Meral Birbir - Academia.edu (original) (raw)

Papers by Meral Birbir

Journal of The Society of Leather Technologists and Chemists, 2007

The Kaldmm and Kayacik Salterns of Tuz Lake in Central Anatolia are the main salt sources of Turk... more The Kaldmm and Kayacik Salterns of Tuz Lake in Central Anatolia are the main salt sources of Turkey. 55% of the salt requirements of Turkey is supplied from these salterns. 492 000 and 620 000 tons of salt were produced from Kaldmm and Kayacik Salterns in 2004, respectively. Crude salt extracted from these salt sources is commonly used in hide preservation. Lipolytic extremely halophilic Archaea found in the salt may reduce hide quality. Therefore, a microbial survey was conducted to examine lipolytic activities of the strains isolated from Kaldmm and Kayacik Salterns and determine whether or not halocins which were produced by the strains of Kaldinm and Kayacik Salterns may be used to inhibit lipolytic haloarchaeal strains in brine solutions. The levels of lipase producer strains in the both salterns was found to be almost similar. 39% of Kaldinm Saltern's strains and 43% of Kayacik Saltern's strains produced lipase. 89% of Kaldmm Saltern's strains and 29% of Kayacik Saltern's strains produced halocins effective against each other. It was found that lipase negative halocin producers of both Kaldinm and Kayacik Salterns were able to inhibit lipase positive strains in these salterns. Hence, it is recommended that lipase negative halocin producers or their halocin extracts may be used in preventing the haloarchaeal deterioration that can occur during brine curing of hides when using crude salt from whatever source.

Journal of The Society of Leather Technologists and Chemists, 2002

Journal of The American Leather Chemists Association, Dec 1, 2011

Journal of The Society of Leather Technologists and Chemists, 2005

Tuz Lake and its salterns Kaldinm and Kayacik are major sources of solar salt for the Turkish hid... more Tuz Lake and its salterns Kaldinm and Kayacik are major sources of solar salt for the Turkish hide industry. The fungal community on the salt, which may have detrimental effects if unprocessed salt is used in industrial processes such as in the leather industry, has not been previously investigated. Ten salt crystal and five brine samples were collected from Tuz Lake and its salterns for investigation. A total of 18 species belonging to 10 genera were encountered. Absidia, Acremonium, Eurotium, Aspergillus, Alternaria. Cladosporium, Eupenicillium, Penicillium, Stachybotrys, Trichoderma and Ulocladium species were isolated and identified. The results showed that Tuz Lake and its salterns contained diverse fungal communities. In conclusion the salt should not be used for the preservation of hide without purification because of the fungal contamination.

HiJYEN VE DENEYSEL BlYOLOJl DERGlSl

... Dr. Ismail PEKER MÜ Cenlor tor Wild Planls and Waler Lile Conservahon and Research-Gözlepe/ i... more ... Dr. Ismail PEKER MÜ Cenlor tor Wild Planls and Waler Lile Conservahon and Research-Gözlepe/ islanbul TEL/FAX 1 (0216) 337 16 ... Asbestos fibers in shower water may be released to the air and cause respiratory problems (1). Microorganisms can cause more disease than ...

A tremendously diverse group of microorganisms originated from animal skins/hides, animals' feces... more A tremendously diverse group of microorganisms originated from animal skins/hides, animals' feces, preservation salt, dust, barn, water, air, soil, feed have been found on salted hides/skins. Growth and catabolic activities of these microorganisms have been supported by high organic and inorganic contents of salted hides/skins. As known, detail examination of catabolic activities of microorganisms offers an important information about their critical roles on hide/skin biodegradation. The goal of this review is to summarize experimental results of the previous studies to understand biodegradation capabilities of the microorganisms isolated from leather industry. Catabolic activities of microorganisms belonging to non-halophilic bacteria, moderately halophilic bacteria, extremely halophilic archaea and the members of family Enterobacteriaceae were summarized in the present study. The characterization of these microorganisms was performed according to molecular methods, conventional biochemical tests in the previous studies. Examination of research articles showed that aerobic microorganisms isolated from salted hides/skins produced protease, caseinase, lipase, β-galactosidase, amylase, cellulase, DNase, lecithinase and urease. Moreover, the isolates produced acid from different carbon sources, reduced nitrate to nitrite, produced NH3 from peptone, decarboxylated different amino acids found in hides/skins. These studies demonstrated that salted hides/skins had a wide diversity of microorganisms which have different catabolic activities to breakdown carbon and energy sources for their growth.

Applied Biochemistry and Microbiology, Sep 1, 2012

World Journal of Microbiology & Biotechnology, 2004

Chemical Biology & Drug Design, Aug 8, 2017

The ability of Archaea to adapt their membrane lipid compositions to extreme environments has bro... more The ability of Archaea to adapt their membrane lipid compositions to extreme environments has brought in archaeosomes into consideration for the development of drug delivery systems overcoming the physical, biological blockades that the body exhibits against drug therapies. In this study, we prepared unilamellar archaeosomes, from the polar lipid fraction extracted from Haloarcula 2TK2 strain, and explored its potential as a drug delivery vehicle. Rifampicin and isoniazid which are conventional drugs in tuberculosis medication were loaded separately and together in the same archaeosome formulation for the benefits of the combined therapy. Particle size and zeta potential of archaeosomes were measured by photon correlation spectroscopy, and the morphology was assessed by with an atomic force microscope. Encapsulation efficiency and loading capacities of the drugs were determined, and in vitro drug releases were monitored spectrophotometrically. Our study demonstrates that rifampicin and isoniazid could be successfully loaded separately and together in archaeosomes with reasonable drug-loading and desired vesicle-specific characters. Both of the drugs had greater affinity for archaeosomes than a conventional liposome formulation. The results imply that archaeosomes prepared from extremely halophilic archaeon were compatible with the liposomes for the development of stable and sustained release of antituberculosis drugs.

International journal of advances in engineering and pure sciences, Jun 30, 2022

Twenty-five food salts, collected from seven-country, were examined for moisture contents and ash... more Twenty-five food salts, collected from seven-country, were examined for moisture contents and ash contents, pH values, total numbers of bacteria, and total numbers of halotolerant bacteria. The growth and biochemical reactions of halotolerant bacteria at different NaCl concentrations, pH, and temperature values were investigated. The efficacy of dry-heat sterilization and highpressure steam sterilization for the inactivation of bacteria was examined using six food salts. Moisture contents, ash contents, and pH values of salts were respectively found as 2.3-3.7%, 95-97%, and 6.37-9.94. Total numbers of bacteria and halotolerant bacteria were detected as between 1-58 CFU/g and 1-40 CFU/g on Modified Nutrient Agar media, respectively. While bacteria were found in twenty salt samples, halotolerant bacteria were detected in seventeen samples. One hundred thirty-eight rodshaped halotolerant bacteria were isolated from seventeen samples. One hundred eighteen and twenty isolates were found Gram-positive and Gram-negative, respectively. While 131 isolates were motile, seven isolates were observed as non-motile. All isolates grew in both absence of NaCl and presence of 10% NaCl, pH 5, 7, and 9, 24°C, and 37°C. Eighty-six isolates showed different pigmentations. Ammonia production was detected at sixty isolates. Catalase, oxidase, protease, lipase, amylase, caseinase were produced by 138, 83, 84, 48, 92, 100 isolates, respectively. Fifty-seven percent of halotolerant bacteria formed endospores. All bacteria in six salts were killed using both dry-heat sterilization (175 o C for 2 hours) and high-pressure steam sterilization (121 o C for 30 minutes). In conclusion, we suggest using dry-heat sterilization or high-pressure steam sterilization to kill Gram-negative halotolerant bacteria containing endotoxin and Gram-positive halotolerant bacteria with endospores in food salts to prevent food spoilage and foodborne diseases in humans.

Journal of The Society of Leather Technologists and Chemists, 2010

A high bacterial population belonging to the domains of Bacteria and Archaea originating from ina... more A high bacterial population belonging to the domains of Bacteria and Archaea originating from inadequate salt curing and soaking processes may cause an important quality reduction in leather. A simple and rapid molecular technique such as Fluorescent In Situ Hybridization technique (FISH) which may be applied in leather making processes may assist to solve this problem. Therefore, in the present study the FISH technique was used to track Bacterial and Archaeal domains in salt (n=15), salted (n=15), soaked hides (n=15) and soak liquor (n=15) samples. Although Archaeal population was dominant in the salt samples, a Bacterial population was dominant in the soaked hide and soak liquor samples. The salted hide samples contained both Archaeal and Bacterial populations. The FISH method applied to the samples showed that high extremely halophilic Archaeal population on the salted hides and high Bacterial population in soak liquors and soaked hides originated from the salt and the salted hides, respectively. As a conclusion, the FISH technique was found suitable for the rapid assesment and tracking microbial domains in salt, salted and soaked hide and soak liquor samples.

Journal of The Society of Leather Technologists and Chemists, 2016

International Journal of Bioscience, Biochemistry and Bioinformatics, 2016

Proteolytic and lipolytic bacteria may be found in hide-soak liquors. These microorganisms may af... more Proteolytic and lipolytic bacteria may be found in hide-soak liquors. These microorganisms may affect leather quality adversely and cause important economic losses. Therefore, we examined lethal effect of 1 A DC treatment implemented with 1.5 A AC on mixed culture of Gram-positive and Gram-negative hide bacteria in Nutrient Broth containing 3% NaCl in this study. Proteolytic and lipolytic Gram-positive Bacillus lentus, Staphylococcus intermedius, Aerococcus viridans and Enterococcus avium, Gram-negative Enterobacter cloacae and Pseudomonas putida, which were isolated from hide soak liquor in our previous study, were used as test microorganisms in this study. Log10 reduction factors of 1.40, 1.62, 2.00 and 2.10 belonging to the mixed culture were detected after first, second, third and fourth cycles of electric current treatments, respectively. This study results exhibited that the electric treatment was efficient in reducing the cell counts of microorganisms found in hide-soak liquors.

Journal of The Society of Leather Technologists and Chemists, 2013

Journal of The Society of Leather Technologists and Chemists, 2008

Proteolytic enzymes which are produced by extremely halophilic Archaea present in salt may cause ... more Proteolytic enzymes which are produced by extremely halophilic Archaea present in salt may cause serious damage on salted hides and may result in significant economic losses in the leather industry. Hence, protease activities of 24 protease producing extremely halophilic archaeal strains isolated from Tuz Lake, Kaldinm and Kayacik salterns and Tuzkoy salt mine were determined in this study. The protease activities of Tuz Lake, Kaldinm saltern, Kayacik saltern and Tuzkoy salt mine strains were found as between 80.0 and 83.3, 81.1 and 83.8, 83.3 and 83.4, 82.0 and 83.4 Units, respectively. To prevent proteolytic haloarchaeal damage on brine cured hides, the protease producing strains were treated with 0.5A direct electric current for 20min. Although proteolytic strains of Tuz Lake and Tuzkoy salt mine in the liquid gelatin media were killed by 0.5A direct electric current within 15min, lOmin direct electric current treatment were enough to kill all proteolytic strains of Kaldinm and Kayacik salterns. Also, the effect of 0.5A direct electric current on protease activities of the test strains was examined during 20min treatment in this study. It was found that 0.5A direct electric current caused a slight decrease on protease activities of the test strains. Therefore, it is necessary to kill protease producing strains in brine solution with direct electric current before the excretion of their protease into the brine solution.

Journal of Electrostatics, Jul 1, 2009

Inactivation effect of alternative electric current on Escherichia coli ATCC 25922 and fecal E. c... more Inactivation effect of alternative electric current on Escherichia coli ATCC 25922 and fecal E. coli MAAG 1405 found resistant to antibiotics was examined in water samples collected from Ayamama River, Sarısu River, and their discharge points into sea and from Black Sea and Marmara Sea. In addition to water samples, lauryl sulfate broth was used as an organic rich medium. Both test strains were inactivated within 1-3 min in media containing marine waters (1 A), 5-10 min in Ayamama River water (1 A), 5 min in Sarısu River water (0.5 A), 20-35 min in lauryl sulfate broth (1 A) by applying alternative electric current.

Journal of Electrostatics, Jul 1, 2008

Inactivation of bacteria by electric currents has received much attention due to its high efficie... more Inactivation of bacteria by electric currents has received much attention due to its high efficiency, low cost, and ease of application. Therefore, the antibacterial effect of passing 2 A direct electric current for 50 min on mesophilic bacteria in both first and main hide-soak liquors obtained from different tanneries in Tuzla-_ Istanbul, Tü rkiye was examined. The mesophilic bacterial numbers in the main hide-soak liquors were higher than that of the first hide-soak liquors. The total numbers of gram-negative bacteria (10 1-10 4 CFU/mL) and halotolerant bacteria (10 3-10 4 CFU/mL), in both first and main hide-soak liquors, were almost the same. The numbers of total of proteolytic and lipolytic mesophilic bacteria and the total of proteolytic and lipolytic halotolerant bacteria in the main hide-soak liquors were higher than that of the first hide-soak liquors. Mesophilic bacteria in the first (seven samples) and main (three samples) hidesoak liquors were inactivated after 20-30 min of electrical treatment. In the other four main hide-soak liquors, the inactivation occurred after 50 min of treatment. The most important result of this experiment is that there was a correlation between the voltage level and the numbers of bacteria in the electrolysis cell. The bacterial populations in the hide-soak liquors decreased proportionally to the voltage level until all of the bacterial population was inactivated. After the bacteria in the hide-soak liquors were completely destroyed by direct electric current, the voltage level started to increase. This important clue might be used to predict the inactivation time of all of the bacterial population in hidesoak liquors in the hide industry. It is suggested that the bacterial inactivation in hide-soak liquors by electrical treatment might be used in tanneries, which do not have a waste treatment system and discharge their effluents directly into environment.