PMID- 25809221
OWN - NLM
STAT- MEDLINE
DCOM- 20160405
LR  - 20181202
IS  - 1365-2672 (Electronic)
IS  - 1364-5072 (Linking)
VI  - 118
IP  - 6
DP  - 2015 Jun
TI  - Whole cell kinetics of ureolysis by Sporosarcina pasteurii.
PG  - 1321-32
LID - 10.1111/jam.12804 [doi]
AB  - AIMS: Ureolysis drives microbially induced calcium carbonate precipitation 
      (MICP). MICP models typically employ simplified urea hydrolysis kinetics that do 
      not account for cell density, pH effect or product inhibition. Here, ureolysis 
      rate studies with whole cells of Sporosarcina pasteurii aimed to determine the 
      relationship between ureolysis rate and concentrations of (i) urea, (ii) cells, 
      (iii) NH4+ and (iv) pH (H(+) activity). METHODS AND RESULTS: Batch ureolysis rate 
      experiments were performed with suspended cells of S. pasteurii and one parameter 
      was varied in each set of experiments. A Michaelis-Menten model for urea 
      dependence was fitted to the rate data (R(2)  = 0.95) using a nonlinear mixed 
      effects statistical model. The resulting half-saturation coefficient, Km , was 
      305 mmol l(-1) and maximum rate constant, Vmax , was 200 mmol l(-1)  h(-1) . 
      However, a first-order model with k1  = 0.35 h(-1) fit the data better (R(2) 
       = 0.99) for urea concentrations up to 330 mmol l(-1) . Cell concentrations in 
      the range tested (1 x 10(7) -2 x 10(8)  CFU ml(-1) ) were linearly correlated 
      with ureolysis rate (cell dependent Vmax' = 6.4 x 10(-9)  mmol CFU(-1)  h(-1) ). 
      CONCLUSIONS: Neither pH (6-9) nor ammonium concentrations up to 0.19 mol l(-1) 
       had significant effects on the ureolysis rate and are not necessary in kinetic 
      modelling of ureolysis. Thus, we conclude that first-order kinetics with respect 
      to urea and cell concentrations are likely sufficient to describe urea hydrolysis 
      rates at most relevant concentrations. SIGNIFICANCE AND IMPACT OF THE STUDY: 
      These results can be used in simulations of ureolysis driven processes such as 
      microbially induced mineral precipitation and they verify that under the stated 
      conditions, a simplified first-order rate for ureolysis can be employed. The 
      study shows that the kinetic models developed for enzyme kinetics of urease do 
      not apply to whole cells of S. pasteurii.
CI  - (c) 2015 The Society for Applied Microbiology.
FAU - Lauchnor, E G
AU  - Lauchnor EG
AD  - Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA.
AD  - Department of Civil Engineering, Montana State University, Bozeman, MT, USA.
FAU - Topp, D M
AU  - Topp DM
AD  - Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA.
AD  - Department of Chemical and Biological Engineering, Montana State University, 
      Bozeman, MT, USA.
FAU - Parker, A E
AU  - Parker AE
AD  - Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA.
AD  - Department of Mathematical Sciences, Montana State University, Bozeman, MT, USA.
FAU - Gerlach, R
AU  - Gerlach R
AD  - Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA.
AD  - Department of Chemical and Biological Engineering, Montana State University, 
      Bozeman, MT, USA.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
DEP - 20150421
PL  - England
TA  - J Appl Microbiol
JT  - Journal of applied microbiology
JID - 9706280
RN  - 0 (Bacterial Proteins)
RN  - 8W8T17847W (Urea)
RN  - EC 3.5.1.5 (Urease)
RN  - H0G9379FGK (Calcium Carbonate)
SB  - IM
MH  - Bacterial Proteins/chemistry/metabolism
MH  - Calcium Carbonate/chemistry/metabolism
MH  - Hydrolysis
MH  - Kinetics
MH  - Sporosarcina/chemistry/enzymology/*metabolism
MH  - Urea/chemistry/*metabolism
MH  - Urease/chemistry/metabolism
OTO - NOTNLM
OT  - Michaelis-Menten model
OT  - Sporosarcina pasteurii
OT  - ammonium inhibition
OT  - microbial kinetics
OT  - pH inhibition
OT  - ureolysis
EDAT- 2015/03/27 06:00
MHDA- 2016/04/06 06:00
CRDT- 2015/03/27 06:00
PHST- 2014/11/17 00:00 [received]
PHST- 2015/02/10 00:00 [revised]
PHST- 2015/02/26 00:00 [accepted]
PHST- 2015/03/27 06:00 [entrez]
PHST- 2015/03/27 06:00 [pubmed]
PHST- 2016/04/06 06:00 [medline]
AID - 10.1111/jam.12804 [doi]
PST - ppublish
SO  - J Appl Microbiol. 2015 Jun;118(6):1321-32. doi: 10.1111/jam.12804. Epub 2015 Apr 
      21.