Occurrence of Bacillus cereus and the Bacteriological Quality of Chinese “Take-Out” Foods

1978 ◽  
Vol 41 (6) ◽  
pp. 450-454 ◽  
Author(s):  
D. A. SCHIEMANN
Keyword(s):  
Bacillus Cereus ◽  
Nitrate Reduction ◽  
Biochemical Characterization ◽  
Bacteriological Examination ◽  
Bacteriological Quality ◽  
Litmus Milk ◽  
Aerobic And Anaerobic ◽  
Gelatin Hydrolysis

One hundred sixty-five samples of various foods were collected from 24 different Chinese take-out restaurants for bacteriological examination which included enumeration of Bacillus cereus by three media, MYP, KG and blood agars. Blood agar was less selective but no quantitative differences in recovery were apparent. Twenty-eight samples (15%) yielded B. cereus in excess of 100 per gram, and 20 of these were fried rice (33% positive), which also showed the poorest overall bacteriological quality. Biochemical characterization of 232 isolates of B. cereus showed 96% or more positive for catalase, nitrate reduction, beta-haemolysis, subterminal-ellipsoidal spores, aerobic and anaerobic utilization of glucose, Voges-Proskauer, fermentation of glycerol, gelatin hydrolysis, and alkaline peptonization of litmus milk; and a negative reaction in mannitol. Variable results were obtained for motility, fermentation of sucrose and salicin, and starch hydrolysis. Thirty-three isolates were susceptible to 12 of 19 antibiotics tested, and resistant to colistin. Six (18%) were susceptible to penicillin.

Biochemical characterization of a cortexless mutant of a variant of Bacillus cereus

1976 ◽  
Vol 22 (7) ◽  
pp. 1007-1012 ◽  
Author(s):  
Susanne M. Pearce
Keyword(s):  
Cell Wall ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Bacillus Cereus ◽  
Biochemical Characterization ◽  
Diaminopimelic Acid ◽  
Peptidoglycan Synthesis ◽  
Biochemical Lesion ◽  
Do So

Previous studies on this cortexless mutant of Bacillus cereus var. alesti indicated that the forespore membrane was the site of the biochemical lesion. This hypothesis is supported by the results presented here: fatty acid composition of sporulating cells of the mutant is altered, while in vegetative cells it is comparable to the parent; soluble precursors of peptidoglycan synthesis are accumulated in the mutant, at the time of cortex formation; homogenates of the mutant prepared at the time of cortex formation are unable to incorporate tritiated diaminopimelic acid into peptidoglycan, while homogenates of cells forming germ cell wall do so to an extent comparable to that of the parent; lipid-linked intermediates are formed by the mutant as in the parent. Apparently the mutant is unable either to transfer disaccharide penta-peptide units from the carrier lipid to the growing peptidoglycan acceptor, or to transport lipid-linked intermediates across the forespore membrane.

Biochemical characterization of two chitinases from Bacillus cereus sensu lato B25 with antifungal activity against Fusarium verticillioides P03

2020 ◽  
Author(s):  
Estefanía Morales-Ruiz ◽  
Ricardo Priego-Rivera ◽  
Alejandro Miguel Figueroa-López ◽  
Jesús Eduardo Cazares-Álvarez ◽  
Ignacio E Maldonado-Mendoza
Keyword(s):  
Bacillus Cereus ◽  
Biochemical Characterization ◽  
Fusarium Verticillioides ◽  
Expression System ◽  
Phytopathogenic Fungi ◽  
Fungal Cell ◽  
Synthetic Pesticides ◽  
Bacillus Cereus Sensu Lato ◽  
Dual Substrate

Abstract Bacterial chitinases are a subject of intense scientific research due to their biotechnological applications, particularly their use as biological pesticides against phytopathogenic fungi as a green alternative to avoid the use of synthetic pesticides. Bacillus cereus sensu lato B25 is a rhizospheric bacterium that is a proven antagonist of Fusarium verticillioides, a major fungal pathogen of maize. This bacterium produces two chitinases that degrade the fungal cell wall and inhibit its growth. In this work, we used a heterologous expression system to purify both enzymes to investigate their biochemical traits in terms of Km, Vmax, optimal pH and temperature. ChiA and ChiB work as exochitinases, but ChiB exhibited a dual substrate activity and it is also an endochitinase. In this work, the direct addition of these chitinases inhibited fungal conidial germination and therefore they may play a major role in the antagonism against F. verticillioides.

Biochemical characterization of fruit juice for impact of storage on commercial beverages

2017 ◽  
Vol 36 (04) ◽  
Author(s):  
Sujata Sethy
Keyword(s):  
Biochemical Characterization ◽  
Cadmium Content ◽  
Sunset Yellow ◽  
E Coli ◽  
Duration Of Storage ◽  
Food Colour ◽  
Microbial Analysis ◽  
The Impact

The study was performed to evaluate the impact of storage time on safety and hygienic quality of commercial fruit beverage on the basis of market survey. Three most popular brands and three least popular brands of fruit beverages like squash and syrup were selected and stored for nine months at room temperature. The samples were subjected to chemical analysis for food colour, preservative (SO2), heavy metals (Pb and Cd), pectin and microbial analysis for bacteria, fungus, yeast and E. coli at bimonthly interval. Lead content in all the beverages and synthetic permitted food colours like sunset yellow 136.5 ppm in squash A and tartazine 133.2 ppm in squash B and 310.9 ppm in Syrup F was found which exceeded the permissible limit. Preservative (SO2) and cadmium content remained within the acceptable limit. Total bacterial and fungal count increased sharply with the advancement of storage particularly from 7th month onwards. Duration of storage had no effect on the colour and heavy metal content of the beverages.

Microbiological Quality of Dry Dessert Mixes Sold in Canada

1987 ◽  
Vol 50 (2) ◽  
pp. 136-140 ◽  
Author(s):  
D.W. WARBLTRTON ◽  
P.I. PETERKIN ◽  
G.A. JARVIS ◽  
K.F. WEISS ◽  
G. RIEDEL
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Bacillus Cereus ◽  
Microbiological Quality ◽  
Colony Count ◽  
Practical Consideration ◽  
Bacteriological Quality

A study done in 1977–1978, assessed the bacteriological quality of five types of dry desserts including starch-, gelatin- and rennet- based products. One hundred and ninety-seven lots were randomly selected across Canada and analyzed for aerobic colony count, aerobic sporeformers, Bacillus cereus, coliforms, Escherichia coli, Staphylococcus aureus and Salmonella. Micro-biological and practical consideration do not warrant the establishment of standards or guidelines for such products at this time.

scholarly journals Study of Nutritional and Organoleptic Quality of Formulated Juices from Jujube (Ziziphus lotus L.) and Dates (Phoenix dactylifera L.) Fruits

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Meryem Benidir ◽  
Soukaina El Massoudi ◽  
Lahsen El Ghadraoui ◽  
Abderrahim Lazraq ◽  
Meryem Benjelloun ◽  
...  
Keyword(s):  
Biochemical Characterization ◽  
Reducing Power ◽  
Phoenix Dactylifera ◽  
Organoleptic Evaluation ◽  
Strong Activity ◽  
Phoenix Dactylifera L ◽  
Total Antioxidant ◽  
L Proteins

The present work aims to elaborate many juice formulas (F1 to F8) from two dried fruits (jujubes: Ziziphus lotus L. and dates: Phoenix dactylifera L.). Physicochemical and biochemical characterization of the formula juices shows that juices rich in dates fruits (F1, F3, F5, and F7) are loaded, on average, in total sugars (129.5 g/l), proteins (3.02 g/l), lipids (1.08 g/l), and carotenoid (0.02 mg/l), while juices rich in jujube fruits (F2, F4, F6, and F8) are overloaded, on average, in phenolic compounds (697 mg/l), flavonoids (6.32 mg/l), condensed tannins (2.1 mg/l), hydrolysable tannins (359.5 mg/l), and viscosity (1.062 mm 10–3 s). All formulations developed have a pH that rotates between 5.12 and 5.20. Total antioxidant capacity (CAT) reveals that formulations F1, F3, F5, and F7 show a strong activity compared to the other formulas. The DPPH test shows that all formulated juices have the same antioxidant profile with IC50 values lower than the template (BHT and Vit C). The FRAP test reveals that F2, F4, F6, and F8 formulas have a strong reducing power. Organoleptic evaluation by a jury shows that F4 formula is the best in terms of odor, aroma, and aftertaste agreeability.

Prevalence and Characterization of Bacillus cereus Isolates from Clinical and Natural Sources

1996 ◽  
Vol 59 (2) ◽  
pp. 193-196 ◽  
Author(s):  
GHADA HASSAN ◽  
NASSIM NABBUT
Keyword(s):  
Bacillus Cereus ◽  
Antimicrobial Susceptibility ◽  
Nitrate Reduction ◽  
The Other ◽  
Clinical Isolates ◽  
Natural Sources ◽  
Natural Isolates ◽  
Esculin Hydrolysis ◽  
Biochemical Profiles

Bacillus cereus clinical isolates recovered from blood, wounds and diarrheal feces as well as natural isolates from normal feces, rice, dehydrated milk, and soil were characterized with respect to their biochemical profiles, antimicrobial susceptibility and enterotoxigenicity. The biochemical profiles of all the isolates were similar regardless of their sources. However, some degree of variability was shown in the Voges-Proskauer, nitrate reduction, and esculin hydrolysis tests and in the ability to grow in the presence of 40% bile. All the isolates were resistant to amoxicillin, oxacillin, and penicillin and susceptible to gentamicin and vancomycin. Susceptibility to cephalothin was variable among the clinical isolates, whereas susceptibility to clindamycin and erythromycin was inconsistent for all of them. The B. cereus clinical isolates recovered from human diarrheal feces were found to be strong producers of diarrheal enterotoxin as revealed by induction of diarrhea in mice and vascular permeability reaction. The clinical isolates recovered from wounds and blood and the natural isolates recovered from rice, milk, and normal feces, on the other hand, were weak producers of diarrheal enterotoxin.

Structural and biochemical characterization of the Bacillus cereus 3-hydroxyisobutyrate dehydrogenase

2016 ◽  
Vol 474 (3) ◽  
pp. 522-527 ◽  
Author(s):  
Sun Cheol Park ◽  
Pyeung-Hyeun Kim ◽  
Geun-Shik Lee ◽  
Seung Goo Kang ◽  
Hyun-Jeong Ko ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Biochemical Characterization

434. The bacteriological quality of National Dried Milk

1951 ◽  
Vol 18 (1) ◽  
pp. 34-42 ◽  
Author(s):  
A. T. Parsons ◽  
J. R. Fraser
Keyword(s):  
General Trend ◽  
Milk Powder ◽  
General Level ◽  
Bacteriological Examination ◽  
Bacteriological Quality ◽  
Set Up ◽  
Statistical Form

This paper presents in statistical form the results of the bacteriological examination of over 1200 samples of National Dried Milk during the period 1944–9. Factors which may affect the results are discussed. The general level of bacterial quality disclosed is high, but appreciable differences are shown in the standards reached at different factories and repacking depots. No general trend with time was observed in the figures throughout the period of 6 years considered, and no correlation was observed between the counts obtained and the time which had elapsed since packing into 20 oz. tins. Between counts at 37 and at 55° C. some correlation was noted in the products of most factories and depots, and the significance of this observation is discussed. The counts obtained are compared with various standards which have been put forward or are now in operation, and ways are suggested in which the figures might be used to set up standards of bacterial quality for roller-dried milk powder in this country.

Plant Pathology Diagnosed by X-Ray Microanalysis

1987 ◽  
Vol 45 ◽  
pp. 974-975
Author(s):  
J. H. Resau ◽  
N. Howell ◽  
S. H. Chang
Keyword(s):  
Electron Microscopy ◽  
Plant Pathology ◽  
Biochemical Characterization ◽  
Nutrient Deficiency ◽  
Green Leaf ◽  
Parasitic Infestation ◽  
X Ray

Spinach grown in Texas developed “yellow spotting” on the peripheral portions of the leaves. The exact cause of the discoloration could not be determined as there was no evidence of viral or parasitic infestation of the plants and biochemical characterization of the plants did not indicate any significant differences between the yellow and green leaf portions of the spinach. The present study was undertaken using electron microscopy (EM) to determine if a micro-nutrient deficiency was the cause for the discoloration.Green leaf spinach was collected from the field and sent by express mail to the EM laboratory. The yellow and equivalent green portions of the leaves were isolated and dried in a Denton evaporator at 10-5 Torr for 24 hrs. The leaf specimens were then examined using a JEOL 100 CX analytical microscope. TEM specimens were prepared according to the methods of Trump et al.

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