella from positive blood culture with MALDI-TOF SP could help preventing laboratory-acquired infection of Brucella.

New Insights into Lichenization in Agaricomycetes Based on an Unusual New Basidiolichen Species of Omphalina s. str.

The genus Omphalina is an ideal genus for studying the evolutionary mechanism of lichenization. Based on molecular phylogeny using ITS and nuLSU sequences by means of Bayesian and maximum likelihood analyses and morphological examination, combining the existence of green algae in basidiomata stipe and a Botrydina-type vegetative thallus, we described a bryophilous new basidiolichen species, Omphalina licheniformis, from a residential area of Jiangxi Province, China. This finding of unusual new basidiolichen species updated our understanding of the delimitation of Omphalina, indicating that both non-lichen-forming and lichen-forming fungal species are included simultaneously. The presence of algal cells in the basidiomata should receive more attention, as this would be helpful to distinguish more potential basidiolichens and explore the cryptic species diversity. This work provides new insights and evidence for understanding the significance of lichenization during the evolution of Agaricomycetes.