• Journal of Microbiology
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• v.38 no.4
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• pp.230-238
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• 2000

Class III chitin synthases in filamentous fungi are important for hyphal growth and differentiation of several filamentous fungi. A genomic clone containing the full gene encoding Chs4, a class III chitin synthase in Penicillium chrysogenum, was cloned by PCR screening and colony hybridization from the genomic library. Nucleotide sequence analysis and transcript mapping of chs4 revealed an open reading frame (ORF) that consisted of 5 exons and 4 introns and encoded a putative protein of 915 amino acids. Nucleotide sequence analysis of the 5'flanking region of the ORF revealed a potential TATA box and several binding sites for transcription activators. The putative transcription initiation site at -716 position was identified by primer extension and the expression of the chs4 during the vegetative growth was confirmed by Northern blot analysis. Amino acid sequence analysis of the Chs4 revealed at least 5 transmembrane helices and several sites for past-transnational modifications. Comparison of the amino acid sequence of Chs4 with those of other fungi showed a close relationship between P chrysogenum and genus Aspergillus.

• Mycobiology
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• v.36 no.3
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• pp.167-172
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• 2008

Beef luncheon meat is one of the most popular meals in several countries in the world including Egypt. Thirty one fungal species and 3 species varieties were recovered from 30 samples of beef luncheon meat collected from different supermarkets in Qena. Alternaria, Aspergillus, Emericella, Mucor, Mycosphaerella, Penicillium and Rhizopus were the most common genera on the two types of media. From the above genera, the most prevalent species were Alternaria alternate, Aspergillus flavus, A. fumigatus, A. niger, A. terreus, Emericella nidulans, Mucor racemosus, Mycosphaerella tassiana, Penicillium chrysogenum and Rhizopus stolonifer. Screening of fungi for their abilities to produce lipase enzyme showed that, ten isolates represented 32.26% of total isolates appeared high lipase production, while sixteen isolates (51.61%) were moderate and 5 isolates (16.13%) were low producers. Aspergillus niger, Fusarium oxysporum and Nectria haematococca produced the highest amount of lipase enzyme, so these fungi were used in further studies. The incorporation of five food preservatives (Disodium phosphate, sodium benzoate, citric acid, potassium sorbate and sodium citrate) individually in the culture medium of lipase production exhibited an inhibitive effect on the mycelial growth and enzyme production by Aspergillus niger, Fusarium oxysporum and Nectria haematococca.

• The Plant Pathology Journal
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• v.24 no.1
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• pp.24-30
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• 2008

Colletotrichum gloeosporioides forms an appressorium, a specialized infection structure, to infect its hosts. Among 400 and 600 culture filtrates from fungi and class Actinomycetes, six methanol extracts (A5005, A5314, A5387, A5560, A5597, and A5598) from the class Actinomycetes significantly inhibited appressorium formation in C. gloeosporioides infecting pepper fruits in a dose-dependent manner, while conidial germination was slightly enhanced. Two (A5005 and A5560) of them also exhibited distinctive inhibitory effect on the disease progress of pepper anthracnose. Water fractions of both culture filtrates also specifically inhibited appressorium formation in C. gloeosporioides and pepper anthracnose disease. Inhibition of appressorium formation by culture filtrate of A5005 was partially restored by the exogenous calcium. This results suggests that chemicals within A5005 extents its biological activity through disturbance of intracellular $Ca^{2+}$ regulation during prepenetration morphogenesis by C. gloeosporioides. Together, cell-based and target-oriented screening system used in this study should be applicable for other plant pathogenic fungi prerequisite appressorium formation to infect their hosts.

• Journal of Microbiology and Biotechnology
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• v.32 no.4
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• pp.504-513
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• 2022

Chitin deacetylase (CDA) inhibitors were developed as novel antifungal agents because CDA participates in critical fungal physiological and metabolic processes and increases virulence in soil-borne fungal pathogens. However, few CDA inhibitors have been reported. In this study, 150 candidate CDA inhibitors were selected from the commercial Chemdiv compound library through structure-based virtual screening. The top-ranked 25 compounds were further evaluated for biological activity. The compound J075-4187 had an IC50 of 4.24 ± 0.16 µM for AnCDA. Molecular docking calculations predicted that compound J075-4187 binds to the amino acid residues, including active sites (H101, D48). Furthermore, compound J075-4187 inhibited food spoilage fungi and plant pathogenic fungi, with minimum inhibitory concentration (MIC) at 260 ㎍/ml and minimum fungicidal concentration (MFC) at 520 ㎍/ml. Therefore, compound J075-4187 is a good candidate for use in developing antifungal agents for fungi control.

• Journal of Applied Biological Chemistry
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• v.44 no.3
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• pp.147-153
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• 2001

Methanol extracts from 51 fruits were tested for their fungicidal activities against six phytopathogenic fungi in a greenhouse. The efficacy varied with both the plant pathogen and fruit species used. At 10 and 5 mg/pot, methanol extracts of Poncirus trifoliata peel and seed gave over 80% control values against Pyricularia grisea, and strong fungicidal activities against Rhizoctonia solani were showed from the extracts of Citrus paradisi peel and Punica granatum leaf. In a test with Botrytis cinerea at 5 mg/pot, the extracts of C. sinensis seed and D. kaki leaf produced potent fungicidal activities, and the extracts of C. crenata peel and leaf, Ch. sinensis seed, P. trifoliata peel, and Z. jujuba leaf had strong fungicidal activities. At 5 mg/pot, strong fungicidal activities were produced in the extracts of P. trifoliata peel and seed against Phytophthora infestans and in the extracts of P. ussriensis var. macrostipes fruit and seed, C. crenata peel, C. crenata leaf, C. paradisi peel, P. trifoliata peel, P. granatum peel, and Z. jujuba leaf against Puccinia recondita. In a test with E. graminis, potent activities at 10 mg/pot were produced from the extracts of Ch. sinensis seed, C. sinensis seed, P. trifoliata leaf, P. ussriensis var. macrostipes fruit and seed, and Vitis vinifera seed. In the control effect of seven extracts against B. cinerea strains resistant to carbendazim, procymidone, and diethofencarb, extracts of C. crenata peel and leaf, Ch. sinensis seed, and P. trifoliata peel were highly effective against all strains of B. cinerea. Furthermore, potent fungicidal activities were produced from the extracts of C. sinensis seed and D. kaki leaf against the SSR, SRR, and RRS, and Z. jujuba leaf against the SSR and RRS strains. As a naturally occurring fungicide, these fruit-derived materials could be useful as new fungicidal products against phytopathogenic fungi.

• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.651-658
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• 2010

Garcinia is commonly found in Malaysia, but limited information is available regarding endophytic fungi associated with this plant. In this study, 24 endophytic fungi were successfully recovered from different parts of two Garcinia species. Characterization of endophytic fungi was performed based on the conserved internal transcribed spacer (ITS) region sequence analysis and the antimicrobial properties. Results revealed that fruits of the plant appeared to be the highest inhabitation site (38%) as compared with others. Glomerella sp., Guignardia sp., and Phomopsis sp. appeared to be the predominant endophytic fungi group in Garcinia mangostana and Garcinia parvifolia. Phylogenetic relationships of the isolated endophytic fungi were estimated from the sequences of the ITS region. On the other hand, antibacterial screening showed 11 of the isolates possessed positive response towards pathogenic and nonpathogenic bacteria. However, there was no direct association between certain antibacterial properties with the specific genus observed.

• The Plant Pathology Journal
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• v.16 no.4
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• pp.189-199
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• 2000

To search for the antifungal substances, various actino-mycete isolates were obtained from various soils of Korea using plate dilution method on the humic acid vitamin agar plates. In the screening procedures using a dual culture method, 32 actionomycete isolates were selected, which showed the inhibitory activity against mycelial growth of plant pathogenic fungi Altirnaria mali, Colletotrichum gloeosporides, Fusarium oxysporum f.sp. cucumerinum, Magnaporthe grisea, Phytophthora capsici, and Rhizoctonia solani. Bioassay of the crude extracts from culture filtrates and mycelial mets revealed that 12 antagonistic actionomycetes produced highly active antifungal substances. Actinomycete strain S5-55 which showed the substantial antifungal activity against the tested fungi was selected for production of the antifungal substances. Based on the cytochemical and morphological characteristics, strain S5-55 was identified as a Streptomyces species. The results of the numerical identification using the TAXON program confirmed that Streptomyces strain S5-55 was identical with Streptomyces humidus including in TAXON major cluster 19. The production of antifungal substance was most favorable when S. humidus strain S5-55 was cultivated for 10 dats on soluble starch broth supplemented with $K_2$HPO$_4$. The antifungal substances active against the plant pathogenic fungi P. capsici and M. grisea were partially purified using $\textrm{C}_{18}$ reversed-phase column chromatography.

• Korean journal of applied entomology
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• v.39 no.2
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• pp.111-115
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• 2000

Fifty-two nematode predatory fungi were isolated from 37 soil samples collected from eight provinces in Korea. Isolated fungi were tested their predacity against Rhabditis sp. and Meloidogyne incognita in petri dish, and against M. incognita in greenhouse pot experiments. Fifty isolates had trapping organ of adhesive networks and two isolates had adhesive column or adhesive knob. In petri dish experiments, 5 1 isolates against Rhubditis sp. and 26 isolates against M. incognita showed over 91 % of predacity; in greenhouse experiments, however, only three isolates showed over 81% of predacity. These results imply that the results from the laboratory experiments are not consistent with those from the greenhouse experiments. Therefore, to select a promising biocontrol predatory fungi for plant-parasitic nematodes, the screening experiment should be conducted in conditions close to nature.

• Journal of Microbiology and Biotechnology
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• v.19 no.9
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• pp.922-931
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• 2009

Screening-scale studies were performed with 26 fungal cultures for their ability to transform the anti-inflammatory drug meloxicam. Among the different fungi screened, a filamentous fungus, Cunninghamella blakesleeana NCIM 687, transformed meloxicam to three metabolites in significant quantities. The transformation of meloxicam was confirmed by high-performance liquid chromatography (HPLC). Based on the liquid chromatography-tandem mass spectrometry (LC-MS/MS) data, two metabolites were predicted to be 5-hydroxymethyl meloxicam and 5-carboxy meloxicam, the major mammalian metabolites reported previously. A new metabolite was produced, which is not detected in mammalian systems. Glucose medium, pH of 6.0, temperature of $27^{\circ}C$, 5-day incubation period, dimethylformamide as solvent, and glucose concentration of 2.0% were found to be suitable for maximum transformation of meloxicam when studied separately. It is concluded that C. blakesleeana can be employed for biotransformation of drugs for production of novel metabolites.

• Journal of Food Hygiene and Safety
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• v.5 no.3
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• pp.131-138
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• 1990

Aflatoxins is a chemically diverse group of toxic secondary metabolites that are produced by fungi and often occur in agricultural commodities. Because of their wide range of toxic effects, Aflatoxins cause severe economic losses to farmers and livestock producers and pose a health to human consuming contaminated foods. Long term prospects for biotechnological control of Aflatoxins require elucidation of the specific steps and regulation of their biosynthetic pathways . Aflatoxin determinations can be approached many ways. It is essential to safely handle all experimental materials associated with aflatoxin analysis or aflatoxigenic fungi Visual screening of suspect samples, base on the presence of conidial head of the aspergillus flavus group, and screening samples for the presence of bright greenish yellow flourescence are not chemical tests and such screening techniques may allow aflactoxin contaminated lots into commerce. Microcolumn screening procedures should always be used in conjunction with a quantitative method. Several thin layer chromatography(TLC) and high performance liquid chromatography(HPLC) methods are suitable for quantitation and are in general use. Immunochemical Methods such as the ELISA or affinity column chromatography methods are being rapidly developed. The chemical and immunochemical methods can be reliable if care is taken, using suitable controls and personnel that are well trained . All analytical laboratories should stress safety and include suitable analytical validation procedure. Especially a worldwide enquiry was undertaken in recent to obtain up-to-date information about aflatoxin legislation in as many countries of the world as possible. The information concerns aflatoxin in foodstuffs. aflatoxin MI in dairy products, aflatoxins in animal feedstuffs. Limits and regulations for aflatoxin have been expended in recent with more countries having legislation on subject, more products, and more aflatoxins covered by this legislation.