scholarly journals First Recognition of Issatchenkia orientalis in Mature Citrus Fruits in Spain

Plant Disease ◽  
2001 ◽  
Vol 85 (3) ◽  
pp. 335-335
Author(s):  
J. J. Tuset ◽  
R. Perucho
Keyword(s):  
Carbon Sources ◽  
Morphological Characteristics ◽  
Nitrogen Sources ◽  
Fruit Fly ◽  
Geotrichum Candidum ◽  
Climatic Conditions ◽  
Yeast Cells ◽  
Hypodermic Injection ◽  
Issatchenkia Orientalis ◽  
Pure Cultures

During the first four months of 2000, mature fruit of clementine cvs. Clemenules and Hernandina, mandarin cvs. Ortanique and Fortune, and orange cv. Navelina from several packinghouses located in Valencia Province were affected by a soft, watery, colorless or very light brown decay. The incidence of the decay was 5 to 12% in clementines and mandarins and 0.2 to 0.8% in oranges. A yeast was isolated consistently on potato-dextrose agar from affected tissues and from the juice of decayed fruits. Colonies of this yeast were butyrous, light cream in color, and smooth with a dry surface (or with a flattened center) and lobed margins with sparse, branched pseudohyphae. Some isolates that were light pink in color later turned cream colored. Yeast cells were ovoid to elongate, single or in pairs, with one or two buds at one end (multilateral budding). The cells were 1.1 to 5.7 μm × 3.2 to 12.8 μm. Ascospores were not observed. Fermentation and growth on carbon sources (several carbohydrates), growth on nitrogen sources (nitrate, cadaverine, L-lysine, etc.), requirement for vitamins, and growth at 40°C were used for identification. Based on the results of such tests and morphological characteristics, the fungus was identified as Issatchenkia orientalis Kudryavtsev (anamorph: Candida krusei (Castellani) Berkhout) (2). To satisfy Koch's postulates in pathogenicity tests, cells from pure cultures on agar or in orange juice were inoculated by hypodermic injection into the peel and flesh of oranges, clementines, mandarins, grapefruits, and lemons. After 10 to 20 days in a moist chamber at 24°C, a decay resembling symptoms that occurred in the packinghouse were observed in the inoculated fruits (1,3). The lemon fruits were the most affected. The fungus reisolated from decayed fruits was identical to the original isolates. This is the first report of this yeast as a decay of citrus produced in Europe. Climatic conditions (rainfall in spring and dry in summer and autumn) in citrus-growing areas in Spain, together with the presence of the Mediterranean fruit fly, may have been factors in disease development. A similar decay is caused by Geotrichum candidum, and previously this may have been mistaken for decay caused by I. orientalis. References: (1) P. R. Harding. Plant Dis. Rep. 52:433, 1968. (2) C. D. Kurtzman. 1998. The Yeasts, A Taxonomic Study. 4th ed. Elsevier Science, Amsterdam. (3) K. V. Shankhapal and V. G. Hatwalne. Plant Dis. Rep. 60:237, 1976.

scholarly journals Characterization of a rare species of Neurospora isolated from a river water sample in China

2015 ◽  
Vol 67 (2) ◽  
pp. 685-693 ◽  
Author(s):  
Xia Yang ◽  
Siliang Huang ◽  
Yubian Zhang ◽  
Xiaoqiang Zhang
Keyword(s):  
Water Sample ◽  
River Water ◽  
Growth Rates ◽  
Rare Species ◽  
Vegetative Growth ◽  
Carbon Sources ◽  
Morphological Characteristics ◽  
Nitrogen Sources ◽  
Fungal Species ◽  
River Water Sample

A fungal isolate (ZZS4408) was obtained from a river water sample in Henan, China, and identified as a member of Neurospora brevispora, a rare species of Neurospora based on its morphological characteristics and ribosomal DNA internal transcribed spacer (rDNA-ITS) sequence. The temperatures suitable for growth of the isolate were 28-37?C with 31?C as the optimum. The growth rates of hyphal tips were 19.1-42.5 (av. 31.9) ?m min-1 at 32?C. The pH suitable for vegetative growth ranged from 5 to 7, with pH 5.5 as the optimum. The heterodisaccharides (sucrose and lactose) and D-alanine were found to be most favorable for vegetative growth of the isolate, as carbon and nitrogen sources, respectively. The vegetative growth of the isolate was more significantly influenced by nitrogen sources compared to carbon sources. N. brevispora could be considered a desirable fungal species for morphodifferentiation studies due to its rapid growth rates under favorable conditions.

scholarly journals Stem Blight of Blueberry Caused by Lasiodiplodia vaccinii sp. nov. in China

Plant Disease ◽  
2019 ◽  
Vol 103 (8) ◽  
pp. 2041-2050 ◽  
Author(s):  
Lin Zhao ◽  
Yu Wang ◽  
Wei He ◽  
Ying Zhang
Keyword(s):  
Rna Polymerase Ii ◽  
Mycelial Growth ◽  
Economic Value ◽  
Carbon Sources ◽  
Elongation Factor ◽  
Morphological Characteristics ◽  
Nitrogen Sources ◽  
Fungal Species ◽  
Stem Blight ◽  
Nutritional Benefits

Blueberries (Vaccinium spp.) are largely cultivated in China because of their nutritional benefits and economic value. Blueberry stem blight caused by members of the Botryosphaeriaceae has become one of the most severe diseases affecting blueberry cultivation in China. In this study, we examined the causal agent of blueberry stem blight at commercial greenhouse farms in the suburban area of Beijing, China. In total, 37 isolates of Botryosphaeriaceae were obtained from 100 stem blight samples of blueberry. Twelve of 37 strains were morphologically consistent with the genus Lasiodiplodia, showing ellipsoid to ovoid, one-celled, hyaline conidia that sometimes turned brown, with median septa and longitudinal striations when mature. These 12 strains were identified as belonging to a novel fungal species, Lasiodiplodia vaccinii, based on phylogenetic analysis of the concatenated internal transcribed spacer, RNA polymerase II gene, β-tubulin gene, and translation elongation factor-1α gene sequences as well as morphological characteristics. Pathogenicity tests indicated that L. vaccinii can cause twig blight on blueberry seedlings in the greenhouse. Mycelial growth of L. vaccinii occurred at pH values ranging from 3.0 to 10.0, with an optimum at 6.2, and at temperatures from 15 to 40°C, with an optimum at 30.3°C. Of the seven carbon sources tested, sucrose, fructose, and glucose were all highly efficient in supporting the mycelial growth of L. vaccinii, and xylose was the least effective. Of six nitrogen sources tested, yeast extract and tryptone best promoted mycelial growth of L. vaccinii. The ability of L. vaccinii to grow at high temperatures may help to explain its occurrence in Beijing greenhouses in this study.

Evaluation of the growth and sporulation of different entomopathogenic fungi in different liquid and solid media at varied concentrations

2017 ◽  
Vol 6 (8) ◽  
pp. 5459
Author(s):  
Chandra Teja K. ◽  
Rahman S. J.
Keyword(s):  
Entomopathogenic Fungi ◽  
Large Scale ◽  
Insect Pests ◽  
Culture Media ◽  
Virulent Strain ◽  
Carbon Sources ◽  
Nitrogen Sources ◽  
Maximum Growth ◽  
Nutritional Requirements ◽  
Virulent Strains

Entomopathogenic fungi like Beauveria bassiana, Metarhizium anisopliae and Lecanicillium lecanii are used in biological control of agricultural insect pests. Their specific mode of action makes them an effective alternative to the chemical Insecticides. Virulent strains of Entomopathogenic fungi are effectively formulated and used as bio-insecticides world-wide. Amenable and economical multiplication of a virulent strain in a large scale is important for them to be useful in the field. Culture media plays a major role in the large-scale multiplication of virulent strains of Entomopathogens. Different substrates and media components are being used for this purpose. Yet, each strain differs in its nutritional requirements for the maximum growth and hence it is necessary to standardize the right components and their optimum concentrations in the culture media for a given strain of Entomopathogen. In the current study, three different nitrogen sources and two different carbon sources were tried to standardize the mass multiplication media for seven test isolates of Entomopathogenic fungi. A study was also conducted to determine the ideal grain media for the optimum conidial yields of the test isolates. Yeast extract was found to be the best Nitrogen source for the isolates. The isolates tested, differed in their nutritional requirements and showed variation in the best nitrogen and carbon sources necessary for their growth. Variation was also found in the optimum concentration of both the ingredients for the growth and sporulation of the isolates. In the solid-state fermentation study, rice was found to be the best grain for the growth of most of the fungi followed by barley. The significance of such a study in the development of an effective Myco-insecticide is vital and can be successfully employed in agriculture is discussed.

scholarly journals Studies on the Role of the are a Gene in the Regulation of Nitrogen Catabolism in Aspergillus nidulans

1975 ◽  
Vol 28 (3) ◽  
pp. 301 ◽  
Author(s):  
MJ Hynes
Keyword(s):  
Nitrogen Source ◽  
Aspergillus Nidulans ◽  
Carbon Sources ◽  
Nitrogen Sources ◽  
Selection Methods ◽  
Growth Responses ◽  
Dominance Relationships ◽  
Regulatory Circuits ◽  
Specific Activities

Mutants of Apergillus nidulanswith lesions in a gene, areA (formerly called amdT), have been isolated by a variety of different selection methods. The areA mutants show a range of pleiotropic growth responses to a number of compounds as sole nitrogen sources, but are normal in utilization of carbon sources. The levels of two amidase enzymes as well as urease have been investigated in the mutants and have been shown to be affected by this gene. Most of the areA mutants have much lower amidase-specific activities when grown in ammonium-containing medium, compared with mycelium incubated in medium la9king a nitrogen source. Some of the areA. mutants do not show derepression of urease upon relief of ammonium repression. The dominance relationships of areA alleles have been investigated in� heterozygous diploids, and these studies lend support to the proposal that areA codes for a positively acting regulatory product. One of the new areA alleles is partially dominant to areA + and areA102. This may be a result of negative complementation or indicate that areA has an additional negative reiuIatory function. Investigation.of various amdR; areA double mutants has led to the conclusion that amdR and areA participate in independent regulatory circuits in the control of acetamide utilizatiol1. Studies on an amdRc; areA.double mutant indicate that areA is involved in derepression of acetamidase upon relief of ammo.nium repression.

scholarly journals Identification of Listeria monocytogenes Genes Contributing to Intracellular Replication by Expression Profiling and Mutant Screening

2006 ◽  
Vol 188 (2) ◽  
pp. 556-568 ◽  
Author(s):  
Biju Joseph ◽  
Karin Przybilla ◽  
Claudia Stühler ◽  
Kristina Schauer ◽  
Jörg Slaghuis ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Stress Proteins ◽  
Carbon Sources ◽  
Brain Heart Infusion ◽  
Nitrogen Sources ◽  
Pentose Phosphate ◽  
Intracellular Growth ◽  
Cell Infection ◽  
Phosphotransferase System ◽  
Isoleucine Leucine

ABSTRACT A successful transition of Listeria monocytogenes from the extracellular to the intracellular environment requires a precise adaptation response to conditions encountered in the host milieu. Although many key steps in the intracellular lifestyle of this gram-positive pathogen are well characterized, our knowledge about the factors required for cytosolic proliferation is still rather limited. We used DNA microarray and real-time reverse transcriptase PCR analyses to investigate the transcriptional profile of intracellular L. monocytogenes following epithelial cell infection. Approximately 19% of the genes were differentially expressed by at least 1.6-fold relative to their level of transcription when grown in brain heart infusion medium, including genes encoding transporter proteins essential for the uptake of carbon and nitrogen sources, factors involved in anabolic pathways, stress proteins, transcriptional regulators, and proteins of unknown function. To validate the biological relevance of the intracellular gene expression profile, a random mutant library of L. monocytogenes was constructed by insertion-duplication mutagenesis and screened for intracellular-growth-deficient strains. By interfacing the results of both approaches, we provide evidence that L. monocytogenes can use alternative carbon sources like phosphorylated glucose and glycerol and nitrogen sources like ethanolamine during replication in epithelial cells and that the pentose phosphate cycle, but not glycolysis, is the predominant pathway of sugar metabolism in the host environment. Additionally, we show that the synthesis of arginine, isoleucine, leucine, and valine, as well as a species-specific phosphoenolpyruvate-dependent phosphotransferase system, play a major role in the intracellular growth of L. monocytogenes.

The Cloning and Mapping of ADR6, a Gene Required for Sporulation and for Expression of the Alcohol Dehydrogenase II Isozyme From Saccharomyces cerevisiae

Genetics ◽  
1987 ◽  
Vol 116 (4) ◽  
pp. 531-540
Author(s):  
Aileen K W Taguchi ◽  
Elton T Young
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Alcohol Dehydrogenase ◽  
Single Gene ◽  
Carbon Sources ◽  
Transcription Unit ◽  
Yeast Cells ◽  
Recessive Mutation ◽  
Yeast Saccharomyces Cerevisiae ◽  
Upstream Activating Sequence ◽  
A Site

ABSTRACT The alcohol dehydrogenase II (ADH2) gene of the yeast, Saccharomyces cerevisiae, is not transcribed during growth on fermentable carbon sources such as glucose. Growth of yeast cells in a medium containing only nonfermentable carbon sources leads to a marked increase or derepression of ADH2 expression. The recessive mutation, adr6-1, leads to an inability to fully derepress ADH2 expression and to an inability to sporulate. The ADR6 gene product appears to act directly or indirectly on ADH2 sequences 3' to or including the presumptive TATAA box. The upstream activating sequence (UAS) located 5' to the TATAA box is not required for the Adr6- phenotype. Here, we describe the isolation of a recombinant plasmid containing the wild-type ADR6 gene. ADR6 codes for a 4.4-kb RNA which is present during growth both on glucose and on nonfermentable carbon sources. Disruption of the ADR6 transcription unit led to viable cells with decreased ADHII activity and an inability to sporulate. This indicates that both phenotypes result from mutations within a single gene and that the adr6-1 allele was representative of mutations at this locus. The ADR6 gene mapped to the left arm of chromosome XVI at a site 18 centimorgans from the centromere.

scholarly journals Factorial Design to Optimize Biosurfactant Production byYarrowia lipolytica

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Gizele Cardoso Fontes ◽  
Priscilla Filomena Fonseca Amaral ◽  
Marcio Nele ◽  
Maria Alice Zarur Coelho
Keyword(s):  
Surface Tension ◽  
Factorial Design ◽  
Ammonium Sulfate ◽  
Yeast Extract ◽  
Carbon Sources ◽  
Nitrogen Sources ◽  
Biosurfactant Production ◽  
Standard Process ◽  
Emulsification Index ◽  
Full Factorial

In order to improve biosurfactant production byYarrowia lipolyticaIMUFRJ 50682, a factorial design was carried out. A24full factorial design was used to investigate the effects of nitrogen sources (urea, ammonium sulfate, yeast extract, and peptone) on maximum variation of surface tension (ΔST) and emulsification index (EI). The best results (67.7% of EI and 20.9 mNm−1ofΔST) were obtained in a medium composed of 10 g 1−1of ammonium sulfate and 0.5 g 1−1of yeast extract. Then, the effects of carbon sources (glycerol, hexadecane, olive oil, and glucose) were evaluated. The most favorable medium for biosurfactant production was composed of both glucose (4% w/v) and glycerol (2% w/v), which provided an EI of 81.3% and aΔST of 19.5 mN m−1. The experimental design optimization enhancedΔEI by 110.7% andΔST by 108.1% in relation to the standard process.

scholarly journals First Report of Choke Disease Caused by Epichloë typhina on Orchardgrass (Dactylis glomerata) in China

Plant Disease ◽  
2009 ◽  
Vol 93 (6) ◽  
pp. 673-673 ◽  
Author(s):  
C. J. Li ◽  
Z. F. Wang ◽  
N. Chen ◽  
Z. B. Nan
Keyword(s):  
Dactylis Glomerata ◽  
The United States ◽  
Leaf Sheath ◽  
Climatic Conditions ◽  
Disease Spread ◽  
Willamette Valley ◽  
First Report ◽  
Epichloë Typhina ◽  
Pure Cultures ◽  
Choke Disease

Orchardgrass or cocksfoot (Dactylis glomerata L.) has been widely cultivated as a forage crop in many provinces of China (1). It is also a native perennial forage grass, which grows at the edge of forests, shrubs, and mountainous grasslands in Xinjiang and Sichuan (2). In September of 2007, signs of choke disease on orchardgrass were observed in a native grassland under birch woodland near Altai City, Xinjiang, China. Stromata, which formed on culms of diseased grass, enclosing the inflorescence and leaf sheath, were 4.5 to 5.5 mm long, smooth or wrinkled, white and later becoming yellowish or yellow, tuberculate, dry, and covered with perithecia. Inflorescences surrounded by fungal stromata were choked and failed to mature, thus restricting seed production. Pure cultures were obtained by directly scraping stromata from the surface and incubating it on antibiotic potato dextrose agar (PDA). The colonies were cottony, white on the upper surface, and white to yellow on the reverse. The growth rate was 13 to 21 mm per week at 25°C on PDA. Conidia were hyaline, lunate to reniform, and measured 4.1 ± 0.5 × 2.2 ± 0.5 μm. They accumulated in small globose heads at the tips of conidiogenous cells and were produced singly on conidiophores of 13 to 33 μm long and 2.7 to 4.1 μm wide at the base. Internal transcribed spacer (ITS) sequence by BLAST search had 99% similarity with an Epichloë typhina isolate of orchardgrass in Spain (GenBank Accession No. AM262420.1). Cultural characteristics, microscopic examination, and phylogenetic analysis showed that this choke disease on D. glomerata was caused by the fungus E. typhina (Pers.) Tul. & C. Tul. as described by White (4). To our knowledge, this is the first report of E. typhina causing choke disease on orchardgrass in China. The pathogen has been identified in France, England, Germany, Sweden, Switzerland, and the United States (3,4) with the same symptoms as those reported here. In 1997, choke disease was found in 70% of the fields in the Willamette Valley of Oregon, with disease incidences ranging from 0.05 to 28%. It was predicted to increase and spread under the prevailing climatic conditions (3). This new disease report is to provide observational and diagnostic information to help with recognition and prevention of disease spread in orchardgrass cultivation regions of China. References: (1) X. R. Chao et al. Shandong Agric. Sci. 1:7, 2005. (2) S. X. Jia, ed. China Forage Plant Flora. China Agriculture Press, Beijing, 1987. (3) W. F. Pfender and S. C. Alderman. Plant Dis. 83:754, 1999. (4) J. W. White. Mycologia 85:444, 1993.

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