Characterization of the Community of Black Meristematic Fungi Inhabiting the External White Marble of the Florence Cathedral.

Meristematic black fungi are a highly damaging group of microorganisms responsible for the deterioration of outdoor exposed monuments. Their resilience to various stresses poses significant challenges for removal efforts. This study focuses on the community of meristematic fungi inhabiting the external white marble of the Cathedral of Santa Maria del Fiore, where they contribute to its darkening.

Characterization of the Bacterial Communities Inhabiting Tropical Propolis of Puerto Rico.

Propolis is a resinous material produced by honeybees from different plant sources and used in the hive as a building material and to protect the colony from parasites and pathogens. Despite its antimicrobial properties, recent studies showed that propolis hosts diverse microbial strains, some with great antimicrobial potential. In this study, the first description of the bacterial community of propolis produced by the gentle Africanized honeybee was reported.

Ruthenium(II) Polypyridyl Complexes and Metronidazole Derivatives: A Powerful Combination in the Design of Photoresponsive Antibacterial Agents Effective under Hypoxic Conditions.

Ruthenium(II) polypyridyl complexes (RPCs) are gaining momentum in photoactivated chemotherapy (PACT), thanks to the possibility of overcoming the classical reliance on molecular oxygen of photodynamic therapy while preserving the selective drug activation by using light. However, notwithstanding the intriguing perspectives, the translation of such an approach in the development of new antimicrobials has been only barely considered. Herein, MTZH-1 and MTZH-2, two novel analogues of metronidazole (MTZ), a mainstay drug in the treatment of anaerobic bacterial infections, were designed and inserted in the strained ruthenium complexes [Ru(tpy)(dmp)(MTZ-1)]PF () and [Ru(tpy)(dmp)(MTZ-2)]PF () (tpy = terpyridine, dmp = 2,9-dimethyl-1,10-phenanthroline) (Chart 1).

Essential oils to contrast biodeterioration of the external marble of Florence Cathedral.

The search for more sustainable strategies to contrast biodeterioration of stone cultural heritage has been developing in recent years to find alternatives to synthetic biocides, since their toxicity and potential impact on the environment and health. In this study, the application of the oregano and thyme essential oils (EOs) was tested to control microbial growth on the external marble of Florence Cathedral affected by extended darkening. Before in situ application, preliminary tests were carried out to evaluate the interference of the EOs with marble (colorimetric and water absorption assays on marble specimens) and their efficacy in inhibiting marble microbiota (sensitivity test on nutrient media).

MinION technology for microbiome sequencing applications for the conservation of cultural heritage.

The MinION single-molecule sequencing system has been attracting the attention of the community of microbiologists involved in the conservation of cultural heritage. The use of MinION for the conservation of cultural heritage is extremely recent, but surprisingly the only few applications available have been exploring many different substrates: stone, textiles, paintings and wax. The use of MinION sequencing is mainly used to address the metataxonomy (with special emphasis on non-cultivable microorganisms) with the effort to identify species involved in the degradation of the substrates.

Bacterial Calcium Carbonate Mineralization Strategies for Conservation of Stone Artworks: From Cell Components to Microbial Community.

Calcareous stones have been widely used in artworks and buildings by almost all human cultures. Now, more than ever, the increased environmental pollution and global warming are threatening the stone cultural heritage. Weathering due to physical, chemical and biological factors results in monumental calcareous stone deterioration.

Propolis hosts a diversemicrobial community.

Despite the deep knowledge of the honey bee (Apis mellifera) gut microbiome, information on the microbial communities of other hive components is still scarce. Propolis originates from a natural resinous mixture that honeybees collect from different plants sources and modify; it is used mainly to ensure the hygiene of the hive. By virtue of its antimicrobial properties, propolis has been considered relatively aseptic, yet its ability to harbor microorganisms has not been previously investigated.

No evidence of queen immunisation despite transgenerational immunisation in Crematogaster scutellaris ants.

Like vertebrates, invertebrates evolved acquired immunity based on memory-like mechanisms, known as immunisation. Immunisation and its transmission among individuals are phylogenetically ancestral and conserved characters that have been reported in different insect orders. Physiological mechanisms are still largely unknown, and the high variability in responses in different host-parasite systems led to different conclusions.

Home economics in an oak gall: behavioural and chemical immune strategies against a fungal pathogen in Temnothorax ant nests.

Nest architecture is a fundamental character shaping immune strategies of social insects. The arboreal ant Temnothorax unifasciatus nests in cavities such as oak galls where the entire colony lives in a unique small chamber. In these conditions, physiological and behavioural strategies likely prevail over compartmentalisation and are presumably tuned with colony size.

A method to assess bioavailability of antibiotics in anthropogenic polluted ecosystems by using a bacterial fitness test.

Antibiotics released in the environment exert a selective pressure on the resident microbiota. It is well accepted that the mere measurement of antibiotics does not reflect the actual bioavailability. In fact, antibiotics can be adsorbed or complexed to particles and/or chemicals in water and soil.

Trans-generational immunization in the acrobat ant .

Trans-generational immunization is defined as the transmission of an enhanced resistance to a pathogen from parents to offspring. By using the host-parasite system of the ant and the entomopathogenic fungus , we describe this phenomenon for the first time in ants. We exposed four groups of hibernating queens to different treatments (i) a non-lethal dose of live conidiospores in Triton, (ii) a dose of heat-killed conidiospores in Triton, (iii) a control Triton solution, and (iv) a naive control.

Evidence of immunocompetence reduction induced by cadmium exposure in honey bees (Apis mellifera).

In the last decades a dramatic loss of Apis mellifera hives has been reported in both Europe and USA. Research in this field is oriented towards identifying a synergy of contributing factors, i.e.

Antibacterial activity of silver nanoparticles obtained by pulsed laser ablation in pure water and in chloride solution.

Silver nanoparticles (AgNPs) have increasingly gained importance as antibacterial agents with applications in several fields due to their strong, broad-range antimicrobial properties. AgNP synthesis by pulsed laser ablation in liquid (PLAL) permits the preparation of stable Ag colloids in pure solvents without capping or stabilizing agents, producing AgNPs more suitable for biomedical applications than those prepared with common, wet chemical preparation techniques. To date, only a few investigations into the antimicrobial effect of AgNPs produced by PLAL have been performed.

Antibiotic delivery by liposomes from prokaryotic microorganisms: Similia cum similis works better.

To date the effectiveness of antibiotics is undermined by microbial resistance, threatening public health worldwide. Enhancing the efficacy of the current antibiotic arsenal is an alternative strategy. The administration of antimicrobials encapsulated in nanocarriers, such as liposomes, is considered a viable option, though with some drawbacks related to limited affinity between conventional liposomes and bacterial membranes.

Antibacterial activity of silver nanoparticles grafted on stone surface.

Microbial colonization has a relevant impact on the deterioration of stone materials with consequences ranging from esthetic to physical and chemical changes. Avoiding microbial growth on cultural stones therefore represents a crucial aspect for their long-term conservation. The antimicrobial properties of silver nanoparticles (AgNPs) have been extensively investigated in recent years, showing that they could be successfully applied as bactericidal coatings on surfaces of different materials.

Molecular basis of bacterial calcium carbonate precipitation.

Calcium carbonate precipitation is a widespread process, occurring in different bacterial taxonomic groups and in different environments, at a scale ranging from the microscopic one of cells to that of geological formations. It has relevant implications in natural processes and has great potentiality in numerous applications. For these reasons, bacterial precipitation has been investigated extensively both in natural environments and under laboratory conditions.

Physiological requirements for carbonate precipitation during biofilm development of Bacillus subtilis etfA mutant.

Although the implications of calcium carbonate (CaCO(3)) precipitation by microorganisms in natural environments are quite relevant, the physiology and genetics of this phenomenon are poorly understood. We have chosen Bacillus subtilis 168 as our model to study which physiological aspects are associated with CaCO(3) (calcite) formation during biofilm development when grown on precipitation medium. A B.

Bacillus subtilis gene cluster involved in calcium carbonate biomineralization.

Calcium carbonate precipitation, a widespread phenomenon among bacteria, has been investigated due to its wide range of scientific and technological implications. Nevertheless, little is known of the molecular mechanisms by which bacteria foster calcium carbonate mineralization. In our laboratory, we are studying calcite formation by Bacillus subtilis, in order to identify genes involved in the biomineralization process.

Dominulin A and B: two new antibacterial peptides identified on the cuticle and in the venom of the social paper wasp Polistes dominulus using MALDI-TOF, MALDI-TOF/TOF, and ESI-ion trap.

Two new antibacterial peptides, denominated as Dominulin A and B, have been found on the cuticle and in the venom of females of the social paper wasp Polistes dominulus. The amino acidic sequence of the two peptides, determined by mass spectrometry, is INWKKIAE VGGKIL SSL for Dominulin A (MW = 1854 Da) and INWKKIAEIGKQVL SAL (MW = 1909 Da) for Dominulin B. Their presence on the cuticle was confirmed using MALDI-TOF by means of micro-extractions and direct analyses on body parts.

Growth phase-dependent expression of an endoglucanase encoding gene (eglS) in Streptomyces rochei A2.

Different growth phases of Streptomyces rochei A2, a cellulolytic strain isolated from termite gut, were determined in liquid culture. The strain exhibited a multiphasic growth curve typical of streptomycetes. In S.

Characterization of bacterial pectinolytic strains involved in the water retting process.

Pectinolytic microorganisms involved in the water retting process were characterized. Cultivable mesophilic anaerobic and aerobic bacteria were isolated from unretted and water-retted material. A total of 104 anaerobic and 23 aerobic pectinolytic strains were identified.

[Compulsory and additional parameters in water control].

The authors have analyzed 22 water samples from the Arno River (both river and drinking samples), as well as 11 effluent samples from an urban plant. Chemical and microbiological features of river samples were in line with the A3 class, needing treatment for drinking use (Executive Order n. 152/99); drinkable water met requirements (Presidents Decree n degrees 236/1988 and Executive Order n degrees 31/2001).

Molecular nature of RAPD markers from Haemophilus influenzae Rd genome.

Despite the widespread application of the random amplified polymorphic DNA (RAPD) technique, there is no experimental evidence of the molecular mechanism of random amplification starting from a complex template. To investigate this mechanism, we cloned and sequenced 23 selected RAPD bands amplified from Haemophilus influenzae Rd genomic DNA using eight decamer primers different in GC content and/or nucleotide sequence. As the whole genome sequence of H.

A putative sigma factor from Streptomyces sp. strain A21 can activate the expression of the cryptic operon bgl in Escherichia coli K-12.

Streptomyces sp A21 is a cellulolytic strain isolated from soil which was assigned to the genus Streptomyces on the basis of distinctive morphological features. A genomic library of A21 DNA has been constructed and transformed into Escherichia coli K-12 using a high-copy-number vector. One of the recombinant plasmids activates the cryptic bgl operon when inserted into appropriate strains.

Paralogous histidine biosynthetic genes: evolutionary analysis of the Saccharomyces cerevisiae HIS6 and HIS7 genes.

The HIS6 gene from Saccharomyces cerevisiae strain YNN282 is able to complement both the S. cerevisiae his6 and the Escherichia coli hisA mutations. The cloning and the nucleotide sequence indicated that this gene encodes a putative phosphoribosyl-5-amino-1-phosphoribosyl-4-imidazolecarboxiamide isomerase (5' Pro-FAR isomerase, EC 5.