Application of fuzzy model for the shelf-life determination of whole sea bass (<em>Dicentrarchus labrax</em>) under refrigerated temperatures

In this study, microbiological deterioration of whole sea bass stored at refrigerator temperatures (4°C) was determined through fuzzy modeling. Total Mesophilic Aerobic Bacteria (TMAB), Total Psychrophilic Aerobic Bacteria (TPAB), Lactic Acid Bacteria (LAB), *Pseudomonas sp*., and Enterobacteriaceae counts were observed during 12 days of storage. Quality Index Method (QIM) was used for sensory analysis of the samples and shelf life was determined according to sensory deterioration. The growth of the microorganisms was statistically significant (p\<0.05) at the end of the storage period. Additionally, significant differences (p\<0.05) were observed for QI scores after the 8^th^ day of the storage in whole sea bass stored under refrigerated conditions. A total of 12 rules were determined in the fuzzy logic application. Mamdani was used as the fuzzy type for fuzzy modeling, and centroid was used as the defuzzification method. Fuzzy membership values were computed using triangular membership functions. According to the research results, the shelf life of sea bass fish was determined as 8 days from the time of 12 days storage. As a result, it was observed that the sensory score could be determined by using Fuzzy logic (R^2^=0.96) according to microbiological parameters in sea bass stored in refrigerator conditions. In this context, it was concluded that Fuzzy logic could be used in shelf-life estimation in seafood products

Effect of aqueous ozone treatment on some quality changes of vacuum-packed meagre (<em>Argyrosomus regius</em>) fillets

In this study, microbiological, sensory and color changes in vacuum-packed meagre fillets treated with aqueous ozone for different periods of time were investigated. Meagre fillets were treated with ozone for 15 (O-15) and 30 (O-30) minutes and vacuum-packed and stored at +2 °C for 12 days. Control group (C) was not treated with ozone and stored after vacuum packaging. For microbiological changes, Total Mesophilic Aerobic Bacteria (TMAB), Pseudomonas sp., Lactic Acid Bacteria (LAB) and Total Psychrophilic Aerobic Bacteria (TPAB) counts were analyzed. At the end of storage, the highest bacterial counts were found in group C (>7.00 log cfu/g). In ozone-treated samples, Pseudomonas sp. counts did not exceed 7.00 log cfu/g only in the O-30 group. In the sensory evaluation of the samples, it was determined that the total demerit points were 18 points for group C, 16.25 points for O-15 and 14.75 points for O-30 at the end of storage over 30. No significant change was found according to the color results of the samples, but at the end of storage, it was observed that the L value of the ozone-treated samples was higher and the samples had a lighter color. In the conclusion of the results, it was observed that ozone treatment prolonged the shelf life of vacuum-packed meagre fillets for 4 days for the O-30 group compared to control and O-15 group without causing the sensory and color loss

Investigation of the acoustic and mechanical properties of homogenous and hybrid jute and luffa bio composites

Design and development of new biomaterials has become a necessity due to adverse effects of chemical materials on people and nature. As the mechanical properties of biomaterials are not as good as those of chemical materials, their different configurations should be developed and tested before considering them for practical applications. Acoustic and mechanical properties of homogenous and hybrid jute and luffa biocomposites are investigated here. Homogenous and hybrid composites using jute and luffa fibers and epoxy are designed and manufactured and methods for identification of the acoustic and mechanical properties are summarized. Acoustic and structural frequency response functions are measured using homogenous and hybrid composite plates to determine their natural frequencies and loss factors. Using the experimental modal parameters of the plates and their theoretical models, elasticity moduli of biomaterials are determined. The acoustic absorption properties and transmission losses of homogeneous and hybrid composites are determined using impedance tube method. Results show that homogenous and hybrid jute and luffa composites can have moderate absorption coefficients (0.1 for a thickness of 4 mm) and superior damping performance of luffa and stiffness property of jute can be used together to produce hybrid composites with high damping (2.2–2.6%) and elasticity modulus (3–5 GPa).TÜBİTAK, 1002, 119M115WOS:000537898700001Scopus - Affiliation ID: 60105072Science Citation Index ExpandedQ1Article; Early AccessUluslararası işbirliği ile yapılmayan - HAYIRMayıs2020YÖK - 2019-2

Jute and luffa fiber-reinforced biocomposites: Effects of sample thickness and fiber/resin ratio on sound absorption and transmission Loss Performance

The acoustic properties of natural fiber-reinforced composites should be identified before using these materials in various engineering applications including sound and vibration isolation. This study investigates the effects of sample thickness and fiber/resin ratio on the acoustic performance of jute and luffa fiber-reinforced biocomposites. For this purpose, jute and luffa composite samples with different thicknesses and fiber/epoxy ratios are manufactured and their sound absorption coefficients (SACs) and transmission losses (TLs) are determined using impedance tube method. Thickness-dependent tendencies of the SACs and TLs of jute and luffa composites for low-, medium-, and high-frequency ranges are identified. The effect of fiber/epoxy ratio on the acoustic properties of jute and luffa composites as a function of frequency are determined. Furthermore, the SACs and TLs of some natural fiber-based samples with different thicknesses are predicted using mathematical models and the theoretical and experimental results are compared and evaluated.TUBITAK (The Scientific and Technological Research Council of Turkey) under Grant 119M115.WOS:000638569100001Scopus - Affiliation ID: 60105072Science Citation Index ExpandedQ1Article; Early AccessUluslararası işbirliği ile yapılmayan - HAYIRNisan2021YÖK - 2020-2

Metabolism-dependent bioaccumulation of uranium by Rhodosporidium toruloides isolated from the flooding water of a former uranium mine

Remediation of former uranium mining sites represents one of the biggest challenges worldwide that have to be solved in this century. During the last years, the search of alternative strategies involving environmentally sustainable treatments has started. Bioremediation, the use of microorganisms to clean up polluted sites in the environment, is considered one the best alternative. By means of culture-dependent methods, we isolated an indigenous yeast strain, KS5 (Rhodosporidium toruloides), directly from the flooding water of a former uranium mining site and investigated its interactions with uranium. Our results highlight distinct adaptive mechanisms towards high uranium concentrations on the one hand, and complex interaction mechanisms on the other. The cells of the strain KS5 exhibit high a uranium tolerance, being able to grow at 6 mM, and also a high ability to accumulate this radionuclide (350 mg uranium/g dry biomass, 48 h). The removal of uranium by KS5 displays a temperature- and cell viability-dependent process, indicating that metabolic activity could be involved. By STEM (scanning transmission electron microscopy) investigations, we observed that uranium was removed by two mechanisms, active bioaccumulation and inactive biosorption. This study highlights the potential of KS5 as a representative of indigenous species within the flooding water of a former uranium mine, which may play a key role in bioremediation of uranium contaminated sites.This work was supported by the Bundesministerium für Bildung und Forschung grand nº 02NUK030F (TransAqua). Further support took place by the ERDF-co-financed Grants CGL2012-36505 and 315 CGL2014-59616R, Ministerio de Ciencia e Innovación, Spain

Ciprofloxacin, diclofenac, ibuprofen and 17α-ethinylestradiol differentially affect the activity of acetogens and methanogens in anaerobic communities

Pharmaceutical compounds end up in wastewater treatment plants but little is known on their effect towards the different microbial groups in anaerobic communities. In this work, the effect of the antibiotic Ciprooxacin (CIP), the non-steroidal anti-inammatory drugs Diclofenac (DCF) and Ibuprofen (IBP), and the hormone 17-ethinylestradiol (EE2), on the activity of acetogens and methanogens in anaerobic communities, was investigated. Microbial communities were more affected by CIP, followed by EE2, DCF and IBP, but the response of the different microbial groups was dissimilar. For concentrations of 0.01 to 0.1 mg/L, the specic methanogenic activity was not affected. Acetogenic bacteria were sensitive to CIP concentrations above 1 mg/L, while DCF and EE2 toxicity was only detected for concentrations higher than 10 mg/L, and IBP had no effect in all concentrations tested. Acetoclastic methanogens showed higher sensitivity to the presence of these micropollutants, being affect by all the tested pharmaceutical compounds although at different degrees. Hydrogenotrophic methanogens were not affected by any concentration, indicating their lower sensitivity to these compounds when compared to acetoclasts and acetogens.e Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Ana Rita Silva holds a Grant from FCT, reference SFRH/BD/131905/2017info:eu-repo/semantics/publishedVersio