Number Of Coliforms Research Articles

Selection of resistant coliform bacteria in the intestine of pigs following flock versus individual treatment with neomycin against post-weaning diarrhoae or amoxicillin against umbilical infection.

The aim of this study was to investigate the effect of avoiding flock treatment on resistance levels in the intestine of pigs. To investigate this, studies, each in two pig herds, quantified resistant coliforms by culture method in pigs treated as flock or as individual animal treatments orally with neomycin against post-weaning diarrhea (PWD) or intramuscularly with amoxicillin to prevent umbilical infection. Individual oral treatment against PWD did not lead to a lower number or proportion of resistant coliforms compared to flock treated pigs in any of the two herds under study, despite reduction of treatment incidences to 32% and 35% of pigs. After intramuscular treatment against umbilical infection, fewer resistant bacteria were seen in individually treated piglets in a herd with low treatment incidence (33%), while no reduction of resistant coliform bacteria compared to flock treatment was observed in the other herd with higher treatment incidence (86%). Thus, individual animal treatment reduced the amount of antimicrobial used, but concurrent reduction in resistant coliform bacteria was not always observed.

Impact of stormwater on biofilm density and microbial community composition in water distribution networks.

Harvesting of stormwater and injecting it into aquifers for storage and recovery during high water demand periods is a promising technology for augmenting conventional water reserves. However, little has been known on how stormwater impacts the biofouling of water distribution infrastructure. This study evaluated the effect on harvested and limestone aquifer treated stormwater on biofilm formation in a pilot distribution pipe network compared to an identical drinking water pipe rig. Coupons made of cement, copper and polyvinyl chloride (PVC) pipe materials were installed to each pipe rig and exposed to stormwater or drinking water. The total cell counts determined by flow cytometry on the pilot rig coupons were in the order of 105 to 107 cells/cm2 for both source waters and showed some variation over the duration of the study. The culturable cell counts were somewhat higher for stormwater exposed coupons than for coupons in mains water rig. The total number of thermotolerant coliforms was notably higher on coupons exposed to stormwater than on those exposed to mains water. Considerable differences were observed in the bacterial and eukaryotic communities on coupons made of various materials and exposed to mains water and stormwater using pyrosequencing. Moreover, seasonal variations were observed in community composition and diversity. A number of bacterial and eukaryotic families and genera harbouring potential human pathogens were detected in both mains water and stormwater systems, with larger numbers of genera observed in the latter indicating a potentially increased risk of exposure to pathogens with stormwater. The stormwater system also harboured sulfur reducers, and a greater diversity of iron oxidisers. A number of bacterial genera that contribute to nitrogen cycling were observed in both mains water and stormwater systems. A number of bacteria grazing eukaryotes were detected, indicating that the biofilm communities are quite dynamic and the abundance of bacteria is able to support higher level eukaryotes.

Detection of Bacterial Pollution from School Drinking Water Tanks in the Habbaniyah District West of Iraq

This study was conducted to evaluate the bacterial contamination in drinking water tanks from 20 randomly distributed primary schools in Habbaniyah district. The most probable number and the total plate count methods were used to determine the numbers of coliform, fecal coliform, streptococci and fecal streptococci. Chemical and physical properties of the water were measured, including residual chlorine, total dissolved solids, temperature and pH. Biochemical methods were used to detect various bacterial species contaminating the water samples and the results were confirmed using the VITEK 2 compact system. High levels of bacterial contamination were indicated. The highest value of coliform numbers reached 12 cells/100 ml. The total plate count recorded the highest values reaching 300 cells/ml. The concentration of residual chlorine was very low or non-detectable in most of samples below the required concentration and the concentrations of total dissolved solids exceeded the permissible limit (855 mg/L). The genetic relationship between environmental isolates of Escherichia coli bacteria from tank water and clinical isolates from children’s health centers were also studied. The results for Escherichia coli demonstrated a similarity ratio between environmental and clinical isolates of 64% by using dendrogram and Enterobacterial Repetitive Intergenic Consensus PCR. Nevertheless, this study recommends the need to monitor drinking water quality that supplies these reservoirs, as well as to prevent and treat problems that result in drinking water contamination and the spread of diseases.

Characterization of D-Limonene and its applications as antimicrobial antioxidant and enhancing of drinking water quality

The D-limonene was extracted from orange peel and used for testing of Antimicrobial Activity, Antioxidant Activity and Most Probable Number. FTIR shows presence of chemical groups such as C-C, CH3; CH2, C=C which indicates presence of D-limonene oil in the orange peel extract. Test organism isolated from water sample, was E. coli and other test organisms namely Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans and Aspergillus niger were used to check the antimicrobial activity. Zone of inhibition was observed on the plates against E. coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans but no zone of inhibition was observed against Aspergillus niger. The test for antioxidant activity indicates that the D-limonene has antioxidant activity (63.69 %). The antimicrobial test was performed. The MPN test was performed before and after addition of D-limonene to water sample. The total number of coliforms were reduced after treatment of drinking with D-limonene. Therefore, D-limonene is a good alternative for the purification of drinking water.

Study the effect of lactoperoxidase activation in combination with heat treatment or nisin on the microbiological quality of raw milk

The aim of the current study was to improve the microbiological quality of raw cow milk by activating the lactoperoxidase system using either nisin or heat treatment. A central composite experimental design with three factors was used to evaluate the effect of thiocyanate (SCN), hydrogen peroxide (H202) and nisin on the microbiological quality of raw milk. The experimental response was measured in terms of the logarithmic reduction in total microbial, total coliforms count, yeasts and molds. Our results indicate that the combination of both treatments was highly effective in destroying various microorganisms. In fact, the optimal values of each parameter (SCN, H202 and nisin) for a 6log, 5log and 4log reductions of the initial number of total aerobic mesophilic bacteria, coliforms, yeasts and molds were around 7 mg/L of SCN, 15 mg/L of H202 and 50 IU/mL of nisin, obtained after 72 h of incubation at 25 °C. Concerning the LPS activation at moderate temperature, our data suggest that this combination was very effective in destroying different microorganisms. Certainly, the total destruction of coliforms, yeasts and molds was noted after 96 h incubation at 25 °C after LPS activation for 4 h and 6 h followed by heat treatment (63 °C for 30 min). These results highlight a synergistic effect between the LPS activation and nisin or heat treatment in preserving microbiological quality of raw milk for 72 h or 96 h at 25 °C, respectively. Such treatments could be implemented by the dairy industry to enhance the quality of fresh milk and consequently of dairy products.

Rapid counting of coliforms and Escherichia coli by deep learning‐based classifier

AbstractTo ensure that food has been handled hygienically, manufacturers routinely examine the numbers of indicator bacteria, such as coliforms and Escherichia coli. Using the deep‐learning algorithm YOLO, we developed a classifier that automatically counts the number of coliforms (red colonies) and E. coli (blue colonies) on a chromogenic agar plate. Using Citrobacter freundii IAM 12471T and E. coli NBRC 3301, we trained our YOLO‐based classifier with images of Petri dishes grown with each strain alone (10 images) and/or with a mixture of both strains (5 images). When the performance of the classifier was evaluated using 83 images, the accuracy rates for coliforms and E. coli reached 99.4% and 99.5%, respectively. We then investigated whether this classifier could detect other, non‐trained coliform species (22 species) and E. coli strains (13 strains). The accuracy rates for coliforms and E. coli were 98.7% (90 Petri dishes) and 94.1% (46 Petri dishes), respectively. Furthermore, we verified the practical feasibility of the developed classifier using 38 meats (chicken, pork, and beef). The accuracy rates for coliforms and E. coli in meat isolates were 98.8% (80 Petri dishes) and 93.8% (35 Petri dishes), respectively. The time required to count coliforms/E. coli on a single plate was ~70 ms. This novel method should enable users to rapidly quantify coliforms/E. coli without relying on a human inspector's color vision, leading to improved assurance of food safety.

Study of the use of fermented Moringa leaves with probiotics to increase feed digestibility and reduce pathogenic bacteria in ducklings

Fermentation is an easy way to increase the nutritional value of feed and the results are palatable and act as probiotics.Fermentation products by probiotics and savonin compounds in herbal leaves can suppress pathogenic bacteria. This study aims to test the effect of giving fermented Moringa oleifera leaf flour (FML) by probiotics on the digestibility of nutrients and pathogenic bacteria in the digetive truct of duckling. Two hundred eighty eight healthy two-week-old male Bali ducklings with homogeneous average body weight were divided into four treatment groups, six replications and each replication used 72 ducklings. The four treatments, namely a group of ducks that were given rations without the addition of FML as control (A); ration with 2% FML (B); ration with 4% FML (C); and a ration with 6% FML (D), repectively. The results showed that the digestibility of dry matter (DM), organic matter (OM), crude protein (CP) and crude fiber (CF) in duck groups B, C and D was higher (P<0.05) compared to Group A (control ). On the other hand, the number of Coliform and Eschericia coli bacteria in duck groups B, C, and D, was significantly (P<0.05) lower than duck group A. It was concluded that the administration of 2-6% fermented Moringa oleifera leaf flour in feed can increase the digestibility of nutrients and can suppress the population of pathogenic bacteria in the duckling's digestive tract.

Wastewater as a nutrient source for hydroponic production of lettuce: Summer and winter growth

Solutions combining soilless cropping systems with wastewater reuse can offer benefits in the agriculture sector, reducing pressure on water resources, promoting sustainable production, and reclaiming wastewater. However, assessing the sanitary risks associated with wastewater reuse is of utmost importance. This study aimed to investigate the hydroponic growth of lettuce (Lactuca sativa var. crispa L.) in wastewater from an urban treatment plant with different levels of treatment and evaluate potential sanitary risks. Crop growth took place in a greenhouse, during summer and winter periods, using wastewater after primary (PTW) or secondary (STW) treatment, and a nutrient solution (NS), as control. Physical and chemical water quality parameters, morphological crop growth parameters, and environmental conditions inside the greenhouse were monitored. Toxicity analyses were carried out through cell viability assays with the Caco-2 cell line and total coliforms and Escherichia coli (E. coli) were determined. Wastewater-grown plants achieved acceptable growth, even though presenting lower fresh weight than NS-plants. STW-plants’ growth was limited essentially by nutrient deficiency, and PTW-plants were affected by nutrient deficiency, pH values, solid load, and N-NO2 concentration. Higher temperatures in summer led to faster crop growth, and lower temperatures in winter allowed better nutrient uptake by the crop. Wastewater-grown plants did not evidence toxicity in leaf extracts up to 1 % w/v. Coliform enumeration data indicated an accumulation in plant roots, with high removal from the wastewater. E. coli was not detected on plants’ leaves and total coliforms were within acceptable limits. Furthermore, the results point to an improvement in the wastewater quality, with minimum removal values of 75.2 % BOD5, 83.1 % COD, 43.4 % P, 44.9 % N, and 90.4 % K. The results demonstrated the viability of wastewater reuse for hydroponic production allowing a better understanding of its processes and contributing to mitigating water scarcity for food production, and the impacts of treated wastewater discharge in freshwater courses, particularly those associated with nutrient delivery to aquatic systems.

Microbiological characterization and functional evaluation in formulation made on farm at different times of production

Microbial formulations are routinely produced in several rural areas in Brazil. Its production is made using agricultural remnants, easily accessible products and soil microorganisms captured using cooked rice. However, studies on the microbial population and its functions in these products are still very scarce. The aim of this work was to evaluate the microbial diversity and dynamics, its functions and capacity to produce auxins (IAA). Microorganisms were isolated of the formulation with different times of production, quantified by serial dilution and then identified by DNA sequencing. The IAA production was evaluated by high performance liquid chromatography. The results showed a high variability of microorganisms and was extremely variable over production time. The formulation with 10 days of production showed the highest density of microorganisms and IAA concentration. There was no presence of Salmonella spp. and the mean number of thermotolerant coliforms is within sanitary limits. In conclusion, the formulation with 10 days of production is the most suitable for use.

Low-frequency transmission and persistence of antimicrobial-resistant bacteria and genes from livestock to agricultural soil and crops through compost application.

Livestock excrement is composted and applied to agricultural soils. If composts contain antimicrobial-resistant bacteria (ARB), they may spread to the soil and contaminate cultivated crops. Therefore, we investigated the degree of transmission of ARB and related antimicrobial resistance genes (ARGs) and, as well as clonal transmission of ARB from livestock to soil and crops through composting. This study was conducted at Rakuno Gakuen University farm in Hokkaido, Japan. Samples of cattle feces, solid and liquid composts, agricultural soil, and crops were collected. The abundance of Escherichia coli, coliforms, β-lactam-resistant E. coli, and β-lactam-resistant coliforms, as well as the copy numbers of ARG (specifically the bla gene related to β-lactam-resistant bacteria), were assessed using qPCR through colony counts on CHROMagar ECC with or without ampicillin, respectively, 160 days after compost application. After the application of the compost to the soil, there was an initial increase in E. coli and coliform numbers, followed by a subsequent decrease over time. This trend was also observed in the copy numbers of the bla gene. In the soil, 5.0 CFU g-1 E. coli was detected on day 0 (the day post-compost application), and then, E. coli was not quantified on 60 days post-application. Through phylogenetic analysis involving single nucleotide polymorphisms (SNPs) and using whole-genome sequencing, it was discovered that clonal blaCTX-M-positive E. coli and blaTEM-positive Escherichia fergusonii were present in cattle feces, liquid compost, and soil on day 0 as well as 7 days post-application. This showed that livestock-derived ARB were transmitted from compost to soil and persisted for at least 7 days in soil. These findings indicate a potential low-level transmission of livestock-associated bacteria to agricultural soil through composts was observed at low frequency, dissemination was detected. Therefore, decreasing ARB abundance during composting is important for public health.

Aflatoxin and microbial safety in commercial confectionery peanut paçoca produced in São Paulo state – Brazil

Paçoca is a typical Brazilian confectionery of Indigenous origin prepared by mixing ground roasted peanuts, sugar, and salt. A total of 52 samples of paçoca (37 pressed, 15 cooked), produced and sold in the state of São Paulo, were evaluated for aflatoxin content (AFB1, AFB2, AFG1 and AFG2), moisture content and water activity. The microbiological quality was assessed by counting mesophilic aerobic bacteria, fungal and yeast counts, most likely number of thermotolerant coliforms and Escherichia coli and Salmonella sp. The limit of quantification (LOQ) by Ultra Performance Liquid Chromatography coupled to the Mass Spectrometer (UPLC-MS/MS) ranged from 0.29 μg kg−1 for AFB1 and AFG2; 0.36 μg kg−1 for AFG1 and 0.37 μg kg−1 for AFB2. The recovery averages were 89.2, 83.5, 80.5 and 82.8% for AFB1, AFB2, AFG1 and AFG2. 71% of the samples showed aflatoxin contamination, ranging from 0.29 to 38.8 μg kg−1 (mean of 7.06 μg kg−1). Six samples (16%) exceeded the limit value tolerated by the Brazilian guideline for AFT (20 μg kg−1). The mean AFT content in cooked paçocas (19.55 μg kg−1) was higher than the levels in pressed paçocas (9.08 μg kg−1) (p < 0.05). AFB1 had a higher incidence in the two groups of paçocas (75% pressed and 60% cooked). The mean moisture content and water activity of cooked paçocas (8.86% and 0.7081) were higher than those of pressed paçocas (2.08% and 0.4863). Twenty-one samples (56%) showed fungal and yeast contamination ranging from 1.0 to 4.25 log CFU g−1. The total count of aerobic mesophilic bacteria in cooked paçocas (4.85 log CFU g−1) was also higher than in pressed paçocas (2.77 log CFU g−1) (p < 0.05). E. coli was confirmed in these samples in the range of 3.0–160 NMP g−1. Salmonella sp. was detected in 2 samples of pressed paçocas, indicating poor hygiene, inefficient heat treatment or possible cross-contamination. The results of this study demonstrate the need for greater control of the paçoca production chain through the adoption of Good Manufacturing Practices and process control, to prevent exposure of the population to aflatoxins and possible pathogenic microorganisms.

WITHDRAWN: An Investigation of a Hybrid Solar-Mineral Disinfection Technique Using Zeolite and Dead Sea Clay

Effluents from water treatment plants (WTP) can often contain a complex mixture of residual micro-contaminants and organisms, not removed during wastewater treatment. A combined trickling filter, activated sludge treatment, ozonation, membrane filtration, and suspended biofilm reactors have been shown to reduce these contaminants in waste effluent but at high capita cost. This study examined an inexpensive method of purifying water, which combines solar water disinfection with natural mineral clays (SOMIN-DIS). The study involved the addition of two types of mineral clays, Zeolite and Dead Sea minerals, to containers of polluted wastewater, at varying concentrations. The containers were then subjected to different durations of sunlight exposure. Then, samples were taken from all of the containers to quantify the overall numbers of Total Coliform, Pseudomonas aeruginosa (P.aeruginosa), and Escherichia coli (E.coli), utilizing the IDEXX system. The findings indicated that incorporating Dead Sea clay and Zeolite into SODIS-treated wastewater decreased the overall number of harmful microorganisms and shortened the disinfection duration, as compared to using natural minerals and solar water disinfection (SODIS) independently. Additionally, the study determined that the most effective concentration of Dead Sea minerals, resulting in the least amounts of harmful microorganisms and shortest purification duration, was 0.001g/ml. In contrast, the optimum concentration of Zeolite was 0.002g/ml. In general, the addition of Dead Sea and Zeolite minerals to the wastewater increased the inactivation of bacteria under SODIS from 40% to 65%.

Bioenergy-producing two-stage septic tank and floating wetland for onsite wastewater treatment: Circuit connection and external aeration

This study designed a two-stage, electrode-integrated septic tank-floating wetland system and assessed their pollutant removal performances under variable operational conditions. The two-stage system achieved mean organic, nitrogen, phosphorus, and coliform removal percentages of 99, 78, 99, and 97%, respectively, throughout the experimental run. The mean metals (chromium, cadmium, nickel, copper, zinc, lead, iron, and manganese) removal percentages ranged between 81 and 98%. Accumulated sludge, filler media, and the hanging root mass contributed to pollutant removals by supporting physicochemical and biological pathways. The mean effluent organic concentration and coliform number across the two-stage system were 20 mg/L and 1682 CFU/100 mL, respectively, during the closed-circuit protocol, which was beneath the open-circuit-based performance profiles, i.e., 32 mg/L and 2860 CFU/100 mL, respectively. Effluent organic, nitrogen, phosphorus, metals, and coliform number ranges across the two-stage system were 9–17 mg/L, 13–24 mg/L, 1–1.5 mg/L, 0.001–0.2 mg/L, and 1410–2270 CFU/100 mL, respectively during intermittent and continuous aeration periods. The air supply rate differences influenced pollutant removal depending on the associated removal mechanisms. The non-aeration phase produced higher effluent pollutant concentrations than the aeration periods-based profiles. The overall mean power density production of the septic tank ranged between 107 and 596 mW/m3; 110 and 355 mW/m3 with the floating wetland. The bioenergy production capacity of the septic tank was positively correlated to external air supply rates. This study demonstrates the potential application of the novel bioenergy-producing septic tank-floating wetland system for wastewater treatment in decentralized areas.

Schoenoplectus americanus as a potential phytoremediator: in vitro assessment of its ability to remove contaminants in domestic and tannery wastewater

ABSTRACT Growing industrialization and urbanization have led to increased water pollution due to the inadequate treatment and disposal of domestic wastewater (DW) and wastewater produced by industries such as tanneries (TW). These wastewaters are characterized by high concentrations of organic matter, nutrients, sulphates, chlorides and high microbial load. TW also contains phenols and chromium, which disturb and harm the ecosystem the local. The decontamination of wastewater prior to their discharge through biological tools, especially the use of species that are native to the site in need of treatment, has been described as effective and advantageous. This study evaluated the ability of Schoenoplectus americanus, a native plant species from Cordoba (Argentina), to phytoremediate local DW and TW samples at a laboratory scale. The aim was to ascertain whether this system could potentially be considered for the remediation of wastewater in real-world scenarios. S. americanus was able to tolerate pure DW and a 1/20 (v/v) dilution of TW for 30 days under hydroponic conditions. Removal rates ranging from 50% to 89% were obtained for residual organic matter (determined as chemical oxygen demand or COD), total nitrogen (TN) and total phosphorus (TP). Significant removal of total chromium (TCr) and total phenols (TPhs) was also observed in TW (85% and 98%). The number of total coliforms (TC), was reduced by about 96% and 99%. These results indicate that S. americanus is a good candidate for the phytoremediation of regional DW and TW. For this reason, it may be considered for full-scale applications in the future.

QUALITY CHARACTERISTICS OF RAW MILK SAMPLES PURCHASED FROM AUTOMATIC MİLK VENDING MACHINES IN NİĞDE PROVINCE

In the regulation published by the Ministry of Agriculture and Forestry in Turkey, it is stated that only automatic milk machines can be used to put raw milk on sale. This study aims to examine some physical, chemical and microbiological properties of a total of 40 raw milk samples sold in automatic vending machines and unpackaged, by egulations in Niğde province, and to compare the milk samples according to the retailer from which they were purchased. The study also aimed to quantitatively determine carbonate and hydrogen peroxide residues in milk samples and the presence of beta-lactam and tetracycline group antibiotics with a commercial kit. At the end of the study, the average value of lactic acid (%) density, fat, protein, non-fat dry matter, lactose, freezing point and pH values of the samples were determined as 0.153% ± (0.022); 1.028± (0.03) g/ml; 3.525%± (0.656); 3.5%± (0.107); 9% 4± (0.277); 5.134± (0.152); -0.549°C ± (0.018) and 6.55 ± (0.102) respectively. As a result of microbiological analysis of milk, the average number of total aerobic mesophilic organisms, coliforms, fecal coliforms, yeast-molds and micrococci-staphylococci was determined as 5.38 ± (0.47); 3.73 ± (1.11); 2.76 ± (1.66); 2.33 ± (1.86) and 4.29± (1.20) log cfu/ml respectively. Carbonate, hydrogen peroxide, beta-lactam and tetracycline antibiotic residues could not be detected in the milk samples. The fact that some of the results obtained in the study were outside the limits specified in the codexes and different from the study average reveals that the milk sold in businesses selling street milk should be analyzed regularly.

Total coliforms, microbial diversity and multiple characteristics of Salmonella in soil-irrigation water-fresh vegetable system in Shaanxi, China

Global occurrences of foodborne disease outbreaks have been documented, involving fresh agricultural produce contaminated by various pathogens. This contamination can occur at any point in the supply chain. However, studies on the prevalence of total coliforms, Salmonella and microbial diversity in vegetable and associated environments are limited. This study aimed to assess 1) the number of total coliforms (n = 299) and diversity of microbial communities (n = 52); 2) the prevalence, antibiotic susceptibility, genomic characteristics, and potential transmission relationships of Salmonella in soil-irrigation water-vegetable system (n = 506). Overall, 84.28 % samples were positive to total coliforms, with most frequently detected in soil (100 %), followed by irrigation water (79.26 %) and vegetables (62.00 %). A seasonal trend in coliform prevalence was observed, with significantly higher levels in summer (P < 0.05). Detection rates of Salmonella in soil, vegetable and irrigation water were 2.21 %, 4.74 % and 9.40 %. Fourteen serotypes and sequence types (STs) were respectively annotated in 56 Salmonella isolates, ST13 S. Agona (30.36 %, 17/56), ST469 S. Rissen (25.00 %, 14/56), and ST36 S. Typhimurium (12.50 %, 7/56) were dominant serotypes and STs. Thirty-one (55.36 %) isolates were multi-drug resistant, and the resistance was most frequently found to ampicillin (55.36 %, 31/56), followed by to sulfamethoxazole (51.79 %, 29/56) and tetracycline (50.00 %, 28/56). The genomic characteristics and antibiotic resistance patterns of Salmonella isolates from soil, vegetables, and irrigation water within a coherent geographical locale exhibited remarkable similarities, indicating Salmonella may be transmitted among these environments or have a common source of contamination. Microbial alpha diversity indices in soil were significantly higher (P < 0.05) than that in vegetable and irrigation water. The microbial phylum in irrigation water covered that in the vegetable, demonstrating a significant overlap in the microbial communities between the vegetables and the irrigation water.

Effect of Plasma-Activated Water (PAW) on the Postharvest Quality of Shepherd's Purse (Capsella bursa-pastoris).

Plasma-activated water (PAW) treatment is an effective technique for the quality retention of fresh vegetables with cold atmospheric plasma using controllable parameters. This study investigated the effect of PAW on the postharvest quality of shepherd's purse (Capsella bursa-pastoris). The results displayed that PAW treatment with an activation time of 5, 10, 15, and 20 min reduced the yellowing rate and weight loss of the shepherd's purse during 9 days of storage. Compared with untreated samples, PAW treatment at different times reduced the number of total bacteria, coliform, yeast, and mold by 0.18-0.94, 0.59-0.97, 0.90-1.18, and 1.03-1.17 Log CFU/g after 9 days of storage, respectively. Additionally, the treatments with PAW-5 and PAW-10 better preserved ascorbic acid, chlorophyll, total phenol, and total flavonoid contents. They also maintained the higher antioxidant and CAT activity and inhibited the formation of terpenes, alcohols, and nitrogen oxide compounds of the shepherd's purse at the end of storage. The microstructural result illustrated that the cells of the shepherd's purse treated with PAW-5 and PAW-10 were relatively intact, with a small intercellular space after storage. This study demonstrated that PAW treatment effectively improved the postharvest quality of shepherd's purse.

Effects of bacterial cellulose/thyme essential oil emulsion coating on the shelf life of chilled chicken meat.

Bacterial cellulose (BC) is a fiber substance produced by microbial fermentation. It is widely used in the food preservation industry because of its extremely pure texture, high crystallinity and high biocompatibility. In the present study, bacterial cellulose/thyme essential oil (BC/TEO-E) with antibacterial and fresh-keeping functions was prepared by ultrasonic treatment of modified bacterial cellulose for encapsulation of thyme essential oil, which effectively inhibited the spoilage of chilled chicken. The purified BC, produced by Acetobacter xylinum ATCC 53524, was ultrasonically treated wih different times (0, 30, 60 and 90 min). Transmission electron microscopy, scanning electron microscopy, Fourier transformed infrared spectroscopy, X-ray diffraction, differential scanning calorimetry and zeta potential were used to characterize the structure of BC after ultrasound, showing that BC, treated for 30 min, had the optimal fiber structure, crystallinity (85.8%), thermal stability (347.77 °C) and solution stability (-26.63 ± 1.96 mV). BC/TEO-E was prepared by a homogenizer for the preservation of chilled chicken. Optical microscopy indicated that the BC/TEO-E prepared by 0.5% BC had optimal dispersion and stability, and even no delamination was observed in the emulsion. Compared with other groups (control, 0.5% BC and Tween-E), the total number of colonies and coliforms in chilled chicken treated with 0.5% BC/TEO-E was the lowest during the whole storage period (12 days), indicating that it can effectively inhibit bacterial growth. In addition, total volatile base nitrogen (TVB-N), thiobarbituric acid reactive substances, pH and drip loss results showed that 0.5% BC/TEO-E could effectively inhibit the spoilage of chilled chicken compared to the other treatment groups. All of the results acquired in the present study indicate that BC/TEO-E has a potential application in chilled chicken preservation. © 2024 Society of Chemical Industry.

Isolation and Identification of Saccharomyces boulardii as a Probiotic Yeast and Investigation of its In vitro and In vivo Beneficial Applications

Background: Yeasts are becoming increasingly popular as possible new resources to improve the nutritional value of food qualities like flavor, color, and vitamin content, as well as tools for preventing food spoiling due to their anti-microbial capabilities. Objective: This study aims to test the role of isolated Saccharomyces boulardii as a promising probiotic as well as Jerusalem artichoke as a prebiotic in a feeding animal model to test their possible functions in regulating lipid profile and bacterial count in the faeces of tested animals. Methods: For the isolation of yeast cultures on YM agar medium, five milk samples were randomly obtained from the Faculty of Agriculture at Al-Azhar University in Cairo, Egypt. S. boulardii was morphologically, physiologically, and molecularly identified and deposited in the gene bank; additionally, identification was confirmed using the BIOLOG system. For 30 days, researchers compared the roles of S. boulardii as a probiotic and Jerusalem artichoke as a prebiotic in controlling serum lipid profile and faeces microbial count in the tested animal groups. Results: The acid and bile tolerance tests illustrate the promising ability of S. boulardii. Additionally, S. boulardii could survive on simulated stomach and intestinal fluids. An in vivo feeding test showed that rats fed S. boulardii grew and gained weight faster. Furthermore, eating S. boulardii causes a marked increase in HDL levels and a marked drop in LDL, cholesterol, and triglycerides. Rats that consumed Jerusalem artichokes and a probiotic strain had significantly lower numbers of coliforms and Staphylococcus sp. in their stools. Conclusion: These results revealed the possible beneficial role of S. boulardii in overcoming hyperlipidemia, which should be applied on a large scale after verification of outcomes.

An investigation of a hybrid solar-mineral disinfection technique using Zeolite and Dead Sea clay

Effluents from water treatment plants (WTP) can often contain a complex mixture of residual micro-contaminants and organisms, not removed during wastewater treatment. A combined trickling filter, activated sludge treatment, ozonation, membrane filtration, and suspended biofilm reactors have been shown to reduce these contaminants in waste effluent but at high capita cost. This study examined an inexpensive method of purifying water, which combines solar water disinfection with natural mineral clays (SOMIN-DIS). The study involved the addition of two types of mineral clays, Zeolite and Dead Sea minerals, to containers of polluted wastewater, at varying concentrations. The containers were then subjected to different durations of sunlight exposure. Then, samples were taken from all of the containers to quantify the overall numbers of Total Coliform, Pseudomonas aeruginosa (P.aeruginosa), and Escherichia coli (E.coli), utilizing the IDEXX system. The findings indicated that incorporating Dead Sea clay and Zeolite into SODIS-treated wastewater decreased the overall number of harmful microorganisms and shortened the disinfection duration, as compared to using natural minerals and solar water disinfection (SODIS) independently. Additionally, the study determined that the most effective concentration of Dead Sea minerals, resulting in the least amounts of harmful microorganisms and shortest purification duration, was 0.001 g/ml. In contrast, the optimum concentration of Zeolite was 0.002 g/ml. In general, the addition of Dead Sea and Zeolite minerals to the wastewater increased the inactivation of bacteria under SODIS from 40% to 65%.