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Article Citation - Scopus: 2The Effects of Paddy Cultivation and Microbiota Members on Arsenic Accumulation in Rice Grain(Mdpi, 2023) Ersoy Omeroglu, Esra; Bayer, Asli; Sudagidan, Mert; Ozalp, Veli Cengiz; Yasa, IhsanAccess to safe food is one of the most important issues. In this context, rice plays a prominent role. Because high levels of arsenic in rice grain are a potential concern for human health, in this study, we determined the amounts of arsenic in water and soil used in the rice development stage, changes in the arsC and mcrA genes using qRT-PCR, and the abundance and diversity (with metabarcoding) of the dominant microbiota. When the rice grain and husk samples were evaluated in terms of arsenic accumulation, the highest values (1.62 ppm) were obtained from areas where groundwater was used as irrigation water, whereas the lowest values (0.21 ppm) occurred in samples from the stream. It was observed that the abundance of the Comamonadaceae family and Limnohabitans genus members was at the highest level in groundwater during grain formation. As rice development progressed, arsenic accumulated in the roots, shoots, and rice grain. Although the highest arsC values were reached in the field where groundwater was used, methane production increased in areas where surface water sources were used. In order to provide arsenic-free rice consumption, the preferred soil, water source, microbiota members, rice type, and anthropogenic inputs for use on agricultural land should be evaluated rigorously.Article Citation - WoS: 29Citation - Scopus: 40Development of Electrochemical Aptasensors Detecting Phosphate Ions on Tmb Substrate With Epoxy-Based Mesoporous Silica Nanoparticles(Pergamon-elsevier Science Ltd, 2022) Altuner, Elif Esra; Ozalp, Veli Cengiz; Yilmaz, M. Deniz; Sudagidan, Mert; Aygun, Aysenur; Acar, Elif Esma; Sen, FatihThis study, it is aimed to develop an electrochemical aptasensor that can detect phosphate ions using 3.3 & PRIME;5.5 & PRIME; tetramethylbenzidine (TMB). It is based on the principle of converting the binding affinity of the target molecule phosphate ion (PO43-) into an electrochemical signal with specific aptamer sequences for the aptasensor to be developed. The aptamer structure served as a gate for the TMB to be released and was used to trap the TMB molecule in mesoporous silica nanoparticles (MSNPs). The samples for this study were characterized by transmission electron spectroscopy (TEM), Brunner-Emmet-Teller, dynamic light scattering & electrophoretic light scattering, and induction coupled plasma atomic emission spectroscopy. According to TEM analysis, MSNPs have a morphologically hexagonal structure and an average size of 208 nm. In this study, palladium-carbon nano particles (Pd/C NPs) with catalytic reaction were used as an alternative to the biologically used horseradish peroxidase (HRP) enzyme for the release of TMB in the presence of phosphate ions. The limit of detection (LOD) was calculated as 0.983 mu M, the limit of determination (LOQ) was calculated as 3.276 mu M, and the dynamic linear phosphate range was found to be 50-1000 mu M. The most important advantage of this bio-based aptasensor assembly is that it does not contain molecules such as a protein that cannot be stored for a long time at room temperature, so its shelf life is very long compared to similar systems developed with antibodies. The proposed sensor shows good recovery in phosphate ion detection and is considered to have great potential among electrochemical sensors.Article Citation - WoS: 1Citation - Scopus: 1Long-Term Intermittent Caloric Restriction Remodels the Gut Microbiota in Mice Genetically Prone To Breast Cancer(Elsevier Science inc, 2024) Keles, Nazim Arda; Dogan, Soner; Dogan, Aysenur; Sudagidan, Mert; Balci, Tugce Nur; Cetiner, Ozlem; Tuna, Bilge GuvencObjectives: Gut microbiota dysbiosis is among the risk factors for breast cancer development, together with genetic background and dietary habits. However, caloric restriction has been shown to remodel the gut microbiota and slow tumor growth. Here, we investigated whether the gut microbiota mediates the preventive effects of long-term chronic or intermittent caloric restriction on breast cancer predisposition. Methods: 10-week-old transgenic breast cancer-prone mice were randomly assigned to dietary groups (ad libitum, chronic caloric restriction, and intermittent caloric restriction groups) and fed up to week 81. Stool samples were collected at weeks 10 (baseline), 17 (young), 49 (adult), and 81 (old). 16S rRNA gene sequencing was performed to identify the gut microbiota profile of the different groups. In order to investigate the breast cancer gut microbiota profile within genetically predisposed individuals regardless of diet, mammary tumor-bearing mice and mammary tumor-free but genetically prone mice were selected from the ad libitum group (n = 6). Results: Intermittent caloric restriction increased the microbial diversity of adult mice and modified age- related compositional changes. A total of 13 genera were differentially abundant over time. Pathogenic Mycoplasma was enriched in the re-feeding period of the old intermittent caloric restriction group compared with baseline. Furthermore, mammary tumor-free mice showed shared gut microbiota characteristics with mammary tumor-bearing mice, suggesting an early link between genetic predisposition, gut microbiota, and breast cancer development. Conclusions: Our study revealed the role of gut microbes in the preventive effects of caloric restriction against breast cancer development, implying the significance of diet and microbiome interplay. (c) 2024 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.Article Citation - WoS: 16Citation - Scopus: 16Targeted mesoporous silica nanoparticles for improved inhibition of disinfectant resistant Listeria monocytogenes and lower environmental pollution(Elsevier, 2021) Sudagidan, Mert; Yildiz, Gulsah; Onen, Selin; Al, Rabia; Temiz, S. Sevval Nur; Yurt, Mediha Nur Zafer; Ozalp, Veli C.Benzalkonium chloride (BAC) is a common ingredient of disinfectants used for industrial, medical, food safety and domestic applications. It is a common pollutant detected in surface and wastewaters to induce adverse effects on Human health as well as aquatic and terrestrial life forms. Since disinfectant use is essential in combatting against microorganisms, the best approach to reduce ecotoxicity level is to restrict BAC use. We report here that encapsulation of BAC in mesoporous silica nanoparticles can provide an efficient strategy for inhibition of mi-crobial activity with lower than usual concentrations of disinfectants. As a proof-of-concept, Listeria mono-cytogenes was evaluated for minimum inhibitory concentration (MIC) of nanomaterial encapsulated BAC. Aptamer molecular gate structures provided a specific targeting of the disinfectant to Listeria cells, leading to high BAC concentrations around bacterial cells, but significantly reduced amounts in total. This strategy allowed to inhibition of BAC resistant Listeria strains with 8 times less the usual disinfectant dose. BAC encapsulated and aptamer functionalized silica nanoparticles (AptBACNP) effectively killed only target bacteria L. monocytogenes, but not the non-target cells, Staphylococcus aureus or Escherichia coli. AptBACNP was not cytotoxic to Human cells as determined by in vitro viability assays.Article Citation - WoS: 28Citation - Scopus: 30Microbial Community of Soda Lake Van as Obtained From Direct and Enriched Water, Sediment and Fish Samples(Nature Portfolio, 2021) Omeroglu, Esra Ersoy; Sudagidan, Mert; Yurt, Mediha Nur Zafer; Tasbasi, Behiye Busra; Acar, Elif Esma; Ozalp, Veli Cengiz; Ersoy Omeroglu, EsraSoda lakes are saline and alkaline ecosystems that are considered to have existed since the first geological records of the world. These lakes support the growth of ecologically and economically important microorganisms due to their unique geochemistry. Microbiota members of lakes are valuable models to study the link between community structure and abiotic parameters such as pH and salinity. Lake Van is the largest endroheic lake and in this study, bacterial diversity of lake water, sediment, and pearl mullet (inci kefali; Alburnus tarichi), an endemic species of fish which are collected from different points of the lake, are studied directly and investigated meticulously using a metabarcoding approach after pre-enrichment. Bacterial community structures were identified using Next Generation Sequencing of the 16S rRNA gene. The analysis revealed that the samples of Lake Van contain high level of bacterial diversity. Direct water samples were dominated by Proteobacteria, Cyanobacteria, and Bacteroidota, on the other hand, pre-enriched water samples were dominated by Proteobacteria and Firmicutes at phylum-level. In direct sediment samples Proteobacteria, whereas in pre-enriched sediment samples Firmicutes and Proteobacteria were determined at highest level. Pre-enriched fish samples were dominated by Proteobacteria and Firmicutes at phylum-level. In this study, microbiota members of Lake Van were identified by taxonomic analysis.Article Citation - WoS: 24Citation - Scopus: 26Identification of Bacterial Communities of Fermented Cereal Beverage Boza by Metagenomic Analysis(Elsevier, 2022) Ucak, Samet; Yurt, Mediha Nur Zafer; Tasbasi, Behiye Busra; Acar, Elif Esma; Altunbas, Osman; Soyucok, Ali; Sudagidan, MertBacterial microbiota of directly studied and pre-enriched Boza samples were investigated by metagenomic analysis. Virulence gene contents, biofilm formation, antibiotic susceptibility and clonal relationships of enterococci present in pre-enriched Boza samples were determined. Chemical properties of the samples were also investigated. Although directly studied samples showed a dominance by Lactococcus, Lactobacillus, Leuconostoc, and Streptococcus. NGS upon pre-enrichment of the same Boza samples demonstrated a dominance by Lactococcus, Enterococcus, Escherichia/Shigella, Bacillus, and Lactobacillus. All enterococci were identified as Enterococcus faecium and none of them was positive for vanA, vanB, vanC1, vanD, vanE, vanG, agg, gelE, efaAfs, cylA, ace, hyl, cob, cylB, and cylM genes. However, efaAfm, ccf, cpd, and esp genes were detected in the strains. Only one strain formed biofilm and seven strains showed low adherence. E. faecium strains were resistant to rifampin and erythromycin. PFGE revealed 54-100% clonal relationships of E. faecium strains. Percent acidity of Boza samples were 0.14%-0.51%, pH was 3.00-4.07, protein content was 0.35-1.23 mg/100 mg, total sugar content was 9.64-19.21 mg/100 mg Boza, crude ash content was 0.05-0.18 mg/100 mg dry sample, total dry matter was 13.79-28.04 mg/100 mg. Our results indicate to importance of the dynamics nature of microbial communities involved in Boza fermentation and virulence properties of enterococci.Article Citation - WoS: 3Citation - Scopus: 2Targeted Multidrug Delivery Systems To Kill Antibiotic-Resistant Staphylococcus Aureus(Elsevier, 2023) Ozalp, Veli Cengiz; Ucak, Samet; Dursun, Ali D.; Sudagidan, Mert; Icin, Oyku; Vakifahmetoglu, Cekdar; Gurlo, AleksanderDifferent ordered mesoporous silica (OMS) nanoparticles, ranging from regular COK-12 to COK-12 modified in terms of pore shape and size, have been employed as standard drug carriers for the controlled adsorption and release of drug molecules in comparison to well-known OMS SBA-15 and MCM-41. The cytotoxicity analysis demonstrated that regular COK-12 particles were less harmful to mammalian cultured cells, causing lower apoptosis induction than modified COK-12, MCM-41, and SBA-15 particles.Thus, regular COK-12 was further used to prepare a dual antibiotic-loaded drug delivery material, followed by surface functionalization with Staphylococcus aureus-specific aptamers for targeting. The results demonstrated that the joint loading of lysozyme and vancomycin in regular COK-12 improved the ability of the antibiotic treatments to kill methicillin-resistant Staphylococcus strains via aptamer targeting. The minimum inhibitory concentration (MIC) values decreased 4.1-fold and 12-fold compared to the non-targeted use of the antimicrobial agents in homogeneous solutions for vancomycin and lysozyme, respectively, clearly demonstrating the high potential of COK-12 to be used as a carrier in multidrug therapy.Article Citation - WoS: 8Citation - Scopus: 8Bacterial Skin Microbiota of Seabass From Aegean Fish Farms and Antibiotic Susceptibility of Psychrotrophic pseudomonas(Mdpi, 2023) Aydin, Ali; Sudagidan, Mert; Mamatova, Zhanylbubu; Yurt, Mediha Nur Zafer; Ozalp, Veli Cengiz; Zornu, Jacob; Brun, EdgarFarming seabass (Dicentrarchus labrax) is an essential activity in the Mediterranean basin including the Aegean Sea. The main seabass producer is Turkey accounting for 155,151 tons of production in 2021. In this study, skin swabs of seabass farmed in the Aegean Sea were analysed with regard to the isolation and identification of Pseudomonas. Bacterial microbiota of skin samples (n = 96) from 12 fish farms were investigated using next-generation sequencing (NGS) and metabarcoding analysis. The results demonstrated that Proteobacteria was the dominant bacterial phylum in all samples. At the species level, Pseudomonas lundensis was identified in all samples. Pseudomonas, Shewanella, and Flavobacterium were identified using conventional methods and a total of 46 viable (48% of all NGS+) Pseudomonas were isolated in seabass swab samples. Additionally, antibiotic susceptibility was determined according to standards of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and Clinical and Laboratory Standards Institute (CLSI) in psychrotrophic Pseudomonas. Pseudomonas strains were tested for susceptibility to 11 antibiotics (piperacillin-tazobactam, gentamicin, tobramycin, amikacin, doripenem, meropenem, imipenem, levofloxacin, ciprofloxacin, norfloxacin, and tetracycline) from five different groups of antibiotics (penicillins, aminoglycosides, carbapenems, fluoroquinolones, and tetracyclines). The antibiotics chosen were not specifically linked to usage by the aquaculture industry. According to the EUCAST and CLSI, three and two Pseudomonas strains were found to be resistant to doripenem and imipenem (E-test), respectively. All strains were susceptible to piperacillin-tazobactam, amikacin, levofloxacin, and tetracycline. Our data provide insight into different bacteria that are prevalent in the skin microbiota of seabass sampled from the Aegean Sea in Turkey, and into the antibiotic resistance of psychrotrophic Pseudomonas spp.
