Disinfection of Water and Wastewater Using ZnO Nanofluids - Effect of Shaking Speed of Incubator

Nanofluids are liquids containing nanoparticles, nanotube or nanowire suspensions. This work investigates the disinfection properties of ZnO nanofluids, especially the change of ZnO disinfection properties when facing different shaking speeds of incubator (50rpm, 100rpm, 200rpm and 300rpm). In this work, E. coli was used as model bacteria to test the disinfection property of ZnO nanofluids. Plant counting method was used to examine the number of bacteria before and after the treatment of ZnO nanofluids. The results demonstrate that both ZnO nanofluids sample A and B could inhibit or kill E. coli bacteria. ZnO sample B with smaller particle size showed better antimicrobial activities. Treated with higher concentration of ZnO sample B exhibited better antimicrobial activities. Besides, this work also demonstrated that with higher shaking speed of incubator, ZnO nanofluids showed better antimicrobial activities. The antimicrobial mechanism is thought to be associated with physical interaction between ZnO particles and the biological cells and enhanced mass transfer of possible chemical species produced due to the presence of ZnO particles.

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Study on the Antimicrobial Properties of ZnO Suspension against Gram-Positive and Gram-Negative Bacteria Strains

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.393-395.1488 ◽

2011 ◽

Vol 393-395 ◽

pp. 1488-1491 ◽

Cited By ~ 8

Author(s):

Ling Ling Zhang ◽

Bo Chen ◽

Lan Lan Xie ◽

Zi Fu Li

Keyword(s):

Antimicrobial Properties ◽

Growth Curves ◽

Antimicrobial Activities ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

E Coli ◽

Ph Values ◽

Killing Action ◽

Number Of Bacteria

Because of the excellent properties and wide applications on nanomaterials, recent years, researchers start to focus on the use of nanomaterials in wastewater treatment. This paper investigated the antimicrobial activities of ZnO against Gram-positive and Gram-negative bacteria strains – E. coli and Sarcinic pseudomycosis. Growth curves of bacteria strains were used to estimate the antimicrobial activities of ZnO suspensions. This work showed pH values of ZnO suspension did not affect the antimicrobial activities of ZnO. Besides, when treating small number of bacteria slurry, ZnO expressed the killing action. Based on this work, the possible antimicrobial mechanism is also discussed in this paper.

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Milk quality and its technological suitability for processing after the disinfection of the udder teats in cows

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/845/1/012100 ◽

2021 ◽

Vol 845 (1) ◽

pp. 012100

Author(s):

A V Filatova ◽

Yu V Bibaeva ◽

M V Nistratova ◽

S V Kozlov ◽

A V Molchanov ◽

...

Keyword(s):

Subclinical Mastitis ◽

Milk Quality ◽

Hazard Class ◽

Staph Aureus ◽

E Coli ◽

Preclinical Evaluation ◽

Economic Experience ◽

Before And After ◽

Disinfectant Solution ◽

Number Of Bacteria

Abstract Experiments on the study of preclinical evaluation of disinfectants based on chlorhexidine bigluconate hydrochloride / aloe tree oil (CGB aloe) and polyhexamethylene biguanide hydrochloride / eucalyptus oil (Teasfoam Supercow) showed their low hazard when exposed to warm-blooded animals. Disinfectants are assigned to the fourth hazard class according to GOST 12.1.007-76. The concentration of Staph. aureus, Strep. agalactiae was lower when teats were immersed in Teasfoam Supercow disinfectant solution before and after milking, compared to untreated teats. It is concluded that the application of CGB aloe is very efficient against Staph. aureus, Strep. Agalactiae, E. coli and Strep. uberis. Based on the results of scientific and economic experience, it can be concluded that controlled disinfection of the udder teats with a disinfectant CGB aloe before and after milking cows with high milk yield does not prevent udder teat hyperkeratosis in 2.4% of animals. In addition, subclinical mastitis is diagnosed in 12.1%; 3.3% of cows during the disinfection of the udder teats with Teasfoam Supercow were diagnosed hyperkeratosis of the udder teats. Another 12.9% of animals had subclinical mastitis. Udder teats of control animals were not disinfected. Udder hyperkeratosis was diagnosed in 5.4% of cows. Another 26.5% of the animals fell ill with subclinical mastitis. In cows, after controlled disinfection of the udder teats, an increase in milk production by 1-2 liters was observed. No color, taste or odor changes were observed in the milk. It has been proven that teats disinfection reduces the number of bacteria on the teats skin, improves the sanitary milk quality and its manufacturability.

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APPLICATION OF THE ATP-BIOLUMINESCENCE METHOD TO ASSESS THE QUALITY OF SANITATION OF MILKING EQUIPMENT

Problems of Veterinary Sanitation, Hygiene and Ecology ◽

10.36871/vet.san.hyg.ecol.202004010 ◽

2020 ◽

Vol 1 (4) ◽

pp. 468-472

Author(s):

P.A. Popov ◽

◽

D.V. Gruznov ◽

S.V. Tokarev ◽

◽

...

Keyword(s):

Dairy Farms ◽

Laboratory Studies ◽

Before And After ◽

Atp Bioluminescence ◽

Microbial Number ◽

Proportional Relationship ◽

The Relationship ◽

Number Of Bacteria ◽

Bioluminescence Method

The article presents the results of determining the relationship between the total microbial number and microbial ATP on the surface of milking equipment before and after treatment with neutral anolyte ANK-SUPER. The possibility of using the ATP-bioluminescence method to control the quality of sanitation of milking equipment on dairy farms is shown. Laboratory studies revealed a proportional relationship between the level of bacterial ATP and the number of bacteria on the surface of milking equipment before and after sanitation.

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Synergistic Antimicrobial Activities of Combinations of Vanillin and Essential Oils of Cinnamon Bark, Cinnamon Leaves and Cloves

Foods ◽

10.3390/foods10061406 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1406

Author(s):

Rita Cava-Roda ◽

Amaury Taboada-Rodríguez ◽

Antonio López-Gómez ◽

Ginés Benito Martínez-Hernández ◽

Fulgencio Marín-Iniesta

Keyword(s):

Antimicrobial Activity ◽

Essential Oils ◽

Food Packaging ◽

Antimicrobial Effect ◽

Antimicrobial Activities ◽

Inhibitory Effects ◽

Cinnamon Bark ◽

E Coli ◽

Pure Compounds ◽

Main Component

Plant bioactive compounds have antimicrobial and antioxidant activities that allow them to be used as a substitute for synthetic chemical additives in both food and food packaging. To improve its sensory and bactericidal effects, its use in the form of effective combinations has emerged as an interesting possibility in the food industry. In this study, the antimicrobial activities of essential oils (EOs) of cinnamon bark, cinnamon leaves, and clove and the pure compounds vanillin, eugenol, and cinnamaldehyde were investigated individually and in combination against Listeria monocytogenes and Escherichia coli O157:H7. The possible interactions of combinations of pure compounds and EOs were performed by the two-dimensional checkerboard assay and isobologram methods. Vanillin exhibited the lowest antimicrobial activity (MIC of 3002 ppm against L. monocytogenes and 2795 ppm against E. coli O157:H7), while clove and cinnamon bark EOs exhibited the highest antimicrobial activity (402–404 against L. monocytogenes and 778–721 against E. coli O157:H7). For L. monocytogenes, pure compound eugenol, the main component of cinnamon leaves and clove, showed lower antimicrobial activity than EOs, which was attributed to the influence of the minor components of the EOs. The same was observed with cinnamaldehyde, the main component of cinnamon bark EO. The combinations of vanillin/clove EO and vanillin/cinnamon bark EO showed the most synergistic antimicrobial effect. The combination of the EOs of cinnamon bark/clove and cinnamon bark/cinnamon leaves showed additive effect against L. monocytogenes but indifferent effect against E. coli O157:H7. For L. monocytogenes, the best inhibitory effects were achieved by cinnamon bark EO (85 ppm)/vanillin (910 ppm) and clove EO (121 ppm)/vanillin (691 ppm) combinations. For E. coli, the inhibitory effects of clove EO (104 ppm)/vanillin (1006 ppm) and cinnamon leaves EO (118 ppm)/vanillin (979 ppm) combinations were noteworthy. Some of the tested combinations increased the antimicrobial effect and would allow the effective doses to be reduced, thereby offering possible new applications for food and active food packaging.

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Curcumin-loaded polyvinyl butyral film with antibacterial activity

e-Polymers ◽

10.1515/epoly-2020-0042 ◽

2020 ◽

Vol 20 (1) ◽

pp. 673-681

Author(s):

Yanchao Qiao ◽

Lijie Duan

Keyword(s):

Mechanical Property ◽

Thermal Stability ◽

Antibacterial Activity ◽

Polyvinyl Butyral ◽

Counting Method ◽

E Coli ◽

Antibacterial Materials ◽

Good Antibacterial Activity ◽

Colony Counting ◽

Widespread Interest

AbstractAntibacterial materials have found widespread interest in different fields nowadays. In this study, curcumin (Cur) was incorporated into the polyvinyl butyral (PVB) matrix by dissolving in ethanol for improving the functional properties of a pure PVB film. We found that Cur was uniformly dispersed in the PVB matrix, which showed good compatibility. Moreover, the incorporation of Cur could also improve thermal stability, hydrophilicity, and mechanical property. The UV-vis spectra of the PVB–Cur film demonstrated that the film could block ultraviolet radiation. Subsequently, the antibacterial activity of the PVB–Cur film was measured by the colony-counting method against S. aureus and E. coli. The results showed that the PVB–Cur film exhibited good antibacterial activity. Therefore, the PVB–Cur film was considered as a promising material for food and medical packaging applications.

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Antimicrobial and Immunomodulating Activities of Two Endemic Nepeta Species and Their Major Iridoids Isolated from Natural Sources

Pharmaceuticals ◽

10.3390/ph14050414 ◽

2021 ◽

Vol 14 (5) ◽

pp. 414

Author(s):

Neda Aničić ◽

Uroš Gašić ◽

Feng Lu ◽

Ana Ćirić ◽

Marija Ivanov ◽

...

Keyword(s):

Biofilm Formation ◽

Food Industry ◽

Balkan Peninsula ◽

Antimicrobial Activities ◽

Natural Sources ◽

E Coli ◽

Food Borne ◽

Metabolite Profiles ◽

Aspergillus Sp ◽

First Time

Two Balkan Peninsula endemics, Nepeta rtanjensis and N. argolica subsp. argolica, both characterized by specialized metabolite profiles predominated by iridoids and phenolics, are differentiated according to the stereochemistry of major iridoid aglycone nepetalactone (NL). For the first time, the present study provides a comparative analysis of antimicrobial and immunomodulating activities of the two Nepeta species and their major iridoids isolated from natural sources—cis,trans-NL, trans,cis-NL, and 1,5,9-epideoxyloganic acid (1,5,9-eDLA), as well as of phenolic acid rosmarinic acid (RA). Methanol extracts and pure iridoids displayed excellent antimicrobial activity against eight strains of bacteria and seven strains of fungi. They were especially potent against food-borne pathogens such as L. monocytogenes, E. coli, S. aureus, Penicillium sp., and Aspergillus sp. Targeted iridoids were efficient agents in preventing biofilm formation of resistant P. aeruginosa strain, and they displayed additive antimicrobial interaction. Iridoids are, to a great extent, responsible for the prominent antimicrobial activities of the two Nepeta species, although are probably minor contributors to the moderate immunomodulatory effects. The analyzed iridoids and RA, individually or in mixtures, have the potential to be used in the pharmaceutical industry as potent antimicrobials, and in the food industry to increase the shelf life and safety of food products.

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Synthesis and In Vitro Antimicrobial Evaluation of Photoactive Multi—Block Chalcone Conjugate Phthalimide and 1,8-Naphthalimide Novolacs

Polymers ◽

10.3390/polym13111859 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1859

Author(s):

Periyan Durairaju ◽

Chinnasamy Umarani ◽

Govindasami Periyasami ◽

Perumberkandigai Adikesavan Vivekanand ◽

Mostafizur Rahaman

Keyword(s):

Spectroscopic Analysis ◽

Photophysical Properties ◽

Gel Permeation Chromatography ◽

13C Nmr Spectroscopy ◽

Antimicrobial Activities ◽

Microbial Activities ◽

E Coli ◽

Molecular Weights ◽

Antimicrobial Evaluation

Herein we report new multiblock chalcone conjugate phthalimide and naphthalimide functionalized copolymers with a topologically novel architecture synthesis using nucleophilic substitution and polycondensation methodology. The structures of the synthesized novolacs were elucidated on the basis of their spectroscopic analysis including FTIR, 1H NMR, and 13C NMR spectroscopy. Further, the number-average and weight-average molecular weights of the novolac polymers were determined by gel permeation chromatography (GPC). We examined the solubility of the synthesized polymers in various organic solvents including CHCl3, CH3CN, THF, H2O, CH3OH, DMSO, and DMF and found they are insoluble in both methanol and water. The novolac polymers were evaluated for their photophysical properties and microbial activities. The investigation of the antimicrobial activities of these polymers reveals significant antimicrobial activity against the pathogens E. coli, S. aureus, C. albicans, and A. niger.

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Airborne Dissemination of Bacteria (Enterococci, Staphylococci and Enterobacteriaceae) in a Modern Broiler Farm and Its Environment

Animals ◽

10.3390/ani11061783 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1783

Author(s):

Susana Sanz ◽

Carmen Olarte ◽

Raquel Hidalgo-Sanz ◽

Laura Ruiz-Ripa ◽

Rosa Fernández-Fernández ◽

...

Keyword(s):

Selective Media ◽

E Coli ◽

Predominant Species ◽

Bacterial Dissemination ◽

Low Emission ◽

Broiler Farm ◽

Cardinal Directions ◽

Dna Profiles ◽

Number Of Bacteria

The role of the air as a vehicle of bacteria dissemination in the farming environment has been previously reported, but still scarcely studied. This study investigated the bacteria density/diversity of the inside and outside air and of litter samples at a broiler farm. Samples were collected considering two seasons, three outside air distances (50/100/150 m) and the four cardinal directions. Selective media was used for staphylococci, enterococci, and Enterobacteriaceae recovery. A high number of bacteria was detected in the litter (2.9 × 105–5.8 × 107 cfu/g) and in the inside air (>105 cfu/m3), but a low emission of bacteria was evidenced in the outside air (<6 cfu/m3). Moreover, the bacteria detected in the farm’s outside air decreased the further from the farm the sample was taken. A total of 544 isolates were identified by MALDI-TOF (146 from the litter, 142 from inside air and 256 from outside air). From these, 162 staphylococci (14 species; S. saprophyticus 40.7%), 176 Enterobacteriaceae (4 species; E. coli 66%) and 190 enterococci (4 species; E. hirae 83%) were detected. E. hirae was the predominant species, and identical PFGE clones were detected in inside and outside samples. The detection of identical DNA profiles in E. hirae isolates from inside and outside samples suggests the role of the air in bacterial dissemination from the inside of the broiler farm to the immediate environment.

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A Novel Method for Preparation of Antimicrobial Cellulose Textile by Surface Carbamatization and N-Chlorination

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.399-401.1088 ◽

2011 ◽

Vol 399-401 ◽

pp. 1088-1092

Author(s):

Liu Yang Wang ◽

Fang Ying Wang ◽

Biao Bing Wang

Keyword(s):

Nitrogen Content ◽

Shake Flask ◽

Antimicrobial Activities ◽

Sodium Hypochlorite Solution ◽

E Coli ◽

Cellulose Fabric ◽

Carbamate Group ◽

Novel Method ◽

Cellulose Fabrics ◽

Temperature Time

Surface carbamatization of cellulose fabric was accomplished through co-heating with urea. The carbamate group on textile surface was transformed to N-chlorocarbamate after exposure to sodium hypochlorite solution. Effect of carbamatization temperature, time on Nitrogen content of fabrics was investigated, and the effect of bleach technology on chlorine content on fabrics was also studied. Using shake flask method antimicrobial activities against E. coli and S. aureus were studied. The results showed that when carbamatization temperature was 138°C and the time was 3 hours, nitrogen content of cellulose fabric was the highest: 1.47%. Antibacterial ability of cellulose fabrics with 0.81mg/g chlorine against E. coli and S. aureus was 99.9999% and 100%, respectively.

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Energy and Resources Recovery from Gasified Screenings and Toxic Sludge

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1045.194 ◽

2021 ◽

Vol 1045 ◽

pp. 194-202

Author(s):

Siviwe H. Bunge ◽

James L. Topkin ◽

Joshua Gorimbo ◽

Diakanua B. Nkazi

Keyword(s):

Liquid Fuel ◽

Energy Content ◽

Chemical Species ◽

Adsorption Properties ◽

Fuel Production ◽

Management Options ◽

High Quality ◽

Oil Resources ◽

Bio Oil ◽

Before And After

Sludge and screenings management is increasingly becoming a dilemma due its accumulating and tightening environmental regulations that limit its disposal methods. Various sludge management options have been researched, ranging from incineration, thermochemical liquefaction, to pyrolysis and gasification. This work proposes syngas, bio-oil, chemical resources and bio-char production for beneficiation through gasification of a mixture of sludge and screenings at different ratios of 25/75, 50/50 and 75/25. It also studies mass loss and toxins possible destruction by gasification temperatures and reactions. Toxicity and CHNS analysis before and after gasification were aimed at finding sludge energy content, while thermogravimetric analysis (TGA), was to find sampling and stopping temperatures during gasification. The overall best results of high syngas quality (high LHV, H2, CO and CH4 contents) and high quality bio-oil (i.e. cleanest, with high crude oil equivalent bonds such as C1 up to C36 and higher applicable bio-oil resources and chemical species obtained) was achieved by a 75/25 ratio, followed by a 50/50 ratio. The results also showed some possibility of biological and chlorinated hydrocarbon toxins (PCBs and PAHs) break down as well as the reduction of sludge and screenings to about 32% of the initial mass. These results can be further investigated for syngas application in power generation and liquid fuel production. Char toxicity can be analysed for its application in agriculture and for its adsorption properties. Char can be analysed for the presence of metals in it.

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