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Restrictions about the use of chemicals have limited the availability of control measures against plant-parasitic nematodes. The search for more sustainable approaches has focused the attention on biological control agents, such as Trichoderma species. In recent years, there has been a growing interest in the use of biopolymers for a wide range of applications. These polysaccharide-based compounds may be 20 good carriers of microbial agents or act as barriers against pathogens or pests for their ability to form coating films. In this study, we evaluated the combination of a biopolymer obtained from the leguminous plant Ceratonia siliqua and T. harzianum M10, T. atroviride P1 or T. longibrachiatum MK1, as root protector or adjuvant agents, for the management of the root-knot nematode Meloidogyne incognita. Coating tomato roots with the carob galactomannan biopolymer followed by soil application of selected Trichoderma strains reduced the root galling index caused by M. incognita and soil nematode population in comparison to untreated control under greenhouse conditions. 25 Scanning electron microscopy revealed that coated tomato roots were embedded within a polymeric material. The sedimentation test showed that the addition of this biopolymer retarded the tendency of Trichoderma spores to settle in the bottom of aqueous suspension. In conclusion, beneficial fungi combined or formulated with a biopolymer could represent a promising strategy to increase their activity in plant protection and enhance their proliferation or distribution into rhizosphere.

Biocontrol fungal strains of the genus Trichoderma can antagonize numerous plant pathogens and promote plant growth using different mechanisms of action, including the production of secondary metabolites (SMs). In this work we analyzed the effects of repeated applications of selected Trichoderma strains or SMs on young olive trees on the stimulation of plant growth and on the development of olive leaf spot disease caused by Fusicladium oleagineum. In addition, metabolomic analyses and gene expression profiles of olive leaves were carried out by LC&ndash, MS Q-TOF and real-time RT-PCR, respectively. A total of 104 phenolic compounds were detected from olive leave extracts and 20 were putatively identified. Targeted and untargeted approaches revealed significant differences in both the number and type of phenolic compounds accumulated in olive leaves after Trichoderma applications, as compared to water-treated plants. Different secoiridoids were less abundant in treated plants than in controls, while the accumulation of flavonoids (including luteolin and apigenin derivatives) increased following the application of specific Trichoderma strain. The induction of defense-related genes, and of genes involved in the synthesis of the secoiridoid oleuropein, was also analyzed and revealed a significant variation of gene expression according to the strain or metabolite applied.

Mass testing is fundamental to face the pandemic caused by the coronavirus SARS-CoV-2 discovered at the end of 2019. To this aim, it is necessary to establish reliable, fast and cheap tools to detect viral particles in biological material so to identify the people capable to spread the infection. We demonstrate that a colorimetric biosensor based on gold nanoparticle (AuNP) interaction induced by SARS-CoV-2 lends itself as an outstanding tool for detecting viral particles in nasal and throat swabs. The extinction spectrum of a colloidal solution of multiple viral-target gold nanoparticles – AuNPs functionalized with antibodies targeting three surface proteins of SARS-CoV-2 (spike, envelope and membrane) – is redshifted in few minutes when mixed to a solution containing the viral particle. The optical density of the mixed solution measured at 560 nm was compared to the threshold cycle (Ct) of a Real Time-PCR (gold standard for detecting the presence of viruses) finding that the colorimetric method is able to detect very low viral load with a detection limit approaching that of RT-PCR. Since the method is sensitive to the infecting viral particle rather than to its RNA, the achievements reported here open new perspective not only in the context of the current and possible future pandemics, but also in microbiology as the biosensor proves itself to be a powerful though simple tool for measuring the viral particle concentration.

The development of fast and ultrasensitive methods to detect bacterial pathogens at low concentrations is of high relevance for human and animal health care and diagnostics. In this context, surface-enhanced Raman scattering (SERS) offers the promise of a simplified, rapid, and high-sensitive detection of biomolecular interactions with several advantages over previous assay methodologies. In this work, we have conceived reproducible SERS nanosensors based on tailored multilayer octupolar nanostructures which can combine high enhancement factor and remarkable molecular selectivity. We show that coating novel multilayer octupolar metastructures with proper self-assembled monolayer (SAM) and immobilized phages can provide label-free analysis of pathogenic bacteria via SERS leading to a giant increase in SERS enhancement. The strong relative intensity changes of about 2100% at the maximum scattered SERS wavelength, induced by the Brucella bacterium captured, demonstrate the performance advantages of the bacteriophage sensing scheme. We performed measurements at the single-cell level thus allowing fast identification in less than an hour without any demanding sample preparation process. Our results based on designing well-controlled octupolar coupling platforms open up new opportunities toward the use of bacteriophages as recognition elements for the creation of SERS-based multifunctional biochips for rapid culture and label-free detection of bacteria.

A total of fifteen potential methyl t-butyl ether (MtBE)-degrading bacterial strains were isolated from contaminated soil. They have been identified as belonging to the genera Bacillus, Pseudomonas, Kocuria, Janibacter, Starkeya, Bosea, Mycolicibacterium, and Rhodovarius. Bacillus aryabhattai R1B, S. novella R8b, and M. mucogenicum R8i were able to grow using MtBE as carbon source, exhibiting different growth behavior and contaminant degradation ability. Their biocontrol ability was tested against various fungal pathogens. Both S. novella R8b and B. aryabhattai were effective in reducing the development of necrotic areas on leaves within 48 hours from Botritys cinerea and Alternaria alternata inoculation. Whereas, M. mucogenicum effectively controlled B. cinerea after 72 hours. Similar results were achieved using Pythium ultimum, in which the application of isolated bacteria increased seed germination. Only M. mucogenicum elicited tomato plants resistance against B. cinerea. This is the first report describing the occurrence of bioremediation and biocontrol activities in M. mucogenicum, B. aryabhattai and S. novella species. The production of maculosin and its antibiotic activity against Rhizoctonia solani has been reported for first time from S. novella. Our results highlight the importance of multidisciplinary approaches to achieve a consistent selection of bacterial strains useful for plant protection and bioremediation purposes.

The development of a simple and low cost electrochemical impedance immunosensor based on screen printed gold electrode for rapid detection of Escherichia coli in water is reported. The immunosensor is fabricated by immobilizing anti-E. coli antibodies onto a gold surface in a covalent way by the photochemical immobilization technique, a simple procedure able to bind antibodies upright onto gold surfaces. Impedance spectra are recorded in 0.01 M phosphate buffer solution (PBS) containing 10 mM Fe(CN)63&minus, /Fe(CN)64&minus, as redox probe. The Nyquist plots can be modelled with a modified Randles circuit, identifying the charge transfer resistance Rct as the relevant parameter after the immobilization of antibodies, the blocking with BSA and the binding of E. coli. The introduction of a standard amplification procedure leads to a significant enhancement of the impedance increase, which allows one to measure E. coli in drinking water with a limit of detection of 3 &times, 101 CFU mL&minus, 1 while preserving the rapidity of the method that requires only 1 h to provide a &ldquo, yes/no&rdquo, response. Additionally, by applying the Langmuir adsorption model, we are able to describe the change of Rct in terms of the &ldquo, effective&rdquo, electrode, which is modified by the detection of the analyte whose microscopic conducting properties can be quantified.

A diketopiperazine has been purified from a culture filtrate of the endophytic fungus Paraphaeosphaeria sporulosa, isolated from healthy tissues of strawberry plants in a survey of microbes as sources of anti-bacterial metabolites. Its structure has been determined by nuclear magnetic resonance (NMR) and liquid chromatography–mass spectrometry (LC–MS) analyses and was found to be identical to cyclo(L-Pro-L-Phe) purified from species of other fungal genera. This secondary metabolite has been selected following bioguided-assay fractionation against two strains of Salmonella enterica, the causal agent of bovine gastroenteritis. The diketopiperazine cyclo(L-Pro-L-Phe), isolated for the first time from Paraphaeosphaeria species, showed minimum inhibitory concentration (MIC) values of 71.3 and 78.6 μg/mL against the two S. enterica strains. This finding may be significant in limiting the use of synthetic antibiotics in animal husbandry and reducing the emergence of bacterial multidrug resistance. Further in vivo experiments of P. sporulosa diketopiperazines are important for the future application of these metabolites.

The aim of this study was to evaluate the effect of two different conditions of space allowance on reproductive performance and oxidative parameters, biochemical and hormonal profiles in buffalo. The trial was carried out on one hundred pluriparous buffaloes divided into two different groups. Buffaloes in group HDG (high density group - n = 50) were maintained in open yards that allowed 10 m(2)/head while those in group LDG (low density group -n = 50) were maintained in 22 m(2)/head. After 60 days, 45 buffaloes in each group underwent synchronization of ovulation by Ovsynch and were artificially inseminated to assess the reproductive efficiency. On the day of AI blood samples were collected to evaluate oxidative stress, hormonal and metabolic profile. Furthermore, on the same day, blood, saliva and hair samples were collected to assess cortisol levels. Simultaneously, five buffaloes/group, were synchronized but not inseminated and on the day of the hypothetical timed artificial insemination (TAI), follicular fluid was recovered by OPU and blood samples were collected from each animal to evaluate the redox status on both plasma and follicular fluid. Conception rate on day 70 post-AI was similar between the two groups (57.5 vs. 62.5%, in LDG and HDG, respectively). No significant differences were found on redox status, metabolic and hormonal profile and cortisol levels between the groups. In conclusion, on the conditions of this experiment it was observed that the space allowance of 10 m(2)/head did not affect reproductive efficiency in buffalo cows.

Three bacteriophages, 118970_sal1, 118970_sal2, and 64795_sal3, were isolated from water buffalo feces in southern Italy, exhibiting lytic activity against Salmonella enterica serovar Enteritidis. These bacteriophages belong to the Siphoviridae family and have a 60,113-bp, 123,930-bp, and 48,094-bp double-stranded DNA (dsDNA) genome containing 72, 173, and 80 coding sequences (CDSs), respectively.

Fungi of the genus Sepedonium have been studied for their properties as antagonist agents of various plant pathogens, as well as antibiotic and pigment producers. We investigated the antimicrobial ability of S. chrysospermum strain 704 isolated from fruit bodies of wild basidiomycetes and found to be not pathogenic on cultivated mushrooms. A strong antagonistic activity versus different pathogenic fungi and a high level of production of enzymes and antibiotic compounds were observed. The best growth conditions for the production of specific hydrolytic enzymes were determined. From fungal culture filtrate we purified and characterised a metabolite that strongly inhibit spore germination and hyphal growth of the necrotrophic pathogen Botrytis cinerea. The metabolite was identified as a 3,6-dimethyl--resorcylaldehyde, and showed a strong inhibition of the pathogen at concentrations starting from 0.05 ppm. Furthermore, a low level of phytotoxicity of the purified antibiotic, analysed by infiltration in bean leaves, was observed.