Modelling the combined effects of pH, temperature and sodium chloride stresses on the thermal inactivation of Bacillus subtilis spores in a buffer system*

Jagannath, A.; Nakamura, Ichiro; Tsuchido, Tetsuaki

doi:10.1046/j.1365-2672.2003.01952.x

Cited by 17 publications

(10 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this study, maximal yield of spore obtained in uncontrolled pH cultivations. This is in contrast to previous reports, where the pH was maintained at a constant value during the whole experiment in a 2‐l bioreactor, a significant increase of the vegetative cells concentration and sporulation efficiency was achieved by B. subtilis (Jagannath et al. 2003; Monteiro et al.…”

Section: Discussioncontrasting

confidence: 99%

Effect of cultivation conditions on spore production from Bacillus amyloliquefaciens B128 and its antagonism to Botrytis elliptica

et al. 2008

View full text Add to dashboard Cite

Aims: To maximize spore production by Bacillus amyloliquefaciens B128, and its antagonism to the fungal pathogen Botrytis elliptica B061. Methods and Results: In the 5‐l stirred‐tank bioreactor (STR), with the 0·5 vvm aeration rate, an agitation rate of 200 rev min−1 significantly enhanced the spore yield compared to the same in 300 rev min−1 cultivations. In a 20‐l airlift bioreactor (ALR) the maximal spore production was further increased with a controlled aeration rate of 2·5 vvm operated in a 24‐mesh net‐draft tube mode, and no pH control cultivation. This spore yield in the 20‐l ALR was five‐ and eightfold higher; in addition the cultivation period was 19 h shorter, compared to that obtained from shaker flask and in the 5‐l STR cultivations respectively. Conclusions: Although culture conditions are still to be optimized, by using an ALR with net‐draft tube, a scaling up from shaker flasks and STR to ALR of spore production by the strain B128 is technically feasible. Significance and Impact of the Study: The spore yields obtained using bioreactors were much higher than those previously reported. The freshly produced spore preparations from the B128 strain significantly antagonized the grey mould pathogen B. elliptica.

show abstract

Section: Discussioncontrasting

confidence: 99%

Effect of cultivation conditions on spore production from Bacillus amyloliquefaciens B128 and its antagonism to Botrytis elliptica

et al. 2008

View full text Add to dashboard Cite

show abstract

“…The bacterium used as an experimental model was type strain Bacillus subtilis ATCC 6051 that was obtained from American Type Culture Collection (Manassas, VA). B. subtilis is regarded as a model Gram‐positive organism for genetic and physiological studies 8…”

Section: Methodsmentioning

confidence: 99%

Novel methods for storage stability and release of Bacillus spores

Sorokulova

Krumnow

Pathirana

et al. 2008

Biotechnology Progress

View full text Add to dashboard Cite

Bacillus subtilis spores were immobilized in activated charcoal and tapioca and filled with acacia gum. These formulations were tested for spore stability during storage at temperatures ranging from 408C to 908C and for bacterial release. Thermodynamic analysis showed that immobilization of spores in acacia gum significantly increased their viability compared with unprotected spores. The viability was further increased when suspensions of spores in acacia gum were added to granules of charcoal and tapioca. The number of the spores released after storage was also increased when spores were treated with acacia gum prior to immobilization in tapioca and charcoal. Formulations of Bacillus spores with acacia gum and porous carriers (charcoal and tapioca) prolong the anticipated shelf-life of spores even under ambient temperature and provide slow and steady bacterial release consistent with their high viability.

show abstract

“…These cells grown till the logarithmic phase were inoculated into the sporulation medium consisting of double strength nutrient broth supplemented with 0·01% MnCl 2 ·H 2 O (Wako Pure Chemicals Industries Ltd., Osaka, Japan). The production, treatment and storage of spores were as described elsewhere (Jagannath et al. 2003).…”

Section: Spore Productionmentioning

confidence: 99%

“…Studies on the inactivation of bacterial spores in milk will enable milk processors to better design their thermal processes thereby ensuring a longer shelf life of milk and milk products. In the present study, the thermal inactivation of B. subtilis 168 spores was studied in pre‐sterilized or ultrahigh temperature (UHT) treated whole and skim milks and the D ‐values were compared with the predictions of a polynomial regression equation used in our earlier work (Jagannath et al. 2003).…”

Section: Introductionmentioning

confidence: 99%

Validation of a polynomial regression model: the thermal inactivation of Bacillus subtilis spores in milk

Jagannath¹,

Tsuchido

2003

Lett Appl Microbiol

Self Cite

View full text Add to dashboard Cite

Aims: The predicted survival of Bacillus subtilis 168 spores from a polynomial regression equation was validated in milk. Methods and Results: Bias factor suggested as an index of model performance was used to validate the polynomial model predictions in ultrahigh temperature (UHT) treated and sterilized whole and skim milk. Model predictions were fail safe, predicting higher D-values (decimal reduction times) in buffer than actually noted in milk. Conclusions: The D-values for spores were lower in milk as compared with those predicted in potassium phosphate buffer contrary to the popular expectation of better spore survival in complex food systems. The Bias factor, a quantitative measure of the model performance, indicated that on average the model predictions exceed the observations by 40% in the case of whole milk and by 60% in the case of skim milk. Significance and Impact of the Study: The present work is an attempt to ascertain the extent of reliability that one can safely place in polynomial model predictions, without compromising on the safety or palatability of foods where it is eventually intended to be applied. The work has also highlighted the differences in the thermal inactivation pattern of spores in buffer and in milk with a possible influence of the various constituents of milk. The work will assist the dairy industry to better design thermal processes to ensure longer shelf life of dairy foods.

show abstract

Modelling the combined effects of pH, temperature and sodium chloride stresses on the thermal inactivation of Bacillus subtilis spores in a buffer system*

Cited by 17 publications

References 25 publications

Effect of cultivation conditions on spore production from Bacillus amyloliquefaciens B128 and its antagonism to Botrytis elliptica

Effect of cultivation conditions on spore production from Bacillus amyloliquefaciens B128 and its antagonism to Botrytis elliptica

Novel methods for storage stability and release of Bacillus spores

Validation of a polynomial regression model: the thermal inactivation of Bacillus subtilis spores in milk

Contact Info

Product

Resources

About