Production of kojic acid by resuspended mycelia of Aspergillus flavus

1982 ◽  
Vol 28 (12) ◽  
pp. 1340-1346 ◽  
Author(s):  
Pratima Bajpai ◽  
P. K. Agrawala ◽  
L. Vishwanathan
Keyword(s):  
Aspergillus Flavus ◽  
Growth Medium ◽  
Yeast Extract ◽  
Phosphate Buffer ◽  
Kojic Acid ◽  
Acid Biosynthesis ◽  
Yeast Extract Sucrose ◽  
Rotary Shaker

Efforts have been made to develop a simple chemically defined resuspended mycelial system which may be used for carrying out fundamental studies regarding the mechanism of kojic acid biosynthesis. As a first step, it was found that mycelia grown in yeast extract sucrose (YES) medium and resuspended in YES medium or in 0.2 M phosphate buffer, pH 6.5, supplemented with 20% glucose or sucrose produced kojic acid almost to the same extent as in the case of growth medium. No kojic acid was formed if buffers or media used for resuspension lacked carbohydrate. Intact mycelia preincubated in buffer alone for 7 days and 3-week-old mycelia could still form kojic acid in large amounts if resuspended in buffer containing glucose. The amount of kojic acid produced by the intact mycelia was found to be more than that produced by the disrupted mycelia. In contrast with static resuspension studies, when Aspergillus flavus mycelia were resuspended in flasks placed on a rotary shaker, much smaller amounts of kojic acid were synthesized.

Inhibition of Production of Cyclopiazonic Acid and Ochratoxin A by the Fungicide Iprodione‡

1997 ◽  
Vol 60 (7) ◽  
pp. 849-852 ◽  
Author(s):  
CÉLESTIN MUNIMBAZI ◽  
JYOTI SAXENA ◽  
WEI-YUN J. TSAI ◽  
LLOYD B. BULLERMAN
Keyword(s):  
Ochratoxin A ◽  
Incubation Period ◽  
Aspergillus Flavus ◽  
Growth Medium ◽  
Yeast Extract ◽  
Active Ingredient ◽  
Cyclopiazonic Acid ◽  
Aspergillus Ochraceus ◽  
Growth Media ◽  
Yeast Extract Sucrose

Aspergillus flavus NRRL 1290 and Aspergillus ochraceus NRRL 3174 were grown on a glucose-salts medium and yeast extract-sucrose broth containing the fungicide iprodione at concentrations of 0, 1,3,5, 10, 15, and 20 μg of active ingredient per ml of growth medium. Cultures were analyzed for cyclopiazonic acid, ochratoxin A, and mycelium production after 4,7, 10, 14, and 21 days of incubation at 25°C. Increasing concentrations of iprodione in the growth media resulted in greater reduction of cyclopiazonic acid, ochratoxin A, and mycelium production at the end of each incubation period. More than 50% reduction of cyclopiazonic acid, ochratoxin A, and mycelium production was observed when iprodione was added to growth media at a concentration of 5 μg/ml of medium. Higher concentrations of iprodione (10 to 20 μg/ml of growth medium) inhibited the production of cyclopiazonic acid and mycelium by A. flavus NRRL 1290 almost completely, but not the production of ochratoxin A and mycelium by A. ochraceus NRRL 3174.

Effects of Potassium Sorbate on Growth and Aflatoxin Production by Aspergillus parasiticus and Aspergillus flavus1

1983 ◽  
Vol 46 (11) ◽  
pp. 940-942 ◽  
Author(s):  
LLOYD B. BULLERMAN
Keyword(s):  
Aspergillus Flavus ◽  
Yeast Extract ◽  
Aflatoxin B1 ◽  
Spore Germination ◽  
Mycelial Growth ◽  
Aspergillus Parasiticus ◽  
Aflatoxin Production ◽  
Potassium Sorbate ◽  
Mycelial Mass ◽  
Yeast Extract Sucrose

Growth and aflatoxin production by selected strains of Aspergillus parasiticus and Aspergillus flavus in the presence of potassium sorbate at 12°C were studied. Potassium sorbate at 0.05, 0.10 and 0.15% delayed or prevented spore germination and initiation of growth, and slowed growth of these organisms in yeast-extract sucrose broth at 12°C. Increasing concentrations of sorbate caused more variation in the amount of total mycelial growth and generally resulted in a decrease in total mycelial mass. Potassium sorbate also greatly reduced or prevented production of aflatoxin B1 by A. parasiticus and A. flavus for up to 70 d at 12°C. At 0.10 and 0.15% of sorbate, aflatoxin production was essentially eliminated. A 0.05% sorbate, aflatoxin production was greatly decreased in A. flavus over the control, but only slightly decreased in A. parasiticus.

scholarly journals Detection and Quantitation of Aflatoxin for the Diagnosis of Aspergillus flavus

2015 ◽  
Vol 3 (1) ◽  
pp. 6-9 ◽  
Author(s):  
Geeta Rajbhandari Shrestha ◽  
Amin Udhin Mridha
Keyword(s):  
Aspergillus Flavus ◽  
Yeast Extract ◽  
Aflatoxin B1 ◽  
Sucrose Concentration ◽  
Synthetic Medium ◽  
Enzyme Linked Immunosorbent Assay ◽  
P Value ◽  
Detection And Diagnosis ◽  
Immunological Assays ◽  
Yeast Extract Sucrose

Aflatoxins are the potent mycotoxins produced by Aspergillus flavus, which is hepatotoxic causing hepatocellular carcinoma. A. flavus produces sufficient amount of Aflatoxin B1 under favourable environments. Inhalation of spores and use of Aflatoxin B1, contaminated food by Aspergillus spp., could transfuse the toxins in the blood streams. The presence of these toxins in body fluid can be detected by immunological assays and which provides an effective technique for the diagnosis of the disease caused by A. flavus. Aflatoxins producing strain of A. flavus were screened in Aflatoxin Producing Medium. Production of Aflatoxin B1 by A. flavus was studied in different parameters such as incubation periods, temperatures, pH variations, sucrose concentration in Yeast Extract Sucrose medium and different natural media such as par-boiled rice, corn and groundnuts. The detection of toxins was done by TLC using silica gel (Merk) coated plates and confirmative test was done by Association of Official Analytical Chemists (AOAC) method. Presence and quantization was done by Enzyme Linked Immunosorbent Assay (ELISA) technique. Highest amount of Aflatoxin B1 was reported 68.56 ng/ml by ELISA in synthetic medium (Yeast Extract Sucrose) with 2% sucrose, pH 5.5, on 14th days of incubation, at 28±1°C (p-value 0.05). Similarly, highest amount was recorded in groundnuts (121.20ng/g) by ELISA and (500ng/kg) by TLC methods. ELISA is one of the most efficient methods used for detection and diagnosis of human diseases cause due to exposure of Aflatoxin B1 and A. flavus.Nepal Journal of Biotechnology. Dec. 2015 Vol. 3, No. 1: 6-9

scholarly journals Aeration and yeast extract requirements for kojic acid production by Aspergillus flavus link

1996 ◽  
Vol 19 (7) ◽  
pp. 545-550 ◽  
Author(s):  
A.B. Ariff ◽  
M.S. Salleh ◽  
B. Ghani ◽  
M.A. Hassan ◽  
G. Rusul ◽  
...  
Keyword(s):  
Aspergillus Flavus ◽  
Yeast Extract ◽  
Acid Production ◽  
Kojic Acid ◽  
Kojic Acid Production

Mycoflora and Aflatoxin-Producing Strains in Animal Mixed Feeds

1994 ◽  
Vol 57 (3) ◽  
pp. 256-258 ◽  
Author(s):  
M. L. ABARCA ◽  
M. R. BRAGULAT ◽  
G. CASTELLÁ ◽  
F. J. CABAÑES
Keyword(s):  
Aspergillus Flavus ◽  
Yeast Extract ◽  
Penicillium Chrysogenum ◽  
Fusarium Moniliforme ◽  
Dominant Species ◽  
Aflatoxin Production ◽  
Fungal Species ◽  
Sucrose Medium ◽  
Mixed Feeds ◽  
Yeast Extract Sucrose

The mycoflora of 69 samples of animal mixed feeds were studied. Fungal counts ranged from 102 to 108 CFU/g, the lowest counts corresponding to the samples of rabbit feeds. Seventy-one fungal species belonging to 26 genera were identified. The pre- dominant species were Aspergillus flavus, Fusarium moniliforme, and Penicillium chrysogenum. Thirty-six strains of A. flavus and one strain of A. parasiticus were screened for aflatoxin production in yeast extract-sucrose medium. The final pH, weight of mycelium, and production of aflatoxins were determined after 14 days of incubation. Five strains (13.5%) were aflatoxigenic. No statistical differences were observed in mycelial dry weights and final pH between aflatoxin-producing strains and nonaflatoxigenic strains.

scholarly journals Enzymes Relevant to Kojic Acid Biosynthesis in Aspergillus flavus

Microbiology ◽  
1981 ◽  
Vol 127 (1) ◽  
pp. 131-136
Author(s):  
P. BAJPAI ◽  
P.K. AGRAWALA ◽  
L. VISHWANATHAN
Keyword(s):  
Aspergillus Flavus ◽  
Kojic Acid ◽  
Acid Biosynthesis

Identification and characterization of genes involved in kojic acid biosynthesis in Aspergillus flavus

2017 ◽  
Vol 67 (10) ◽  
pp. 691-702 ◽  
Author(s):  
Hala A. M. Ammar ◽  
Ali Y. Srour ◽  
Saeid M. Ezzat ◽  
Asmaa M. Hoseny
Keyword(s):  
Aspergillus Flavus ◽  
Kojic Acid ◽  
Acid Biosynthesis ◽  
Identification And Characterization

Production of Kojic Acid by Aspergillus candidus in Three Culture Media

1991 ◽  
Vol 54 (7) ◽  
pp. 546-548 ◽  
Author(s):  
C. I. WEI ◽  
T. S. HUANG ◽  
J. S. CHEN ◽  
M. R. MARSHALL ◽  
K. T. CHUNG
Keyword(s):  
Liquid Medium ◽  
Yeast Extract ◽  
Acid Production ◽  
Kojic Acid ◽  
Culture Media ◽  
Sucrose Medium ◽  
Kojic Acid Production ◽  
Aspergillus Candidus ◽  
Yeast Extract Sucrose

Aspergillus candidus ATCC 44054 grown without agitation produced more kojic acid in the modified Czapek-Dox liquid medium than cultures shaken at 100 rpm. Of the three culture media tested, yeast extract-sucrose medium permitted more kojic acid production by the fungus than modified Czapek-Dox liquid medium or Tadera medium. Maximal kojic acid (57–59 mg/ml) was produced in the yeast extract-sucrose medium on days 9–12. No aflatoxin by the fungus was detected.

scholarly journals The Fungi-specific histone Acetyltransferase Rtt109 mediates morphogenesis, Aflatoxin synthesis and pathogenicity in Aspergillus flavus by acetylating H3K9

IMA Fungus ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ruilin Sun ◽  
Meifang Wen ◽  
Lianghuan Wu ◽  
Huahui Lan ◽  
Jun Yuan ◽  
...  
Keyword(s):  
Aspergillus Flavus ◽  
Histone Acetyltransferase ◽  
Epigenetic Modification ◽  
Aerial Mycelium ◽  
Environmental Stress Response ◽  
New Thought ◽  
Conidium Formation ◽  
Complementary Strain ◽  
And Control ◽  
Yeast Extract Sucrose

AbstractAspergillus flavus is a common saprophytic filamentous fungus that produces the highly toxic natural compound aflatoxin during its growth process. Synthesis of the aflatoxins, which can contaminate food crops causing huge losses to the agricultural economy, is often regulated by epigenetic modification, such as the histone acetyltransferase. In this study, we used Aspergillus flavus as an experimental model to construct the acetyltransferase gene rtt109 knockout strain (△rtt109) and its complementary strain (△rtt109·com) by homologous recombination. The growth of △rtt109 was significantly suppressed compared to the wild type (WT) strain and the △rtt109·com strain. The sclerotium of △rtt109 grew smaller, and the amount of sclerotia generated by △rtt109 was significantly reduced. The number of conidiums of △rtt109 was significantly reduced, especially on the yeast extract sucrose (YES) solid medium. The amount of aflatoxins synthesized by △rtt109 in the PDB liquid medium was significantly decreased We also found that the △rtt109 strain was extremely sensitive to DNA damage stress. Through the maize seed infection experiment, we found that the growth of △rtt109 on the surface of affected corn was largely reduced, and the amount of aerial mycelium decreased significantly, which was consistent with the results on the artificial medium. We further found that H3K9 was the acetylated target of Rtt109 in A. flavus. In conclusion, Rtt109 participated in the growth, conidium formation, sclerotia generation, aflatoxin synthesis, environmental stress response, regulation of infection of A. flavus. The results from this study of rtt109 showed data for acetylation in the regulation of life processes and provided a new thought regarding the prevention and control of A. flavus hazards.

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