Efeito de extratos naturais de origem vegetal sobre esporos de Desulfotomaculum nitrificans

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

04/03/1994

RESUMO

This research aimed to determine the effect of natural plant and spice extracts on the germination, vegetative growth and heat resistance of Desulfotomaculum nigrificans spores, a contaminant of sugar and vegetables. The method of Donnelly and Busta (1980) was used to prepare and activate (40min/97°C) a lot of spores of D. nigrificans in Soytone Broth (SB) and Sugar Cane Juice (SC). Spore counts were determined in Sulphite Agar by colony counts in screw cap tubes, or in Tiaglycolate Fluid Broth with neutralizer by the NMP-3 method, exhausted, sealed with Vaspar and incubated at 55 °C, Among 29 natural plant and spice extracts tested against 102spores/ml, ginger root, angelica, rosemary and eucalyptus (EFE) inhibited the vegetative growth at 0,01%v/v or higher, and citric seeds extract (CSE) inhibited the vegetative growth at 0,001%v/v or higher. When the concentration of D. nigrificans spares was 105/ml, CSE and EFE showed the best results: 0.1 and 1%v/v, respectively inhibited the vegetative growth. Only CSE at 0.001 and 0.0001%v/v, and EFE at 0,1 and 1%v/v were tested on the germination of D. nigrificans spares in SC and SB broth by the heat resistance loss method: at the tested concentrations, none of them showed inhibitory effect upon germination in these media. The effect of thermo-chemical treatments on the resistance of D.nigrificans spores was evaluated by the addition of CSE at 0,05%v/v in SB (pH 7,6) and SC (pH 5,15) broths using TDT tube method. CSE decreased the heat resistance of D. nigrificans spares at approximately 5%, 25%, and 30%, respectively on thermal treatments at 115, 120 and 125°C, using either SB or SC. The D(min) values obtained in SB were greater than those on SC, probably due the lower pH of the SC. The Z(ºC) values observed agree with those reported in the literature (8-10 °C) for this microorganism

ASSUNTO(S)

esporos bacterianos alimentos - conservação

ACESSO AO ARTIGO

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