Encapsulated peracetic acid as a valid broad‑spectrum antimicrobial alternative,leading to beneficial microbiota compositional changes and enhanced performance in broiler chickens

Background Antimicrobial alternatives are urgently needed,including for poultry production systems.In this study,we tested the potential broad-range antimicrobial alternative peracetic acid,delivered in feed via the hydrolysis of encapsulated precursors through a 28-day study using 375 Ross 308 broiler chickens.We tested two peracetic acid concentrations,30 and 80 mg/kg on birds housed on re-used litter,and we evaluated the impact of both levels on gut microbial communities,bacterial concentration,antimicrobial resistance genes relative abundance and growth performance when compared to control birds housed on either clean or re-used litter.Results Body weight gain and feed conversion ratio improved in peracetic acid fed birds.At d 28,birds given 30 mg/kg of peracetic acid had a decreased Firmicutes and an increased Proteobacteria abundance in the jejunum,accompanied by an increase in Bacillus,Flavonifractor and Rombustia in the caeca,and a decreased abundance of tetracycline resistance genes.Chicken given 80 mg/kg of peracetic acid had greater caecal abundance of macrolides lincosamides and streptogramins resistance genes.Growth performance on clean litter was reduced compared to reused litter,which concurred with increased caecal abundance of Blautia,decreased caecal abundance of Escherichia/Shigella,Anaerostipes and Jeotgalicoccus,and greater gene abundance of vancomycin,tetracycline,and macrolides resistance genes.Conclusions Peracetic acid could be used as a safe broad-spectrum antimicrobial alternative in broilers.Encapsulated precursors were able to reduce the bacterial concentration in the jejunum whilst promoting the proliferation of probiotic genera in the caeca,especially at the low peracetic acid concentrations tested,and improve growth performance.Moreover,our findings offer further insights on potential benefits of rearing birds on re-used litter,suggesting that the latter could be associated with better performance and reduced antimicrobial resistance risk compared to clean litter rearing.

Boron promoted Fe^(3+)/peracetic acid process for sulfamethazine degradation:Efficiency,role of boron,and identification of the reactive species

In this work,boron(B)was used to promote Fe^(3+)/peracetic acid(Fe^(3+)/PAA)for the degradation of sulfamethazine(SMT).An SMT degradation efficiency of 9.1%was observed in the Fe^(3+)/PAA system over 60 min,which was significantly increased to 99.3%in the B/Fe^(3+)/PAA system over 10 min.The B/Fe^(3+)/PAA process also exhibited superior resistance to natural substances,excellent adaptability to different harmful substances,and good removal of antibiotics in natural fresh water samples.The mechanism of action of boron for Fe^(3+)reduction was determined using scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),Fourier transform infrared(FT-IR)spectroscopy,density functional theory(DFT)calculations,and electrochemical tests.The dominant role of^(·)OH was confirmed using quenching experiments,electron spin resonance(EPR)spectroscopy,and quantitative tests.Organic radicals(R-O^(·))and Fe(IV)also significantly contribute to the removal of SMT.DFT calculations on the reaction between Fe^(2+)and the PAA were conducted to further determine the contribution from ^(·)OH,R-O^(·),and Fe(IV)from the perspective of thermodynamics and the reaction pathways.Different boron dosages,Fe^(3+)dosages,and initial pH values were also investigated in the B/Fe^(3+)/PAA system to study their effect of SMT removal and the production of the reactive species.Fe(IV)production determined the k_(R-O·+Fe(IV))value suggesting that Fe(IV)may play a more important role than R-O^(·).A comparison of the results with other processes has also proved that the procedure described in this study(B/Fe^(3+)/PAA)is an effective method for the degradation of antibiotics.

In-situ construction of Co(OH)_(2) nanoparticles decorated biochar for highly efficient degradation of tetracycline hydrochloride via peracetic acid activation

Peracetic acid(CH_(3)C(O)OOH,PAA)-based heterogeneous advanced oxidation process(AOP)has attacked intensive interests due to production of various reactive species.Herein,Co(OH)_(2)nanoparticles decorated biochar(Co(OH)_(2)/BC)was fabricated by a simple and controllable method,which was used to degrade tetracycline hydrochloride(TTCH)in water through PAA activation.The results indicated that 100%TTCH(C_(0)=10μmol/L)degradation efficiency was realized within 7 min at pH 7,with a high kinetic rate constant(k_(1))of 0.64 min^(-1)by the optimized Co(OH)_(2)/BC.Material characterizations suggested that Co(OH)_(2)nanoparticle was successfully decorated on biochar,leading to more active sites and electronic structure alteration of biochar,thus greatly promoting the catalytic cleavage of PAA for radicals production.Then,the reactive oxygen species(ROS)quenching experiments and electron paramagnetic resonance(EPR)analysis demonstrated the key species were alkoxyl radicals(R–O^(·),mainly CH_(3)CO_(2)^(·)and CH_(3)CO_(3)^(·)),HO^(·)and^(1)O_(2)in this system.Besides,density functional theory(DFT)calculation on Fukui index further revealed that the vulnerable sites of TTCH and three possible degradation pathways were proposed.This study can provide a new strategy for synthesis functional materials in PAA activation AOPs for removal of antibiotics in water.

Activation of peracetic acid by metal-organic frameworks(ZIF-67)for efficient degradation of sulfachloropyridazine

Peracetic acid(PAA)-based system is becoming an emerging advanced oxidation process(AOP)for effective removal of organic contaminants from water.Various approaches have been tested to activate PAA,while no previous researches reported the application of metal-organic frameworks(MOFs)materials for PAA activation.In this study,zeolitic imidazole framework(ZIF)-67,a representative MOFs,was facile synthesized via direct-mixing method at room temperature,and tested for PAA activation and sulfachloropyridazine(SCP)degradation.The as-synthesized ZIF-67 exhibited excellent performance for PAA activation and SCP degradation with 100%of SCP degraded within 3 min,owing to the specific MOFs structure and abundant Co^(2+) sites.The pseudo-first-order kinetic model was applied to fit the kinetic data,with rate constant k_(1) of ZIF-67 activated PAA system 34.2 and 156.5 times higher than those of conventional Co_(3)O_(4)activated PAA and direct oxidation by PAA.Radical quenching experiments and electron paramagnetic resonance(EPR)analysis indicated that CH_(3)C(O)OO^(·)played a major role in this PAA activation system.Then,the Fukui index based on density functional theory(DFT)calculation was used to predict the possible reaction sites of SCP for electrophilic attack by CH_(3)C(O)OO^(·).In addition,the degradation pathway of SCP was proposed based on Fukui index values and intermediates detection,which mainly included the S-N bond cleavage and SO_(2)extrusion and followed by further oxidation,dechlorination,and hydroxylation.Therefore,ZIF-67 activated PAA is a novel strategy and holds strong potential for the removal of emerging organic contaminants(EOCs)from water.

Factors affecting production of nonaqueous peracetic acid in tubular packed reactors

The synthesis of nonaqueous peracetic acid inacetone by acetaldehyde oxidation was carried out in atubular packed reactor. The influencing factors of thereacting system including packing material, oxygen carrier,and reactor configuration were investigated. Theresults show that porous materials are inappropriate forperacetic acid synthesis and only non porous materialwith appropriate surface area can provide good peraceticacid selectivity and yield. Among the six kinds of packingmaterial investigated, SA-5118 is the best one. As oxidizinggas, pure oxygen is superior to air. The optimumlength-to-inner diameter ratio of the reactor is about 40.Under the proper reaction conditions, the highest peraceticacid yield of 84.15% and the highest selectivity of93.34% can be achieved which indicates that the novelreacting system is effective and economical for nonaqueousperacetic acid production.

Role of Disinfection in Food Industry

At present microbiological risk are still the most frequent in the food industry and the disinfection is one of the procedures that can be carried out in the general prevention of foodborne infectious diseases. In the industrial process of food transformation the cleaning and disinfection procedures of surfaces and machinery have to be considered an integrate system with food production,a technological aspect that surely affects the finished product quality and safety. First of all to carry out properly these operations it is necessary that the factory and the equipment have been designed and constructed with high standard of hygiene to reduce the risk of contamination and to facilitate the sanitation. The procedures involve several stages which generally include pre-washing with water,cleaning,real disinfection,and a final rinsing with water. In order to assure a right disinfections of surfaces areas and of processing equipment the choice of disinfectant takes on particular importance. Some of the most widely used disinfectants include the hypochlorous acid,the chlorine dioxide and the peroxides like peracetic acid; the latter is widely used in soft drink and mineral water industries. The efficiency of these chemical agents depends on various factors as pH,temperature and the presence of organic substances with which the disinfectants can react to give by-products which can reduce the activity and can present toxicity. The use of hypochlorite may led to the formation of carcinogenic substance such as trialomethanes (THM) while the use of chlorine dioxide may lead to the formation of chlorites and chlorates. The peracetic acid is a good alternative compounds and it doesn’t lead to the formation of carcinogenic by-products. In our researches we evaluated the effectiveness of peracetic acid to inactivate some resistant micro-organism like hepatitis A virus; our results show that in practical application in CIP (cleaning in place) it’s necessary to use concentration of 600～1300mg/L of peracetic acid for 15～ 30min of contact time for an inactivation >99.99%.

Sterilization and disinfection methods for decellularized matrix materials:Review,consideration and proposal

Sterilization is the process of killing all microorganisms,while disinfection is the process of killing or removing all kinds of pathogenic microorganisms except bacterial spores.Biomaterials involved in cell experiments,animal experiments,and clinical applications need to be in the aseptic state,but their physical and chemical properties as well as biological activities can be affected by sterilization or disinfection.Decellularized matrix(dECM)is the low immunogenicity material obtained by removing cells from tissues,which retains many inherent components in tissues such as proteins and proteoglycans.But there are few studies concerning the effects of sterilization or disinfection on dECM,and the systematic introduction of sterilization or disinfection for dECM is even less.Therefore,this review systematically introduces and analyzes the mechanism,advantages,disadvantages,and applications of various sterilization and disinfection methods,discusses the factors influencing the selection of sterilization and disinfection methods,summarizes the sterilization and disinfection methods for various common dECM,and finally proposes a graphical route for selecting an appropriate sterilization or disinfection method for dECM and a technical route for validating the selected method,so as to provide the reference and basis for choosing more appropriate sterilization or disinfection methods of various dECM.