scholarly journals Growth of Bacillus toyonensis in Tofu Wastewater

2021 ◽  
Vol 934 (1) ◽  
pp. 012021
Author(s):  
N Nursyirwani ◽  
D Yoswaty ◽  
D A Oktavia

Abstract Bacillus toyonensis has been isolated in Dumai mangrove ecosystem of Riau Province. One of factors affecting the growth of the bacteria is growth substrate. Tofu wastewater is rich in nutrition which can be used as substrate for bacterial growth. This research aimed to observe the growth of B. toyonensis in different concentration of tofu wastewater. The bacteria was grown in tofu wastewater at concentrations 8%, 10% and 12% was supplemented with 0.1 g K2HPO4, 0.15 g KH2PO4, 0.15 g NaCl and 0.5 g vitamin B12 in 100 mL distilled water. The bacterial growth was observed by using spectrophotometer at λ 610 nm and by analysis the total plate counts on plate count agar (PCA) at 0, 24, 48, 72 and 96 hour cultivation. Spectrophotometric observation showed that the highest bacterial growth of all tofu wastewater treatments indicated by the addition of 12% tofu wastewater, although the absorbance value was lower than culture in tryptic soy broth (TSB) as control. Exponential growth occurred between 0-24 hour incubation, and the highest growth indicated in substrate contained 12% tofu wastewater. Similarly, total plate count (TPC) analysis indicated that the highest bacterial growth of all treatment occurred at 24 hours incubation, and the highest count was also indicated by treatment of 12% tofu wastewater (2.42±0.06×108 CFU/mL). In conclusion, tofu wastewater can be an alternative substrate for the bacterial growth.

1991 ◽  
Vol 54 (6) ◽  
pp. 443-447 ◽  
Author(s):  
L. R. BEUCHAT ◽  
B. V. NAIL ◽  
R.E. BRACKETT ◽  
T. L. FOX

Petrifilm™ Yeast and Mold (YM) plates were compared to acidified potato dextrose agar (APDA) and chloramphenicol-supplemented plate count agar (CPCA) for its suitability to enumerate yeasts and molds in 13 groups of food products. These products consisted of beans (dry and frozen, green), corn meal, flour (wheat), fruit (apple), a meat/vegetable entree (chicken pot pie), a precooked meat (beef), milk (dehydrated, nonfat), nuts (pecans), pasta, potatoes (dehydrated), precooked sausage, and a spice (black pepper). Correlation coefficients of Petrifilm™ YM plates versus APDA and CPCA pour plates for recovering total yeasts and molds from a composite of the thirteen test foods were, respectively, 0.961 and 0.974. Individually, Petrifilm™ YM plate counts were equivalent or higher than APDA and CPCA for some food groups and lower for other food groups. Because food particle interference can make enumeration of yeast and mold colonies on Petrifilm™ YM plates difficult for some food groups, potential food interference will need to be evaluated for each food group tested.


1985 ◽  
Vol 48 (9) ◽  
pp. 770-771 ◽  
Author(s):  
WEI-TSYI TING ◽  
GEORGE J. BANWART

A naturally contaminated dried soup sample was reconstituted by three different methods (1:1 swirl, 1:9 soak and 1:9 rapid rehydration) and analyzed for enterococci on m-enterococcus agar and aerobic mesophilic plate count on plate count agar. The enterococcal counts obtained by the 1:1 swirl and the 1:9 soak methods were 41.6% and 26.5%, respectively, higher than that of the commonly used 1:9 rapid rehydration method. The aerobic mesophilic plate counts for the three systems were not significantly different.


1979 ◽  
Vol 42 (5) ◽  
pp. 407-409 ◽  
Author(s):  
R. J. ALVAREZ ◽  
J. A. KOBURGER

To determine the effect of delayed heading on shrimp quality, shrimp were stored on ice with and without heads for 10 days. Some shrimp were delay-headed after 5 days and returned to ice for the remainder of the storage period. Microbiological studies were conducted at 0, 5 and 10 days of storage. Total aerobic plate counts were done using Standard Plate Count agar with an added 0.5% NaCl. Incubation was at 20 C for 5 days. Analyses indicated similar counts on shrimp tails stored with or without heads and those delayed-headed. Counts ranged from 2.4 × 106 bacteria/gram at 0 day to 1.6 × 109 bacteria/gram on the 10th day. Identification of the flora present revealed that the same major groups of organisms predominated on shrimp tails subjected to the different storage treatments and the head did not alter development of the usual flora. Flavobacterium, Pseudomonas, Planococcus, Moraxella and the Vibrio/Aeromonas group were the major genera encountered. A shift in bacterial populations was observed during storage. Flavobacterium species predominated during the first 5 days of storage; however, after the fifth day Pseudomonas species predominated. Sensory panel data revealed no differences in acceptability between shrimp tails stored with or without heads and those delay-headed.


2004 ◽  
Vol 67 (1) ◽  
pp. 168-171 ◽  
Author(s):  
BANG-HYUN KIM ◽  
AERA JANG ◽  
SANG O. LEE ◽  
JOONG S. MIN ◽  
MOOHA LEE

The combined effects of organic acids and irradiation on shelf life of pork loins were examined. Fresh pork loins were sprayed with organic acids (lactic, citric, and acetic) at 2%, packaged aerobically, and irradiated with an electron beam at 1, 2, and 3 kGy. During 14 days of storage, total plate count, coliform number, pH, and thiobarbituric acid–reactive substances were measured. Combinations of organic acid and irradiation were more effective in reducing and maintaining low total plate counts and coliform levels during storage than either treatment alone. Higher lipid oxidations were observed in all combination treatments at 1 day of storage than in the irradiation-only group. However, lower lipid oxidations were the result after 14 days of storage when combination treatments were used with irradiations of 2 and 3 kGy. Combined treatments involving lower irradiation doses than those required for irradiation alone could be used to extend the shelf life of pork loins during postirradiation storage without increasing lipid oxidation.


1967 ◽  
Vol 30 (7) ◽  
pp. 213-218 ◽  
Author(s):  
R. B. Maxcy

Summary The microflora of freshly pasteurized, packaged milk is heterogeneous, and the numbers are generally low. While it is commonly assumed all bacteria are included in assays of numbers with plate count agar and standard methods, under normal conditions few are able to grow and contribute significantly to spoilage. Post-pasteurization contamination, which contributes insignificantly to the total count on freshly pasteurized, packaged milk, contributes most of the bacteria that are capable of growth to cause spoilage during subsequent storage. Though there is a delay after pasteurization before significant bacterial growth takes place, the same group of bacteria is responsible at either 5 C or 32 C. The growth response of these bacteria was measured with a selective medium of nutrient agar containing alkyl aryl sulfonate. Data obtained by the use of the selective medium indicated a potentially useful approach to quality control.


Author(s):  
Asnate Ķirse ◽  
Daina Kārkliņa ◽  
Sandra Muižniece-Brasava

Abstract The aim of this study was to determine the effect of sous vide packaging on the shelf life of maple pea (Pisum sativum var. arvense L.) spread. Pea spreads were made of ground re-hydrated cooked maple peas ‘Bruno’ (Pisum sativum var. arvense L.), to which salt, citric acid, oil, and spices were added. Pea spread was stored in polyamide/polyethylene (PA/PE) film pouches, packaged in vacuum and hermetically sealed. Pea spread pouches were heat treated in a water bath, then rapidly cooled in ice-water and stored at 4.0 ± 0.5 °C. Sous vide was applied in three different heat regimens +(65.0; 80.0 and 100.0) ± 0.5 °C with cooking times 5, 10, 15, 20, 25, and 30 min at a constant temperature. Total plate count was determined according to ISO 4833-1:2014 on Plate Count Agar and Enterobacteriaceae determination was performed in accordance with ISO 21528-2:2004 on Violet Red Bile Glucose Agar. Total plate count in pea spread without thermal treatment was 3.41 log10 CFU g−1, in all sous vide packaged pea spread samples microbial contamination was significantly lower (p < 0.05). Enterobacteriaceae were not detected in any samples. It is possible to extend the shelf life of sous vide maple pea spread up to 14 weeks when stored at 4.0 ± 0.5 °C.


1999 ◽  
Vol 62 (12) ◽  
pp. 1404-1410 ◽  
Author(s):  
C. F. SMITH ◽  
D. E. TOWNSEND

SimPlate for Total Plate Count–Color Indicator (TPC-CI, IDEXX Laboratories, Inc., Westbrook, Me.) is a new medium that incorporates the redox dye resazurin to detect and quantify bacteria in food. Enumeration is achieved by the most probable number method using a SimPlate device. Viable bacteria are detected in each well of the SimPlate device by the biochemical reduction of resazurin, which is blue, to the pink resorufin or the clear dihydroresorufin indicators. Results after 24 h of incubation for TPC-CI are highly correlated with standard plate count agar after 48 h of incubation. Correlation coefficients from studies conducted at five laboratories ranged from 0.94 to 0.98 in side-by-side comparisons against standard plate count agar. Four additional test sites, using alternative methods for determining the aerobic plate count in food, reported similar results in comparison studies (r = 0.91 to 0.97). The slopes from linear regression analysis at all sites ranged from 0.91 to 0.98, with y intercepts ranging from 0.11 to 0.84. Samples used for the validation of TPC-CI included raw food products (i.e., liver and grains), which may contain natural enzymes that interfere with enzyme-based detection methods. No interference was seen from the foods tested. These results suggest that TPC-CI is a suitable alternative to existing plate count methods and has reduced incubation time.


1980 ◽  
Vol 43 (8) ◽  
pp. 592-594 ◽  
Author(s):  
J. E. KENNEDY ◽  
P. E. PHILLIPS ◽  
J. L. OBLINGER

The surface plate method, using freshly pre-poured agar plates and/or stored pre-poured plates and the pour plate method were compared for enumeration of microorganisms in fresh bologna, fresh ground beef, frozen turkey pot pie and bacterial suspensions of Pseudomonas fluorescens and Streptococcus faecalis. Stored pre-poured Plate Count Agar (PCA) plates were packaged in plastic bags and held at 5 C for up to 6 weeks before use. Aerobic plate counts were derived from plates incubated at 35 C for 48 h, 20 C for 5 days and 7 C for 10 days. Differences in counts between methods for a given sample, incubation and pre-poured plate storage period were less than 0.5 log cycle in 97% of the comparisons. Regression and correlation coefficients between methods were highly significant; correlation coefficients varied from 0.987 to 0.999, and regression coefficients from 0.977 to 1.068 between any pair of methods. Storage of pre-poured plates for up to 6 weeks appeared to have no significant effect on recovery of microorganisms, using the surface plate technique.


1977 ◽  
Vol 23 (6) ◽  
pp. 716-720
Author(s):  
A. Chopin ◽  
G. Mocquot ◽  
Y. Le Graet

In this paper a method which allows the measure of microbial death rate during spray-drying by means of a streptomycin-resistant mutant that can be grown on a streptomycin-containing agar is described. Plate counts of Microbacterium lacticum, Escherichia coli, and Staphylococcus aureus recovered from skim milk powders were done on plate count agar in the presence and absence of streptomycin and on various selective media. The powders were produced from evaporated milk previously inoculated with those organisms.Our results showed that the proposed method allows the recovery of 78% of M. lacticum, 61% of E. coli, and 100% of S. aureus that survived spray-drying. Recoveries of surviving E. coli on violet bile agar and brilliant green bile 2% were 34% and 29% respectively. Baird-Parker and mannitol salt agar media allow the recovery of all surviving S. aureus, thus showing that S. aureus cells did not lose their ability to grow in media containing 7.5% NaCl. Our results show that physiological injury of the cells during spray-drying differs from injury due to heating only. [Traduit par le journal]


2009 ◽  
Vol 55 (4) ◽  
pp. 410-418 ◽  
Author(s):  
C. P. Champagne ◽  
Y. Raymond ◽  
J. Gonthier ◽  
P. Audet

Pasteurized and unfermented milks supplemented with probiotic bacteria are appearing on the market. It then becomes a challenge to ascertain the undesirable contamination microbiota in the presence of a largely superior population of probiotic bacteria. A method to enumerate the contaminating microbial microbiota in such probiotic-enriched milks was developed. The probiotic cultures, Lactobacillus rhamnosus Lb-Immuni-T™ and Bifidobacterium animalis subsp. lactis BB-12®, were added to a pasteurized unfermented milk to reach a minimum of 1 billion CFU per 250 mL portion, as ascertained by plating on de Man – Rogosa – Sharpe (MRS) agar in anaerobic conditions. No growth of B. animalis subsp. lactis BB-12 was noted on plate count agar (PCA) or Petrifilm™ plates, and the presence of this culture did not affect standard plate counts (SPC) of contaminating bacteria. However, L. rhamnosus formed colonies on PCA and Petrifilm™ plates. Attempts were thus made to inhibit the growth of the probiotic lactobacilli in PCA. The addition of 2% sodium phosphate (SP) or 5% glycerophosphate (GP) inhibited the growth of the lactobacilli in broths, but pin-point colonies of L. rhamnosus Lb-Immuni-T nevertheless appeared on PCA supplemented with phosphates. SPC could be obtained on PCA + 2% SP by only counting the large colonies, but this resulted in a significant (4.4 fold) underestimation of SPC values. On Petrifilm™ AC, at dilutions 0 to 2, all colonies were considered as being contaminants, while at dilutions 3 and 4, only large colonies were counted for SPC determinations. There was a direct correlation (R2 = 0.99) between SPC values with Petrifilm™ in uninoculated milks and those obtained on probiotic-enriched milks. The high correlation obtained over the 102 to 106 CFU/mL range of SPC values show that this Petrifilm™ method is appropriate to evaluate the microbiological quality of pasteurized milks enriched with L. rhamnosus Lb-Immuni-T and B. animalis subsp. lactis BB-12.


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