caa a22 4500 605504741 CHVBK 20210128100618.0 cr unu---uuuuu 210128e20151201xx s 000 0 eng 10.1007/s00253-015-6887-4 doi (NATIONALLICENCE)springer-10.1007/s00253-015-6887-4 Towards an effective biosensor for monitoring AD leachate: a knockout E. coli mutant that cannot catabolise lactate [Elektronische Daten] [Joseph Sweeney, Cormac Murphy, Kevin McDonnell] Development of a biosensor for the convenient measurement of acetate and propionate concentrations in a two-phase anaerobic digestor (AD) requires a bacterium that will be unresponsive to the other organic acids present in the leachate, of which lactate is the most abundant. Successive gene knockouts of E.coli W3110 d-lactate dehydrogenase (dld), l-lactate dehydrogenase (lldD), glycolate oxidase (glcD) and a suspected l-lactate dehdrogenase (ykgF) were performed. The resulting quadruple mutant (IMD Wldgy) was incapable of growth on d- and l-lactate, whereas the wild type grew readily on these substrates. Furthermore, the O2 consumption rates of acetate-grown IMD Wldgy cell suspensions supplied with either acetate (0.1mM) or a synthetic leachate including acetate (0.1mM) and dl-lactate (1mM) were identical (2.79 and 2.70mgl−1min−1, respectively). This was in marked contrast to similar experiments with the wild type which gave initial O2 consumption rates of 2.00, 2.36 and 2.97mgl−1min−1 when cell suspensions were supplied with acetate (0.1mM), acetate (0.1mM) plus d-lactate (1mM) or acetate (0.1mM) plus l-lactate (1mM), respectively. The knockout strain provides a platform for the design of a biosensor that can accessibly monitor acetate and propionate concentrations in AD leachate via O2-uptake measurements. Springer-Verlag Berlin Heidelberg, 2015 Anaerobic digestion nationallicence Biosensor nationallicence Volatile fatty acids nationallicence Synthetic leachate nationallicence Sweeney Joseph UCD Schools of Biosystems Engineering, Food and Agriculture, University College Dublin, Belfield, Dublin 4, Ireland aut Murphy Cormac UCD School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland aut McDonnell Kevin UCD Schools of Biosystems Engineering, Food and Agriculture, University College Dublin, Belfield, Dublin 4, Ireland aut Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/23(2015-12-01), 10209-10214 0175-7598 99:23<10209 2015 99 253 https://doi.org/10.1007/s00253-015-6887-4 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00253-015-6887-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Sweeney Joseph UCD Schools of Biosystems Engineering, Food and Agriculture, University College Dublin, Belfield, Dublin 4, Ireland aut NATIONALLICENCE 700 1- Murphy Cormac UCD School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland aut NATIONALLICENCE 700 1- McDonnell Kevin UCD Schools of Biosystems Engineering, Food and Agriculture, University College Dublin, Belfield, Dublin 4, Ireland aut NATIONALLICENCE 773 0- Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/23(2015-12-01), 10209-10214 0175-7598 99:23<10209 2015 99 253