Levels Of Aerobic Bacteria Research Articles

Effect of Gamma Irradiation on Cannabinoid, Terpene, and Moisture Content of Cannabis Biomass

In recent years, cannabis has been proposed and promoted not only as a medicine for the treatment of a variety of illnesses, but also as an industrial crop for different purposes. Being an agricultural product, cannabis inflorescences may be contaminated by environmental pathogens at high concentrations, which might cause health problems if not controlled. Therefore, limits have to be placed on the levels of aerobic bacteria as well as yeast and mold. To ensure the safety of cannabis plant material and related products, a remediation process has to be put in place. Gamma irradiation is a sterilization process mainly used for pharmaceuticals, foods, cosmetics, agricultural, and herbal products including cannabis plant material. This study was designed to determine the effect of irradiation on the microbial count as well as on the chemical and physical profiles of the cannabis biomass, particularly cannabinoids, terpenes, and moisture content. The full cannabinoid profile was measured by GC/FID and HPLC analysis, while terpene profile and moisture content were determined using GC/MS and Loss on Drying (LoD) methods, respectively. Analyses were conducted on the samples before and after gamma irradiation. The results showed that the minimum and maximum doses were 15 and 20.8 KiloGray (KGY), respectively. Total Aerobic Microbial Count (TAMC) and Total Yeast and Mold Count (TYMC) were determined. The study showed that irradiation has no effect on the cannabinoids and little effect on terpenes and moisture content, but it did result in the virtual sterilization of the plant material, as evidenced by the low levels of bacterial and fungal colony-forming units (CFUs) < 10 after gamma irradiation.

Shelf life of grass carp, bighead carp, Siberian sturgeon, and wels catfish stored under refrigerated conditions

AbstractMicrobiological, pH, color and texture changes in the muscles of grass carp, bighead carp, Siberian sturgeon, and wels catfish during 14 days of refrigeration storage were investigated. The level of aerobic bacteria that is unacceptable for fresh fish (7.0 log cfu/g) was reached only in wels catfish muscles during this period. The pH values in the muscle tissues that were of unacceptable quality, from the investigated fish species, ranged between 6.32 and 6.75. The herbivorous fish species displayed a change in the muscle tissue color. The L* parameter value for the fish of unacceptable quality was higher by 9.7% (grass carp) and up to 22.7% (bighead carp) than for fresh fish. The fish species gradually lost hardness and toughness during the storage period. The hardness of the fish of unacceptable quality was lower by 25.8–64% and the toughness by 25.2–60.8% as against fresh fish. The earliest unacceptable organoleptic quality occurred in wels catfish (6 days of storage), followed by grass carp, bighead carp, and S. sturgeon (12 days of storage).Practical applicationsGrass carp, bighead carp, Siberian sturgeon, and wels catfish are food fish of commercial significance in many countries. Fresh fish are highly perishable foods. One of the methods of preservation fresh fish is storage in refrigeration conditions. This method is widely used in the fish industry and distribution. The results of this study can be used by manufacturers, distributors, traders, and in scientific studies on the shelf life of fish stored in refrigeration conditions.

Microbiological Status of Broiler Respiratory Tracts Before and During Catching for Transport to the Processing Plant

SUMMARY A significant point of entry for Salmonella into a processing plant is within the broilers to be processed. Prior to transport to the processing plant, feed (4 h) and water are withdrawn from the broilers on the farm before they are caught and cooped. During catching, an increased presence of dust in the house air is visible and may affect the presence of bacteria within the broiler’s respiratory tract. The objective of this study was to examine the effect of catching on the levels of aerobic bacteria (aerobic plate count [APC]), levels and prevalence of Enterobacteriaceae (EB), and prevalence of Salmonella within broiler respiratory tracts. To determine flock Salmonella status 1 wk prior to catching, broiler carcasses were sampled for APC, EB, and Salmonella by respiratory tract flushing and ceca were sampled for Salmonella. At 1 d prior to catching and when half of the broilers in the house were caught, broilers were again collected, transported to the pilot plant, euthanized, and sampled. In Trial 1, there were no significant differences between sampling times for ceca Salmonella or respiratory EB and APC. However, Salmonella prevalence in the respiratory tract was significantly higher at 1 wk preharvest compared to during catching. In Trial 2, EB was significantly lower during catching compared to 1 wk preharvest. No significant differences were detected in Trial 3. Based on these results, the presence of aerosolized dust in the broiler house during catching does not appear to lead to increases in broiler respiratory tract microbial contamination.

SilTech: A New Approach to Treat Aerobic Vaginitis

Background: The aerobic vaginitis (AV) is characterized by increased levels of aerobic bacteria, vaginal inflammation and depressed levels of lactobacilli. Objective: The purpose of this study was to investigate the therapeutic efficacy of SilTechTM vaginal softgel capsules, containing new microcrystals of silver monovalent ions, for aerobic vaginitis (AV). Methods: This prospective study enrolled 32 women diagnosed with AV. All recruited women were treated with SilTechTM vaginal softgel capsules once daily for 7 days (one course). Therapeutic efficacy was evaluated based on clinical and microscopic criteria, and cure rates were calculated. Women who were improved (but not cured) received a second course of therapy. Patients classified with clinical and microscopic failure were treated using other strategies. Results: After one course of therapy, 59.2% (19/32) of women were cured, 19.0% (6/32) were improved (but not cured) and 21.8% (7/32) failed to respond to the therapy. After two courses of therapy, clinical improvement was achieved in additional two women. The therapy was very well tolerated, and during the entire study no drop out related to the SylTechTM vaginal capsules treatment was observed; only two patients (6.2%) experienced a mild transient burning after application. Conclusion: SylTechTM vaginal capsules is an effective therapeutic option for patients with AV, and most women with AV were cured with one course of therapy.

Influence of Elicitation and Germination Conditions on Biological Activity of Wheat Sprouts

The influence of elicitation, time, and temperature of germination on the biological activity of wheat sprouts was studied. The total phenolics content (TPC), antioxidant activity (AA), and microbiological purity of seeds of three wheat cultivars elicited withSaccharomyces cerevisiae(Y) andSalix daphnoidesbark extracts (W) and their mixture (1 : 1) germinated in different conditions were studied. The increase of germination time caused an increase the TPC and AA for all tested wheat cultivars. Germination temperature also influenced these parameters. Generally the highest values in TPC were obtained for sprouts germinated at 20°C. This tendency was found for all tested wheat cultivars. The highest values of TPC and AA were obtained after elicitation byS. daphnoidesbark extract. The results of microbiological examination showed that generally for seeds germinated at lower temperature (15°C and 20°C) and during 2 and 4 days the molds were not detected and the levels of aerobic bacteria did not exceed the usually accepted limits. Taking into account both biological activity and microbiological purity of samples the best quality sprouts were in the most cases obtained for wheat germinated during four days at 20°C and elicited by W.

Microbiological hazard analysis of ready-to-eat meats processed at a food plant in Trinidad, West Indies

BackgroundA bacteriological assessment of the environment and food products at different stages of processing was conducted during the manufacture of ready-to-eat (RTE) chicken franks, chicken bologna and bacon at a large meat processing plant in Trinidad, West Indies.MethodsSamples of air, surfaces (swabs), raw materials, and in-process and finished food products were collected during two separate visits for each product type and subjected to qualitative or quantitative analysis for bacterial zoonotic pathogens and fecal indicator organisms.ResultsStaphylococcus aureus was the most common pathogen detected in pre-cooked products (mean counts = 0.66, 1.98, and 1.95 log10CFU/g for franks, bologna, and bacon, respectively). This pathogen was also found in unacceptable levels in 4 (16.7%) of 24 post-cooked samples. Fifty percent (10 of 20) of pre-cooked mixtures of bacon and bologna were contaminated with Listeria spp., including four with L. monocytogenes. Pre-cooked mixtures of franks and bologna also contained E. coli (35 and 0.72 log10 CFU/g, respectively) while 5 (12.5%) of 40 pre-cooked mixtures of chicken franks had Salmonella spp. Aerobic bacteria exceeded acceptable international standards in 46 (82.1%) of 56 pre-cooked and 6 (16.7%) of 36 post-cooked samples. Both pre-and post-cooking air and surfaces had relatively high levels of aerobic bacteria, Staphylococcus aureus and coliforms, including equipment and gloves of employees. A drastic decrease in aerobic counts and Staphylococcus aureus levels following heat treatment and subsequent increase in counts of these bacteria are suggestive of post-cooking contamination.ConclusionA relatively high level of risk exists for microbial contamination of RTE meats at the food plant investigated and there is a need for enhancing the quality assurance programs to ensure the safety of consumers of products manufactured at this plant.

Effect of antimicrobial spice and herb extract combinations on Listeria monocytogenes, Staphylococcus aureus, and spoilage microflora growth on cooked ready-to-eat vacuum-packaged shrimp.

Two spice and herb extract combinations from galangal (Alpinia galanga), rosemary (Rosmarinus officinalis), and lemon iron bark (Eucalyptus staigerana) were evaluated for their ability to inhibit the growth of inoculated Listeria monocytogenes and Staphylococcus aureus and naturally present spoilage microflora on cooked ready-to-eat shrimp stored for 16 days at 4 or 8 °C. A combination of galangal, rosemary, and lemon iron bark significantly reduced (P < 0.05) levels of aerobic bacteria and lactic acid bacteria at 4 °C on day 12 by 1.6 and 1.59 log CFU/g, respectively. By day 16, levels of these bacteria were equivalent to those of controls. The shrimp treated with this spice and herb extract combination had significantly lower (P < 0.05) lipid oxidation from day 4 to day 16. Similarly, a combination of galangal and rosemary extract significantly reduced (P < 0.05) levels of aerobic bacteria and lactic acid bacteria at 8 °C on day 8 by 2.82 and 2.61 log CFU/g, respectively. By days 12 and 16, levels of these bacteria were equivalent to those of controls. The shrimp treated with this spice and herb combination had significantly lower (P < 0.05) lipid oxidation on days 4 and 16. None of the spice and herb extract combinations had an effect on levels of L. monocytogenes or S. aureus or changed the color or pH of the shrimp during storage. The results of this study indicate that combinations of galangal, rosemary, and lemon iron bark extracts can be used to control the growth of spoilage microflora on ready-to-eat shrimp.

Prevalence of Escherichia coli O157 and Levels of Aerobic Bacteria and Enterobacteriaceae Are Reduced When Hides Are Washed and Treated with Cetylpyridinium Chloride at a Commercial Beef Processing Plant

The objective of this experiment was to test the potential of a combined water wash and cetylpyridinium chloride (CPC) treatment as a hide intervention applied to cattle in the holding pens of a processing plant immediately before stunning. Over 2 processing days, 149 control and 139 treated cattle were tested. Control cattle were processed in the normal manner. The treatment group was prewashed with water the day before harvest. Immediately before stunning, these cattle were sprayed twice with 1% CPC, first for 3 min, then for 1 min. Hides and preevisceration carcasses were sampled to determine aerobic plate counts, Enterobacteriaceae counts (EBC), and Escherichia coli O157 prevalence. The treatment reduced the prevalence of E. coli O157 on hides from 56% to 34% and the prevalence on preevisceration carcasses from 23% to 3%. The treatment decreased aerobic plate counts from 4.9 log CFU/100 cm2 to 3.4 log CFU/100 cm2 and EBC from 3.1 log CFU/100 cm2 to 2.0 log CFU/100 cm2 on preevisceration carcasses. The treatment of hides did not result in any detectable CPC contamination of the chilled carcasses. These data indicated that a 1% CPC treatment preceded by a water wash was capable of reducing hide prevalence of E. coli O157 from as high as 80% to less than 50%, resulting in preevisceration carcass prevalence of 5% or less. We conclude that water washing followed by an antimicrobial treatment, such as CPC, has great potential as an effective hide intervention step and should be further evaluated for implementation as a processing step after stunning and before hide removal.

Effect of Chemical Dehairing on the Prevalence of Escherichia coli O157:H7 and the Levels of Aerobic Bacteria and Enterobacteriaceae on Carcasses in a Commercial Beef Processing Plant

The objective of this experiment was to test the hypothesis that cleaning cattle hides by removing hair and extraneous matter before hide removal would result in improved microbiological quality of carcasses in commercial beef processing plants. To test this hypothesis, we examined the effect of chemical dehairing of cattle hides on the prevalence of Escherichia coli O157:H7 and the levels of aerobic bacteria and Enterobacteriaceaeon carcasses. Samples from 240 control (conventionally processed) and 240 treated (chemically dehaired before hide removal) hides (immediately after stunning but before treatment) and preevisceration carcasses (immediately after hide removal) were obtained from four visits to a commercial beef processing plant. Total aerobic plate counts (APC) and Enterobacteriaceae counts (EBC) were not (P > 0.05) different between cattle designated for chemical dehairing (8.1 and 5.9 log CFU/100 cm2 for APC and EBC, respectively) and cattle designated for conventional processing (8.0 and 5.7 log CFU/100 cm2 for APC and EBC, respectively). However, E. coli O157:H7 hide prevalence was higher (P < 0.05) for the control group than for the treated group (67% versus 88%). In contrast to hides, the bacterial levels were lower (P < 0.05) on the treated (3.5 and 1.4 log CFU/100 cm2 for APC and EBC) than the control (5.5 and 3.2 log CFU/100 cm2 for APC and EBC) preevisceration carcasses. Prevalence of E. coli O157:H7 was lower (P > 0.05) on treated than on control preevisceration carcasses (1% versus 50%). These data indicate that chemical dehairing of cattle hides is an effective intervention to reduce the incidence of hide-to-carcass contamination with pathogens. The data also imply that any effective hide intervention process incorporated into beef processing procedures would significantly reduce carcass contamination by E. coli O157:H7.

A Laboratory Study of an Aerated Lagoon Bio-Blanket for Swine Manure Odor Control

The effectiveness of an aerated, submerged bio-blanket for controlling the release of odorous and volatile compounds from swine manure storage lagoons was examined. Hydrogen peroxide was used as oxidizing agent to simulate aeration by increasing the dissolved oxygen level in the bio-blanket. Commercially available dry aerobic microbes were added into the bio-blanket aiming at increasing the aerobic population. The results showed that the aerobic environment in the bio-blanket was not established by adding hydrogen peroxide and the levels of aerobic bacteria in the bio-blanket were not enhanced due to the addition of aerobic microbes. The reduction of volatile fatty acids could be caused by the direct oxidization by the H2O2 added, which resulted in up to 65% reduction in odor threshold compared with the control samples. The effect of this bio-blanket on the emissions of aerial ammonia and hydrogen sulfide as well as on the other liquid parameters such as total and ammonia nitrogen, pH, and total and volatile solids was not significant according to this study.

Microbiological comparison of inner and outer surfaces of commercially processed broilers and the adhesion of bacteria to these tissues

A microbiological evaluation of broiler carcass cavities and outer surfaces was made using 36 carcasses from each of 3 sampling points in a commercial processing plant, viz. post‐evisceration, pre‐chill and post‐chill. The level of aerobic bacteria on broiler skin and the level within the carcass cavity did not differ significantly at each sampling point. Similarly, the number of carcass cavities and outer surfaces which were Salmonella‐positive did not differ significantly at each sampling point. Levels of Enterobacteriaceae were not different for the outer and inner surfaces of post‐evisceration carcasses, but levels from the carcass cavity were significantly higher from pre‐ and post‐chill broilers indicating a more effective washing of the surface than the cavity of the bird. Levels of aerobes and Enterobacteriaceae were slightly lower in the carcass cavity than on the surface of manually eviscerated controls, indicating that automatic eviscerators contribute only marginally to the contamination of th...

The Impact of Commercial Processing Procedures on the Bacterial Contamination and Cross-Contamination of Broiler Carcasses

Levels of aerobic bacteria, Enterobacteriaceae, and the incidence of Salmonella were determined at six sampling points in a commercial processing plant: (1) pre-scald (at bleed line); (2) post-scald; (3) post-pick (4) post-evisceration; (5) pre-chill (after the final washer); and, (6) post-chill. The level of aerobic bacteria and Enterobacteriaceae on broiler carcasses was reduced significantly by commercial processing procedures, but cross-contamination still occurred. There was no increase in Salmonella incidence on carcasses from the five sampling points starting with the kill line through the final washer. There was a significant increase in Salmonella incidence on carcasses exiting the immersion chiller, indicating that this may be the point of most significant cross-contamination in broiler processing plants.

Microflora related to the nitrogen cycle in the tropical paddy soils

Abstract Paddy soils collected in 103 sites of Thailand consisted of surface soil (0-1 cm) and subsurface soil (1-10 cm). Collections were made twice, in the middle of the rainy season and in the middle of the dry season. The counts of 12 groups of microbes related to the nitrogen cycle were determined. In the soils sampled in the rainy season the population level of aerobic bacteria per 1 g of dry soil ranged from 107 to 106. For other microorganisms, the values were as follows: actinomycetes—l04 to 104, anaerobic bacteria—l05, cellulose decomposer—104, denitrifier—105, ammonifier—104 to 104, nitrite oxidizer—103, ammonia oxidizer-105, Clostridium-105 to 104, nitrogen-fixing blue green algae, Azotobacter and purple nonsulfur bacteria-103, respectively. Populations of all 12 groups examined were larger in the oxidized surface soil than in the subsurface soil and, in particular, the populations of aerobic nitrite oxidizer and photosynthetic purple nonsulfur bacteria were more than 4 times higher than those...