Publication: Assessment of biological hydrazine production using anammox bacteria
Abstract
Hidrazin (N2H4), çeşitli uygulamalara sahip değerli bir endüstriyel bileşiktir. N2H4’e yönelik küresel talep artmakta olup, 2030 yılına kadar yaklaşık 806 milyon dolara ulaşması beklenmektedir. Şu anda, N2H4'ün endüstriyel ölçekte üretimi, çeşitli dezavantajlarla birlikte yalnızca kimyasal işlemlere dayanmaktadır. Anammox bakterileri, metabolizmalarında N2H4 sentezleme konusunda eşsiz bir yeteneğe sahiptir. N2H4’ün anammox üzerindeki arttırıcı etkisi farklı amaçlar için kapsamlı olarak incelenmiştir. Fakat, N2H4’nin uzun vadeli inhibe edici etkileri halâ tartışmalıdır ve anammox bakterilerinin yüksek N2H4 seviyelerine kısa vadeli tepkisi halâ belirsizdir. Bu tez kapsamında, zenginleştirilmiş anammox kültürünün harici N2H4’e hem kısa hem de uzun vadeli tepkileri kapsamlı bir şekilde incelenmiştir. Ayrıca, bu çalışmada anammox sistemleri kullanılarak uzun vadede biyolojik N2H4 üretiminin arttırılması değerlendirilmiştir. Son olarak, mevcut N2H4 üretim ve ayırma yöntemlerinin detaylı bir incelemesi yapılmıştır.Genel sonuçlar, anammox bakterilerinin mevcut ve yaygın uygulamalarının yanı sıra, N2H4 içeren atık suların arıtımı için potansiyel adaylar olduğunu göstermiştir. Fakat, yüksek seviyelerdeki N2H4 stresine akut maruziyet, zenginleştirilmiş anammox kültürünün ifade profillerini önemli ölçüde azaltmıştır, bu da anammox bakterilerinin yüksek konsantrasyonlardaki şok N2H4 yüklerine karşı hassas olduğunu ortaya koymuştur. Buna ek olarak, optimize edilmiş koşullar altında, anammox biyoreaktöründe literatürde raporlanandan 2,5 kat daha yüksek N2H4 biyobirikimine ulaşılmıştır. Biyoreaktör çalışma koşullarının manipülasyonu başlangıçta N2H4 biyobirikiminde önemli bir artışa neden olsa da akabinde anammox aktivitesinde ciddi bir bozulmaya neden olmuştur. Ancak bu durum, anammox sistemlerinin işletim koşullarının düzenlenmesiyle önlenebilir. Sonuç olarak, N2H4 içeren atık suların arıtılması ve N2H4 üretilmesi için anammox bakterilerinin kullanılması klasik yöntemlere umut verici bir alternatiftir. Anammox bakterilerine yönelik bu yeni yaklaşımların henüz başlangıç aşamasında olduğunu vurgulamak gerekir. Bu nedenle, temel zorlukların üstesinden gelmek için daha fazla araştırmaya ihtiyaç vardır.
Hydrazine (N2H4) is a valuable industrial compound with diverse applications. Global demand for N2H4 is increasing and is expected to reach nearly $806 million by 2030. Currently, industrial-scale production of N2H4 relies solely on chemical processes, with several disadvantages. Anammox bacteria have the unique ability to synthesize N2H4 in their metabolism. The enhancing effect of N2H4 on anammox has been extensively studied for different purposes. However, its long-term inhibitory effect remains controversial, and the short-term response of the anammox bacteria to high levels of N2H4 is still unclear. In the scope of this thesis, both short-term and long-term responses of the enriched anammox culture to external N2H4 were comprehensively examined. Moreover, this study assessed the enhancement of biological N2H4 production using the anammox systems in a long-term manner. Finally, a detailed review of current N2H4 production and separation methods was conducted.Overall results indicated that anammox bacteria are potential candidates for the treatment of N2H4-containing wastewaters in a long-term period, alongside their current widespread applications. However, acute exposure to high levels of N2H4 stress significantly decreased the expression profiles of the enriched anammox culture, suggesting that anammox bacteria are susceptible to shock loads of N2H4 at high concentrations. In addition, 2.5 times higher N2H4 bioaccumulation was achieved in the anammox bioreactor compared to values reported in the literature. Although manipulation of the bioreactor operating conditions initially resulted in a significant increase in N2H4 bioaccumulation, it subsequently caused a severe deterioration in anammox activity. However, this could be mitigated by adjusting process conditions of the anammox systems. In conclusion, employing anammox bacteria to treat N2H4-containing wastewaters and produce N2H4 is a promising alternative to classical methods. It must be emphasized that these new approaches to anammox bacteria are still in their early stages. Therefore, further research is required to address the key challenges.
Hydrazine (N2H4) is a valuable industrial compound with diverse applications. Global demand for N2H4 is increasing and is expected to reach nearly $806 million by 2030. Currently, industrial-scale production of N2H4 relies solely on chemical processes, with several disadvantages. Anammox bacteria have the unique ability to synthesize N2H4 in their metabolism. The enhancing effect of N2H4 on anammox has been extensively studied for different purposes. However, its long-term inhibitory effect remains controversial, and the short-term response of the anammox bacteria to high levels of N2H4 is still unclear. In the scope of this thesis, both short-term and long-term responses of the enriched anammox culture to external N2H4 were comprehensively examined. Moreover, this study assessed the enhancement of biological N2H4 production using the anammox systems in a long-term manner. Finally, a detailed review of current N2H4 production and separation methods was conducted.Overall results indicated that anammox bacteria are potential candidates for the treatment of N2H4-containing wastewaters in a long-term period, alongside their current widespread applications. However, acute exposure to high levels of N2H4 stress significantly decreased the expression profiles of the enriched anammox culture, suggesting that anammox bacteria are susceptible to shock loads of N2H4 at high concentrations. In addition, 2.5 times higher N2H4 bioaccumulation was achieved in the anammox bioreactor compared to values reported in the literature. Although manipulation of the bioreactor operating conditions initially resulted in a significant increase in N2H4 bioaccumulation, it subsequently caused a severe deterioration in anammox activity. However, this could be mitigated by adjusting process conditions of the anammox systems. In conclusion, employing anammox bacteria to treat N2H4-containing wastewaters and produce N2H4 is a promising alternative to classical methods. It must be emphasized that these new approaches to anammox bacteria are still in their early stages. Therefore, further research is required to address the key challenges.
Description
Keywords
Aanammox, hidrazin, hidrazin uygulamaları, biyoteknoloji, biyoenerji, metatranskriptomik anammox, hydrazine, hydrazine applications, biotechnology, bioenergy, metatranscriptomics