TY - JOUR

T1 - The effect of acetate on population heterogeneity in different cellular characteristics of Escherichia coli in aerobic batch cultures

AU - Heins, Anna-Lena

AU - Lundin, Luisa

AU - Nunes, Inês

AU - Gernaey, Krist V.

AU - Sørensen, Søren Johannes

AU - Eliasson Lantz, Anna

N1 - © 2019 American Institute of Chemical Engineers.

PY - 2019

Y1 - 2019

N2 - Acetate as the major by-product in industrial scale bioprocesses with E. coli is found to decrease process efficiency as well as to be toxic to cells, which has several effects like a significant induction of cellular stress responses. However, the underlying phenomena are poorly explored. Therefore we studied time-resolved population heterogeneity of the E. coli growth reporter strain MG1655/pGS20PrrnBGFPAAV expressing destabilized green fluorescent protein during batch growth on acetate and glucose as sole carbon sources. Additionally, we applied five fluorescent stains targeting different cellular properties (viability as well as metabolic and respiratory activity). Quantitative analysis of flow cytometry data verified that bacterial populations in the bioreactor are more heterogeneous in growth as well as stronger metabolically challenged during growth on acetate as sole carbon source, compared to growth on glucose or acetate after diauxic shift. Interestingly, with acetate as sole carbon source significant subpopulations were found with some cells that seem to be more robust than the rest of the population. In conclusion, following batch cultures population heterogeneity was evident in all measured parameters. Our approach enabled a deeper study of heterogeneity during growth on the favoured substrate glucose as well as on the toxic by-product acetate. Using a combination of activity fluorescent dyes proved to be an accurate and fast alternative as well as a supplement to the use of a reporter strain. However the choice of combination of stains should be well considered depending on which population traits to aim for. This article is protected by copyright. All rights reserved.

AB - Acetate as the major by-product in industrial scale bioprocesses with E. coli is found to decrease process efficiency as well as to be toxic to cells, which has several effects like a significant induction of cellular stress responses. However, the underlying phenomena are poorly explored. Therefore we studied time-resolved population heterogeneity of the E. coli growth reporter strain MG1655/pGS20PrrnBGFPAAV expressing destabilized green fluorescent protein during batch growth on acetate and glucose as sole carbon sources. Additionally, we applied five fluorescent stains targeting different cellular properties (viability as well as metabolic and respiratory activity). Quantitative analysis of flow cytometry data verified that bacterial populations in the bioreactor are more heterogeneous in growth as well as stronger metabolically challenged during growth on acetate as sole carbon source, compared to growth on glucose or acetate after diauxic shift. Interestingly, with acetate as sole carbon source significant subpopulations were found with some cells that seem to be more robust than the rest of the population. In conclusion, following batch cultures population heterogeneity was evident in all measured parameters. Our approach enabled a deeper study of heterogeneity during growth on the favoured substrate glucose as well as on the toxic by-product acetate. Using a combination of activity fluorescent dyes proved to be an accurate and fast alternative as well as a supplement to the use of a reporter strain. However the choice of combination of stains should be well considered depending on which population traits to aim for. This article is protected by copyright. All rights reserved.

U2 - 10.1002/btpr.2796

DO - 10.1002/btpr.2796

M3 - Journal article

C2 - 30816011

VL - 35

JO - Biotechnology Progress

JF - Biotechnology Progress

SN - 8756-7938

IS - 3

M1 - e2796

ER -