scholarly journals Strain Improvement and Genetic Characterization of Indigenous Aspergillus Flavus for Amylolytic Potential

2009 ◽  
Vol 4 (7) ◽  
pp. 1934578X0900400
Author(s):  
Sobiya Shafique ◽  
Rukhsana Bajwa ◽  
Shazia Shafique
Keyword(s):  
Enzyme Activity ◽  
Aspergillus Flavus ◽  
Production Control ◽  
Strain Improvement ◽  
Chemical Mutagenesis ◽  
Pcr Analysis ◽  
Native Strain ◽  
Rapd Pcr ◽  
Mutant Strains

Aspergillus flavus FCBP–231, a filamentous fungus, was genetically modified for its ability to reveal extra cellular α-amylase activity. For strain improvement, the selected strains were subjected to UV irradiation (5-40 min exposure) and EMS treatment (50–300 μg mL−1) for hyper activity of an α-amylase enzyme. The mutants were quantitatively compared with the parental strain. UV and chemical mutagenesis brought about a dramatic enhancement in enzymatic activity. The mutant strains Af-UV-5.3 and Af-Ch-5.7 exhibited 79 and 110% more enzyme activity than the native strain A. flavus FCBP-231. This improvement in enzyme activity of the mutants suggests that they are suitable strains to be used in biotechnology. RAPD–PCR analysis revealed different patterns of amplicons of native as well as mutant derivatives, which suggested that the mutation imparted changes in the genetic make up of the mutants probably involved enzyme production control.

scholarly journals Application of molecular methods for characterization of Botrytis fabae and Botrytis cinerea of faba bean

2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 314-318
Author(s):  
N.M. Abou-Zeid ◽  
I.H. Dorriah ◽  
A.A. Marwa
Keyword(s):  
Botrytis Cinerea ◽  
Faba Bean ◽  
Morphological Characters ◽  
Molecular Methods ◽  
Pcr Analysis ◽  
Conidial Morphology ◽  
Rapd Pcr ◽  
Botrytis Fabae

Application of the RAPD methods allowed to clearly characterization of isolates of Botrytis fabae and isolates of B. cinerea. Results from RAPD-PCR analysis indicate different groups. Clusters were related with groups based on conidial morphology, morphological characters of the isolates of Botrytis spp.

Characterization of a unique population of Fusarium oxysporum f.sp. cubense causing Fusarium wilt in Cavendish bananas at Carnarvon, Western Australia

1995 ◽  
Vol 46 (1) ◽  
pp. 167 ◽  
Author(s):  
KG Pegg ◽  
RG Shivas ◽  
NY Moore ◽  
S Bentley
Keyword(s):  
Fusarium Oxysporum ◽  
Vegetative Compatibility ◽  
Pcr Analysis ◽  
Banding Patterns ◽  
Vegetative Compatibility Groups ◽  
Rapd Pcr ◽  
Race 1 ◽  
Race 4 ◽  
Volatile Production

A unique population of Fusarium oxysporum f. sp. cubense affecting Cavendish cv. Williams banana plants was characterized using vegetative compatibility, volatile production, RAPD-PCR analysis, pectic enzyme production and pathogenicity. The isolates were more like race 1 isolates than race 4 isolates, although they were capable of attacking Cavendish clones. The Carnarvon isolates did not belong to any of the vegetative compatibility groups (VCGs) known to occur in Australia or overseas; they belonged in the 'inodoraturn' volatile group; they had 29% genetic similarity to race 4 isolates and 76% similarity to race 1 isolates based on RAPD-PCR banding patterns; they belonged in the same pectic zymogram group as race 1 isolates and were virulent on 3-month-old Cavendish cv. Williams, Gros Michel and Pisang Gajih Merah plants in glasshouse tests.

Genotypic and technological characterization of enterococci isolated from artisanal Fiore Sardo cheese

2004 ◽  
Vol 71 (4) ◽  
pp. 444-450 ◽  
Author(s):  
Sofia Cosentino ◽  
M Barbara Pisano ◽  
Arianna Corda ◽  
M Elisabetta Fadda ◽  
Carla Piras
Keyword(s):  
Wide Spectrum ◽  
Health Concern ◽  
Pcr Analysis ◽  
Gelatinase Activity ◽  
Rapd Pcr ◽  
Vancomycin Resistant ◽  
Low Incidence ◽  
Almost All ◽  
Hydrolyse Casein

A total of 118 enterococcal strains isolated from artisanal Fiore Sardo cheese were characterized technologically and genetically. The presence of potential virulence factors was also investigated. Strains were classified as Ec. faecium (84 strains), Ec. durans (24 strains) and Ec. faecalis (10 strains). RAPD-PCR analysis with two different primers (M13 and XD9) confirmed species identification and proved useful for the detection of interstrain variations, especially among Ec. faecium isolates. Most strains could hydrolyse casein and had weak acidifying activity in milk. None of the isolates produced lipolytic reactions. Gelatinase activity was observed in two strains of Ec. faecalis and one strain of Ec. durans. β-Haemolysis on horses' blood was never detected in any of the strains, independently of species. Most strains produced tyramine from tyrosine but none decarboxylated lysine, histidine or ornithine. Overall, a wide spectrum of resistance was observed. Almost all strains were resistant to the aminoglycosides, gentamycin, kanamycin, streptomycin, neomycin, and to the semisynthetic penicillin, oxacillin, but resistance to vancomycin was not widespread among our strains: only one Ec. faecium and one Ec. durans strain were found to be vancomycin resistant. Our results show a certain diversity in technological traits of the enterococcal strains isolated from artisanal Fiore Sardo, together with a low incidence of some potentially pathogenic traits of health concern.

scholarly journals Mutagenesis and Genotypic Characterization of Aspergillus niger FCBP-02 for Improvement in Cellulolytic Potential

2009 ◽  
Vol 4 (4) ◽  
pp. 1934578X0900400
Author(s):  
Shazia Shafique ◽  
Rukhsana Bajwa ◽  
Sobiya Shafique
Keyword(s):  
Aspergillus Niger ◽  
Wild Strain ◽  
Cellulase Activity ◽  
Soluble Carbohydrates ◽  
Wild Type ◽  
Methane Sulfonate ◽  
Ethyl Methane ◽  
Rapd Pcr ◽  
Mutant Strains

Cellulase is a collective term that encompasses enzymes which catalyze reactions that participate in the degradation of insoluble cellulose to soluble carbohydrates. In the present study, production of extra cellular cellulases by a filamentous fungus, Aspergillus niger FCBP-02, was studied in solid-state fermentation (SSF) as well as in submerged fermentation (SmF). Trials were conducted to evaluate the effect of mutagenesis by UV irradiation (5–40 min) and ethyl methane sulfonate (EMS) treatment (50–300 μg mL−1) to obtain hyper active cellulase enzyme producers among the potential strains. The enzyme activity assays of parental and mutant strains clearly revealed significantly higher cellulase activity of mutant A-Ch-5.5 (96 Units mL−1), followed by A-UV-5.6 (71 Units mL−1) with respect to the wild strain of A. niger FCBP–02 (53.7 Units mL−1). The profile of genetic variability among wild and mutant derivatives was scrutinized through RAPD–PCR. The expression pattern of mutants exhibited that the mutants were isogenic variants of the wild type and the out performance of the mutants could be attributed to the change in genetic make up.

scholarly journals Occurrence and Characterization of Fungi and Mycotoxins in Contaminated Medicinal Herbs

Toxins ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 30 ◽  
Author(s):  
Ling Chen ◽  
Weipeng Guo ◽  
Yuqing Zheng ◽  
Jinzhen Zhou ◽  
Tingting Liu ◽  
...  
Keyword(s):  
Aspergillus Flavus ◽  
High Performance ◽  
Medicinal Herbs ◽  
Pcr Analysis ◽  
Trichoderma Spp ◽  
Scutellariae Radix ◽  
Liquid Chromatography Tandem Mass ◽  
Mycotoxigenic Fungi ◽  
And Storage

Traditional medicinal herbs are widely used and may be contaminated with mycotoxigenic fungi during cultivation, harvesting, and storage, causing spoilage and mycotoxin production. We evaluated the predominant mycoflora and extent of mycotoxin contaminations in 48 contaminated samples of 13 different medicinal herbs. In total, 70.8% of herbs were slightly contaminated with aflatoxins (<5 μg kg−1). Codonopsis radix samples contained ochratoxin A (OTA) (360–515 μg kg−1), and Scutellariae radix samples contained OTA (49–231 μg kg−1) and citrinin (15–53 μg kg−1). Forty samples (83.3%) contained fungal contamination. Sixty-nine strains were characterized via morphological and molecular identification. The predominant mycoflora comprised four genera, Aspergillus spp. (26.1%), Penicillium spp. (24.6%), Rhizopus spp. (14.5%), and Trichoderma spp. (11.6%). Aflatoxins, OTA, and citrinin were detected in 37 cultures by high-performance liquid chromatography-tandem mass spectrometry. Approximately 21.6% of Aspergillus and Penicillium isolates produced mycotoxins. One Penicillium polonicum strain isolated from Scutellariae radix synthesized citrinin. Multiplex PCR analysis showed that three Aspergillus flavus strains harbored aflatoxin biosynthesis genes. One Aspergillus flavus strain isolated from Amomi fructus produced AFB1 and AFB2. To the best of our knowledge, the citrinin production by Aspergillus chevalieri and Penicillium sacculum was first reported in this study, which poses a potential risk of mycotoxin contamination in medicinal herbs.

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