Dry‐heat Resistance of <i>Bacillus subtilis</i> Spores in Contact with Serum Albumin, Carbohydrates or Lipids

Molin, Göran

doi:10.1111/j.1365-2672.1977.tb00674.x

Cited by 10 publications

(5 citation statements)

References 20 publications

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“…Both values were obtained for spores heated in soybean oil. Under a constant a, of 0.33, Molin (1977) found a z value of 23°C for B. subtilis spores heated in olive oil and 27°C in soybean oil. Senhaji & Loncin (1977) did not derive a z value from their data, as the thermal reduction time curve was not linear.…”

Section: Resultsmentioning

confidence: 95%

“…Moreover, because of the complexity of bacterial spores, only a very few systematic studies have been conducted using Bacillus spores (Molin & Snygg 1967;Molin 1977;Senhaji & Loncin 1977;Senhaji 1977), and no data on clostridial spores have been reported because of the inherent dificulty of working with anaerobes. The toxic nature of the toxin of Clnstridium botulinurn further limits work with this anaerobe.…”

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confidence: 99%

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Effect of thermal treatments in oils on bacterial spore survival

Ababouch

Busta

1987

Journal of Applied Bacteriology

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The heat resistance of Bacillus cereus F4165/75, Clostridium sporogenes PA 3679 and Cl. botulinum 62A spores suspended in buffer (pH 7.2), olive oil and a commercial oil (a mixture of rapeseed oil and soy oil) was investigated. Linear survivor curves were obtained with B. cereus spores in the three menstrua and with 62A and PA 3679 spores suspended in buffer. However, the inactivation kinetics of the clostridial spores suspended in oils were concave upward with a characteristic tailing-off for 62A spores suspended in olive oil. These deviations from the semi-log model could not be ascribed to a heterogeneity in heat resistance of the spore population or to the variation of aw during heating. Spore resistance to heat increased in the order: buffer much less than commercial oil less than olive oil. The greater heat resistance of oil-suspended spores was ascribed to the low aw (0.479 and 0.492 for commercial oil and olive oil, respectively) and to the composition of the oils. The difference in z values (ca 28 degrees C in oils and 10 degrees-12 degrees C in buffer) suggested that the mechanism of inactivation differs for spores suspended in lipids and in aqueous systems. The thermodynamic data were consistent with this hypothesis.

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Section: Resultsmentioning

confidence: 95%

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confidence: 99%

Effect of thermal treatments in oils on bacterial spore survival

Ababouch

Busta

1987

Journal of Applied Bacteriology

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“…It was also found that feed imparted a greater in-hibitory effect (P ≤ 0.001) on the antimicrobial property of TC than feces at both storage temperatures. This difference in the inhibitory effect between feed and feces could be attributed to the protective effect of fats [38,39], carbohydrates [38,40,41], or proteins in the feed on bacteria. Previously, Gradel et al [42] reported a greater relative survivability of Salmonella in dried feed than in dried feces.…”

Section: Resultsmentioning

confidence: 97%

Antibacterial Effect of Trans-Cinnamaldehyde on Salmonella Enteritidis and Campylobacter jejuni in Chicken Drinking Water ,

Johny

Darre

Hoagland

et al. 2008

Journal of Applied Poultry Research

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Primary Audience: Flock Supervisors, Quality Assurance and Laboratory Personnel, Researchers and Veterinarians SUMMARYSalmonella Enteritidis and Campylobacter jejuni are 2 major foodborne pathogens in the United States, estimated to cause more than 3 million cases of human illness annually. Chickens are the natural hosts of these bacteria, and their drinking water can be a source of S. Enteritidis and C. jejuni, contributing to the colonization of birds. In this study, trans-cinnamaldehyde (TC), a natural, generally recognized as safe ingredient in cinnamon oil was evaluated for its efficacy to inactivate S. Enteritidis and C. jejuni in the drinking water of chickens. Well water containing 0, 0.016, 0.03, and 0.06% TC was inoculated with a 5-strain mixture of S. Enteritidis or C. jejuni (~6 log 10 cells/mL). Water samples containing 1% chicken feces or feed were also included. The samples were incubated at 12.5 or 25°C for 7 d and analyzed for bacterial populations on d 0, 1, 3, 5, and 7. Duplicate samples of treatments and control were included, and the study was replicated 3 times. Trans-cinnamaldehyde at 0.06% inactivated Salmonella completely after 24 h in water with 1% feces at both temperatures. In water containing 1% feed, TC (0.06%) reduced S. Enteritidis to undetectable levels after 3 d at 12.5°C or 7 d at 25°C. Presence of feed or feces in water reduced the antibacterial effect (P < 0.001) of TC. The effect of TC on C. jejuni was more pronounced than that on S. Enteritidis. The TC at 0.06% completely inactivated the pathogen after 1 d of incubation at both temperatures. The presence of feces or feed did not have any effect (P > 0.001) on the antibacterial property of TC on C. jejuni. Results indicate that TC is effective in killing S. Enteritidis and C. jejuni in chicken drinking water and may decrease the likelihood that water will contribute to colonization of chickens by these pathogens.

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“…Salmonella was more heat resistant in dried feed than dried faeces, which could indicate the protective effect of fats, carbohydrates and/or proteins in the former, phenomena that have been confirmed mainly for fats (Molin 1977; Ababouch et al 1995) and carbohydrates (Goepfert et al 1970; Corry 1974; Molin 1977). Other studies have shown that increasing numbers and densities of bacteria might increase their heat resistance (Hansen and Riemann 1963; Humphrey et al 1990; Duffy et al 1995; Aldsworth et al 1998; Humpheson et al 1998) and this would favour survival in faeces compared with feed, but in our study the presence of the above compounds seemed more important.…”

Section: Discussionmentioning

confidence: 94%

Laboratory heating studies with Salmonella spp. and Escherichia coli in organic matter, with a view to decontamination of poultry houses

Gradel¹,

Jørgensen²,

Andersen³

et al. 2003

J Appl Microbiol

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Aims: To determine a temperature-humidity-time treatment that eliminates Salmonella and Escherichia coli in substrates representing organic matter in poorly cleaned poultry houses, i.e. worst case scenario laboratory tests. Methods and Results: Organic matter (poultry faeces and feed) in a 2AE5-cm layer was inoculated with 2 · 10 5 -3 · 10 6 Salmonella g )1 , left undried or dried at ca. 30% relative humidity (RH) during a 10-day period, and temperature increased at 1°C h )1 to the final heating temperature of 50, 55, 60, 65 or 70°C and held at 16-30 or 100% RH. All samples were tested for Salmonella according to predetermined sampling time schedules and faecal samples were also tested for naturally occurring E. coli. Overall, humidity was an important factor in the elimination of Salmonella and E. coli. Results for recovery of Salmonella and E. coli were highly associated. Conclusions: The application of ‡60°C and 100% RH during a 24-h period eliminated Salmonella and E. coli in all samples. Escherichia coli could be used as an indicator bacterium for the elimination of Salmonella. Significance and Impact of the Study: The results from worst case scenario laboratory tests could be applied in steam heating of persistently Salmonella-infected poultry houses. The use of E. coli as an indicator bacterium for the validation of Salmonella results should be considered.

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Dry‐heat Resistance of Bacillus subtilis Spores in Contact with Serum Albumin, Carbohydrates or Lipids

Cited by 10 publications

References 20 publications

Effect of thermal treatments in oils on bacterial spore survival

Effect of thermal treatments in oils on bacterial spore survival

Antibacterial Effect of Trans-Cinnamaldehyde on Salmonella Enteritidis and Campylobacter jejuni in Chicken Drinking Water ,

Laboratory heating studies with Salmonella spp. and Escherichia coli in organic matter, with a view to decontamination of poultry houses

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