Blood Serum Stimulates the Virulence Potential of Mucorales through Enhancement in Mitochondrial Oxidative Metabolism and Rhizoferrin Production.

This study analyzed the role of blood serum in enhancing the mitochondrial metabolism and virulence of Mucorales through rhizoferrin secretion. We observed that the spores of clinically relevant Mucorales produced in the presence of serum exhibited higher virulence in a heterologous infection model of Galleria mellonella. Cell-free supernatants of the culture broth obtained from spores produced in serum showed increased toxicity against Caenorhabditis elegans, which was linked with the enhanced secretion of rhizoferrin. Spores from Mucoralean species produced or germinated in serum showed increased respiration rates and reactive oxygen species levels. The addition of non-lethal concentrations of potassium cyanide and N-acetylcysteine during the aerobic or anaerobic growth of Mucorales decreased the toxicity of the cell-free supernatants of the culture broth, suggesting that mitochondrial metabolism is important for serum-induced virulence. In support of this hypothesis, a mutant strain of Mucor lusitanicus that lacks fermentation and solely relies on oxidative metabolism exhibited virulence levels comparable to those of the wild-type strain under serum-induced conditions. Contrary to the lower virulence observed, even in the serum, the ADP-ribosylation factor-like 2 deletion strain exhibited decreased mitochondrial activity. Moreover, spores produced in the serum of M. lusitanicus and Rhizopus arrhizus that grew in the presence of a mitophagy inducer showed low virulence. These results suggest that serum-induced mitochondrial activity increases rhizoferrin levels, making Mucorales more virulent.

Optimization of production of xylanases with low cellulases in Fusarium solani by means of a solid state fermentation using statistical experimental design.

Demand for fungal xylanases in industrial biotechnological processes shows a clear increase worldwide, so there is an interest in adjusting the conditions of microbial xylanases production. In this study, the ability of the fungus Fusarium solani to produce extracellular xylanases with low cellulolytic activity was optimized by Box Wilson design. The best culture conditions were determined to obtain a crude enzyme preparation with significant xylanolytic activity and little cellulolytic activity. In most treatments, the xylanolytic activity was higher than the cellulolytic activity. A negative effect on the production of endoxylanases, ß-xylosidases and endocellulases was observed with the increasing of xylan concentration. Increasing the incubation time adversely affected the production of endocellulases and ß-xylosidases. According to the mathematical model and experimental tests, it is possible to produce endoxylanases with minimal endocellulase activity increasing incubation time and the concentration of ammonium sulfate. The optimal culture conditions to produce a greater amount of endoxylanases (10.65U/mg) and low endocellulases from F. solani were: 2.5% (w/v) xylan, 5.0, 2.0 and 0.4g/l, of yeast extract, ammonium sulfate and urea, respectively, with 120h of incubation.

Chemical composition of the essential oil from Ageratina jocotepecana and its repellent effect on drywood termite incisitermes marginipennis / Composición química del aceite esencial de Ageratina jocotepecana y su efecto repelente en termitas de madera seca incisitermes marginipennis

Essential oils obtained from new plant species with metabolomes unexplored or poorly known are a natural resource to find molecules with deterrent (irritant) effect. The aim of this study was to evaluate the chemical composition and the termite repellent activity of the essential oils from Ageratina jocotepecana. The repellent effect was determined by the pine drywood termite Incisitermes marginipennis behavior of to sense the contact of the tunnel wall in the wooden colony in the presence of an irritant obstacle caused by essential oils. Gas chromatographic analysis of the essential oils from flower, leaf, and stem showed quantitative and qualitative differences in components. Twenty-eight volatile components were identified by their mass spectra (MS). beta-caryophyllene, carvacrol, spathulenol, and terpinen-4-ol were the four major components, of them in relation 0.1 M citronellol, the 0.1 M carvacrol was the best repellent of the termite. Essential oils from A. jocotepecana exhibited a termite repellent effect due to their major components. Additionally, more research about the termite repellent action of carvacrol is still needed.

Los aceites esenciales obtenidos de nuevas especies de plantas con metabolomas inexplorados o poco conocidos son un recurso natural para encontrar moléculas con efecto disuasivo (irritante). El propósito del estudio fue evaluar la composición química de los aceites esenciales de Ageratina jocotepecana y su actividad repelente de termitas. El efecto repelente fue determinado por el comportamiento de las termitas de la madera seca de pino Incisitermes marginipennis de sentir el contacto de la pared del túnel en la colonia de madera en la presencia de un obstáculo irritante causado por los aceites esenciales. El análisis de cromatografía de gases de los aceites esenciales de flores, hojas y tallo mostró diferencias cuantitativas y cualitativas en componentes. Veintiocho componentes volátiles fueron identificados por sus espectros de masas (MS). beta-cariofileno, carvacrol, spathulenol y terpinen-4-ol fueron los cuatro componentes mayoritarios, de ellos en relación con 0,1 M citronelol el control positivo, el carvacrol 0,1 M fue el mejor repelente de la termita. Además, más investigación sobre la acción repelente de termitas de carvacrol se necesita realizar.

[Bacterium Arthrobacter agilis UMCV2 and diverse amines inhibit in vitro growth of wood-decay fungi]. / La bacteria Arthrobacter agilis UMCV2 y diversas aminas inhiben el crecimiento in vitro de hongos destructores de madera.

The kingdom Fungi is represented by a large number of organisms, including pathogens that deteriorate the main structural components of wood, such as cellulose, hemicellulose and lignin. The aim of our work was to characterize the antifungal activity in Arthrobacter agilis UMCV2 and diverse amines against wood-decaying fungi. Four fungal organisms (designated as UMTM) were isolated from decaying wood samples obtained from a forest in Cuanajo-Michoacán, México. Two of them showed a clear enzymatic activity of cellulases, xylanases and oxido-reducing enzymes and were identified as Hypocrea (UMTM3 isolate) and Fusarium (UMTM13 isolate). In vitro, the amines showed inhibitory effect against UMTM growth and one of the amines, dimethylhexadecylamine (DMA16), exhibited strong potential as wood preventive treatment, against the attack of decaying fungi.

La bacteria Arthrobacter agilis UMCV2 y diversas aminas inhiben el crecimiento in vitro de hongos destructores de madera / Bacterium Arthrobacter agilis UMCV2 and diverse amines inhibit in vitro growth of wood-decay fungi

El reino Fungi está representado por innumerable cantidad de organismos entre los cuales se encuentran hongos patógenos que deterioran los principales componentes estructurales de la madera, como celulosa, hemicelulosa y lignina. El objetivo de nuestro trabajo fue caracterizar la actividad antifúngica y la producción de diversas aminas de Arthrobacter agilis UMCV2 con acción antagónica sobre hongos xilófagos. Para ello, se aislaron 4 organismos fúngicos (designados en conjunto UMTM) a partir de madera en descomposición en un bosque de pino encino de la comunidad de Cuanajo, Michoacán, México. Dos de ellos presentaron una clara actividad enzimática de celulasas, xilanasas y enzimas accesorias óxido-reductoras, y fueron identificados como pertenecientes a 2 géneros agresivos para la madera: Hypocrea (aislado UMTM3) y Fusarium (aislado UMTM13). In vitro, las aminas evaluadas mostraron tener efecto inhibitorio sobre el crecimiento de los UMTM y la dimetilhexadecilamina; uno de estos compuestos mostró un fuerte potencial para ser utilizado como tratamiento preventivo contra el ataque de hongos destructores de madera.

The kingdom Fungi is represented by a large number of organisms, including pathogens that deteriorate the main structural components of wood, such as cellulose, hemicellulose and lignin. The aim of our work was to characterize the antifungal activity in Arthrobacter agilis UMCV2 and diverse amines against wood-decaying fungi. Four fungal organisms (designated as UMTM) were isolated from decaying wood samples obtained from a forest in Cuanajo-Michoacán, México. Two of them showed a clear enzymatic activity of cellulases, xylanases and oxido-reducing enzymes and were identified as Hypocrea (UMTM3 isolate) and Fusarium (UMTM13 isolate). In vitro, the amines showed inhibitory effect against UMTM growth and one of the amines, dimethylhexadecylamine (DMA16), exhibited strong potential as wood preventive treatment, against the attack of decaying fungi.

Absolute configuration of (13R)- and (13S)-labdane diterpenes coexisting in Ageratina jocotepecana.

Chemical investigation of the hexanes extracts of Ageratina jocotepecana afforded (-)-(5S,9S,10S,13S)-labd-7-en-15-oic acid (1), methyl (-)-(5S,9S,10S,13S)-labd-7-en-15-oate (2), (+)-(5S,8R,9R,10S,13R)-8-hydroxylabdan-15-oic acid (3), and (-)-(5S,9S,10S,13Z)-labda-7,13-dien-15-oic acid (5). The coexistence of (13R)- and (13S)-labdanes in this member of the Asteraceae family was demonstrated by vibration circular dichroism measurements of ester 2 and methyl (+)-(5S,8R,9R,10S,13R)-8-hydroxylabdan-15-oate (4) in comparison to the DFT B3LYP/DGDZVP-calculated spectra. In addition, transformation of 1 and 3 with HClO4 in MeOH yielded epimeric methyl (+)-(5S,10S,13S)-labd-8-en-15-oate (6) and methyl (+)-(5S,10S,13R)-labd-8-en-15-oate (7), respectively, confirming the presence of C-13 epimers in this plant. Diterpene 1 showed remarkable antibacterial activity against Bacillus subtilis (MIC 0.15 mg/mL) and Staphylococcus aureus (MIC 0.78 mg/mL), while diterpene 3 exhibited moderate activities against the same organisms.

Cassane diterpenes from Caesalpinia platyloba.

The dichloromethane extract from the leaves of Caesalpinia platyloba provided cassane diterpenes whose structures were determined as (-)-(5S,6R,8S,9S,10R,14R)-6-acetoxyvouacapane (1), (-)-(5S,6R,8S,9S,10R,12Z,14R)-6-acetoxycassa-12,15-diene (3), and (-)-(5S,6R,8S,9S,10R,13E)-6-acetoxycassa-13,15-diene (4). Compound 1 was chemically correlated with (-)-(5S,6R,8S,9S,10R,14R)-6-hydroxyvouacapane (2), (+)-(5S,8S,9S,10R,14R)-6-oxovouacapane (5), and (+)-(5S,6S,8S,9S,10R,14R)-6-acetoxyvouacapane (6), the last one previously isolated from Dipteryx lacunifera. The absolute configurations of all six diterpenes 1-6 were established by comparison of DFT calculated vibrational circular dicroism spectra of 1, 2 and 5 with those obtained experimentally. In addition, several reported chemical shifts for 2 and 5 were reassigned based on two-dimensional NMR measurements.

The Neurospora crassa chr-1 gene is up-regulated by chromate and its encoded CHR-1 protein causes chromate sensitivity and chromium accumulation.

The ChrA membrane protein belongs to the CHR superfamily of chromate ion transporters, which includes homologues from bacteria, archaea and eukaryotes. Bacterial ChrA homologues confer chromate resistance by exporting chromate ions from the cell's cytoplasm. The Neurospora crassa strain 74-A chr-1 gene encodes a putative CHR-1 protein of 507 amino acid residues, which belongs to the CHR superfamily. RT-PCR assays showed that expression of the chr-1 gene was up-regulated by chromate exposure of N. crassa cultures. Introduction in N. crassa of sense and antisense fragments of the chr-1 gene, as part of a silencing module within the pSilent-1 vector, produced transformants with a phenotype of resistance to chromate and diminished accumulation of chromium, as compared with the control strain containing only the vector. A chromate-resistance phenotype was also observed in N crassa strains deleted in the genomic chr-1 gene, thus confirming that the absence of CHR-1 protein confers chromate resistance to the fungus. The cDNA from N. crassa chr-1 gene (Ncchr-1) was cloned into the pYES2 vector under the control of a GAL promoter and the resulting recombinant plasmid was transferred to the yeast Saccharomyces cerevisiae. Galactose-induced S. cerevisiae transformants expressing Ncchr-1 were more sensitive to chromate and accumulated 2.5 times more chromium than the induced strain containing only the vector. Excess sulfate, a chromate analog, was unable to protect S. cerevisiae chr-1 transformants from chromate toxicity. These data indicate that the N. crassa CHR-1 protein functions as a transporter that takes up chromate; it also appears that this transport occurs in a sulfate-independent fashion. This is the first report assigning a role as a chromate transporter to a nonbacterial CHR protein.

Effect of citric acid on the proteolytic activity of Zea mays L. / Efeito do ácido cítrico sobre a atividade proteolítica de Zea mays L.

Hybrids of Zea mays L. (Buffalo, Falcon, H360 y HV313) were treated with citric acid (2000 ppm). Grain yield, soluble protein and proteolytic activity were monitored when the crop reached physiological maturity. Citric acid was applied before the appearance of the flag leaf, and induced an increase in the grain yield from 4222 to 5780 kg/ha, in the soluble protein from 6.34 to 7.91 mg/mg and into the proteolytic activity from 14.3 to 65.7 µU mg prot-1. This is an increase of 2 to 12 times in the Falcon, H360 and HV313 hybrids, while the Buffalo hybrid responded with less intensity to the treatment with citric acid. In the H360 hybrid treated with citric acid, an increase in the proteolytic activity of aspartyl serine proteases was observed. The results indicate that citric acid differentially induces proteolytic activity and vigor in the corn hybrids analyzed.

Zea mays L. híbridos (Buffalo, Falcão, H360 e HV313) foram tratados com ácido cítrico (2000 ppm). O rendimento de grãos, proteína solúvel e atividade proteolítica foram monitorados na fase de maturação fisiológica do cultivo. O ácido cítrico aplicado antes do aparecimento da folha bandeira induziu um aumento na produção de grãos 4222 a 5780 kg/ha, na proteína solúvel de 6.34 7.91 mg/mg de peso seco e atividade proteolítica de 14.3 to 65.7 µU mg prot-1, esto é, um incremento de 2-12 vezes nos híbridos Falcao, H360 e HV313, enquanto o híbrido Buffalo responderam com menor intensidade ao tratamento com ácido cítrico. No híbrido H360, tratadas com ácido cítrico, apresentou-se um aumento na atividade proteolítica de aspartil proteases e serin protease. Os resultados indicam que o ácido cítrico diferencialmente induz a atividade proteolítica e o vigor de híbridos de milho testados.

Efficient chemical and enzymatic saccharification of the lignocellulosic residue from Agave tequilana bagasse to produce ethanol by Pichia caribbica.

Bagasse of Agave tequilana (BAT) is the residual lignocellulosic waste that remains from tequila production. In this study we characterized the chemical composition of BAT, which was further saccharified and fermented to produce ethanol. BAT was constituted by cellulose (42%), hemicellulose (20%), lignin (15%), and other (23%). Saccharification of BAT was carried out at 147 °C with 2% sulfuric acid for 15 min, yielding 25.8 g/l of fermentable sugars, corresponding to 36.1% of saccharificable material (cellulose and hemicellulose contents, w/w). The remaining lignocellulosic material was further hydrolyzed by commercial enzymes, ~8.2% of BAT load was incubated for 72 h at 40 °C rendering 41 g/l of fermentable sugars corresponding to 73.6% of the saccharificable material (w/w). Mathematic surface response analysis of the acid and enzymatic BAT hydrolysis was used for process optimization. The results showed a satisfactory correlation (R (2) = 0.90) between the obtained and predicted responses. The native yeast Pichia caribbica UM-5 was used to ferment sugar liquors from both acid and enzymatic hydrolysis to ethanol yielding 50 and 87%, respectively. The final optimized process generated 8.99 g ethanol/50 g of BAT, corresponding to an overall 56.75% of theoretical ethanol (w/w). Thus, BAT may be employed as a lignocellulosic raw material for bioethanol production and can contribute to BAT residue elimination from environment.

D-(+)-pinitol, a component of the heartwood of Enterolobium cyclocarpum (Jacq.) Griseb.

D-(+)-Pinitol, a natural product of the group of cyclitols, was purified for the first time from an aqueous extract of the heartwood of Enterolobium cyclocarpum, and its chemical structure was determined.