Spore formation by Bacillus cereus in broth as affected by temperature, nutrient availability, and manganese

Jee-Hoon Ryu, Hoikyung Kim, Larry R. Beuchat

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

A study was done to determine the effect of interacting factors on sporulation of Bacillus cereus in broth. Vegetative cells (1.4 to 2.2 log CFU/ml) of B. cereus strain 038-2 (capable of growing at 12°C) and strain F3812/84 (capable of growing at 8°C) were inoculated into 30 ml of tryptic soy broth (TSB), TSB supplemented with manganese (50 μg/ml), diluted (10%) TSB (dTSB), and dTSB supplemented with manganese (50 μg/ml) and incubated at 8, 12, or 22°C for up to 30, 30, or 10 days, respectively. Unheated and heated (80°C for 10 min) cultures were plated on brain heart infusion agar to determine total cell counts (vegetative cells plus spores) and the number of spores produced, respectively. Both strains of B. cereus survived in TSB and dTSB for 30 days at 8°C but did not sporulate. At 12°C, cells grew in TSB to a population of 6.0 ± 0.8 log CFU/ml, which was maintained for 30 days. Neither strain grew in dTSB at 12°C and survived for at least 30 days. Spores were not produced in any of the test broths at 12°C. At 22°C, cells reached a stationary growth phase between 12 and 24 h in TSB, TSB supplemented with manganese, and dTSB supplemented with manganese, and approximately 1% of the CFU were spores. In dTSB, cell growth and spore formation were retarded at 22°C and a significantly lower number of spores was produced compared with the number of spores produced in TSB, TSB supplemented with manganese, and dTSB supplemented with manganese. The addition of manganese to TSB did not affect cell growth or spore formation, but manganese did enhance sporulation in dTSB. This study provides useful information on spore formation by B. cereus as affected by conditions that may be imposed in liquid milieus on the surface of foods and on food contact surfaces in processing environments.

Original languageEnglish
Pages (from-to)1734-1738
Number of pages5
JournalJournal of Food Protection
Volume68
Issue number8
Publication statusPublished - 2005 Aug 1
Externally publishedYes

Fingerprint

Bacillus cereus
Manganese
Spores
nutrient availability
manganese
spores
Food
Temperature
temperature
vegetative cells
sporulation
cell growth
Growth
food contact surfaces
trypticase-soy broth
cells
foods
Agar
agar
heart

ASJC Scopus subject areas

  • Food Science
  • Applied Microbiology and Biotechnology
  • Biotechnology

Cite this

Spore formation by Bacillus cereus in broth as affected by temperature, nutrient availability, and manganese. / Ryu, Jee-Hoon; Kim, Hoikyung; Beuchat, Larry R.

In: Journal of Food Protection, Vol. 68, No. 8, 01.08.2005, p. 1734-1738.

Research output: Contribution to journalArticle

@article{979ac0e4523b4d70a2173ab7fdb1a5cd,
title = "Spore formation by Bacillus cereus in broth as affected by temperature, nutrient availability, and manganese",
abstract = "A study was done to determine the effect of interacting factors on sporulation of Bacillus cereus in broth. Vegetative cells (1.4 to 2.2 log CFU/ml) of B. cereus strain 038-2 (capable of growing at 12°C) and strain F3812/84 (capable of growing at 8°C) were inoculated into 30 ml of tryptic soy broth (TSB), TSB supplemented with manganese (50 μg/ml), diluted (10{\%}) TSB (dTSB), and dTSB supplemented with manganese (50 μg/ml) and incubated at 8, 12, or 22°C for up to 30, 30, or 10 days, respectively. Unheated and heated (80°C for 10 min) cultures were plated on brain heart infusion agar to determine total cell counts (vegetative cells plus spores) and the number of spores produced, respectively. Both strains of B. cereus survived in TSB and dTSB for 30 days at 8°C but did not sporulate. At 12°C, cells grew in TSB to a population of 6.0 ± 0.8 log CFU/ml, which was maintained for 30 days. Neither strain grew in dTSB at 12°C and survived for at least 30 days. Spores were not produced in any of the test broths at 12°C. At 22°C, cells reached a stationary growth phase between 12 and 24 h in TSB, TSB supplemented with manganese, and dTSB supplemented with manganese, and approximately 1{\%} of the CFU were spores. In dTSB, cell growth and spore formation were retarded at 22°C and a significantly lower number of spores was produced compared with the number of spores produced in TSB, TSB supplemented with manganese, and dTSB supplemented with manganese. The addition of manganese to TSB did not affect cell growth or spore formation, but manganese did enhance sporulation in dTSB. This study provides useful information on spore formation by B. cereus as affected by conditions that may be imposed in liquid milieus on the surface of foods and on food contact surfaces in processing environments.",
author = "Jee-Hoon Ryu and Hoikyung Kim and Beuchat, {Larry R.}",
year = "2005",
month = "8",
day = "1",
language = "English",
volume = "68",
pages = "1734--1738",
journal = "Journal of Food Protection",
issn = "0362-028X",
publisher = "International Association for Food Protection",
number = "8",

}

TY - JOUR

T1 - Spore formation by Bacillus cereus in broth as affected by temperature, nutrient availability, and manganese

AU - Ryu, Jee-Hoon

AU - Kim, Hoikyung

AU - Beuchat, Larry R.

PY - 2005/8/1

Y1 - 2005/8/1

N2 - A study was done to determine the effect of interacting factors on sporulation of Bacillus cereus in broth. Vegetative cells (1.4 to 2.2 log CFU/ml) of B. cereus strain 038-2 (capable of growing at 12°C) and strain F3812/84 (capable of growing at 8°C) were inoculated into 30 ml of tryptic soy broth (TSB), TSB supplemented with manganese (50 μg/ml), diluted (10%) TSB (dTSB), and dTSB supplemented with manganese (50 μg/ml) and incubated at 8, 12, or 22°C for up to 30, 30, or 10 days, respectively. Unheated and heated (80°C for 10 min) cultures were plated on brain heart infusion agar to determine total cell counts (vegetative cells plus spores) and the number of spores produced, respectively. Both strains of B. cereus survived in TSB and dTSB for 30 days at 8°C but did not sporulate. At 12°C, cells grew in TSB to a population of 6.0 ± 0.8 log CFU/ml, which was maintained for 30 days. Neither strain grew in dTSB at 12°C and survived for at least 30 days. Spores were not produced in any of the test broths at 12°C. At 22°C, cells reached a stationary growth phase between 12 and 24 h in TSB, TSB supplemented with manganese, and dTSB supplemented with manganese, and approximately 1% of the CFU were spores. In dTSB, cell growth and spore formation were retarded at 22°C and a significantly lower number of spores was produced compared with the number of spores produced in TSB, TSB supplemented with manganese, and dTSB supplemented with manganese. The addition of manganese to TSB did not affect cell growth or spore formation, but manganese did enhance sporulation in dTSB. This study provides useful information on spore formation by B. cereus as affected by conditions that may be imposed in liquid milieus on the surface of foods and on food contact surfaces in processing environments.

AB - A study was done to determine the effect of interacting factors on sporulation of Bacillus cereus in broth. Vegetative cells (1.4 to 2.2 log CFU/ml) of B. cereus strain 038-2 (capable of growing at 12°C) and strain F3812/84 (capable of growing at 8°C) were inoculated into 30 ml of tryptic soy broth (TSB), TSB supplemented with manganese (50 μg/ml), diluted (10%) TSB (dTSB), and dTSB supplemented with manganese (50 μg/ml) and incubated at 8, 12, or 22°C for up to 30, 30, or 10 days, respectively. Unheated and heated (80°C for 10 min) cultures were plated on brain heart infusion agar to determine total cell counts (vegetative cells plus spores) and the number of spores produced, respectively. Both strains of B. cereus survived in TSB and dTSB for 30 days at 8°C but did not sporulate. At 12°C, cells grew in TSB to a population of 6.0 ± 0.8 log CFU/ml, which was maintained for 30 days. Neither strain grew in dTSB at 12°C and survived for at least 30 days. Spores were not produced in any of the test broths at 12°C. At 22°C, cells reached a stationary growth phase between 12 and 24 h in TSB, TSB supplemented with manganese, and dTSB supplemented with manganese, and approximately 1% of the CFU were spores. In dTSB, cell growth and spore formation were retarded at 22°C and a significantly lower number of spores was produced compared with the number of spores produced in TSB, TSB supplemented with manganese, and dTSB supplemented with manganese. The addition of manganese to TSB did not affect cell growth or spore formation, but manganese did enhance sporulation in dTSB. This study provides useful information on spore formation by B. cereus as affected by conditions that may be imposed in liquid milieus on the surface of foods and on food contact surfaces in processing environments.

UR - http://www.scopus.com/inward/record.url?scp=24644516555&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=24644516555&partnerID=8YFLogxK

M3 - Article

C2 - 21132988

AN - SCOPUS:24644516555

VL - 68

SP - 1734

EP - 1738

JO - Journal of Food Protection

JF - Journal of Food Protection

SN - 0362-028X

IS - 8

ER -