PMID- 31980427
OWN - NLM
STAT- MEDLINE
DCOM- 20201013
LR  - 20201013
IS  - 1098-5336 (Electronic)
IS  - 0099-2240 (Print)
IS  - 0099-2240 (Linking)
VI  - 86
IP  - 7
DP  - 2020 Mar 18
TI  - In-Depth Profiling of Calcite Precipitation by Environmental Bacteria Reveals 
      Fundamental Mechanistic Differences with Relevance to Application.
LID - 10.1128/AEM.02739-19 [doi]
LID - e02739-19
AB  - Microbially induced calcite precipitation (MICP) has not only helped to shape our 
      planet's geological features but is also a promising technology to address 
      environmental concerns in civil engineering applications. However, limited 
      understanding of the biomineralization capacity of environmental bacteria impedes 
      application. We therefore surveyed the environment for different mechanisms of 
      precipitation across bacteria. The most fundamental difference was in ureolytic 
      ability, where urease-positive bacteria caused rapid, widespread increases in pH, 
      whereas nonureolytic strains produced such changes slowly and locally. These pH 
      shifts correlated well with patterns of precipitation on solid medium. 
      Strikingly, while both mechanisms led to high levels of precipitation, we 
      observed clear differences in the precipitate. Ureolytic bacteria produced 
      homogenous, inorganic fine crystals, whereas the crystals of nonureolytic strains 
      were larger and had a mixed organic/inorganic composition. When representative 
      strains were tested in application for crack healing in cement mortars, 
      nonureolytic bacteria gave robust results, while ureolytic strains showed more 
      variation. This may be explained by our observation that urease activity differed 
      between growth conditions or by the different natures and therefore different 
      material performances of the precipitates. Our results shed light on the breadth 
      of biomineralization activity among environmental bacteria, an important step 
      toward the rational design of bacterially based engineering solutions.IMPORTANCE 
      Biomineralization triggered by bacteria is important in the natural environment 
      and has many applications in industry and in civil and geotechnical engineering. 
      The diversity in biomineralization capabilities of environmental bacteria is, 
      however, not well understood. This study surveyed environmental bacteria for 
      their ability to precipitate calcium carbonate minerals and investigated both the 
      mechanisms and the resulting crystals. We show that while urease activity leads 
      to the fastest precipitation, it is by no means essential. Importantly, the same 
      quantities of calcium carbonate are produced by nonureolytic bacteria, and the 
      resulting crystals appear to have larger volumes and more organic components, 
      which are likely beneficial in specific applications. Testing both precipitation 
      mechanisms in a self-healing concrete application showed that nonureolytic 
      bacteria delivered more robust results. Here, we performed a systematic study of 
      the fundamental differences in biomineralization between environmental bacteria, 
      and we provide important information for the design of bacterially based 
      engineering solutions.
CI  - Copyright (c) 2020 Reeksting et al.
FAU - Reeksting, Bianca J
AU  - Reeksting BJ
AD  - Department of Biology and Biochemistry, Milner Centre for Evolution, University 
      of Bath, Bath, United Kingdom.
FAU - Hoffmann, Timothy D
AU  - Hoffmann TD
AD  - Department of Biology and Biochemistry, Milner Centre for Evolution, University 
      of Bath, Bath, United Kingdom.
FAU - Tan, Linzhen
AU  - Tan L
AD  - Department of Architecture and Civil Engineering, BRE Centre for Innovative 
      Construction Materials, University of Bath, Bath, United Kingdom.
FAU - Paine, Kevin
AU  - Paine K
AD  - Department of Architecture and Civil Engineering, BRE Centre for Innovative 
      Construction Materials, University of Bath, Bath, United Kingdom.
FAU - Gebhard, Susanne
AU  - Gebhard S
AUID- ORCID: 0000-0003-4783-6115
AD  - Department of Biology and Biochemistry, Milner Centre for Evolution, University 
      of Bath, Bath, United Kingdom s.gebhard@bath.ac.uk.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20200318
PL  - United States
TA  - Appl Environ Microbiol
JT  - Applied and environmental microbiology
JID - 7605801
RN  - H0G9379FGK (Calcium Carbonate)
SB  - IM
MH  - Bacteria/*metabolism
MH  - Calcium Carbonate/chemistry/*metabolism
MH  - Chemical Precipitation
MH  - *Environmental Microbiology
PMC - PMC7082560
OTO - NOTNLM
OT  - Bacillus
OT  - microbially induced calcite precipitation
OT  - self-healing concrete
OT  - ureolysis
EDAT- 2020/01/26 06:00
MHDA- 2020/10/21 06:00
PMCR- 2020/03/18
CRDT- 2020/01/26 06:00
PHST- 2019/11/25 00:00 [received]
PHST- 2020/01/12 00:00 [accepted]
PHST- 2020/01/26 06:00 [pubmed]
PHST- 2020/10/21 06:00 [medline]
PHST- 2020/01/26 06:00 [entrez]
PHST- 2020/03/18 00:00 [pmc-release]
AID - AEM.02739-19 [pii]
AID - 02739-19 [pii]
AID - 10.1128/AEM.02739-19 [doi]
PST - epublish
SO  - Appl Environ Microbiol. 2020 Mar 18;86(7):e02739-19. doi: 10.1128/AEM.02739-19. 
      Print 2020 Mar 18.