Proliferation Of Microorganisms Research Articles

Nanoarchitectonics of Bactericidal Coatings Based on CaCO3-Nanosilver Hybrids.

Antimicrobial coatings provide protection against microbes colonization on surfaces. This can prevent the stabilization and proliferation of microorganisms. The ever-increasing levels of microbial resistance to antimicrobials are urging the development of alternative types of compounds that are potent across broad spectra of microorganisms and target different pathways. This will help to slow down the development of resistance and ideally halt it. The development of composite antimicrobial coatings (CACs) that can host and protect various antimicrobial agents and release them on demand is an approach to address this urgent need. In this work, new CACs based on microsized hybrids of calcium carbonate (CaCO3) and silver nanoparticles (AgNPs) were designed using a drop-casting technique. Polyvinylpyrrolidone and mucin were used as additives. The CaCO3/AgNPs hybrids contributed to endowing colloidal stability to the AgNPs and controlling their release, thereby ensuring the antibacterial activity of the coatings. Moreover, the additives PVP and mucin served as a matrix to (i) control the distribution of the hybrids, (ii) ensure mechanical integrity, and (iii) prevent the undesired release of AgNPs. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) techniques were used to characterize the 15 μm thick CAC. The antibacterial activity was determined against Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA), and Pseudomonas aeruginosa, three bacteria responsible for many healthcare infections. Antibacterial performance of the hybrids was demonstrated at concentrations between 15 and 30 μg/cm2. Unloaded CaCO3 also presented bactericidal properties against MRSA. In vitro cytotoxicity tests demonstrated that the hybrids at bactericidal concentrations did not affect human dermal fibroblasts and human mesenchymal stem cell viability. In conclusion, this work presents a simple approach for the design and testing of advanced multicomponent and functional antimicrobial coatings that can protect active agents and release them on demand.

Developmental Formulation Principles of Food Preservatives by Nanoencapsulation-Fundamentals, Application, and Challenges.

The role of food additives is to preserve food by extending shelf life and limiting harmful microorganism proliferation. They prevent spoilage by enhancing the taste and safety of food by utilizing beneficial microorganisms and their antimicrobial metabolites. Current advances in food preservation and processing utilize green technology principles for green preservative formulation, enhancing nutrition and supplying essential micronutrients safely, while also improving quality, packaging, and food safety. Encapsulation is gaining attention for its potential to protect delicate materials from oxidative degradation and extend their shelf life, thereby ensuring optimal nutrient uptake. Nanoencapsulation of bioactive compounds has significantly improved the food, pharmaceutical, agriculture, and nutraceutical industries by protecting antioxidants, vitamins, minerals, and essential fatty acids by controlling release and ensuring delivery to specific sites in the human body. This emerging area is crucial for future industrial production, improving the sensory properties of foods like color, taste, and texture. Research on encapsulated bioactive compounds like bacteriocins, LAB, natamycin, polylysine, and bacteriophage is crucial for their potential antioxidant and antimicrobial activities in food applications and the food industry. This paper reviews nanomaterials used as food antimicrobial carriers, including nanoemulsions, nanoliposomes, nanoparticles, and nanofibers, to protect natural food antimicrobials from degradation and improve antimicrobial activity. This review discusses nanoencapsulation techniques for biopreservative agents like nisin, poly lysine, and natamycin, focusing on biologically-derived polymeric nanofibers, nanocarriers, nanoliposomes, and polymer-stabilized metallic nanoparticles. Nanomaterials, in general, improve the dispersibility, stability, and availability of bioactive substances, and this study discusses the controlled release of nanoencapsulated biopreservative agents.

Unraveling the effects and mechanisms of microplastics on anaerobic fermentation: Exploring microbial communities and metabolic pathways

To investigate the effects of microplastics (MPs) on hydrolysis, acidification and microbial characteristics during waste activated sludge (WAS) anaerobic fermentation process, five different kinds of MPs were added into the WAS fermentation system and results indicated that, compared to the control group, the addition of polyvinyl chloride (PVC)-MPs exhibited the least inhibition on volatile fatty acids (VFAs), reducing them by 13.49 %. Conversely, polyethylene (PE)-MPs resulted in the greatest inhibition, with a reduction of 29.57 %. MPs, while accelerated the dissolution of WAS that evidenced by an increase of lactate dehydrogenase (LDH) release, concurrently inhibited the activities of relevant hydrolytic enzymes (α-Glucosidase, protease). For microbial mechanisms, MPs addition affected the proliferation of key microorganisms (norank_f_Bacteroidetes_vadinHA17, Ottowia, and Propioniclava) and reduced the abundance of genes associated with hydrolysis and acidification (pfkb, gpmI, ilvE, and aces). Additionally, MPs decreased the levels of key hydrolytic and acidogenic enzymes to inhibit hydrolysis and acidification processes. This research provides a basis for understanding and unveils impact mechanisms of the impact of MPs on sludge anaerobic fermentation.

Carbon-ferrous-sulfur mixotrophic denitrification driven by polyferric sulfate (PFS)-conditioned recovered sludge fermentation liquor enhanced nitrogen removal in woolen wastewater

Reducing pollution and carbon emissions synergistically in wastewater treatment is an important part of carbon neutralization. Recycling carbon sources (CSs) in sludge to refeed denitrification has been considered a promising sustainable pathway, but it is limited by CSs purification and recovery. This study evaluated the effects of polyferric sulfate (PFS), polyaluminum chloride (PAC), and polyacrylamide (PAM) conditioning on fermentation CSs recovery and denitrification efficiency. Results indicated PFS-conditioned recovered fermentation liquor showed higher denitrification efficiency for woolen wastewater. CSs recovery test showed that PFS conditioning improved the purity of high-bioavailability CSs by depleting fewer short-chain fatty acids (SCFAs) and removing more total nitrogen (TN), total phosphorus (TP), and humic acids. Under the 0.05 g/gTSS PFS conditioning and recovery, the preservation of soluble chemical oxygen demand (SCOD) and SCFAs were 71.00 % and 84.36 %, respectively, and the nitrate degradation rate achieved 3.19 mgNO3−·h−1·gVSS−1. Importantly, Fe(III) dissociated from PFS oxidized the S2− from woolen wastewater, and generated Fe(II) and S0, which composed a synergistic electron donor system together with SCFAs. They constituted a mixotrophic denitrification dominated by heterotrophic denitrification and reinforced by ferrous and sulfur-autotrophic denitrifications, which contributed 69.56, 17.72, and 12.72 % to nitrogen removal, respectively. In addition, the refeeding of PFS-conditioned recovered fermentation liquor promoted the proliferation of microorganisms involved in iron/sulfur autotrophic denitrification and the abundance of denitrification functional genes, especially the napA, nirS, cnorB, qnorB, and nosZ, forming an efficient Carbon-Ferrous-Sulfur hybrid denitrifiers community to enhanced nitrogen removal from woolen wastewater.

The survival, gene expression, and DNA methylation of Paralichthys olivaceus impacted by the decay of green tide and bacterial infection in both laboratory and field simulation experiments

The recurring appearance of Ulva prolifera green tides has become a pressing environmental issue, especially for marine transportation, tourism, and aquaculture in the stage of decomposition. An abundance of decaying U. prolifera leads to water acidification, hypoxia and pathogenic microorganism proliferation, threatening marine germplasm resources, particularly benthic organisms with weak escape ability. Epigenetic modification is considered to be one of the molecular mechanisms involved in the plastic adaptive response to environmental changes. However, few studies concerning the specific impact of decaying green tide on benthic animals at the epigenetic level. In this study, decomposing algal effluents of U. prolifera, sediments containing uncorrupted U. prolifera, pathogenic microorganism were considered as impact factors, to reveal the effect of decaying U. prolifera on marine economic benthic species, Paralichthys olivaceus, using both field and laboratory simulation experiments. Field simulation experiment showed higher mortality rates and serious histopathological damage than the laboratory simulation experiment. And both the decaying U. prolifera and the sediment containing U. prolifera were harmful to P. olivaceus. Genome-wide DNA methylation and transcription correlation analyses showed that the response of P. olivaceus to green tide stress and bacterial infection was mainly mediated by immune signaling pathways such as PI3K-Akt signaling pathway. DNA methylation regulates the expression of immune-related genes involved in the PI3K-Akt signaling pathway, which enables P. olivaceus to adapt to the adverse environmental stresses by resisting apoptosis. In summary, this research analyzed the potential role of P. olivaceus in decaying U. prolifera, which is of great significance for understanding the impact of decaying green tide on marine commercial fish and also provides some theoretical guidance for the proliferation and release of fish seedlings.

Oxygen vacancies rich polyoxometalate for haloperoxidase mimic involved antibiofouling on self-provided H2O2 from photocatalysis

Biofouling significantly impacts marine environments and economies through pollution and economic loss. Artificial nanozymes, resembling haloperoxidase, are highly effective in combating biofouling due to their ability to facilitate the conversion of Br− to HBrO, thereby inhibiting the survival and proliferation of microorganisms. However, this process necessitates the presence of H2O2. To achieve haloperoxidase mimicry in biofouling prevention without external H2O2, a bifunctional polyoxometalate (POM) with abundant oxygen vacancies has been developed. This compound simultaneously exhibits haloperoxidase mimicry and photocatalytic H2O2 generation. Theoretical analyses suggest that oxygen vacancies elevate the d-band center, improving the adsorption of H2O2 and Br-, and thus enhancing haloperoxidase mimicry. The POM compound demonstrates notable H2O2 production capabilities, with a rate of 1.77 mmol·h−1·g−1, attributed to oxygen vacancies facilitating electron-hole pair separation. This advancement allows for haloperoxidase mimic biofouling prevention without the need for added H2O2. This study not only elucidates the structure–activity relationship in haloperoxidase mimicry and photocatalytic H2O2 production but also presents an effective and eco-friendly method for biofouling prevention.

LAB Antagonistic Activities and Their Significance in Food Biotechnology: Molecular Mechanisms, Food Targets, and Other Related Traits of Interest

The ongoing occurrence of foodborne diseases and the imperative need for efficient spoilage and pathogen control in food products constitute a critical challenge for the food industry. The rising demands of consumers for safe, healthy, and clean-label food products have led to an increased interest in natural antimicrobial alternatives. Lactic acid bacteria (LAB) have proven their value in the food industry in recent years, also in reason of their antagonistic properties against undesired microbes and their significant related protechnological attributes. The natural antimicrobial compounds produced by LAB exhibit inhibitory effects on pathogens and effectively inhibit the activities of food spoilage-related organisms. Applying secondary metabolites of LAB, notably bacteriocins, organic acids, and others, has found commercial utility across multiple food sectors, effectively preventing the proliferation of undesirable microorganisms and simultaneously enhancing the sensory properties and overall quality of various food products. This review comprehensively explores the natural microbial compounds produced by LAB, specifically focusing on their antimicrobial action in supporting effective and sustainable microbial management. Additionally, it highlights their strategic application across various technological contexts within the food industry.

Effect of fermentation agents on the pH, tta and microbial composition of <i>Fufu</i> dough

Fufu, a product of cassava has been adulterated by processors. They add toxic substances to the soaked roots to fasten the fermentation days and make quick money. There is need to evaluate the effect of these fermentation agents on the microbial, pH and total titratable acidity (TTA) of the fufu dough. Fufu dough was produced with fermentation agents; kerosene, detergent and palm ash and also with a control without agent. They were wrapped in polyethylene bags, stored at ambient temperature and evaluated for storage and microbial quality in the Biochemistry Laboratory of National Root Crops Research Institute, Umudike, Nigeria. These samples were assayed for chemical and microbial qualities which include pH and TTA. The results showed that the pH values ranged from 3.70 - 6.80, and Total Titratable Acidity (TTA) values ranged from 0.004 - 0.048 %. The microbial analysis showed increase in fungal (2.1×108 (cfu/g)) and bacterial (1.0 ×106 (cfu/g)) counts as the storage time increased with the control having the least microbial load. The fungal isolates from the samples are Aspergillus niger, Aspergillus flavus and Penicillium spp, while the bacteria isolates from the samples include Bacillus spp and Staphylococcus aureus. Statistically, there were significant differences (p<0.05) in appearance of the fufu as storage time increased. The results from this study showed that the fufu with fermenting agents had higher microbial load than the control. It therefore encourages healthy practices among the fufu producers by stopping the use of fermenting agents to reduce the proliferation of pathogenic microorganisms in processed fufu.

The potential of EGCG in modulating the oral-gut axis microbiota for treating inflammatory bowel disease

Inflammatory bowel disease (IBD) is a recurrent chronic intestinal disorder that includes ulcerative colitis (UC) and Crohn's disease (CD). Its pathogenesis involves intricate interactions between pathogenic microorganisms, native intestinal microorganisms, and the intestinal immune system via the oral-gut axis. The strong correlation observed between oral diseases and IBD indicates the potential involvement of oral pathogenic microorganisms in IBD development. Consequently, therapeutic strategies targeting the proliferation, translocation, intestinal colonization and exacerbated intestinal inflammation of oral microorganisms within the oral-gut axis may partially alleviate IBD. Tea consumption has been identified as a contributing factor in reducing IBD, with epigallocatechin gallate (EGCG) being the primary bioactive compound used for IBD treatment. However, the precise mechanism by which EGCG mediates microbial crosstalk within the oral-gut axis remains unclear. In this review, we provide a comprehensive overview of the diverse oral microorganisms implicated in the pathogenesis of IBD and elucidate their colonization pathways and mechanisms. Subsequently, we investigated the antibacterial properties of EGCG and its potential to attenuate microbial translocation and colonization in the gut, emphasizing its role in attenuating exacerbations of IBD. We also elucidated the toxic and side effects of EGCG. Finally, we discuss current strategies for enhancing EGCG bioavailability and propose novel multi-targeted nano-delivery systems for the more efficacious management of IBD. This review elucidates the role and feasibility of EGCG-mediated modulation of the oral-gut axis microbiota in the management of IBD, contributing to a better understanding of the mechanism of action of EGCG in the treatment of IBD and the development of prospective treatment strategies.

The study on the development of the composition of chewable lozenges with probiotic properties. 1. Substantiation of the active substance

In recent times, a new understanding of the concept of probiotics has emerged – the use of their metabolites instead of living cells of microorganisms. They can both inhibit the development of pathogenic bacteria and effectively stimulate the reproduction of indigenous microflora. It is possible that metabiotics will be more effective than traditional live probiotics. Taking into account the prospects of new-generation probiotic drugs and the rapid growth of interest of pharmaceutical market entities in such a new dosage form as lozenges, we have proposed to create chewable lozenges containing Lactobacillus exometabolites, which pharmacological action is aimed at preventing and treating an imbalance of the oral cavity microflora.Aim. To theoretically and experimentally substantiate the choice of the exometabolite complex of lactobacilli as the active substance of a medicinal product with probiotic properties in the form of chewable lozenges.Materials and methods. The exometabolite complex of the Lactobacillus plantarum UCM-2693 strain was used as the study object. Acidity, the lactic acid content, the optical density of a microbial suspension, as well as the quantitative count of lactobacilli were determined in accordance with the generally accepted methods specified in the State Pharmacopoeia of Ukraine (SPhU).Results and discussion. The bacteriotropic effect of the exometabolite complex of L. plantarum UCM-2693 was detected on lactobacilli of the probiotic drug “Lactobacterin-Biopharma” when cultured on a medium with exometabolites compared to the control sample. This technique has a stimulating effect on the acid formation, proliferation of probiotic microorganisms, changes the characteristics of their growth phases, namely reduces the lag phase, accelerates the exponential phase, which can accelerate the onset of the therapeutic effect, and is the proof of the feasibility of using this active substance in the composition of chewable lozenges with probiotic properties.Conclusions. The choice of the exometabolite complex of lactobacilli as the active substance of a new drug from the group of metabiotics in the form of chewable lozenges has been substantiated. The exometabolite complex of lactobacilli has been obtained, and its bacteriotropic effect has been studied.

Synergizing biotechnology and natural farming: pioneering agricultural sustainability through innovative interventions.

The world has undergone a remarkable transformation from the era of famines to an age of global food production that caters to an exponentially growing population. This transformation has been made possible by significant agricultural revolutions, marked by the intensification of agriculture through the infusion of mechanical, industrial, and economic inputs. However, this rapid advancement in agriculture has also brought about the proliferation of agricultural inputs such as pesticides, fertilizers, and irrigation, which have given rise to long-term environmental crises. Over the past two decades, we have witnessed a concerning plateau in crop production, the loss of arable land, and dramatic shifts in climatic conditions. These challenges have underscored the urgent need to protect our global commons, particularly the environment, through a participatory approach that involves countries worldwide, regardless of their developmental status. To achieve the goal of sustainability in agriculture, it is imperative to adopt multidisciplinary approaches that integrate fields such as biology, engineering, chemistry, economics, and community development. One noteworthy initiative in this regard is Zero Budget Natural Farming, which highlights the significance of leveraging the synergistic effects of both plant and animal products to enhance crop establishment, build soil fertility, and promote the proliferation of beneficial microorganisms. The ultimate aim is to create self-sustainable agro-ecosystems. This review advocates for the incorporation of biotechnological tools in natural farming to expedite the dynamism of such systems in an eco-friendly manner. By harnessing the power of biotechnology, we can increase the productivity of agro-ecology and generate abundant supplies of food, feed, fiber, and nutraceuticals to meet the needs of our ever-expanding global population.

Controlled delivery of mupirocin using chitosan films with silver nanoparticles

Wound healing remains a challenge due to the proliferation of resistant microorganisms caused by burns, chronic illnesses, trauma, and post-surgery wounds. One treatment option is the use of topical antibiotics, such as mupirocin. To this end, we developed polymeric hydrogel films composed of chitosan cross-linked with epichlorohydrin and containing silver nanoparticles. These films serve as a matrix for the controlled delivery of mupirocin. The obtained results indicate that the films are promising for the development of controlled delivery systems for mupirocin. They exhibited favorable permeation kinetics, swelling capacity, uniformity, and antibacterial activity. However, of the films studied, the one containing silver nanoparticles obtained using sodium borohydride showed the best results in terms of antibacterial activity. Therefore, it has greater clinical potential for wound healing.

Self-supporting noncovalent Choline Alginate/Tannic acid/Ag antibacterial films for strawberry preservation

Packaging materials with peculiar antibacterial properties can shield off and inhibit microorganism proliferation, thus achieving packaging goals such as fresh-keeping, good hygiene, and biosafety. Especially, antibacterial films made of biocompatible substances have received wide attentions, which could effectively extend the shelf life, enhance food security, and guarantee economic benefits. Herein, a self-supporting hybrid antibacterial film was prepared based on non-covalently linked choline hydroxide (ChOH) and alginic acid (HAlg). Then tannic acid (TA) and silver ions were added to improve the mechanical and antimicrobial properties of this hybrid film. The rich hydroxyl groups from TA not only form multiple hydrogen bonds with ChAlg, but can also in situ reduce silver ions to silver nanoparticles, which were confirmed with various characterizations. In addition, the quantitative antibacterial test proved that the antibacterial rate was significantly improved after adding silver ions, reaching >60 %. In an actual storage test, we found that choline cation (Ch+) captured in antibacterial film by electrostatic interaction could achieve sustained release, i.e. sustainable bacteriostasis, and keep strawberries fresh for 48 h at room temperature. This work offers a new strategy for preparing antibacterial films via non-covalent weak interactions, explored an alternative antibacterial film for food packaging applications.

Microbiome analysis of the restricted bacteria in radioactive element-containing water at the Fukushima Daiichi Nuclear Power Station.

In the context of nuclear power station decommissioning, the proliferation of microorganisms within the reactor and piping systems constitutes a formidable challenge. Therefore, the identification of microbial communities in such environments is of paramount importance. In the aftermath of the Fukushima Daiichi Nuclear Power Station accident, microbial community analysis was conducted on environmental samples collected mainly outside the site. However, analyses using samples from on-site areas, including adjacent soil and seawater, were not performed. This study represents the first comprehensive analysis of microbial communities, utilizing meta 16S amplicon sequencing, with a focus on environmental samples collected from the radioactive element-containing water in the torus room, including the surrounding environments. Some of the identified microbial genera are shared with those previously identified in spent nuclear fuel pools in countries such as France and Brazil. Moreover, our discussion in this paper elucidates the correlation of many of these bacteria with metal corrosion.

The potential effects of N-Acyl homoserine lactones on aerobic sludge granulation during phenolic wastewater treatment

The formation of aerobic granular sludge (AGS) is relatively difficult during the treatment of refractory wastewater, which generally shows small granular sizes and poor stability. The formation of AGS is regulated by N-Acyl homoserine lactones (AHLs)-mediated quorum sensing (QS). However, the potential role of AHLs in AGS formation under the toxic stress of refractory pollutants and the heterogeneity in the distribution and function of AHLs across different aggregates are not well understood. This study investigated the potential effects of AHLs on the formation of AGS during phenolic wastewater treatment. The distribution and succession of AHLs across varying granular sizes and development stages of AGS were investigated. Results showed that AGS was successfully formed in 13 days with an average granular size of 335 ± 39 μm and phenol removal efficiency of >99%. The levels of AHLs initially increased and then decreased. C4-HSL and 3-oxo-C10-HSL were enriched in large granules, suggesting they may play a pivotal role in regulating the concentration and composition of extracellular polymeric substances (EPS). The content of EPS constantly increased to 149.4 mg/gVSS, and protein (PN) was enriched in small and large granules. Luteococcus was the dominant genus constituting up to 62% after the granulation process, and exhibited a strong association with C4-HSL. AHLs might also regulate the bacterial community responsible for EPS production, and pollutant removal, and facilitate the proliferation of slow-growing microorganisms, thereby enhancing the formation of AGS. The synthesis and dynamics of AHLs were mainly governed by AHLs-producing bacterial strains of Rhodobacter and Pseudomonas, and AHLs-quenching strains of Flavobacterium and Comamonas. C4-HSL and 3-oxo-C10-HSL might be the major contributors to promoting sludge granulation under phenol stress and play critical roles in large granules. These findings enhance our understanding of the roles that AHLs play in sludge granulation under toxic conditions.

Effects of UV/H2O2 degradation on Moringa oleifera Lam. leaves polysaccharides: Composition, in vitro fermentation and prebiotic properties on gut microorganisms

Moringa oleifera Lam. leaves are a new raw food material rich in polysaccharides. These polysaccharides exhibit various biological properties, including antioxidant, hypoglycemic and immunoregulatory effects. However, the use of Moringa oleifera Lam. leaves polysaccharides (MOLP) may be limited by their large molecular weight (MW) and presence of numerous impurities, such as pigments. Research has indicated that degraded polysaccharides usually exhibit high biological activity because of changes in physical structure and chemical properties. In this study, we focused on the extraction of a degraded-modified fraction from MOLP using the Ultraviolet/ Hydrogen peroxide (UV/H2O2) method. Specifically, the physicochemical properties and glycosidic bond composition of a particular fraction (UV/H2O2 degraded Moringa oleifera Lam. leaves polysaccharides in 3 h called DMOLP-3) were investigated. In addition, in vitro simulated digestion experiments showed that DMOLP-3 was only partially degraded during gastrointestinal digestion, indicating that DMOLP-3 can be utilised by gut microorganisms. Furthermore, the prebiotic properties of MOLP and DMOLP-3 was studied using an in vitro faecal fermentation model. The results indicated that compared with MOLP, DMOLP-3 led to a decrease in both the colour and MW of the polysaccharides. In addition, this model exhibited enhanced solubility and antioxidant capabilities while also influencing the surface morphology. Moreover, DMOLP-3 can facilitate the proliferation of advantageous microorganisms and enhance the synthesis of short-chain fatty acids (SCFAs). These results provide valuable insights into the utilization of bioactive components in Moringa oleifera Lam. leaves for the intestinal health.

Dissolved organic nitrogen is a key to improving the biological treatment potential of landfill leachate

Biological treatment is one of the most promising efficient, low-carbon and affordable approaches for the treatment of recalcitrantly degradable wastewater, such as landfill leachate. However, even the macroscopic molecular level analysis of dissolved organic matter (DOM) is limiting to the enhancement of biological treatment efficacy, and there is an urgent need for deeper exploration of DOM to gain insights into the key constraining substances. In the present study targeting at piercing leachate organic at molecular level, nitrogen-containing dissolved organic matter (DOMN) was identified to be the bottleneck that govern the biotreatment potential. The conclusion was made based on two series of experiments that compared the same anoxic-aerobic membrane bioreactor process (A process) operated stably at different regions, and compared with C process that coupling A process with a circulation aeration membrane bioreactor to improve aeration efficiency. The results confirmed that the relative abundance of DOMN was absolutely dominant among the three categories of DOM in all biologically treated samples, contributing to 60.36 %–65.81 % in removed-DOM, 60.33 %–70.95 % in refractory-DOM and 63.14 %–71.36 % in derived-DOM. Specifically, the high latitude A process had much lower DOMN removal rate than the low latitude A process (p < 0.05) and much higher refractory and derivatization rates than the low latitude A process (p < 0.05). DOM had similar results. No statistically significant differences were observed in the proportion of the three categories of DOM (DOMN), the elements composition, and the subcategory composition of the C process compared to the A process, in which the DOM (DOMN) derivation rate of NEC1-C (31.92 % and 33.41 %) was much higher than that of NEC1-A (20.88 % and 22.19 %). However, the AIwa and AImodwa of the derived-DOM (DOMN) were significantly higher in the C process than in the A process, which implied that excessive aeration did not enhance the biological treatment potential of the A process, but instead led to the proliferation of microorganisms and the secretion of extracellular polymer substances, which resulted in the derivation of more complex compounds. The results of the correlation analysis indicated that there were some regional differences in the molecular information of DOMN driven by climate temperature. In addition, it was worth mentioning that the nominal oxidation state of carbon (NOSCwa) of derived-DOMN in different regions of A process was noticeably higher than the corresponding DOM (p < 0.0001), implying that the derived-DOMN were still highly biodegradable, in other words, there was still great room for improving the biological treatment potential of landfill leachate. The present study provided a deeper insight and analysis of landfill leachate at the molecular level (DOMN) through multiple practical engineering cases, with a view to providing a theoretical basis for efficient optimization of biological treatment.

Experimental analysis on Solar Drying of Tomatoes and Cucumbers using PV/T Hybrid Solar Air Dryer

Drying is a method for removing moisture from food that is frequently used for storage and preservation. The most important goods in the agriculture industry are fruits and vegetables. Because of its extremely high nutritional value, it needs to be kept. The best way to maintain a food's nutritional worth is to keep it fresh. There are numerous ways to preserve this food, but nut drying is the most popular because it lengthens the item's shelf life. These items can contain up to and sometimes even more than 90% moisture. The key contributing factor to the proliferation of microorganisms that cause putrefaction is thought to be water content. This study compares the effectiveness of solar drying versus sun drying for drying fruits and vegetables. Rate of drying, weight. The experiments were carried out on tomatoes and cucumbers. The collector is inclined at 45° with horizontal and oriented in South – North direction with drying time of 5 hrs per day. During experimentation 5 temperatures, absolute humidity, air velocity and solar intensity were measured hourly in the month of March and April, 2023 for drying of tomatoes and cucumber slices. The hot air was transferred through the pipes to the chamber to dry the tomatoes and cucumber slices. The drying of tomatoes and cucumbers are reached around 90% with half of the time compared to conventional drying.

Effect of drying type on the physicochemical and phytochemical properties of young and mature Moringa oleifera leaves

Biochemical differences in response to dehydration methods in Moringa oleifera leaves were studied in moringa young and mature leaves. Sun drying, oven drying and Shade-drying were applied to leaves samples. After drying, leaves were powdered and subjected to physicochemical and phytochemical analyses. The results showed a lower concentration of physicochemical components in shade-dried moringa leaves excepted moisture content. However, shade-dried M. oleifera leaves showed higher phytochemical components than sun and Oven-drying leaves without significant difference (p˂ 0.05) between young and mature leaves. Furthermore, shade-dried drying leaves had better antioxidant activity (IC50 = 0.072 mg / ml for mature leaves and IC50 = 0.049 mg / ml for young leaves) than sun and oven-dried leaves. The shade-dried technique would be therefore the most recommended for preserving physicochemical and phytochemical quality. However, the higher moisture content of shade dried leaves could be a source of micro-organism proliferation when the powders are stored.

Edible antimicrobial yeast-based coating with basil essential oil for enhanced food safety

Foodborne pathogen contamination is recognized as a critical public health burden. The application of conventional antimicrobial strategies is significantly restricted in the food industry due to concerns over potential impacts on food quality and human health safety. Herein, this study developed a scalable methodology for encapsulating basil essential oil (BO) into yeast cell wall particles (YCWPs), creating edible antimicrobial coating suspensions for effective pathogen control on real food matrices. Thermal stability and long-term durability of the antimicrobial BO were enhanced after being encapsulated into the YCWPs, which served as a protective barrier, reducing the evaporation of small molecules in the BO mixture. In addition, benefiting from the specific affinity between the YCWP microcarriers and pathogens, the encapsulated BO with a high local concentration around the pathogens could avoid the unexpected consumption caused by organic pollutants encountered in the food system. The obtained BO@YCWPs demonstrated promising antimicrobial efficiency, even under high chemical oxygen demand (COD) conditions, achieving approximately 6 log CFU reductions of S. aureus and E. coli within 30 and 15 min, respectively. Moreover, the antimicrobial BO@YCWPs were suspended in an aqueous solution and then spray-coated onto the fresh basil leaves, significantly inhibiting the proliferation of various microorganisms and demonstrating the great potential application of the BO@YCWPs in ensuring food safety.