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Dezenfektan aktif maddeleri kentsel ve endüstriyel atıksularda oldukça sık rastlanan kirleticilerdir. Bu kirleticilerin biyolojik sistemlerde giderimi oldukça zordur. Yüzeysel sularda da sıkça karşılaşılan bu kirleticiler hem doğal hayatı hem de insan sağlığını tehdit etmektedir. Bu çalışmanın amacı, atıksuda en çok karşılaşılan kirleticilerden biri olan benzalkonyum klorürlerin (BAK’ler) biyolojik sistemlerde en verimli şekilde giderimini sağlayacak koşulların belirlenmesidir. Bu amaçla, atıksudan izole edilmiş BAK gideren bir bakteri olan Pseudomanas sp. BIOMIG1’in farklı koşullarda BAK biyotransformasyon kinetiği belirlenmiştir. Elde edilen veriler ve Michaelis-Menten modeli kullanılarak, bu mikroorganizmanın BAK biotransformasyon kinetiği parametreleri hesaplanmış ve uygulanan koşulların kinetiğe etkisi belirlenmiştir. BIOMIG1, BAK’leri 1.4 mg/L-saat hızında giderebilmekte ve bu kirleticileri amonyak ve karbon dioksite dönüştürmektedir. Mililitrede yüz bin adet bakteri yoğunluğu gibi düşük bakteri yoğunluklarında bile BAK gecikmeli de olsa yüksek hızda giderilebilmektedir. BAK homologlarının biyotransformasyon hızı karşılaştırıldığında, 14 karbon alkil zincir uzunluğuna sahip BAK en hızlı, 16 karbonlu BAK ise en yavaş biyotransformasyon hızına sahiptir. BAK giderim hızının en yüksek olduğu sıcaklık 35°, bu sıcaklık üstündeki sıcaklıklarda BIOMIG1 yaşayamamaktadır. Dolayısıyla yüksek sıcaklıklarda BAK parçalanması ya benzildimetilamin birikmesiyle sonlanmış ya da hiç gerçekleşmemiştir. Bu çalışmanın sonuçları, özellikle BAK gibi mikrokirleticilerin arıtımını hedefleyen ileri arıtma sistemlerinin tasarlanması ve işletilmesinde faydalı olacaktır.

Dezenfektan aktif maddeleri kentsel ve endüstriyel atıksularda oldukça sık rastlanan kirleticilerdir. Bu kirleticilerin biyolojik sistemlerde giderimi oldukça zordur. Yüzeysel sularda da sıkça karşılaşılan bu kirleticiler hem doğal hayatı hem de insan sağlığını tehdit etmektedir. Bu çalışmanın amacı, atıksuda en çok karşılaşılan kirleticilerden biri olan benzalkonyum klorürlerin (BAK’ler) biyolojik sistemlerde en verimli şekilde giderimini sağlayacak koşulların belirlenmesidir. Bu amaçla, atıksudan izole edilmiş BAK gideren bir bakteri olan Pseudomanas sp. BIOMIG1’in farklı koşullarda BAK biyotransformasyon kinetiği belirlenmiştir. Elde edilen veriler ve Michaelis-Menten modeli kullanılarak, bu mikroorganizmanın BAK biotransformasyon kinetiği parametreleri hesaplanmış ve uygulanan koşulların kinetiğe etkisi belirlenmiştir. BIOMIG1, BAK’leri 1.4 mg/L-saat hızında giderebilmekte ve bu kirleticileri amonyak ve karbon dioksite dönüştürmektedir. Mililitrede yüz bin adet bakteri yoğunluğu gibi düşük bakteri yoğunluklarında bile BAK gecikmeli de olsa yüksek hızda giderilebilmektedir. BAK homologlarının biyotransformasyon hızı karşılaştırıldığında, 14 karbon alkil zincir uzunluğuna sahip BAK en hızlı, 16 karbonlu BAK ise en yavaş biyotransformasyon hızına sahiptir. BAK giderim hızının en yüksek olduğu sıcaklık 35°, bu sıcaklık üstündeki sıcaklıklarda BIOMIG1 yaşayamamaktadır. Dolayısıyla yüksek sıcaklıklarda BAK parçalanması ya benzildimetilamin birikmesiyle sonlanmış ya da hiç gerçekleşmemiştir. Bu çalışmanın sonuçları, özellikle BAK gibi mikrokirleticilerin arıtımını hedefleyen ileri arıtma sistemlerinin tasarlanması ve işletilmesinde faydalı olacaktır.

Active ingredients of disinfectants are very common pollutants in urban and industrial wastewater. Removal of these contaminants is very difficult in biological treatment systems. As a result; these pollutants, which are also frequently detected in surface waters, threaten both nature and human health. The objective of this study is to determine the optimum conditions that will provide the most efficient removal of benzalkonium chlorides (BACs), a common contaminant, in biological treatment systems. For this purpose, BAC biotransformation kinetics were determined under different conditions using Pseudomanas sp. BIOMIG1, a bacterium that is the key BAC degrader in the environment. Using the data collected and the Michaelis-Menten growth model, BAC biotransformation kinetic parameters were calculated and the effect of the applied conditions on kinetics was determined. BIOMIG1 can transform BACs at a rate of 1.4 mg/L-hour and converts these pollutants into ammonia and carbon dioxide. BAC mineralization can be achieved even at low bacterial densities such as 100000 cells/mL after a short delay. When biotransformation rate of BAC homologs was compared, BAC with 14 carbon alkyl chain length had the fastest and BAC with 16 carbons had the slowest rate of biotransformation. The temperature at which the BAC biotransformation rate was the highest was 35 degrees. BAC was converted to benzyldimethylamine at all temperatures above 35 degrees since BIOMIG1 does not survive above this temperature. The outcomes presented in this study would be used for the design and operation of advanced treatment systems targetting the removal of micropollutants like BACs. [ABSTRACT FROM AUTHOR]

Objective: Silver sulfadiazine and benzalkonium chloride are biocidal agents known to be effective against microorganisms. Although planktonic cells are easily affected by these agents, bacteria in the biofilm are more resistant to the same chemicals. Agents fixed on nanoparticles are reported to have higher antimicrobial activity against biofilm bacteria. The effects of nanotechnological disinfectants on biofilm bacteria vary with dose and time. The type of surface on which these disinfectants are sprayed also changes their activity. The aim of this study was to investigate the ability of silver sulfadiazine and benzalkonium immobilized on nanoparticles to adhere to surfaces and their effect on biofilm. Methods: Stainless steel coupons were sprayed with nano benzalkonium chloride and nano silver sulfadiazine were air-dried to cure for 24 hours, then the coupons were placed into the biofilm reactor. Bacterial counts in the biofilm layer formed on these surfaces were compared at monthly intervals with control coupons. Bacterial biofilms allowed to form naturally were analyzed by microbiological culture methods and number of live and dead microorganisms were determined by DAPI - CTC staining on epifluorescence microscope. Results: After the test periods, microbial culture and DAPI - CTC (live / dead) results were found significantly lower on disinfectant covered coupons. Furthermore, nano benzalkonium chloride was found to be significantly more effective against biofilm bacteria than nano silver sulfadiazine. Conclusion: The results were examined in order to observe biofilm formation on the surfaces covered with nano benzalkonium chloride and nano silver sulfadiazine compounds, to evaluate their use in industrial and clinical fields as effective disinfectants. Because these disinfectants are frequently used in industrial or clinical environments, results have made an important contribution to the manufacturer to focus on final version of the product. [ABSTRACT FROM AUTHOR]

Rapid developing nanotechnology has provided creation of new products in nano size finding usage in science and technology applications. Nanoparticles provide benefits on different scientific fields as well as using them in production of industrial products. Especially, production of disinfectants using antimicrobial properties of nanoparticles increases against microorganisms that are industrially and clinically important. Silver sulfadiazine and the benzalkonium which are examples of the quaternary ammonium compounds, has been used for a long time as a disinfectant, have been known that they show bacteriostatic and bacteriocidal effect on bacteria, some viruses, fungus and protozoa according to the concentration. Some bacteria such as Staphylococcus aureus, Pseudomonas aeruginosa, Eschericha coli and Klebsiella pneumoniae are clinically and industrially harmful. In addition, these bacteria can cause economic problems with their biofilm structure. Indefensible planktonic cells are affected by this circumstance very easily. The protected biofilm bacteria continue to resist against the disinfectant. The aim of the recent study is to examine minimum bactericidal concentration (MBC) values of nano silver sulfadiazine and nano benzalkonium chloride against planktonic and biofilm forms of these bacteria to determine time and concentration. The minimal effective dose in biofilms were determined as 512 µl ml-1 for nano silver sulfadiazin and 128 µl ml-1 for nano benzalkonium chloride, respectively. Results of this study were evaluated by the producer to determine the final concentration of nano silver sulfadiazin and nano benzalkonium chloride. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect of long-term use of antiglaucomatous drops (AGD), and benzalkonium chloride (BAK) on eyelid and conjunctival flora. Materials and Methods: Forty eyes of 24 subjects who used AGD with a mean usage time of 24±17 (6-72) months, and 40 eyes of 34 subjects who had no glaucoma history as a control group were recruited. In this study, 8 different AGD were used, and all drops contained benzalkonium chloride (BAK) 0.05% (range, 0.02% to 0.075) as a preservative. Cultures of conjunctiva and eyelid samples were obtained by dacron swab, inoculated onto blood and chocolate agar, and incubated at 37°C in an atmosphere of 5-7% CO2 for 2 days. This study was planned as a case-control study. All bacterial isolates was identified, and isolated bacteria in both groups and their sensitivities to antibiotics were compared. Results: Diphtheroid rods were the most frequent isolated bacteria from the conjunctivas in the control group and in the group that used AGD, 23% (9/40) and 25% (10/40), respectively. Coagulase negative Staphylococcus was the most frequently isolated bacteria from the eyelids in the control group and in the group that used AGD, 93% (37/40) and 83% (33/40), respectively. The bacteria isolated from the group that had used AGD were more resistant to antibiotics than the bacteria isolated from the control group (p>0.05). Isolated bacteria were most susceptible to vancomycin, netilmicin and amikacin. There was no statistically significant difference between the groups in the proportion of conjunctival and eyelids' cultures that yielded positive (p>0.05). Conclusions: Isolated bacteria in the group that used AGD were more resistant to antibiotics in comparison with the control group. We conclude that long-term use of AGD containing BAK, which is also a disinfectant agent, may cause colonisation with more resistant bacteria on conjunctivas and eyelids. [ABSTRACT FROM AUTHOR]