When looking back and wonder how we did it, I became even more aware of how my wanderings in microbiology are all linked, from the start of my PhD with Hans Veldkamp on sulphur-oxidizing bacteria in chemostats. My interests broadened from obligate chemolithoautotrophic bacteria to facultative organisms and the question about the ecological niches of these different metabolic types. The sulphide oxidizing bacteria also may be used to produce elemental sulphur, which can easily be removed from wastewater. This fitted in a long-standing collaboration with Dimitry Sorokin on the ecophysiology and application of alkaliphilic sulphur bacteria. Then came the denitrifying sulphur-oxidizing bacteria and their application to remove sulphide from wastewater, which lead to our interest in nitrate, nitrite and ammonium removal in general. The big surprise was the serendipitous discovery of the 'anammox'-process, whereby ammonium is anaerobically oxidized to dinitrogen gas with nitrite as electron acceptor. The early days of our anammox research are the main focus of this article, which describes the struggle of growing and identifying the most peculiar bacteria we ever came across. A specialized organelle, the anammoxosome was shown to be responsible for the key ammonium oxidation, whereby a rocket fuel, hydrazine, turned out to be an intermediate. Soon after we became aware that anammox is everywhere and in the marine environment makes up a major portion of the nitrogen cycle. The intense scientific collaboration with Mike Jetten and Mark van Loosdrecht and colleagues led to our further understanding and application of this fascinating process, which is briefly summarized in this article. My broader interest in environmental microbiology and microbial ecology has been a regularly returning theme, taking me all over the world to great collaborations lasting to this very day.

中文翻译：

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Anammox及以后。

回想一下我们是如何做到的，从与博士学位的汉斯·维尔德坎普（Hans Veldkamp）开始研究化学恒温器中的硫氧化细菌起，我就更加意识到了我在微生物学上的徘徊是如何联系在一起的。我的兴趣从专性化石自养细菌扩展到兼性生物，以及关于这些不同代谢类型的生态位的问题。硫化物氧化细菌也可用于生产元素硫，可以很容易地将其从废水中去除。这与Dimitry Sorokin长期合作研究了嗜碱硫细菌的生态生理和应用。然后是反硝化硫氧化细菌及其在废水中去除硫化物的应用，这引起了我们对总体上硝酸盐，亚硝酸盐和铵的去除的兴趣。最令人惊讶的是偶然发现了“厌氧氨氧化”工艺，该工艺以亚硝酸盐为电子受体，将厌氧氨氧化为二氮气。厌氧氨氧化研究的早期阶段是本文的主要重点，它描述了生长和鉴定我们所遇到的最奇特细菌的努力。研究表明，一种特殊的细胞器-厌氧菌体负责关键的铵氧化反应，从而证明火箭燃料肼是其中的一种中间体。很快，我们意识到厌氧氨氮无处不在，并且在海洋环境中占了氮循环的主要部分。与Mike Jetten和Mark van Loosdrecht及其同事的紧密科学合作使我们对这一迷人的过程有了进一步的了解和应用，本文对此进行了简要总结。我对环境微生物学和微生物生态学的广泛兴趣一直是定期回访的主题，这使我遍布世界各地，直到今天仍在进行巨大的合作。