CotH3 mediates fungal invasion of host cells during mucormycosis

Angioinvasion is a hallmark of mucormycosis. Previously, we identified endothelial cell glucose-regulated protein 78 (GRP78) as a receptor for Mucorales that mediates host cell invasion. Here we determined that spore coat protein homologs (CotH) of Mucorales act as fungal ligands for GRP78. CotH proteins were widely present in Mucorales and absent from noninvasive pathogens. Heterologous expression of CotH3 and CotH2 in Saccharomyces cerevisiae conferred the ability to invade host cells via binding to GRP78. Homology modeling and computational docking studies indicated structurally compatible interactions between GRP78 and both CotH3 and CotH2. A mutant of Rhizopus oryzae, the most common cause of mucormycosis, with reduced CotH expression was impaired for invading and damaging endothelial cells and CHO cells overexpressing GRP78. This strain also exhibited reduced virulence in a diabetic ketoacidotic (DKA) mouse model of mucormycosis. Treatment with anti-CotH Abs abolished the ability of R. oryzae to invade host cells and protected DKA mice from mucormycosis. The presence of CotH in Mucorales explained the specific susceptibility of DKA patients, who have increased GRP78 levels, to mucormycosis. Together, these data indicate that CotH3 and CotH2 function as invasins that interact with host cell GRP78 to mediate pathogenic host-cell interactions and identify CotH as a promising therapeutic target for mucormycosis.

Endosymbiont-dependent host reproduction maintains bacterial-fungal mutualism

Bacterial endosymbionts play essential roles for many organisms, and thus specialized mechanisms have evolved during evolution that guarantee the persistence of the symbiosis during or after host reproduction. The rice seedling blight fungus Rhizopus microsporus represents a unique example of a mutualistic life form in which a fungus harbors endobacteria (Burkholderia sp.) for the production of a phytotoxin. Here we report the unexpected observation that in the absence of endosymbionts, the host is not capable of vegetative reproduction. Formation of sporangia and spores is restored only upon reintroduction of endobacteria. To monitor this process, we succeeded in GFP labeling cultured endosymbionts. We also established a laserbeam transformation technique for the first controlled introduction of bacteria into fungi to observe their migration to the tips of the aseptate hyphae. The persistence of this fungal-bacterial mutualism through symbiont-dependent sporulation is intriguing from an evolutionary point of view and implies that the symbiont produces factors that are essential for the fungal life cycle. Reproduction of the host has become totally dependent on endofungal bacteria, which in return provide a highly potent toxin for defending the habitat and accessing nutrients from decaying plants. This scenario clearly highlights the significance for a controlled maintenance of this fungal-bacterial symbiotic relationship.

In vivo bronchoalveolar macrophage defense against Rhizopus oryzae and Aspergillus fumigatus

The ability of bronchoalveolar macrophages from normal, diabetic, and cortisone-treated mice to inhibit spore germination and kill fungal spores in vivo was investigated. The data indicated that the normal host controls different fungal infections in the lungs by different mechanisms. Prevention of mucormycosis required inhibition of fungal spore germination by alveolar macrophages. In contrast, pulmonary defense against aspergillosis depended on early killing of conidia by alveolar macrophages and not on inhibition of germination by bronchoalveolar macrophages. Bronchoalveolar macrophages in diabetic and cortisone-treated animals allowed fungal spore germination, thereby permitting infection by Rhizopus oryzae. In the cortisone-treated mouse, bronchoalveolar macrophages did not kill fungal conidia and progressive infection by Aspergillus fumigatus occurred. Fungicidal activity of bronchoalveolar macrophages was measured with a new in vivo killing assay.

Specific susceptibility to mucormycosis in murine diabetes and bronchoalveolar macrophage defense against Rhizopus

To assess the influence of diabetes mellitus in predisposing to pulmonary mucormycosis, a murine model of streptozotocin-induced diabetes was used. Intranasal inoculation of Rhizopus oryzae into diabetic mice resulted in mucormycotic infection with histopathology resembling pulmonary mucormycosis observed in humans. There was no mortality nor infection in inoculated normal mice. Diabetic mice had fatal infections caused by R. oryzae but significantly reduced mortality following inoculation with Aspergillus fumigatus. These findings reflect the specific enhanced susceptibility to mucormycosis observed in human diabetics. Normal bronchoalveolar macrophages formed part of an efficient defense against R. oryzae by inhibiting germination, the critical step in the conversion of R. oryzae to its tissue invasive phase. Bronchoalveolar macrophages inhibited spore germination in vitro and appeared to help prevent germination in vivo. In contrast, spore germination occurred in diabetic mice following intranasal inoculation. Diabetic bronchoalveolar macrophages had a decreased ability to attach to hyphae. In diabetic mice, bronchoalveolar macrophages could damage spores or hyphae of R. oryzae, but serum factors appeared to both promote spore germination and impair attachment of macrophages to spores. This murine model of diabetes mellitus provides an opportunity for evaluation of the relative importance of cell and serum-mediated host factors in the pathogenesis of mucormycosis.

Damage to Aspergillus fumigatus and Rhizopus oryzae hyphae by oxidative and nonoxidative microbicidal products of human neutrophils in vitro

Our previous studies established that human neutrophils could damage and probably kill hyphae of Aspergillus fumigatus and Rhizopus oryzae in vitro, primarily by oxygen-dependent mechanisms active at the cell surface. These studies were extended, again quantitating hyphal damage by reduction in uptake of (14)C-labeled uracil or glutamine. Neither A. fumigatus nor R. oryzae hyphae were damaged by neutrophils from patients with chronic granulomatous disease, confirming the importance of oxidative mechanisms in damage to hyphae. In contrast, neutrophils from one patient with hereditary myeloperoxidase deficiency damaged R. oryzae but not A. fumigatus hyphae. Cell-free, in vitro systems were then used to help determine the relative importance of several potentially fungicidal products of neutrophils. Both A. fumigatus and R. oryzae hyphae were damaged by the myeloperoxidase-hydrogen peroxide-halide system either with reagent hydrogen peroxide or enzymatic systems for generating hydrogen peroxide (glucose oxidase with glucose, or xanthine oxidase with either hypoxanthine or acetaldehyde). Iodide with or without chloride supported the reaction, but damage was less with chloride alone as the halide cofactor. Hydrogen peroxide alone damaged hyphae only in concentrations >/=1 mM, but 0.01 mM hypochlorous acid, a potential product of the myeloperoxidase system, significantly damaged R. oryzae hyphae (a 1 mM concentration was required for significant damage to A. fumigatus hyphae). Damage to hyphae by the myeloperoxidase system was inhibited by azide, cyanide, catalase, histidine, and tryptophan, but not by superoxide dismutase, dimethyl sulfoxide, or mannitol. Photoactivation of the dye rose bengal resulted in hyphal damage which was inhibited by histidine, tryptophan, and 1,4-diazobicyclo(2,2,2)octane. Lysates of neutrophils or separated neutrophil granules did not affect A. fumigatus hyphae, but did damage R. oryzae hyphae. Similarly, three preparations of cationic proteins purified from human neutrophil granules were more active in damaging R. oryzae than A. fumigatus hyphae. This damage, as with the separated granules and whole cell lysates, was inhibited by the polyanion heparin. Damage to R. oryzae hyphae by neutrophil cationic proteins was enhanced by activity of the complete myeloperoxidase system or by hydrogen peroxide alone in subinhibitory concentrations. These data support the importance of oxidative products in general and the myeloperoxidase system in particular in damage to hyphae by neutrophils. Cationic proteins may also contribute significantly to neutrophil-mediated damage to R. oryzae hyphae.

Biorefinery

The biorefinery produces fuels, solvents, plastics and food for human beings. In some countries, these biorefinery products are made from waste biomass. The main processes in the biorefinery involve ethanol fermentation and lactic acid fermentation. For the biorefinery, many hybrid technologies were developed from different fields, such as bioengineering, polymer chemistry, food science and agriculture.

Fungal meningitis

Fungi provide many benefits to humans. However, some of these fungi have the ability to become human pathogens. All the major fungal pathogens can produce meningitis. From the common cryptococcal meningitis to the rare fungal meningitis caused by a dimorphic or filamentous fungus, medical issues are discussed in this review on a fungus-specific basis. Both primary (Cryptococcus, Blastomyces, Histoplasma, Coccidioides, and other dimorphic fungi) and secondary (Aspergillus, Candida, and a series of molds) fungal pathogens can produce life-threatening central nervous system infections. These infections require immediate and precise diagnosis and carefully selected management strategies to optimize outcomes. In this review, we examine the epidemiology, pathogenesis, clinical manifestations, and treatment for fungal meningitis in all the major fungal groups.

Characterization of aroma compounds in Chinese rice wine Qu by solvent-assisted flavor evaporation and headspace solid-phase microextraction

The aroma of Chinese rice wine Qu is one of the most important factors that influences the flavor of Chinese rice wine. To better understand the aroma of Qu, aroma compounds in four wheat Qus and two xiao Qus were identified by chromatography-olfactometry (GC-O) after solvent extraction followed by solvent-assisted flavor evaporation (SAFE). A total of 39 aroma compounds were characterized by GC-O. On the basis of aroma intensity, 1-hexanal, ethyl hexanoate, 1-octen-3-ol, and phenylacetaldehyde were found to be the most important aroma compounds in all six Qus. In addition, 3-methylbutanol and 2-phenylethanol also played an important role in the aroma of two xiao Qus. Headspace solid-phase microextraction (HS-SPME) was used for quantifying aroma compounds identified in the Qus. The method enabled limits of detection and quantification of <40.8 and <136.0 microg/L, respectively. Linearity and recovery were satisfied in all cases. Quantitative analysis revealed that volatiles of six Qus had a wide range of concentration. Principal component analysis applied to the data differentiated the six Qus well.

Mycelial pellet formation by Rhizopus oryzae ATCC 20344

Factors in a cultivation medium affecting fungal growth morphology and fumaric acid production by Rhizopus oryzae ATCC 20344 were investigated. These factors included the initial pH value and trace metals such as zinc, magnesium, iron, and manganese in the cultivation medium. It was found that a significant change in the growth morphology of R. oryzae ATCC 20344 occurs when the initial pH value is varied. A lower initial pH value in the cultivation medium was inhibitory to fungal growth, and fast growth in the cultivation medium at a higher initial pH value promoted the formation of large pellets or filamentous forms. Trace metals in the cultivation media also had significant effects on pellet formation and fumaric acid fermentation.

Analysis of isoflavone content in tempeh, a fermented soybean, and preparation of a new isoflavone-enriched tempeh

To produce a tempeh-like functional food containing a high level of isoflavone with a high absorptivity, we analyzed changes in the composition of isoflavone during tempeh fermentation and the difference in isoflavone content depending on the soybean variety and particular tissue. By adding soybean germ (hypocotyl) that contained a large amount of isoflavone, we prepared a new isoflavone-enriched tempeh in the form of a granular fermented soybean-based food, which can serve as a nutritious supplement for the elderly.

Biological control of major postharvest pathogens on apple with Candida sake

Epiphytic microorganisms isolated from apples, pears and the surfaces of apple leaves were screened for antagonistic activity against Penicillium expansum (blue-mold), Botrytis cinerea (gray-mold) and Rhizopus nigricans (Rhizopus rot) on apple (Malus domestica). A total of 933 bacteria and yeasts were tested in primary screening against P. expansum. Ninety-two strains reduced the lesion size on apples by more than 50%, 72 of which were isolated from the surface of apples. For secondary screening against P. expansum, B. cinerea and R. nigricans, 31 strains were selected. The most promising isolate, CPA-1, was identified as Candida sake. This yeast, isolated from apples in storage season was very effective against all three diseases. Wounded Golden Delicious apples protected with the yeast suspension at a concentration of 2.6 x 10(6) CFU/ml and inoculated with conidia of B. cinerea and R. nigricans of 10(5) and 10(4) conidia/ml, respectively, did not develop rot. Complete control of P. expansum was obtained at the same concentration of the antagonist with a pathogen inoculum concentration of 10(3) conidia/ml. This strain, also provided excellent control of rot development under cold storage conditions. The strain of Candida sake can grow actively in aerobic conditions. In drop-inoculated wounds of apples, the populations of C. sake increased by more than 50-fold during the first 24 h at 20 degrees C. The maximum population of C. sake on apple wounds was the same at 20 as at 1 degrees C and was recovered after three and twenty days, respectively.

Bacterial endosymbionts influence host sexuality and reveal reproductive genes of early divergent fungi

Many heritable mutualisms, in which beneficial symbionts are transmitted vertically between host generations, originate as antagonisms with parasite dispersal constrained by the host. Only after the parasite gains control over its transmission is the symbiosis expected to transition from antagonism to mutualism. Here, we explore this prediction in the mutualism between the fungus Rhizopus microsporus (Rm, Mucoromycotina) and a beta-proteobacterium Burkholderia, which controls host asexual reproduction. We show that reproductive addiction of Rm to endobacteria extends to mating, and is mediated by the symbiont gaining transcriptional control of the fungal ras2 gene, which encodes a GTPase central to fungal reproductive development. We also discover candidate G-protein-coupled receptors for the perception of trisporic acids, mating pheromones unique to Mucoromycotina. Our results demonstrate that regulating host asexual proliferation and modifying its sexual reproduction are sufficient for the symbiont's control of its own transmission, needed for antagonism-to-mutualism transition in heritable symbioses. These properties establish the Rm-Burkholderia symbiosis as a powerful system for identifying reproductive genes in Mucoromycotina.

Beneficial effects of Rhizopus oligosporus fermentation on reduction of glucosinolates, fibre and phytic acid in rapeseed (Brassica napus) meal

Solid state fermentation was employed using Rhizopus oligosporus to develop a fermented product from rapeseed meal (RSM). The contents of glucosinolates, thiooxazolidones, phytic acid and crude fibre declined by 43.1%, 34%, 42.4% and 25.5%, respectively, following inoculation with R. oligosporus. Fermentation also increased nitrogen and protein contents of the meal. This study may open a new prospective for a simple and cost effective technique for reduction of toxicants in RSM.

In vitro control of post-harvest fruit rot fungi by some plant essential oil components

Eight substances that are main components of the essential oils from three Mediterranean aromatic plants (Verbena officinalis, Thymus vulgaris and Origanum vulgare), previously found active against some phytopathogenic Fungi and Stramenopila, have been tested in vitro against five etiological agents of post-harvest fruit decay, Botrytis cinerea, Penicillium italicum, P. expansum, Phytophthora citrophthora and Rhizopus stolonifer. The tested compounds were β-fellandrene, β-pinene, camphene, carvacrol, citral, o-cymene, γ-terpinene and thymol. Citral exhibited a fungicidal action against P. citrophthora; carvacrol and thymol showed a fungistatic activity against P. citrophthora and R. stolonifer. Citral and carvacrol at 250 ppm, and thymol at 150 and 250 ppm stopped the growth of B. cinerea. Moreover, thymol showed fungistatic and fungicidal action against P. italicum. Finally, the mycelium growth of P. expansum was inhibited in the presence of 250 ppm of thymol and carvacrol. These results represent an important step toward the goal to use some essential oils or their components as natural preservatives for fruits and foodstuffs, due to their safety for consumer healthy and positive effect on shelf life extension of agricultural fresh products.

Comparison of biosorption properties of different kinds of fungi for the removal of Gryfalan Black RL metal-complex dye

Three kinds of filamentous fungi (Rhizopus arrhizus, Trametes versicolor, Aspergillus niger) were tested for their ability to adsorb Gryfalan Black RL metal-complex dye as a function of pH, temperature and dye concentration. R. arrhizus and T. versicolor exhibited the maximum dye uptake at pH 2.0 and at 25 degrees C while A. niger performed the highest dye biosorption at pH 1.0 and at 35 degrees C. Sorption capacity of each biosorbent increased with increasing initial dye concentration. Among the three fungi, R. arrhizus was the most effective biosorbent showing a maximum dye uptake of 666.7 mg g(-1). The Langmuir model described the equilibrium data of each dye-fungus system accurately in the concentration and temperature ranges studied. Kinetic analysis indicated that both adsorption kinetics and internal diffusion played an important role on controlling the overall adsorption rate for each fungus. Thermodynamic analysis verified that A. niger biosorption was endothermic while the others were exothermic.

Monocyte-mediated damage to Rhizopus oryzae hyphae in vitro

Clinicopathological correlations from human cases and experimental animal studies suggest that neutrophils are critical components of the host response to mucormycosis but that other cellular defense mechanisms appear to be important as well. Since our previous studies demonstrated that Rhizopus oryzae hyphae which are too large to be ingested completely can be damaged and probably killed by human neutrophils, we studied the antihyphal activity of human monocytes. As with neutrophils, light and electron microscopic studies indicated that monocytes attached to hyphae and appeared to destroy them in the absence of serum. As judged by our previously described assay for the leukocyte-induced inhibition of [14C]uracil uptake by hyphae, quantitative damage to hyphae by monocytes was 40.8 +/- 2.2% in 54 experiments. Neither attachment to nor damage of hyphae by monocytes was augmented by the presence of 10% human serum. As with neutrophils, monocyte-mediated damage of R. oryzae was significantly decreased by some inhibitors of oxidative metabolism and scavengers of the potentially microbicidal oxidative leukocyte products, which included 10(-4)M sodium azide, 10 (-3) M sodium cyanide, catalase, 10(-3) M histidine, 10(-3) M tryptophan, and 10(-4) M 1,4-diazobicyclo[2.2.2]octane but not superoxide dismutase, 1.4 X 10(-2) M dimethyl sulfoxide, and 4.0 X 10(-1) M mannitol. Moreover, monocytes from three patients with chronic granulomatous disease failed to damage hyphae at all. In contrast to our previous data for neutrophils, polyanions (10(-5) M polyaspartic or polyglutamic acid) did not inhibit monocyte-mediated hyphal damage. Thus, monocytes can damage and probably kill R. oryzae hyphae by oxidative mechanisms and so may be involved in host defense mechanisms against mucormycosis.

Glyceollins, one of the phytoalexins derived from soybeans under fungal stress, enhance insulin sensitivity and exert insulinotropic actions

Glyceollins are a category of phytoalexins that are produced by soybeans under fungal stress, but their effects on glucose homeostasis remain unknown. We hypothesized that glyceollins play an important role in glucose homeostasis by regulating glucose utilization in adipocytes and improving beta-cell function and survival. Glyceollins improved insulin-stimulated glucose uptake in 3T3-L1 adipocytes without activating the peroxisome proliferator-activated receptor-gamma agonist. They decreased triacylglycerol accumulation in adipocytes. In addition, glyceollins slightly improved glucose-stimulated insulin secretion without palmitate treatment in Min6 cells, and they potentiated insulinotropic actions when 500 microM palmitate was used to induce beta-cell dysfunction. This was associated with decreased beta-cell apoptosis because of the attenuation of endoplasmic reticulum stress, as determined by mRNA levels of XBP-1, ATF-4, ATF-6, and CHOP. Glyceollins also potentiated GLP-1 secretion to enhance insulinotropic actions in enteroendocrine cells. In conclusion, glyceollins help normalize glucose homeostasis by potentiating beta-cell function and survival and improving glucose utilization in adipocytes.

Serum IgG antibodies to mold spores in two Norwegian sawmill populations: relationship to respiratory and other work-related symptoms

Wood trimmers and planing operators from two separate sawmill populations (N = 303 and 170) were studied by serology assessment and a self-administered questionnaire. IgG antibodies to Rhizopus microsporus ssp. rhizopodiformis, Paecilomyces variotii, and Aspergillus fumigatus were measured by ELISA. The questionnaire included questions about general respiratory symptoms and symptoms after handling moldy timber. Personal exposure of wood trimmers to mold spores and wood dust was measured in one part of the sawmills. R. microsporus was the most prevalent mold assessed by serology. Antibody levels were higher and symptoms suggestive of mucous membrane irritation, chronic nonspecific lung disease, allergic alveolitis, and organic dust toxic syndrome were more frequently reported by wood trimmers than by planing operators. The mean level of IgG antibodies to R. microsporus in sawmill workers working in the same work area was the best predictor of symptoms in both populations. The consistent results indicate that exposure to spores of R. microsporus may cause several respiratory symptoms in wood trimmers.

Carotene derivatives in sexual communication of zygomycete fungi

Recognition between mating partners, early sexual morphogenesis and development are regulated by a family of beta-carotene derived signal compounds, the trisporoids, in zygomycete fungi. Mating type-specific precursors are released from the hyphae and exert their physiological effects upon compatible mating partners. In a cooperative synthesis pathway, later intermediates and finally trisporic acid are formed. All trisporoids occur in a number of derivatives. Trisporic acid and some precursors directly influence the transcription of genes involved in sexual development. This has been demonstrated for TSP3, encoding the carotene oxygenase involved in sexually induced cleavage of beta-carotene. Species specificity of mating despite a common and commonly recognized signaling system is maintained by several factors. Specific distribution and recognition patterns of the trisporoid derivatives and the proposed divergence in trisporoid synthesis pathways in diverse species play a role. The derivatives elicit vastly differing, partially mating type-specific responses during early sexual development. Another specificity factor is the realization of different regulation levels for the trisporoid synthesis enzymes in different species. Enzymes in the trisporoid synthesis pathway show remarkable variations in mating type-specific activity and the exact activation time during sexual development. This allows for the observed complex network of possible interactions, but at the same time forbids successful mating between dissimilar partners because the necessary transcripts or gene products are not available at the appropriate developmental stage.

Neutrophil chemotactic responses induced by fresh and swollen Rhizopus oryzae spores and Aspergillus fumigatus conidia

With the induction of germination, Rhizopus oryzae spores and Aspergillus fumigatus conidia activate the complement system and induce neutrophil chemotaxis. In contrast, freshly isolated R. oryzae spores did not induce neutrophil migration into lung tissue of mice after intranasal inoculation. Moreover, in microchemotaxis assays neither fresh R. oryzae spores nor A. fumigatus conidia activated sera to stimulate human neutrophil chemotaxis above control migration until at least 10(7) or 10(8) spores or conidia per ml of sera were used. The increased generation of chemotactic factors by swollen spores and conidia was not due to an increased surface area, as there was decreased neutrophil chemotactic response to Rhizopus or Aspergillus hyphae when compared with swollen spores or conidia.

Study of pellet formation of filamentous fungi Rhizopus oryzae using a multiple logistic regression model

Fungal pellet formation is an important topic of fermentation research. It has been reported that many factors such as agitation, medium nutrients, pH, polymer additives, and inoculum size influence the formation of fungal pellets. However, a few studies on the effects of all of these factors on fungal pellet formation have been reported. This paper conducted a comprehensive investigation using a completely randomized design (CRD) on a filamentous fungus, Rhizopus oryzae NRRL 395, in order to discover the effects of the above factors on fungal pellet formation. In addition, other factors, such as addition of biodegradable polymers and spore storage time that have not been reportedly studied were examined and their effects on pellet formation were investigated. A multiple logistic regression model was established to predict the probability of pellet formation using the above factors and their interactions as predictor variables. Model building and diagnostics were obtained using the Statistical Analysis System (SAS 9.0) program. The model developed in this study can be used to predict the pellet formation of other R. oryzae strains as well.

Preparation and application of a novel bioflocculant by two strains of Rhizopus sp. using potato starch wastewater as nutrilite

A complex bioflocculant MBF917 was prepared by Rhizopus sp. M9 and M17 using potato starch wastewater (PSW) as nutrilite, and its flocculation characteristics of treating PSW were studied. Culture conditions of the two strains were optimized, and flocculating conditions of the bioflocculant for treating PSW were also investigated. The optimal and economical culture conditions were determined as COD of about 1600 mg/L, 0.3 g/L urea and 0.04 g/L potassium dihydrogen phosphate, with no need of adding carbon sources or adjusting pH. When the bioflocculant was used to flocculate PSW, the optimal dosage was 0.1 mL/L with addition of 5 mL/L 10% CaCl2 as coagulant aid, and there was no need to adjust pH. After flocculation, COD and turbidity removal rates of the PSW could reach 54.09% and 92.11%, respectively, and 1.1g/L proteic substance was recycled from the PSW as a byproduct that could be used for animal feed.

Rhizopus microsporus var. rhizopodiformis: a thermotolerant fungus with potential for production of thermostable amylases

The effect of several nutritional and environmental parameters on growth and amylase production from Rhizopus microsporus var. rhizopodiformis was analysed. This fungus was isolated from soil of the Brazilian "cerrado" and produced high levels of amylolytic activity at 45 degrees C in liquid medium supplemented with starch, sugar cane bagasse, oat meal or cassava flour. Glucose in the culture medium drastically repressed the amylolytic activity. The products of hydrolysis were analysed by thin layer chromatography, and glucose was detected as the main component. The amylolytic activity hydrolysed several substrates, such as amylopectin, amylase, glycogen, pullulan, starch, and maltose. Glucose was always the main end product detected by high-pressure liquid chromatography analysis. These results indicated that the amylolytic activity studied is a glucoamylase, but there were also low levels of alpha-amylase. As compared to other fungi, R. microsporus var. rhizopodiformis can be considered an efficient producer of thermostable amylases, using raw residues of low cost as substrates. This information is of technological value, considering the importance of amylases for industrial hydrolysis.

Microbial transformation of dehydroepiandrosterone

Transformation of dehydroepiandrosterone (DHEA) (1) was carried out by a plant pathogen Rhizopus stolonifer, which resulted in the production of seven metabolites. These metabolites were identified as 3beta,17beta-dihydroxyanandrost-5-ene (2), 3beta,17beta-dihydroxyandrost-4ene (3), 17beta-hydroxyandrost-4-ene-3-one (4), 3beta,11-dihydroxyandrost-4-ene-17-one (5), 3beta,7alpha-dihydroandrost-5-ene-17-one (6), 3A,7alpha,17beta-trihydroxyandrost-5-ene (7) and 11beta-hydroxyandrost-4,6-diene-3,17-dione (8). The structures of the transformed products were determined by the spectroscopic techniques.

Diet modification and metformin have a beneficial effect in a fly model of obesity and mucormycosis

In an experimental model of obesity and hyperglycemia in Drosophila melanogaster we studied the effect of diet modification and administration of metformin on systemic infection with Rhizopus, a common cause of mucormycosis in diabetic patients. Female Wt-type Drosophila flies were fed regular (RF) or high-fat diet (HFD; 30% coconut oil) food with or without metformin for 48 h and then injected with R. oryzae. Survival rates, glucose and triglyceride levels were compared between 1) normal-weight flies (RF), 2) obese flies (HFD), 3) obese flies fed with RF, 4) flies continuously fed on HFD + metformin, 5) flies fed on HFD + metformin, then transferred to RF, and 6) obese flies administered metformin after infection [corrected].Glucose levels were compared across groups of non-infected flies and across groups of infected flies. Survival was significantly decreased (P = 0.003) in obese flies, while post-infection glucose levels were significantly increased (P = 0.0001), compared to normal-weight flies. Diet and administration of metformin led to weight loss, normalized glucose levels during infection, and were associated with decreased mortality and tissue fungal burden. In conclusion, diet and metformin help control infection-associated hyperglycemia and improve survival in Drosophila flies with mucormycosis. Fly models of obesity bear intriguing similarities to the pathophysiology of insulin resistance and diabetes in humans, and can provide new insights into the pathogenesis and treatment of infections in obese and diabetic patients.