Gerald F. Bills

Fungi on Plants and Plant Products in the United States

HETEROSIS FOR WEIGHT AT 18 MONTHS AND AT SLAUGHTER IN ACLUSTER ZEBU-CROSS The objectíve of the present investigation was to evaluate the weights at 18 months and at slaughter of males crossed 114 Bos taurus (Aberdeen Angus. Holsteín. American Símmental, German Simmental) with Zebu and pure Brahman animals. Commercial Zebus and halfbreeds. To determine the influence ofdifferent genetíc and non-genetic factors on the studied characteristics. the program ofminimum squares was used. The effects mcluded in the models for weight to 18 months. weight and age to sacrifice were.· month and year at weaning. month and year at 18 months. month and year at slaughter. genetic group of the animal. ranch at 18 months. and fatteníng rancho Depending on the model considered. covariates included: weight at bírth and weaning, weight at 18 months, slaughter weight. age at 18 months and age at slaughter. Most of the factors. genetíc and non-genetíc. produced signif¡cant effects (p 0,0 1); except for weaning age. The heterosis estimaríon for each genetic group was performed once orthogonal contrasts between genetíc groups were made in each one the caracteristlCs that sígnif¡cont results. For the weíght at 18 months analysis. the mean percentage ofheterosís was 5,22%, where the 31 4 Commercial Zebu 114 Holsteín group ofanimals presented the best performance with 7.48%. Weight at sacrífice showed a mean percentage ofheterosis of3.76%. in which the 3/4 Commercial Zebu 1/4 Aberdeen Angus animals obtained the highest percentage of4.85%. For slaughter age a mean percentage ofheterosis of-5,68% was documented, m whích the 3/4 Zebu Commercial 1/4 Aberdeen Angus animals presented the highest percentage of-10.52%.

Biodiversity of fungi : inventory and monitoring methods

Fungi and Their Allies Preparation, Preservation, and Use of Fungal Specimens in Herbaria Preservation and Distribution of Fungal Cultures Electronic Information Resources Fungal Biodiversity Patterns Molecular Methods for Discriminating Taxa, Monitoring Species, and Assessing Fungal Diversity Fungi on Living Plant Substrata, Including Fruits Terrestrial and Lignicolous Macrofungi Lichenized Fungi Sequestrate Fungi Microfungi on Wood and Plant Debris Endophytic Fungi Saprobic Soil Fungi Fungi in Stressful Environments Mutualistic Arbuscular Endomycorrhizal Fungi Yeasts Fungicolous Fungi Insect- and Other Arthropod-Associated Fungi Fungal Parasites and Predators of Rotifers, Nematodes, and Other Invertebrates Fungi Associated With Vertebrates Coprophilous Fungi Anaerobic Zoosporic Fungi Associated with Animals Fungi in Freshwater Habitats Marine and Estuarine Mycelial Eumycota and Oomycota Mycetozoans Fungi Associated with Aquatic Animals

Discovery of Novel Antifungal (1,3)-β-d-Glucan Synthase Inhibitors

ABSTRACT The increasing incidence of life-threatening fungal infections has driven the search for new, broad-spectrum fungicidal agents that can be used for treatment and prophylaxis in immunocompromised patients. Natural-product inhibitors of cell wall (1,3)-β-d-glucan synthase such as lipopeptide pneumocandins and echinocandins as well as the glycolipid papulacandins have been evaluated as potential therapeutics for the last two decades. As a result, MK-0991 (caspofungin acetate; Cancidas), a semisynthetic analogue of pneumocandin Bo, is being developed as a broad-spectrum parenteral agent for the treatment of aspergillosis and candidiasis. This and other lipopeptide antifungal agents have limited oral bioavailability. Thus, we have sought new chemical structures with the mode of action of lipopeptide antifungal agents but with the potential for oral absorption. Results of natural-product screening by a series of newly developed methods has led to the identification of four acidic terpenoid (1,3)-β-d-glucan synthase inhibitors. Of the four compounds, the in vitro antifungal activity of one, enfumafungin, is comparable to that of L-733560, a close analogue of MK-0991. Like the lipopeptides, enfumafungin specifically inhibits glucan synthesis in whole cells and in (1,3)-β-d-glucan synthase assays, alters the morphologies of yeasts and molds, and produces a unique response in Saccharomyces cerevisiae strains with point mutations in FKS1, the gene which encodes the large subunit of glucan synthase.

Abundance and diversity of microfungi in leaf litter of a lowland rain forest in Costa Rica

An efficient method by which to bring tropical leaf-litter fungi into culture was sought in order to survey these organisms for pharmacologically useful metabolites. A simplified particle-filtratio...

Antimicrobial activity of phenolic acids against commensal, probiotic and pathogenic bacteria

Phenolic acids (benzoic, phenylacetic and phenylpropionic acids) are the most abundant phenolic structures found in fecal water. As an approach towards the exploration of their action in the gut, this paper reports the antimicrobial activity of thirteen phenolic acids towards Escherichia coli, Lactobacillus spp., Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. The growth of E. coli ATCC 25922 was inhibited by only four of the phenolic acids tested at a concentration of 1000 microg/mL, whereas pathogenic E. coli O157:H7 (CECT 5947) was susceptible to ten of them. The genetically manipulated E. coli lpxC/tolC strain was highly susceptible to phenolic acids. The growth of lactobacilli (Lactobacillus paraplantarum LCH7, Lactobacillus plantarum LCH17, Lactobacillus fermentum LPH1, L. fermentum CECT 5716, Lactobacillus brevis LCH23, and Lactobacillus coryniformis CECT 5711) and pathogens (S. aureus EP167 and C. albicans MY1055) was also inhibited by phenolic acids, but to varying extents. Only P. aeruginosa PAO1 was not susceptible to any of the phenolic compounds tested. Structure-activity relationships of phenolic acids and some of their diet precursors [(+)-catechin and (-)-epicatechin] were established, based on multivariate analysis of microbial activities. The antimicrobial properties of phenolic acids reported in this paper might be relevant in vivo.

Endophytic mycobiota of leaves and roots of the grass Holcus lanatus

Holcus lanatus is a grass that grows in humid, often waterlogged soils in temperate zones around the world. The purpose of this work was to identify fungal endophytes associated with its roots and leaves, and to describe the diversity and spatial distribution patterns found in its mycobiota. Holcus plants were sampled at 11 locations in western and northern Spain, and endophytes were isolated from leaves and roots of each plant. Morphological and molecular methods based on the ITS1-5.8SrRNA-ITS2 sequence were used for isolate identification. In total, 134 different species were identified, 77 occurred in leaves, 79 in roots, and 22 were common to both organs. The dominant species of the mycobiota were isolated from roots and leaves, and were species generally considered as multi-host endophytes. The species richness was similar in leaves and roots, but the composition of isolates from roots varied more among locations than in leaf mycobiotas, suggesting that soil characteristics may have strongly influenced the root mycobiota. Significant variations with respect to the composition of their mycobiota among different locations indicate that beta diversity is a first order factor governing the richness and distribution of the endophytic mycobiota in grasses.

Enhancement of antibiotic and secondary metabolite detection from filamentous fungi by growth on nutritional arrays

Aims:  We asked to what extent does the application of the OSMAC (one strain, many compounds) approach lead to enhanced detection of antibiotics and secondary metabolites in fungi? Protocols for bacterial microfermentations were adapted to grow fungi in nutritional arrays.

Isolation and structure of chaetomellic acids A and B from Chaetomella acutiseta: farnesyl pyrophosphate mimic inhibitors of ras farnesyl-protein transferase

Abstract Farnesyl-Protein transferase catalyses a post-translational modification of Ras that is obligatory for the cell transforming activity of this oncogene protein. The screening of natural products to identify inhibitors of this enzyme as a potential anticancer agents, has led to the isolation of two novel dicarboxylic acids, named chaetomellic acids from Chaetomella acutiseta, as potent and selective inhibitors which appear to be the first examples of nonphosphorous containing FPP mimics.

The Discovery of Enfumafungin, a Novel Antifungal Compound Produced by an Endophytic Hormonema Species Biological Activity and Taxonomy of the Producing Organisms

In a screening of natural products with antifungal activity derived from endophytic fungi, we detected a potent activity in a culture belonging to the form-genus Hormonema, isolated from leaves of Juniperus communis. The compound is a new triterpene glycoside, showing an antifungal activity highly potent in vitro against Candida and Aspergillus and with moderate efficacy in an in vivo mouse model of disseminated candidiasis. The agent is especially interesting since its antifungal spectrum and its effect on morphology of Aspergillus fumigatus is comparable to that of the glucan synthase inhibitor pneumocandin B,,, the natural precursor of the clinical candidate MK-0991 (caspofungin acetate). An additional search for other Hormonema isolates producing improved titers or derivatives resulted in the isolation of two more strains recovered from the same plant host showing identical activity. The producing isolates were compared with other non-producing Hormonema strains by DNA fingerprinting and sequencing of the rDNA internal transcribed spacers. Comparison of rDNA sequences with other fungal species suggests that the producing fungus could be an undetermined Kabatina species. Kabatina is a coelomycetous genus whose members are known to produce Hormonema-like states in culture.

High diversity and morphological convergence among melanised fungi from rock formations in the Central Mountain System of Spain

Melanised fungi were isolated from rock surfaces in the Central Mountain System of Spain. Two hundred sixty six isolates were recovered from four geologically and topographically distinct sites. Microsatellite-primed PCR techniques were used to group isolates into genotypes assumed to represent species. One hundred and sixty three genotypes were characterised from the four sites. Only five genotypes were common to two or more sites. Morphological and molecular data were used to characterise and identify representative strains, but morphology rarely provided a definitive identification due to the scarce differentiation of the fungal structures or the apparent novelty of the isolates. Vegetative states of fungi prevailed in culture and in many cases could not be reliably distinguished without sequence data. Morphological characters that were widespread among the isolates included scarce micronematous conidial states, endoconidia, mycelia with dark olive-green or black hyphae, and mycelia with torulose, isodiametric or moniliform hyphae whose cells develop one or more transverse and/or oblique septa. In many of the strains, mature hyphae disarticulated, suggesting asexual reproduction by a thallic micronematous conidiogenesis or by simple fragmentation. Sequencing of the internal transcribed spacers (ITS1, ITS2) and 5.8S rDNA gene were employed to investigate the phylogenetic affinities of the isolates. According to ITS sequence alignments, the majority of the isolates could be grouped among four main orders of Pezizomycotina: Pleosporales, Dothideales, Capnodiales, and Chaetothyriales. Ubiquitous known soil and epiphytic fungi species were generally absent from the rock surfaces. In part, the mycota of the rock surfaces shared similar elements with melanised fungi from plant surfaces and fungi described from rock formations in Europe and Antarctica. The possibility that some of the fungi were lichen mycobionts or lichen parasites could not be ruled out.