PMID- 33900669
OWN - NLM
STAT- MEDLINE
DCOM- 20211026
LR  - 20211026
IS  - 1365-2672 (Electronic)
IS  - 1364-5072 (Linking)
VI  - 131
IP  - 5
DP  - 2021 Nov
TI  - Smart soil grouting using innovative urease-producing bacteria and low cost 
      materials.
PG  - 2294-2307
LID - 10.1111/jam.15117 [doi]
AB  - AIMS: Calcium carbonate is a biomineral whose precipitation could be mediated by 
      ureolytic bacteria and contributes in strengthening of sandy soils. The type of 
      bacteria and grade of reagents have significant influence on microbially induced 
      calcite precipitation (MICP). In the present study, factorial experiments based 
      on these two factors were designed to determine their potential on MICP process, 
      taking into consideration the economic advantages while giving quality results as 
      well. METHODS AND RESULTS: For the first time, Alkalibacterium iburiense strain 
      EE1 (GenBank accession no. MF355369.1) is reported for its biogrouting activity. 
      Optimum growth conditions for MICP treatments were pH (9.56 +/- 0.021), EC 
      (44.7 +/- 0.057 mS cm(-1) ), OD(600) (2.04 +/- 0.015), NH(4) (+) concentration 
      (487.06 +/- 1.021 mmol l(-1) ), and urease activity (20.0 +/- 0.75 mmol l(-1) urea 
      hydrolysed min(-1) ) after 72-h incubation. Statistical analysis comparing the 
      growth in technical-grade medium prepared in tap water and analytical-grade 
      medium prepared in deionized water showed no significant differences (P = 1.0) in 
      biomass and urease activity. In contrast to previous studies, the current 
      approach could reduce the bacterial culture and cementation solution ratio by 
      about 50%, using a simple surface percolation method with staged injection 
      instead of parallel injection to treat different sand columns. Using fixation 
      solution could immobilize the bacteria over the full length of columns for better 
      strength improvement. The unconfined compressive strength ranged between 0.64 to 
      2.11 kg cm(-2) , and the corresponding CaCO(3) contents 5.7-38.5%. The scanning 
      electron microscope images indicated that the precipitated CaCO(3) by bacteria 
      was stable calcite. CONCLUSIONS: Alkalibacterium iburiense and technical-grade 
      reagents under nonsterile conditions are satisfactory consolidating agents for 
      sandy soils. SIGNIFICANCE AND IMPACT OF THE STUDY: This approach is considered 
      eco-friendly and cost-effective for future scale-up applications in various 
      geotechnical engineering.
CI  - (c) 2021 The Society for Applied Microbiology.
FAU - Ezzat, S M
AU  - Ezzat SM
AUID- ORCID: 0000-0003-3119-5683
AD  - Microbiology Department, Central Laboratory for Environmental Quality Monitoring 
      (CLEQM), National Water Research Center (NWRC), Cairo, Egypt.
FAU - Ewida, A Y I
AU  - Ewida AYI
AD  - Microbiology Department, Central Laboratory for Environmental Quality Monitoring 
      (CLEQM), National Water Research Center (NWRC), Cairo, Egypt.
LA  - eng
PT  - Journal Article
DEP - 20210512
PL  - England
TA  - J Appl Microbiol
JT  - Journal of applied microbiology
JID - 9706280
RN  - 0 (Soil)
RN  - EC 3.5.1.5 (Urease)
RN  - H0G9379FGK (Calcium Carbonate)
RN  - Alkalibacterium iburiense
SB  - IM
MH  - Bacteria
MH  - Calcium Carbonate
MH  - *Carnobacteriaceae
MH  - Soil
MH  - *Urease
OTO - NOTNLM
OT  - bacteria
OT  - calcite
OT  - low cost
OT  - soil grouting
OT  - urease enzyme
EDAT- 2021/04/27 06:00
MHDA- 2021/10/27 06:00
CRDT- 2021/04/26 12:32
PHST- 2021/02/15 00:00 [revised]
PHST- 2020/12/04 00:00 [received]
PHST- 2021/04/21 00:00 [accepted]
PHST- 2021/04/27 06:00 [pubmed]
PHST- 2021/10/27 06:00 [medline]
PHST- 2021/04/26 12:32 [entrez]
AID - 10.1111/jam.15117 [doi]
PST - ppublish
SO  - J Appl Microbiol. 2021 Nov;131(5):2294-2307. doi: 10.1111/jam.15117. Epub 2021 
      May 12.