Association of Candida guilliermondii with amylolytic filamentous fungi on preharvest corn

1985 ◽  
Vol 31 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Bruce W. Horn

Candida guilliermondii var. guilliermondii was the dominant yeast isolated from preharvest Georgia corn and comprised 3.6–47.0% of the total fungi as measured by dilution plating. The yeast was confined mainly to kernels visibly molded by filamentous fungi, primarily Fusarium moniliforme and Aspergillus flavus. When grown in liquid shake culture, Cand. guilliermondii was unable to utilize starch. Growth of the yeast increased considerably when associated with amylolytic F. moniliforme or Asp. flavus. Utilization of starch hydrolyzates by Cand. guilliermondii in mixed cultures was reflected by a decrease in reducing sugar concentrations and a reduction in growth of F. moniliforme and Asp. flavus. When glucose replaced starch as a carbon source, F. moniliforme and Asp. flavus did not affect the maximum growth of Cand. guilliermondii. The association between Cand. guilliermondii and amylolytic filamentous fungi on preharvest corn is probably commensalistic.

1997 ◽  
Vol 43 (4) ◽  
pp. 362-367 ◽  
Author(s):  
M. J. R. Nout ◽  
C. E. Platis ◽  
D. T. Wicklow

Microflora in wound sites of preharvest maize (including bacteria, yeasts, and filamentous fungi) may play a role in attracting insects to maize plants and may also interact with growth and mycotoxin production by filamentous fungi. As little data are available about the yeasts occurring on maize from the U.S. corn belt, samples of milled maize from experimental plantings at the University of Illinois River Valley Sand Field were analyzed. Yeast counts showed slight yearly fluctuation and varied between 3.60 and 5.88 (log cfu/g maize). The majority of the yeasts were Candida guilliermondii (approximately 55%), Candida zeylanoides (24 %), Candida shehatae (11%), and Debaryomyces hansenii (3%). Also present were Trichosporon cutaneum, Cryptococcus albidus var. aerius, and Pichia membranifaciens. The occurrence of killer yeasts was also evaluated. Killer yeasts were detected in maize for the first time and were identified as Trichosporon cutaneum and Candida zeylanoides. These were able to kill some representative yeasts isolated from maize, including Candida guilliermondii, Candida shehatae, and Cryptococcus albidus var. aerius. Other maize yeasts (Candida zeylanoides, Debaryomyces hansenii, Pichia membranifaciens) were not affected. The majority of yeasts found on maize were unable to ferment its major sugars, i.e., sucrose and maltose. Some (e.g., Candida zeylanoides) were not even able to assimilate these sugars. The importance of these properties in relation to insect attraction to preharvest ears of maize is discussed.Key words: corn, maize, yeast, killer.


2017 ◽  
Vol 9 (3) ◽  
pp. 1662-1665
Author(s):  
Barun Rai ◽  
Sekhar Bandyopadhyay ◽  
Avisak Thapa ◽  
Adeetya Rai ◽  
Deewakar Baral

Isolation of ginger (Zingiber officinale) leaf spot pathogen form the UBKV farm field was done in the laboratory. The isolated pathogen was identified as Phyllosticta zingiberi on the basis of morphological characters as documented in taxonomic keys. The microscopic observation revealed that the pycnidia were globose to subglobose with dark brown colour measuring 124.16 μm × 2.35 μm in average. The pycnidio spores were hyaline, oval to bullet shaped, monoguttulate measuring 4.02 μm × 2.35 μm in average. Among the different media tested for growth highest growth was recorded in Oat meal agar (26.44 cm2) followed by malt extract agar (24.04 cm2) which was statistically at par. The temperature of 25˚C favoured maximum growth (24.20 cm2). However, higher sporulation was observed in 30˚C. Among the different carbon source tested, mannitol supported the highest growth of the pathogen (27.67 cm2).


Author(s):  
M O Oyewale

The mycelial dry weight and dinitrosalicylic acid (D.N.S.A.) method was used to determine growth and amylase production by Aspergillus flavus grown on different carbon sources. Growth of the fungus was determined at 24 h intervals over a period of six days by the dry mycelial weight methods, while the amylase activity in the culture filtrates of A. flavus was determined by the D.N.S.A method. A total of 45 samples were prepared to determine growth and amylase activity of Aspergillus flavus grown on different carbon sources. The concentration of the various carbon sources ranges between 0.4 to 2% W/V. Duncan’s multiple range test was used to determine the level of significance of the different carbon sources for effective growth and amylase production by Aspergillus flavus. Aspergillus flavus demonstrated the capability to produce significant growth and amylase activities in the medium containing soluble starch, sorghum and cassava peel as sole carbon source. The amount of mycelial dry weight produced from soluble starch, sorghum and cassava peel is significantly higher than those produced from other carbon sources. The data revealed that there is a correlation between growth and amylase production by Aspergillus flavus. The available data from this study showed that soluble starch is the best carbon source for optimum growth and amylase production by A flavus while sorghum and cassava peel are close substitute for optimum growth and amylase production by Aspergillus flavus. Keywords: Growth, amylase activity and Aspergillus flavus


1988 ◽  
Vol 51 (6) ◽  
pp. 449-451 ◽  
Author(s):  
PHILIP B. MISLIVEC ◽  
MARY W. TRUCKSESS ◽  
LEONARD STOLOFF

The effect of Aspergillus ochraceus, A. versicolor, Penicillium citrinum, P. cyclopium and P. urticae on production of aflatoxin by A. flavus when grown together with A. flavus in rotary shake culture was investigated. The two aspergilli had no apparent effect on aflatoxin production, whereas all three Penicillium species substantially lowered aflatoxin production. The toxins that these penicillia produced when growing in pure culture were not found when the penicillia were grown with A. flavus. However, these toxins had no effect on aflatoxin production added to the growth media, nor did the three molds metabolize aflatoxin. When A. flavus was grown in both filter- and autoclave-sterilized filtrates of these three species, no aflatoxins were produced, although A. flavus grew well. These results suggest that although A. ochraceus and A. versicolor have no apparent effect on aflatoxin production, P. citrinum, P. cyclopium and P. urticae produce heat-stable, nonfilterable metabolite(s) which inhibit(s) aflatoxin production by actively growing A. flavus.


2006 ◽  
Vol 69 (10) ◽  
pp. 2544-2548 ◽  
Author(s):  
DANTE J. BUENO ◽  
JULIO O. SILVA ◽  
GUILLERMO OLIVER ◽  
SILVIA N. GONZÁLEZ

The effect of two species of lactobacilli, Lactobacillus casei CRL 431 and Lactobacillus rhamnosus CRL 1224, on growth of different Aspergillus flavus strains was determined. A. flavus strains (Ap, TR2,or CF80) were grown in LAPTg broth at 37°C for 7 days as a single culture and in association with L. casei CRL 431 or L. rhamnosus CRL 1224 at initial inoculum ratios of 1:1, 1:10, and 1:100. In most cases, the mixed cultures had a lower fungal growth and a lower pH than the control cultures. Mycelial dry weight was reduced to 73 and 85% using L. casei CRL 431 and L. rhamnosus CRL 1224, respectively. The pH decrease in mixed cultures when the fungal mycelial dry weight is reduced may play an important role in inhibition. The number of viable bacteria was variably affected by fungal growth. These results indicate that L. casei CRL 431 and L. rhamnosus CRL 1224 may be useful as potential biocontrol agent against A. flavus


2006 ◽  
Vol 50 (12) ◽  
pp. 4202-4205 ◽  
Author(s):  
J. C. Bowman ◽  
G. K. Abruzzo ◽  
A. M. Flattery ◽  
C. J. Gill ◽  
E. J. Hickey ◽  
...  

ABSTRACT The echinocandin caspofungin is a potent inhibitor of the activity of 1,3-β-d-glucan synthase from Aspergillus flavus, Aspergillus terreus, and Aspergillus nidulans. In murine models of disseminated infection, caspofungin prolonged survival and reduced the kidney fungal burden. Caspofungin was at least as effective as amphotericin B against these filamentous fungi in vivo.


2012 ◽  
Vol 10 (1) ◽  
pp. 46-50 ◽  
Author(s):  
F. Yeasmin ◽  
M. Ashrafuzzaman ◽  
I. Hossain

Seeds of rice were treated with Garlic (Allium sativum) clove extract @ 1:0, 1:1, 1:2 dilutions in water, allamanda (Allamanda cathartica) leaf extract @ 1:1, 1:2, 1:3 dilutions in water and Provax-200 @ 0.3% for controlling seed borne fungi, where the seed samples of three rice varieties viz. Katharee, Gutee Aus and Kalijira were collected from farmer’s storages of Bangladesh. The seed germination under control ranged from 64 to 77%, where treatments resulted up to 100% germination. The identified seed borne fungi of rice were Bipolaris oryzae, Curvularia oryzae, Fusarium oxysporum, F. moniliforme, Nigrospora oryzae, Aspergillus flavus, Aspergillus niger and Penicillium sp., where prevalence of Bipolaris oryzae (7.5%) and Fusarium moniliforme (8.3%) were the maximum. All the treatments significantly reduced the seed borne fungi up to 100% over the control, where Provax was found best and was statically similar to garlic (1:1) extract against seed borne pathogen of rice.DOI: http://dx.doi.org/10.3329/agric.v10i1.11064The Agriculturists 2012; 10(1): 46-50


Microbiology ◽  
1984 ◽  
Vol 130 (2) ◽  
pp. 319-323 ◽  
Author(s):  
M. J. Perry ◽  
J. F. Makins ◽  
M. W. Adlard ◽  
G. Holt

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