Aster Bio research in AOB & NOB inhibition

From: https://en.wikipedia.org/wiki/Anammox

Ammonia Oxidizing Bacteria (AOB) and Nitrite Oxidizing Bacteria (NOB) are often grouped into what we call nitrifiers.  These organisms grow by converting ammonia into nitrite and finally nitrate.  Organisms working in the nitrogen cycle are diverse and include the following:

• Heterotrophs that degrade organic nitrogen compounds (proteins, amines, etc) into ammonia. They also use nitrogen to build proteins used in cellular activities and reproduciton. Under anoxic conditions, many heterotrophs use nitrate and nitrite as alternative electron acceptors converting the NO3/NO2 into N2 gas.
• Chemoautotrophs - this includes AOB/NOB, COMAMMOX (funtions as both AOB & NOB in one organism), ANAMMOX (under anoxic conditions takes NO2 + NH4+ directly to N2 gas)
• Heterotrophic ammonia oxidation (slower than obligate AOB/NOB but does take place).

So given such diversity, toxicity screens become a complex undertaking.  So, here is what we are doing (while the COVID19 virus has travel and field work at minimum levels).

• Sampling diverse WW systems to see makeup of their nitrifying populations using Mirobial Community Analysis (MCA)
• Using qPCR tests created from MCA data for individual systems to develop baseline data for operating wastewater treatment plants - this involves desigining and refining oligos used in qPCR tests.
• Testing suspected compounds using concentrated AOB cultures for acute toxicity using Tox-N testing. In this we spike buffered water with suspect compounds and add AOB. We compare ammonia oxidation rates versus a control to get % inhibition. 
• More advanced simulation in pilot activated sludge units where we use a healthy MLSS and subject it to influents spiked with compounds of interest. We then monitor ammonia, nitrite, nitrate, and use molecular testing to see drifts in AOB/NOB populations.