PMID- 32785276
OWN - NLM
STAT- MEDLINE
DCOM- 20201006
LR  - 20201006
IS  - 1932-6203 (Electronic)
IS  - 1932-6203 (Linking)
VI  - 15
IP  - 8
DP  - 2020
TI  - Microbially induced calcite precipitation using Bacillus velezensis with guar 
      gum.
PG  - e0236745
LID - 10.1371/journal.pone.0236745 [doi]
LID - e0236745
AB  - Mineral precipitation via microbial activity is a well-known process with 
      applications in various fields. This relevance of microbially induced calcite 
      precipitation (MICP) has pushed researchers to explore various naturally 
      occurring MICP capable bacterial strains. The present study was performed to 
      explore the efficiency of microbially induced calcite precipitation (MICP) via 
      locally isolated bacterial strains and role of guar gum, which is a naturally 
      occurring polymer, on the MICP process. The strains were isolated from local soil 
      and screened for urease activity Further, the urease positive strain was 
      subjected to urea and calcium chloride based medium to investigate the efficacy 
      of isolated strain for microbial induced precipitation. Among screened isolates, 
      the soil bacterium that showed urease positive behaviour and precipitated calcium 
      carbonate was subjected to 16S rRNA gene sequencing. This strain was identified 
      as Bacillus velezensis. Guar gum-a natural polymer, was used as a sole carbon 
      source to enhance the MICP process. It was observed that the isolated strain was 
      able to breakdown the guar gum into simple sugars resulting in two-fold increase 
      in calcium carbonate precipitate. Major bio-chemical activities of isolated 
      strain pertaining to MICP such as ammonium ion concentration, pH profiling, and 
      total reducing sugar with time were explored under four different concentrations 
      of guar gum (0.25%, 0.5%, 0.75% and 1% w/v). Maximum ammonium ion concentration 
      (17.5 mug/ml) and increased pH was observed with 1% guar gum supplementation, 
      which confirms augmented MICP activity of the bacterial strain. Microstructural 
      analysis of microbial precipitation was performed using scanning electron 
      microscopy (SEM) and X-ray diffraction (XRD) techniques, which confirmed the 
      presence of calcium carbonate in different phases. Further, XRD and SEM based 
      studies corroborated that guar gum supplemented media showed significant increase 
      in stable calcite phase as compared to media without guar gum supplementation. 
      Significant diverse group of nitrogenous compounds were observed in guar gum 
      supplemented medium when subjected to Gas Chromatography-Mass spectrometry 
      (GC-MS) profiling.
FAU - Dikshit, Rashmi
AU  - Dikshit R
AD  - Department of Mechanical Engineering, Indian Institute of Science, Bangalore, 
      India.
FAU - Jain, Animesh
AU  - Jain A
AD  - Department of Mechanical Engineering, Indian Institute of Science, Bangalore, 
      India.
FAU - Dey, Arjun
AU  - Dey A
AUID- ORCID: 0000-0003-3727-3056
AD  - Thermal Systems Group, U. R. Rao Satellite Centre (formerly ISRO Satellite 
      Centre), Indian Space Research Organisation, Bangalore, India.
FAU - Kumar, Aloke
AU  - Kumar A
AUID- ORCID: 0000-0002-7797-8336
AD  - Department of Mechanical Engineering, Indian Institute of Science, Bangalore, 
      India.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20200812
PL  - United States
TA  - PLoS One
JT  - PloS one
JID - 101285081
RN  - 0 (Galactans)
RN  - 0 (Mannans)
RN  - 0 (Plant Gums)
RN  - E89I1637KE (guar gum)
RN  - H0G9379FGK (Calcium Carbonate)
SB  - IM
MH  - Bacillus/*metabolism
MH  - Calcium Carbonate/*chemistry/*metabolism
MH  - Chemical Precipitation
MH  - Galactans/*chemistry
MH  - Mannans/*chemistry
MH  - Plant Gums/*chemistry
PMC - PMC7423064
COIS- The authors have declared that no competing interests exist.
EDAT- 2020/08/14 06:00
MHDA- 2020/10/07 06:00
PMCR- 2020/08/12
CRDT- 2020/08/14 06:00
PHST- 2020/03/13 00:00 [received]
PHST- 2020/07/13 00:00 [accepted]
PHST- 2020/08/14 06:00 [entrez]
PHST- 2020/08/14 06:00 [pubmed]
PHST- 2020/10/07 06:00 [medline]
PHST- 2020/08/12 00:00 [pmc-release]
AID - PONE-D-20-07309 [pii]
AID - 10.1371/journal.pone.0236745 [doi]
PST - epublish
SO  - PLoS One. 2020 Aug 12;15(8):e0236745. doi: 10.1371/journal.pone.0236745. 
      eCollection 2020.