TY - JOUR
T1 - Selecting for lactic acid producing and utilising bacteria in anaerobic enrichment cultures
AU - Rombouts, Julius Laurens
AU - Kranendonk, Elsemiek Madeleine Maria
AU - Regueira, Alberte
AU - Weissbrodt, David Gregory
AU - Kleerebezem, Robbert
AU - van Loosdrecht, Mark Cornelis Maria
PY - 2020
Y1 - 2020
N2 - Lactic acid-producing bacteria are important in many fermentations, such as the production of biobased plastics. Insight in the competitive advantage of lactic acid bacteria over other fermentative bacteria in a mixed culture enables ecology-based process design and can aid the development of sustainable and energy-efficient bioprocesses. Here we demonstrate the enrichment of lactic acid bacteria in a controlled sequencing batch bioreactor environment using a glucose-based medium supplemented with peptides and B vitamins. A mineral medium enrichment operated in parallel was dominated by Ethanoligenens species and fermented glucose to acetate, butyrate and hydrogen. The complex medium enrichment was populated by Lactococcus, Lactobacillus and Megasphaera species and showed a product spectrum of acetate, ethanol, propionate, butyrate and valerate. An intermediate peak of lactate was observed, showing the simultaneous production and consumption of lactate, which is of concern for lactic acid production purposes. This study underlines that the competitive advantage for lactic acid-producing bacteria primarily lies in their ability to attain a high biomass specific uptake rate of glucose, which was two times higher for the complex medium enrichment when compared to the mineral medium enrichment. The competitive advantage of lactic acid production in rich media can be explained using a resource allocation theory for microbial growth processes.
AB - Lactic acid-producing bacteria are important in many fermentations, such as the production of biobased plastics. Insight in the competitive advantage of lactic acid bacteria over other fermentative bacteria in a mixed culture enables ecology-based process design and can aid the development of sustainable and energy-efficient bioprocesses. Here we demonstrate the enrichment of lactic acid bacteria in a controlled sequencing batch bioreactor environment using a glucose-based medium supplemented with peptides and B vitamins. A mineral medium enrichment operated in parallel was dominated by Ethanoligenens species and fermented glucose to acetate, butyrate and hydrogen. The complex medium enrichment was populated by Lactococcus, Lactobacillus and Megasphaera species and showed a product spectrum of acetate, ethanol, propionate, butyrate and valerate. An intermediate peak of lactate was observed, showing the simultaneous production and consumption of lactate, which is of concern for lactic acid production purposes. This study underlines that the competitive advantage for lactic acid-producing bacteria primarily lies in their ability to attain a high biomass specific uptake rate of glucose, which was two times higher for the complex medium enrichment when compared to the mineral medium enrichment. The competitive advantage of lactic acid production in rich media can be explained using a resource allocation theory for microbial growth processes.
KW - enrichment cultures
KW - kinetics
KW - lactic acid bacteria
KW - microbial ecology
KW - resource allocation
UR - http://www.scopus.com/inward/record.url?scp=85079719762&partnerID=8YFLogxK
U2 - 10.1002/bit.27301
DO - 10.1002/bit.27301
M3 - Article
C2 - 32034763
AN - SCOPUS:85079719762
SN - 0006-3592
VL - 117
SP - 1281
EP - 1293
JO - Biotechnology and Bioengineering
JF - Biotechnology and Bioengineering
IS - 5
ER -