FATE OF BACILLUS CEREUS IN CULTURED AND DIRECT ACIDIFIED SKIMMILK AND CHEDDAR CHEESE1

1973 ◽  
Vol 36 (6) ◽  
pp. 317-320 ◽  
Author(s):  
E. M. Mikolajcik ◽  
J. W. Kearney ◽  
T. Kristoffersen
Keyword(s):  
Lactic Acid ◽  
Bacillus Cereus ◽  
Spore Germination ◽  
Vegetative Cell ◽  
Acid Production ◽  
Cheddar Cheese ◽  
Cell Multiplication ◽  
Vegetative Cells ◽  
Streptococcus Lactis

Germination, growth, sporulation, and. survival of Bacillus cereus 7 was determined in cultured (Streptococcus lactis C10) and direct acidified (lactic acid) skimmilks. For cultured systems, B. cereus increased initially at approximately the same rate in milks with or without streptococci. However, as the acidity of the milk increased, vegetative B. cereus cells failed to survive but spore counts remained unchanged. B. cereus organisms did not influence acid production or multiplication of the lactic streptococci. In direct acidified skimmilk, spore germination and outgrowth and vegetative cell multiplication decreased as the pH of the system was lowered from 6.5 to 5.0. In skimmilk at pH 5.0, vegetative cells failed to multiply and spore germination ceased. In Cheddar cheese manufacture, B. cereus multiplied rapidly during the period from the end of cooking to milling of the curd. B. cereus survived in the spore state in Cheddar cheese during 52 weeks curing.

IMMUNOGLOBULINS IN SKIMMILK AND MODEL SYSTEMS AND THEIR EFFECT ON BACILLUS CEREUS1

1971 ◽  
Vol 34 (9) ◽  
pp. 435-437 ◽  
Author(s):  
E. M. Mikolajcik ◽  
A. K. Choudhery
Keyword(s):  
Cell Growth ◽  
Bacillus Cereus ◽  
Ammonium Sulfate ◽  
Spore Germination ◽  
Vegetative Cell ◽  
Model Systems ◽  
Vegetative Cells ◽  
Ammonium Sulfate Fractionation ◽  
Sulfate Fractionation ◽  
C 30

Immunoglobulins isolated from milk by ammonium sulfate fractionation were added to skimmilk and the rate of Bacillus cereus spore germination and subsequent vegetative cell growth was determined. At 1 hr incubation at 35 C, 96.6, 96.8, 91.4, and 74.3% of the spores bad germinated in pasteurized (62.8 C - 30 min) skimmilk without added immunoglobulins, skimmilk pasteurized with immunoglobulins added, pasteurized skimmilk supplemented with unheated immunoglobulins, and nonheated unsupplemented skimmilk, respectively. With respect to vegetative cell growth, the number of generations at 4 hr in these systems was 5.9, 5.6, 4.4, and 2.3. Nonheated skimmilk without added immunoglobulins depressed B. cereus spore germination and vegetative cell growth to a greater extent than did pasteurized skimmilk supplemented with unheated immunoglobulins. In model systems composed of protein-free skimmilk dialysate and heated or unheated immunoglobulins, the system with unheated immunoglobulins lowered spore germination by 20% and subsequent cell growth by one-half in comparison with the heated system indicating that vegetative cells of B. cereus 7 are more susceptible to the immunoglobulins than spores.

scholarly journals Correlation of Some Substrate Parameters in Growing Lactobacillus acidophilus on Vegetable and Fruit Cocktail Juices

2010 ◽  
Vol 67 (2) ◽  
Author(s):  
Carmen Leane NICOLESCU ◽  
Lavinia Claudia BURULEANU
Keyword(s):  
Lactic Acid ◽  
Lactobacillus Acidophilus ◽  
Acid Production ◽  
Sugar Content ◽  
Lactic Acid Production ◽  
Biomass Accumulation ◽  
Reducing Sugar ◽  
Fruit Juices ◽  
Cell Multiplication ◽  
Microbiological Methods

Using Lactobacillus acidophilus stains is a challenge in producing lactic acid fermented vegetable and fruit juices. There were analysed the correlation between the most important physico-chemical parameters of the substrate and the bacterial biomass accumulation in two vegetable and fruit juices. The data were collected during a 48 hour lactic acid fermentation using usually chemical and microbiological methods. There was analysed the correlation between the reducing sugar content and the lactic acid production, the correlation between the pH and lactic acid production, the correlation between the reducing sugar of the substrate and the microbial biomass accumulation and also between the lactic acid production and biomass accumulation. These correlations were analysed using simple regression on scatter plots. They were best fitted by the polynomial equation where the highest R2 were calculated. The two last correlations had large differences between the two experimental batches so that regression is not satisfactory to describe them. If all parameters were considered using the multiple regression, the correlation had a medium value because the cell multiplication of the bacteria Lactobacillus acidophilus in vegetable and fruit juices is influenced by many other environmental parameters. These had a large influence because juices are not the natural medium for this kind of lactic acid bacteria.

scholarly journals Detection of Food Poisoning (Bacillus cereus) Pathogen in Cooked and Refrigerated Rice Samples

2019 ◽  
Vol 62 (3) ◽  
pp. 172-177
Author(s):  
Shagufta Ambreen Shaikh ◽  
Anila Sidiqui ◽  
Shagufta Naz ◽  
Seema Ismat
Keyword(s):  
General Population ◽  
Bacillus Cereus ◽  
Vegetative Cell ◽  
Food Poisoning ◽  
Local Market ◽  
Staple Food ◽  
Vegetative Cells ◽  
Cooked Rice ◽  
Rice Samples ◽  
Favorable Conditions

  Rice is a staple food of Pakistan. It is being contaminated with several food poisoning causing bacterial and mold contaminants. In this study 100 different rice samples were collected from local market of Karachi city. The presence of Bacillus cereus vegetative cell and survival of their spores were quantitavely analyzed after cooking and refrigeration. From the study it was observed that out of 100 rice samples, 25% cooked/refrigerated samples were positive for the presence of B.cereus spores , even there were few samples which showed increase of count due to improper (cooking and refrigeration ) which causes the germination and proliferation of spores into vegetative cells under favorable conditions. The detection of increased count of B. cereus even after cooking and refrigeration treatments is very alarming since cooking is supposed to be best treatment given to the raw food. Different rice dishes are being frequently consumed by the general population and are also available on different shops (as biryanis or fried rice), hence, detection of B. cereus in cooked rice samples will be useful to control any outbreak of food poisoning cases especially in summer seasons.    

EFFECT OF MALATHION AND TRICHLORFON ON GROWTH1 AND MORPHOLOGY OF LACTIC CULTURE ORGANISMS

1971 ◽  
Vol 34 (1) ◽  
pp. 16-22 ◽  
Author(s):  
D. D. Deane ◽  
M. M. Van Patten
Keyword(s):  
Lactic Acid ◽  
Cell Size ◽  
Acid Production ◽  
Cell Structure ◽  
Lactic Acid Production ◽  
Lactobacillus Bulgaricus ◽  
Chain Formation ◽  
Streptococcus Lactis ◽  
Litmus Milk ◽  
Dry Milk

Addition of 100 ppm of malathion or trichlorfon had little effect on lactic acid production in reconstituted non-fat dry milk by Streptococus diacetilactis or Streptococus thermophilus. Variation in cell size of Streptococus cremoris 3, Streptococcus lactis W 8 and several strains of S. thermophilus occurred following repeated transfers in litmus milk to which 100 ppm of malathion or 500 ppm trichlorfon had been added. The Lactobacillus bulgaricus A culture, after 15 serial transfers in litmus milk containing 500 ppm of trichlorfon, exhibited increased frequency of chain formation and cell structure 30 to 50 μ long with few visible cross walls. A similar effect was observed with L. bulgaricus A and L. bulgaricus GA after repeated transfers in litmus milk which contained 100 ppm malathion. One of five strains of L. casei studied showed similar changes in morphology after repeated transfers in litmus milk which contained 100 ppm malathion. Adding 500 ppm trichlorfon produced a lesser effect. Changes in morphology of this strain of L. casei were not permanent since cells resumed their usual appearance following three to five transfers in plain litmus milk.

Isolation and Plasmid Characterization of a Lactobacillus Species Involved in the Manufacture of Fermented Sausage1

1985 ◽  
Vol 48 (12) ◽  
pp. 1028-1035 ◽  
Author(s):  
DENNIS A. ROMERO ◽  
LARRY L. McKAY
Keyword(s):  
Lactic Acid ◽  
Polyethylene Glycol ◽  
Plasmid Dna ◽  
Acid Production ◽  
Gas Production ◽  
Lactobacillus Species ◽  
Erythromycin Resistance ◽  
Streptococcus Lactis ◽  
Isolation And Characterization

Isolation and characterization of a Lactobacillus species capable of proper acid production in a sausage environment is described. The isolate from sausage, categorized as a lactobacillus in the subgenus Streptobacterium, was designated Lactobacillus sp. DR1. Growth occurred at 5 and 42°C but not at 45°C. Fructose, galactose, glucose, mannose, melibiose, N-acetylglucosamine, ribose, sucrose and trehalose were fermented. Gas production from glucose was not observed. In MRS glucose broth, D(−) and L(+) lactic acid were produced. Lactobacillus sp. DR1 contained a single cryptic plasmid of approximately 30 megadaltons (Mdal). In sausage fermentation trials, both Lactobacillus sp. DR1 and plasmid-free derivative DR1C lowered the pH to below 5.3 after 8 h in the smokehouse. Conjugation was demonstrated through the transfer of plasmid pAMβ1, which encodes erythromycin resistance, from Streptococcus lactis 2301β to Lactobacillus sp. DR1. Mutanolysin-generated protoplasts could be regenerated using 0.5 M ammonium chloride, lactose, maltose or sucrose as osmotic stabilizers. Regeneration frequencies ranged from less than 1.0% up to 35%; however, transformation of Lactobacillus sp. DR1 protoplasts by plasmid DNA in the presence of polyethylene glycol (PEG) was unsuccessful.

scholarly journals Antimicrobial Activities of Five Strains Of Lactococcus Isolated from Beef Against Indicator Organisms of Public Health Significance

2016 ◽  
Vol 4 (10) ◽  
pp. 887 ◽  
Author(s):  
Olusegun Ayodele Olaoye
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Lactic Acid ◽  
Bacillus Cereus ◽  
Yersinia Enterocolitica ◽  
Acid Production ◽  
Antimicrobial Agents ◽  
Lactic Acid Production ◽  
Antimicrobial Activities ◽  
Indicator Organisms

Five strains of Lactococcus, including L. garviae K2, L. piscium SU4, L. lactis subsp. cremoris E22, L. plantarum L7 and L. lactis subsp. hordinae E91 were screened for production of antimicrobial agents. The strains were also analysed for antimicrobial activities against spoilage and pathogenic organisms, including Staphylococcus aureus, Salmonella Typhimurium, Escherichia coli, Yersinia enterocolitica, Pseudomonas aeruginosa, Klebsiella pneumoniae, Listeria monocytogenes, Bacillus cereus and Pseudomonas fluorescens. Result revealed that L. piscium SU4, L. plantarum L7 and L. lactis subsp. cremoris E22 had lactic acid production (g/107 colony forming units, CFU) of 7.23, 7.20 and 7.19. The value of 6.83 recorded as lactic acid produced by L. garviae K2 was significantly different from those obtained for others. The highest acetic acid production (3.55 g/107 CFU) was recorded for L. garviae K2 while L. piscium SU4 had the lowest (2.99 g/107 CFU). L. lactis subsp. hordinae E91 had diacetyl production of 71.99 (µg/107 CFU), which was higher than those recorded for other Lactococcus strains. Test for antimicrobial activities showed that Escherichia coli NCTC 86, Yersinia enterocolitica NCTC 10460, Pseudomonas aeruginosa NCIMB 10848, Bacillus cereus NCTC 21113 and Pseudomonas flourescens recorded higher susceptibilities to the antimicrobial action of the Lactococcus strains than others; zones of inhibition of 5 mm and above were recorded for the indicator organisms compared to lower values (

“INHIBITION” OF STREPTOCOCCUS LACTIS BY A QUATERNARY AMMONIUM COMPOUND IN CHEESE MILKS

1952 ◽  
Vol 15 (6) ◽  
pp. 278-299 ◽  
Author(s):  
Janet C. Curry ◽  
Franklin W. Barber
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Quaternary Ammonium ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Quaternary Ammonium Compounds ◽  
Quaternary Ammonium Compound ◽  
Ammonium Compound ◽  
Streptococcus Lactis ◽  
Ammonium Compounds

The inhibition of lactic acid bacteria by quaternary ammonium compounds in milk has been shown to be an effect on acid production and not upon growth. Lactic acid production is affected by concentrations of 2.5 – 10 ppm, while growth is not affected unless the concentration is 25 – 50 ppm.

A comparison of the influence of Streptococcus lactis and Str. cremoris starters on the flavour of Cheddar cheese

1961 ◽  
Vol 28 (3) ◽  
pp. 221-229 ◽  
Author(s):  
K. D. Perry
Keyword(s):  
Direct Effect ◽  
Significant Influence ◽  
Manufacturing Process ◽  
Acid Production ◽  
Cheddar Cheese ◽  
Streptococcus Lactis ◽  
Streptococcus Cremoris ◽  
Cheese Flavour ◽  
Phage Development

SummaryComparable cheeses were made using single strains of Streptococcus cremoris and Str. lactis as starters. The three Str. lactis strains imparted a characteristic rather abnormal flavour to the cheese, whereas the three strains of Str. cremoris all gave cheeses of normal flavour. The abnormal flavour caused by the lactis cultures increased in intensity as ripening proceeded, and differed slightly from strain to strain.Bacteriophage usually developed slightly in the whey and in the curd during the manufacturing process, but never to such a degree as to delay acid production unduly. The extent of phage development did not have a significant influence on cheese flavour.All the lactis strains survived in much larger numbers in the cheese than the cremoris strains. The simplest explanation of the data is that the ‘lactis’ flavour was a direct effect, due to flavour substances produced by the Str. lactis cells present in the young cheese.

Inhibition of Bacterial Spores and Vegetative Cells by Glycerides

1996 ◽  
Vol 59 (7) ◽  
pp. 716-722 ◽  
Author(s):  
AHMED CHAIBI ◽  
LAHSEN H. ABABOUCH ◽  
FRANCIS F. BUSTA
Keyword(s):  
Cell Growth ◽  
Spore Germination ◽  
Inhibitory Activity ◽  
Clostridium Botulinum ◽  
Inhibitory Action ◽  
Bacterial Spores ◽  
Cell Multiplication ◽  
Clostridium Sporogenes ◽  
Vegetative Cells ◽  
Bacillus Spores

Monolaurin, monomyristin, monolinolein, and monolinolenin inhibited cell growth from Bacillus cereus T, Clostridium botulinum 62A, and Clostridium sporogenes PA3679 spores and vegetative cells. The inhibitory action increased in the order monolinolein monomyristin, monolaurin, monolinolenin. Monopalmitin, monostearin, and monolein had a partial effect and diglycerides and triglycerides had no effect. B. cereus T spores were more sensitive to monolaurin, monomyristin, monolinolein, and monolinolenin than vegetative cells. Spores and vegetative cells of C. botulinum 62A were similarly affected by monolaurin, whereas vegetative cells were more resistant to monomyristin, monolinolein, and monolinolenin than spores. In general, C. botulinum 62A and C. sporogenes PA 3679 were more resistant than B. cereus T, except for monolinolein and monomyristin, in which Bacillus spores were more resistant than PA3679 spores. C. botulinum 62A spores were equally (monomyristin) or less resistant (monolaurin, monolinolenin) than PA3679. Monomyristin had the same activity on the three strains. Monolaurin (0.073 to 0.109 mM), monomyristin (0.331 to 0.497 mM), and monolinolenin (0.085 to 0.182 mM) affected germination and outgrowth, whereas monolinolein (0.564 to 0.848 mM) inhibited cell multiplication from B. cereus T spores. Monolaurin (0.145 to 0.182 mM) inhibited outgrowth, but monomyristin (0.331 to 0.497 mM) and monolinolenin (0.142 to 0.182 mM) affected germination of 62A spores. Cell multiplication was inhibited by monolinolein (0.564 to 0.848 mM). C. sporogenes PA3679 spore germination and outgrowth were inhibited by monomyristin (0.331 to 0.497 mM) and monolinolenin (0.142 to 0.282 mM), or monolaurin (0.182 to 0.255 mM), monomyristin (0.165 to 0.248 mM), and monolinolenin (0.085 to 0.113 mM) inhibited cell multiplication from PA3679. Starch neutralized the inhibitory activity of monolaurin, monomyristin, monolinolein, and monolinolenin against 62A spores. The starch antagonism decreased as the concentration of glyceride increased.

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