Benzalkonyum klorürlerin Pseudomonas sp. BIOMIG1 tarafından farklı koşullar altında biyotransformasyon kinetiği

Yıl 2019, Cilt: 25 Sayı: 3, 286 - 291, 28.06.2019

Fatma Özge Yılmaz Emine Ertekin Ulaş Tezel

Öz

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.

Anahtar Kelimeler

Benzalkonyum klorür, Biyodönüşüm, Kinetik, Modelleme, Pseudomonas sp. BIOMIG1

Biotransformation kinetics of benzalkonium chlorides by Pseudomonas sp. BIOMIG1 under different conditions

Öz

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.

Anahtar Kelimeler

Benzalkonium chloride, Biotransformation, Kinetics, Modeling, Pseudomonas sp. BIOMIG1

Kaynakça

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