Search results for "Rhizopus"

Antifungal effect of phenolic extract of fermented rice bran with Rhizopus oryzae and its potential use in loaf bread shelf life extension

2018

In this study the antifungal potential of a phenolic extract obtained from rice bran fermented with Rhizopus oryzae CECT 7560 and its application in the elaboration of bread was assessed.; Results: Eighteen compounds with antifungal potential were identified by LC-ESI-qTOF-MS in the extract: organic acids, gallates and gallotannins, flavonoids, ellagic acid and benzophenone derivatives. The extract was active against strains of Fusarium, Aspergillus and Penicillium, with minimum inhibitory concentration ranging from 390 to 3100 µg mL-1 and minimum fungicidal concentration variable from 780 to 6300 µg mL-1 . The strains that were most sensitive to the phenolic extract were F. graminearum, F.…

The logarithmic transformation should be avoided for stabilising the variance of mould growth rate.

2007

Abstract Radial growth rate, μ (mm d − 1 ) was evaluated by plotting the radius of the colony, r (mm) versus time (d) for Alternaria alternata , Aspergillus flavus , Cladosporium cladosporioides , Mucor racemosus , Rhizopus oryzae and Trichoderma harzianum at different T and a w . For each of the 12 data sets, an analysis of variance of the raw growth rate data was performed. It was observed from the P -values that all square-root transformed values of μ were non-significant at the significance level α  = 0.05, whereas for untransformed values of μ , three of the 12 values were significant and for logarithmically transformed μ , nine of the 12 values were significant at the significance lev…

Comparison of the activity of antifungal hexapeptides and the fungicides thiabendazole and imazalil against postharvest fungal pathogens

2003

8 pages, 2 figures, 3 tables.-- PMID: 14623382 [PubMed].-- Printed version published Dec 31, 2003.

Long-chain fatty acyl-CoA esters induce lipase activation in the absence of a water-lipid interface.

2003

In most lipases a mobile element or lid domain covers the catalytic site of the enzyme and the lid opening event, which usually proceed at a lipid-water interface, is required to form the catalytically competent lipase. We report here a noticeable increase in activity of two fungal lipases assayed in aqueous solution in absence of any interface when adding submicellar concentrations of amphipathic physiological molecules like long-chain acyl-CoAs. The catalytic activity was dramatically dependent on the acyl chain length of the amphiphile and could be related with a lid-opening process. Our data support that lipase activation can be triggered in the absence of a well-defined interface, and …

Immunodeficiency Syndromes

2010

The Closed/Open Model for Lipase Activation. Addressing Intermediate Active Forms of Fungal Enzymes by Trapping of Conformers in Water-Restricted Env…

2001

The behavior of prototypic fungal lipases in a water-restricted environment has been investigated by exploiting the reported experimental strategy that allows the trapping (freeze-drying) of the enzyme in the conformation present in aqueous solution and to subsequently assay it in nonaqueous media [Mingarro, I., Abad, C., and Braco, L. (1995) Proc. Natl. Acad. Sci. U.S.A. 92, 3308-3312]. We now report, using simple esterification as well as acidolysis (triglycerides as substrates) as nonaqueous model reactions, that the presence of a detergent (n-octyl-beta-glucopyranoside) in the freeze-drying buffer, at concentrations below the critical micellar concentration, generates different catalyti…

Kinetics of solid-state fermentation of lupin with Rhizophus oligosporus based on nitrogen compounds balance

2021

Solid-state fermentation could be a potentially effective method for improving the nutritional value of legumes. The objective of this study was to explore this technology in Lupinus mutabilis, a species of lupin, using a strain of Rhizopus oligosporus mold for solid-state fermentation. Three L. mutabilis varieties (INIAP-450, INIAP-451, and Criollo) were evaluated, including the effect of the grain status (whole or ground) and integument or husk (presence or absence). Kinetic parameters of the fermentation process were studied to define the specific speed of nitrogen formation and the digestibility and nutritional quality of the resulting protein. After incubation at 28 °C for 96 h, the ti…

Trapping of Different Lipase Conformers in Water-Restricted Environments

1996

Based on a recently reported strategy to rationally activate lipolytic enzymes for use in nonaqueous media [Mingarro, I., et al. (1995) Proc. Natl. Acad. Sci. U.S.A. 92, 3308-3312], we compared the behavior in water-restricted environments of activated vs nonactivated forms of different lipases toward their natural substrates, triacylglycerols. To this end, nine lipases from varied origins (mammalian, fungal, and bacterial) were assayed using simple acidolyses as nonaqueous model reactions. The experimental results for several (though not all) lipases, discussed in the light of current structural and functional information, were collectively consistent with a model where, depending on the "…

Modelling the effect of ethanol on growth rate of food spoilage moulds

2005

The effect of ethanol (E) on the radial growth rate (mu) of food spoilage moulds (Aspergillus candidus, Aspergillus flavus, Aspergillus niger, Cladosporium cladosporioides, Eurotium herbariorum, Mucor circinelloides, Mucor racemosus, Paecilomyces variotii, Penicillium chrysogenum, Penicillium digitatum, Rhizopus oryzae and Trichoderma harzianum) was assessed in Potato Dextrose Agar (PDA) medium at a(w) 0.99, 25 degrees C. In order to model this effect, the Monod type equation described previously by Houtsma et al. (Houtsma, P.C., Kusters, B.J.M., de Wit, J.C., Rombouts, F.M., Zwietering, M.H., 1994. Modelling growth rates of Listeria monocytogenes as a function of lactate concentration. Int…