Thermophilic fungi as new sources for production of cellulases and xylanases with potential use in sugarcane bagasse saccharification.

AIMS: To obtain new cellulases and xylanases from thermophilic fungi; evaluate their potential for sugarcane bagasse saccharification. METHODS AND RESULTS: Thirty-two heat-tolerant fungi were isolated from the environment, identified (morphological/molecular tools) and the production of the enzymes was evaluated by solid state fermentation using lignocellulosic materials as substrates. Myceliophthora thermophila JCP 1-4 was the best producer of endoglucanase (357·51 U g(-1) ), ß-glucosidase (45·42 U g(-1) ), xylanase (931·11 U g(-1) ) and avicelase (3·58 U g(-1) ). These enzymes were most active at 55-70°C and stable at 30-60°C. Using crude enzymatic extract from M. thermophila JCP 1-4 to saccharify sugarcane bagasse pretreated with microwaves and glycerol, glucose and xylose yields obtained were 15·6 and 35·13% (2·2 and 1·95 g l(-1) ), respectively. CONCLUSIONS: All isolated fungi have potential to produce the enzymes; M. thermophila JCP 1-4 enzymatic extract have potential to be better explored in saccharification experiments. Pretreatment improved enzymatic saccharification, as sugar yields were much higher than those obtained from in natura bagasse. SIGNIFICANCE AND IMPACT OF THE STUDY: Myceliophthora thermophila JCP 1-4 produces avicelase (not commonly found among fungi; important to hydrolyse crystalline cellulose) and a ß-glucosidase resistant to glucose inhibition, interesting characteristics for saccharification experiments.

Safety Planning Intervention Training Among Early Career Mental Health Professionals: Perception of Self-Efficacy, Usefulness and Feasibility.

INTRODUCTION: In 2021, in Argentina there were 3,639 deaths by suicide, equivalent to one death every three hours. Evidence indicates that brief suicide preventive interventions in emergency services, such as the Safety Planning Intervention (SPI), effectively reduce future suicidal ideation and attempts in both adults and adolescents. OBJECTIVE: To evaluate the perception of self-efficacy, and the feasibility and usefulness of a training in SPI in early career mental health professionals. METHOD: Sixty-nine early career mental health professionals from Buenos Aires participated in a 3-hour SPI training. Through an online survey, measurements were taken in three times: before and after the training and 8-10 weeks after the training. RESULTS: All participants completed the pre- and post-training measures, and 43 of them completed the follow-up survey. Post-training measures showed an increase in self-efficacy, maintaining the effect at 8-10 weeks. The SPI was found useful and feasible to be implemented in clinical care. More than half of the participants reported having used the SPI during follow-up. CONCLUSION: Results suggest that training in SPI is associated with an increased perception of self-efficacy of early career mental health professionals; this is maintained after 2 months post-training. In addition, the intervention is perceived as feasible, acceptable and useful for professionals in training.

Zinc opposes genotoxicity of cadmium and vanadium but not of lead.

Protection by essential metals against the genotoxic effects of toxic elements is an open question. Here, human Hs27 dermal fibroblasts and B-mel melanoblasts were exposed for 10 days to (1 µM) zinc (Zn) or copper (Cu) or selenium (+ 4, Sei; + 6, Sea). Afterwards, cells were exposed for 3 days to subtoxic concentrations of lead (Pb, 100 µM) or vanadium (+ 5, V, 2 µM) or cadmium (Cd, 3 µM), slightly reducing, by themselves, cell proliferation and unaffecting cell viability and apoptosis. Genotoxic damage was evaluated by cytokinesis-block micronucleus assay (CBMN) and single cell gel electrophoresis (Comet assay, CA). CBMN and CA were preliminarly assessed following 3, 10 and 30 days of exposure to the above concentrations of Pb, V and Cd: Pb induced micronuclei (MN) formation in both Hs27 and B-mel cells, without determining direct DNA damage (as shown by CA); V did not reveal genotoxic effects on fibroblasts (as shown by CBMN and CA) but increased the frequency of MN and comets in melanoblasts; Cd induced a great number of MN and comets in fibroblasts but not in melanoblasts; all these effects did not differ after 3, 10 or 30 days of exposure to such elements so that Hs27 and B-mel cells were exposed to Pb,V and Cd for 3 days following pretreatment with (1 µM) Zn, Cu, Sei or Sea. By itself, the 10 day-exposure to (1 µM) Zn, Cu, Sei or Sea did not affect cell proliferation, viability, apoptosis and formation of MN or comets in either Hs27 or B-mel cells. Only Zn significantly reduced the Cd- and V-induced MN and comet formation in fibroblasts and melanoblasts, respectively; in these cells, however, Zn did not affect the Pb-induced MN formation. These results emphasize the role of Zn, in respect to other essential metals, in opposing the genotoxic effects of cancerogenic (Cd) or potentially cancerogenic elements (V).

Experimental demonstration of emittance compensation with velocity bunching.

In this Letter we report the first experiments aimed at the simultaneous demonstration of the emittance compensation process and velocity bunching in a high brightness electron source, the SPARC photoinjector in INFN-LNF. While a maximum compression ratio up to a factor 14 has been observed, in a particular case of interest a compression factor of 3, yielding a slice current of 120 A with less than 2 microm slice emittance, has been measured. This technique may be crucial in achieving high brightness beams in photoinjectors aiming at optimized performance of short wavelength single-pass free electron lasers or other advanced applications in laser-plasma accelerators.

Test of "crab-waist" collisions at the DAPhiNE Phi factory.

The electron-positron collider DAPhiNE, the Italian Phi factory, has been recently upgraded in order to implement an innovative collision scheme based on large crossing angle, small beam sizes at the crossing point, and compensation of beam-beam interaction by means of sextupole pairs creating a "crab-waist" configuration in the interaction region. Experimental tests of the novel scheme exhibited an increase by a factor of 3 in the peak luminosity of the collider with respect to the performances reached before the upgrade. In this Letter we present the new collision scheme, discuss its advantages, describe the hardware modifications realized for the upgrade, and report the results of the experimental tests carried out during commissioning of the machine in the new configuration and standard operation for the users.

Acute mercury intoxication and use of chelating agents.

There is a great hazard of mercury intoxication in the third world for artisanal miners using mercury as amalgam for extracting and refining gold. In developing countries, there is the possibility of risk regarding exposure to Hg from amalgam tooth fillings, ethyl-Hg (thimerosal) added as antiseptic to vaccines and methyl-Hg in fish. In one case, a 41-year-old man attempted suicide by ingesting 100 mg of HgCl2. After 8 hours, he developed hematemesis and entered the intensive care unit; his urinary Hg was 10.1 mg/l. Treatment with 2,3-dimercaptopropanol (BAL) was started by intramuscular route after 16 hours at the dosage of 5 mg/kg body weight every 4 hours on days 2-3 and 3 mg/kg every 6 hours on days 4-5 and then every 12 hours on days 6-14 without adverse side effects. Acute Hg intoxication can be managed with BAL as first choice chelator, whereas the less toxic 2,3-dimercaptosuccinic acid (DMSA) and 2,3-dimercaptopropane-1-sulfonic acid (DMPS) should be reserved for cases of less severe inorganic Hg or methyl-Hg acute intoxication. Such agents, recommended only for the treatment of acute Hg poisoning, should not be used for patients suffering from neurological diseases in which environmental Hg exposure is hypothesised.

Analysis methodology of movable emittance-meter measurements for low energy electron beams.

The design of photoinjectors for modern free electron laser linac relies heavily on particular beam behavior in the few meters after the gun. To experimentally characterize it a movable emittance meter was proposed and built [L. Catani et al., Rev. Sci. Instrum. 77, 093301 (2006)] based on the beam slicing technique. This paper addresses all the aspects of analysis of the data acquired with the emittance meter and common to any slit based emittance measurement for low energy beams.

Copper(II) catalysis in cyanide conversion into ethyl carbamate in spirits and relevant reactions.

The role of copper(II) species in the oxidation of inorganic cyanide to cyanate and in the conversion of cyanate or urea into ethyl carbamate was investigated. The oxidation process has been shown to be independent from the dissolved oxygen. Elemental analysis and infrared spectroscopy have shown the formation of a mixed copper carbonate/hydroxide in the process of oxidation of cyanide to cyanate in water/ethanol. The complexation to Cu(II) of cyanate formed upon cyanide oxidation makes the former more susceptible to nucleophilic attack from ethanol, with conversion into ethyl carbamate. Comparatively, urea has a minor role with respect to cyanide in the formation of ethyl carbamate. Therefore, the urea present in some samples of Brazilian sugar cane spirit (cachaça) has been shown to have almost no influence on the ethyl carbamate content of cachaças, which comes essentially from cyanide. Fe(II,III) affords results similar to those found with Cu(II). Some suggestions are presented to avoid ethyl carbamate formation in spirits during distillation.

Halotolerance, ligninase production and herbicide degradation ability of basidiomycetes strains.

Fungi have been recently recognized as organisms able to grow in presence of high salt concentration with halophilic and halotolerance properties and their ligninolytic enzyme complex have an unspecific action enabling their use to degradation of a number of xenobiotic compounds. In this work, both the effect of salt and polyols on growth of the basidiomycetes strains, on their ability to produce ligninolytic enzyme and diuron degradation were evaluated. Results showed that the presence of NaCl in the culture medium affected fungal specimens in different ways. Seven out of ten tested strains had growth inhibited by salt while Dacryopinax elegans SXS323, Polyporus sp MCA128 and Datronia stereoides MCA167 fungi exhibited higher biomass production in medium containing 0.5 and 0.6 mol.L(-1) of NaCl, suggesting to be halotolerant. Polyols such as glycerol and mannitol added into the culture media improved the biomass and ligninases production by D. elegans but the fungus did not reveal consumption of these polyols from media. This fungus degraded diuron in medium control, in presence of NaCl as well as polyols, produced MnP, LiP and laccase.

Halotolerance, ligninase production and herbicide degradation ability of basidiomycetes strains

Fungi have been recently recognized as organisms able to grow in presence of high salt concentration with halophilic and halotolerance properties and their ligninolytic enzyme complex have an unspecific action enabling their use to degradation of a number of xenobiotic compounds. In this work, both the effect of salt and polyols on growth of the basidiomycetes strains, on their ability to produce ligninolytic enzyme and diuron degradation were evaluated. Results showed that the presence of NaCl in the culture medium affected fungal specimens in different ways. Seven out of ten tested strains had growth inhibited by salt while Dacryopinax elegans SXS323, Polyporus sp MCA128 and Datronia stereoides MCA167 fungi exhibited higher biomass production in medium containing 0.5 and 0.6 mol.L-1 of NaCl, suggesting to be halotolerant. Polyols such as glycerol and mannitol added into the culture media improved the biomass and ligninases production by D. elegans but the fungus did not reveal consumption of these polyols from media. This fungus degraded diuron in medium control, in presence of NaCl as well as polyols, produced MnP, LiP and laccase.

Production of cyclodextrins by CGTase from Bacillus clausii using different starches as substrates.

Cyclodextrins (CDs) are cyclic oligasaccharides composed by D-glucose monomers joined by alpha-1,4-D glicosidic linkages. The main types of CDs are alpha-, beta- and gamma-CDs consisting of cycles of six, seven, and eight glucose monomers, respectively. Their ability to form inclusion complexes is the most important characteristic, allowing their wide industrial application. The physical property of the CD-complexed compound can be altered to improve stability, volatility, solubility, or bio-availability. The cyclomaltodextrin glucanotransferase (CGTase, EC 2.4.1.19) is an enzyme capable of converting starch into CD molecules. In this work, the CGTase produced by Bacillus clausii strain E16 was used to produce CD from maltodextrin and different starches (commercial soluble starch, corn, cassava, sweet potato, and waxy corn starches) as substrates. It was observed that the substrate sources influence the kind of CD obtained and that this CGTase displays a beta-CGTase action, presenting a better conversion of soluble starch at 1.0%, of which 80% was converted in CDs. The ratio of total CD produced was 0:0.89:0.11 for alpha/beta/gamma. It was also observed that root and tuber starches were more accessible to CGTase action than seed starch under the studied conditions.

Direct measurement of the double emittance minimum in the beam dynamics of the sparc high-brightness photoinjector.

In this Letter we report the first experimental observation of the double emittance minimum effect in the beam dynamics of high-brightness electron beam generation by photoinjectors; this effect, as predicted by the theory, is crucial in achieving minimum emittance in photoinjectors aiming at producing electron beams for short wavelength single-pass free electron lasers. The experiment described in this Letter was performed at the SPARC photoinjector site, during the first stage of commissioning of the SPARC project. The experiment was made possible by a newly conceived device, called an emittance meter, which allows a detailed and unprecedented study of the emittance compensation process as the beam propagates along the beam pipe.