Low doses of lactoferrin supplementation in weaning calves

Different trials demonstrated lactoferrin (LF) to possess antimicrobial, antiviral, antimycotic and anti-inflammatory activity. This molecule is an iron-binding protein that could have preventive effects on calf diseases. Several authors studied the effects of LF at doses between 1 and 10 g/calf/day as a supplement in milk administrated to weaning calves. The results are variable and not always consistent. Twenty-two female replacement calves divided into 2 groups (Control-C and Treated-LF) during a 56-d experimental period were employed to investigate the effect of the use of 0.1 g/d of LF during weaning on growth performances, feed efficiency and health status. The field trial was conducted employing an early weaning protocol (49-d of length, excluding the colostral phase). After parturition, density and immunoglobulin G (IgG) content of dam colostrum were measured as a colostrum quality indicator. Only colostrum with at least 50 mg/mL of IgG was bottle-fed to the calf. Morphometric measurements and feedstuff intake were recorded weekly. Health status and milk consumption were evaluated daily. Calves receiving low doses of LF had numerically less incidence of diarrhoea than the C group (P > 0.05). From a statistical point of view, any significant difference was observed between groups both on growth performances and feed efficiency. A trend for an increase of the FCR was found for LF group at weaning (P = 0.099). More researches are needed to define the optimal dose and the real action of LF in weaning calves

Bryo-Activities: A Review on How Bryophytes Are Contributing to the Arsenal of Natural Bioactive Compounds against Fungi

Usually regarded as less evolved than their more recently diverged vascular sisters, which currently dominate vegetation landscape, bryophytes seem having nothing to envy to the defensive arsenal of other plants, since they had acquired a suite of chemical traits that allowed them to adapt and persist on land. In fact, these closest modern relatives of the ancestors to the earliest terrestrial plants proved to be marvelous chemists, as they traditionally were a popular remedy among tribal people all over the world, that exploit their pharmacological properties to cure the most different diseases. The phytochemistry of bryophytes exhibits a stunning assortment of biologically active compounds such as lipids, proteins, steroids, organic acids, alcohols, aliphatic and aromatic compounds, polyphenols, terpenoids, acetogenins and phenylquinones, thus it is not surprising that substances obtained from various species belonging to such ancestral plants are widely employed as antitumor, antipyretic, insecticidal and antimicrobial. This review explores in particular the antifungal potential of the three Bryophyta divisions\u2014mosses (Musci), hornworts (Anthocerotae) and liverworts (Hepaticae)\u2014to be used as a sources of interesting bioactive constituents for both pharmaceutical and agricultural areas, providing an updated overview of the latest relevant insights

In Vitro Sprouted Plantlets of Citrullus colocynthis (L.) Schrad Shown to Possess Interesting Levels of Cucurbitacins and Other Bioactives against Pathogenic Fungi

Cucurbitacins, structurally different triterpenes mainly found in the members of Cucurbitaceae, possess a vast pharmacological potential. Genus Cucurbita, Cucumis, and Citrullus are affluent in these bioactive compounds, and, amongst them, Citrullus colocynthis (L.) Schrad. is widely exploited in folk medicine, since a huge number of diseases are successfully treated with organic and aqueous extracts obtained from different organs and tissues of the plant. The well-known pharmacological activities of such species have been attributed to its peculiar composition, which includes cucurbitacins and other bioactive molecules; thus, owing to its high importance as a valuable natural resource for pharmaceuticals and nutraceuticals, C. colocynthis propagation and multiplication protocols are considered significant, but the exploitation of its phytochemical potential is limited by the restricted cultivation conditions and the low rate of seed germination in the natural environment; in fact, the assessment of accumulation rate of specific phytochemicals under controlled conditions is still missing. Axenically sprouted plantlets obtained without the use of culture media or the addition of hormones have been evaluated here for the production of bioactive compounds and relevant bioactive features. Our results proved that derived organic extracts contain cucurbitacins and other bioactives, show antioxidant potential, and exert activity against some pathogenic fungi (Candida krusei, C. albicans, C. parapsilosis, C. glabrata, and Aspergillus flavus), supporting the feasibility of a methodology intended to scale-up cultivation of this species as a source of pharmaceutically interesting compounds, achievable from plantlets cultivated under laboratory conditions

Response to metals in the liverwort Lunularia cruciata and in the charophyte Nitella mucronata

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Ochratoxin A Control in Meat Derivatives: Intraspecific Biocompetition between Penicillium nordicum

A Penicillium nordicum strain previously assessed for its atoxigenicity was tested against a toxigenic strain of the same species on salami, in order to assess its effectiveness as a biocontrol agent for OTA containment. Sixty salami were inoculated with different combinations of P. nordicum OTA−/OTA+ suspensions and ripened under controlled thermohygrometric conditions. After 7, 18, 29, and 40 days, both fungal counts and chemical analyses were carried out on casings. OTA was never found in salami used as a control, while it was occasionally detected in traces (0.08–0.76 μg/kg) in salami inoculated with the atoxigenic P. nordicum strain. It was otherwise detected at levels varying from 2.84 to 15.85 μg/kg in coinoculated salami and from 48.66 to 177.79 μg/kg in salami inoculated with the toxigenic P. nordicum strain. OTA levels detected when coinoculation occurred were 91.1%, 85.8%, and 94.2% lower than those found in samples inoculated with the toxigenic strain, respectively, after 18, 29, and 40 ripening days. Biocontrol approach using intraspecific competition proved very effective in reducing both settlement of toxigenic strains and OTA contamination and could be therefore considered an interesting strategy to avoid OTA contamination in moulded meats, if used in association with fungal commercial starters

Phyto-Beneficial Traits of Rhizosphere Bacteria: In Vitro Exploration of Plant Growth Promoting and Phytopathogen Biocontrol Ability of Selected Strains Isolated from Harsh Environments

Beneficial interactions between plants and some bacterial species have been long recognized, as they proved to exert various growth-promoting and health-protective activities on economically relevant crops. In this study, the growth promoting and antifungal activity of six bacterial strains, Paenarthrobacter ureafaciens, Beijerinckia fluminensis, Pseudomonas protegens, Arthrobacter sp., Arthrobacter defluii, and Arthrobacter nicotinovorans, were investigated. The tested strains resulted positive for some plant growth promoting (PGP) traits, such as indole-3-acetic acid (IAA), 1-aminocyclopropane-1- carboxylate-deaminase (ACC-deaminase), siderophore production, and solubilization of phosphates. The effect of the selected bacteria on Arabidopsis thaliana seedlings growth was assessed using different morphological parameters. Bacterial activity against the phytopathogenic fungal species Aspergillus flavus, Fusarium proliferatum, and Fusarium verticillioides was also assessed, since these cause major yield losses in cereal crops and are well-known mycotoxin producers. Strains Pvr_9 (B. fluminensis) and PHA_1 (P. protegens) showed an important growth-promoting effect on A. thaliana coupled with a high antifungal activity on all the three fungal species. The analysis of bacterial broths through ultra performance liquid chromatography–mass spectrometry (UPLC–MS) and liquid chromatography–electrospray ionization–mass spectrometry (LC–ESI–MS/MS) confirmed the presence of potential PGP-compounds, among these are desferrioxamine B, aminochelin, asperchrome B, quinolobactin siderophores, and salicylic acid

Validation and Ecological Niche Investigation of a New Fungal Intraspecific Competitor as a Biocontrol Agent for the Sustainable Containment of Aflatoxins on Maize Fields

Crop yield and plant products quality are directly or indirectly affected by climate alterations. Adverse climatic conditions often promote the occurrence of different abiotic stresses, which can reduce or enhance the susceptibility to pests or pathogens. Aflatoxin producing fungi, in particular, whose diffusion and deleterious consequences on cereals commodities have been demonstrated to highly depend on the temperature and humidity conditions that threaten increasingly larger areas. Biological methods using intraspecific competitors to prevent fungal development and/or toxin production at the pre-harvest level are particularly promising, even if their efficacy could be affected by the ecological interaction within the resident microbial population. A previously characterized Aspergillus flavus atoxigenic strain was applied in two maize fields to validate its effectiveness as a biocontrol agent against aflatoxin contamination. At one month post-application, at the harvest stage, its persistence within the A. flavus population colonizing the maize kernels in the treated area was assessed, and its efficacy was compared in vitro with a representation of the isolated atoxigenic population. Results proved that our fungal competitor contained the aflatoxin level on maize grains as successfully as a traditional chemical strategy, even if representing less than 30% of the atoxigenic strains re-isolated, and achieved the best performance (in terms of bio-competitive potential) concerning endogenous atoxigenic isolates

Filamentous sieve element proteins are able to limit phloem mass flow, but not phytoplasma spread

In Fabaceae, dispersion of forisomes\u2014highly ordered aggregates of sieve element proteins\u2014in response to phytoplasma infection was proposed to limit phloem mass flow and, hence, prevent pathogen spread. In this study, the involvement of filamentous sieve element proteins in the containment of phytoplasmas was investigated in non-Fabaceae plants. Healthy and infected Arabidopsis plants lacking one or two genes related to sieve element filament formation\u2014AtSEOR1 (At3g01680), AtSEOR2 (At3g01670), and AtPP2-A1 (At4g19840)\u2014were analysed. TEM images revealed that phytoplasma infection induces phloem protein filament formation in both the wild-type and mutant lines. This result suggests that, in contrast to previous hypotheses, sieve element filaments can be produced independently of AtSEOR1 and AtSEOR2 genes. Filament presence was accompanied by a compensatory overexpression of sieve element protein genes in infected mutant lines in comparison with wild-type lines. No correlation was found between phloem mass flow limitation and phytoplasma titre, which suggests that sieve element proteins are involved in defence mechanisms other than mechanical limitation of the pathogen

Phytoplasma infection in tomato is associated with re-organization of plasma membrane, ER stacks, and actin filaments in sieve elements

Phytoplasmas, biotrophic wall-less prokaryotes, only reside in sieve elements of their host plants. The essentials of the intimate interaction between phytoplasmas and their hosts are poorly understood, which calls for research on potential ultrastructural modifications. We investigated modifications of the sieve-element ultrastructure induced in tomato plants by ‘Candidatus Phytoplasma solani,’ the pathogen associated with the stolbur disease. Phytoplasma infection induces a drastic re-organization of sieve-element substructures including changes in plasma membrane surface and distortion of the sieve-element reticulum. Observations of healthy and stolbur-diseased plants provided evidence for the emergence of structural links between sieve-element plasma membrane and phytoplasmas. One-sided actin aggregates on the phytoplasma surface also inferred a connection between phytoplasma and sieve-element cytoskeleton. Actin filaments displaced from the sieve-element mictoplasm to the surface of the phytoplasmas in infected sieve elements. Western blot analysis revealed a decrease of actin and an increase of ER-resident chaperone luminal binding protein (BiP) in midribs of phytoplasma-infected plants. Collectively, the studies provided novel insights into ultrastructural responses of host sieve elements to phloem-restricted prokaryotes

The phytochelatin synthase from Nitella mucronata (Charophyta) plays a role in the homeostatic control of iron(II)/(III)

Although some charophytes (sister group to land plants) have been shown to synthesize phytochelatins (PCs) in response to cadmium (Cd), the functional characterization of their phytochelatin synthase (PCS) is still completely lacking. To investigate the metal response and the presence of PCS in charophytes, we focused on the species Nitella mucronata. A 40 kDa immunoreactive PCS band was revealed in mono-dimensional western blot by using a polyclonal antibody against Arabidopsis thaliana PCS1. In two-dimensional western blot, the putative PCS showed various spots with acidic isoelectric points, presumably originated by post-translational modifications. Given the PCS constitutive expression in N. mucronata, we tested its possible involvement in the homeostasis of metallic micronutrients, using physiological concentrations of iron (Fe) and zinc (Zn), and verified its role in the detoxification of a non-essential metal, such as Cd. Neither in vivo nor in vitro exposure to Zn resulted in PCS activation and PC significant biosynthesis, while Fe(II)/(III) and Cd were able to activate the PCS in vitro, as well as to induce PC accumulation in vivo. While Cd toxicity was evident from electron microscopy observations, the normal morphology of cells and organelles following Fe treatments was preserved. The overall results support a function of PCS and PCs in managing Fe homeostasis in the carophyte N. mucronata