Modulation of calcium carbonate precipitation by exopolysaccharide in Bacillus sp. JH7

Modulation of calcium carbonate precipitation by exopolysaccharide in Bacillus sp. JH7 Extracellular polymeric substance (EPS) is proposed to facilitate calcium ion supersaturation through its nucleation effect during the microbially induced calcium carbonate precipitation (MICP) process. However, the supersaturation effect of Ca2+ via EPS in MICP has not been clearly demonstrated. Enhanced exopolysaccharide production of the alkali- and halotolerant MICP-capable bacteria, Bacillus sp. JH7, was achieved through glycerol addition. This was demonstrated by measuring cellular precipitation and Congo red binding. Interestingly, field emission scanning electron microscopy and energy-dispersive X-ray spectrometry analysis demonstrated that there was no MICP under glycerol-amended conditions. Although glycerol promoted exopolysaccharide capture of Ca2+ ions, Ca2+ embedded onto EPS did not participate in MICP formation. The pH was reduced in glycerol-added media, which led us to analyze high acetate production under our test conditions. Purified glycerol-induced exopolysaccharide showed a higher capacity of Ca2+ capture than the control. Quantitative RT-PCR analysis showed that three genes involved in exopolysaccharide production were highly upregulated by glycerol. The amounts of three detected monosaccharides (arabinose, glucose, and mannose) were altered by glycerol. Cell hydrophobicity measurements indicated that glycerol could confer more hydrophilic characteristics to cells, which might enhance Ca2+ binding onto EPS. Unexpectedly, our data demonstrated, for the first time, that glycerol could promote exopolysaccharide and acetate production under our test condition, which could inhibit MICP by reducing the availability of free Ca2+. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Applied Microbiology and Biotechnology Springer Journals

Modulation of calcium carbonate precipitation by exopolysaccharide in Bacillus sp. JH7

Loading next page...
 
/lp/springer_journal/modulation-of-calcium-carbonate-precipitation-by-exopolysaccharide-in-c5OyrtkTM4
Publisher
Springer Berlin Heidelberg
Copyright
Copyright © 2017 by Springer-Verlag GmbH Germany
Subject
Life Sciences; Microbiology; Microbial Genetics and Genomics; Biotechnology
ISSN
0175-7598
eISSN
1432-0614
D.O.I.
10.1007/s00253-017-8372-8
Publisher site
See Article on Publisher Site

Abstract

Extracellular polymeric substance (EPS) is proposed to facilitate calcium ion supersaturation through its nucleation effect during the microbially induced calcium carbonate precipitation (MICP) process. However, the supersaturation effect of Ca2+ via EPS in MICP has not been clearly demonstrated. Enhanced exopolysaccharide production of the alkali- and halotolerant MICP-capable bacteria, Bacillus sp. JH7, was achieved through glycerol addition. This was demonstrated by measuring cellular precipitation and Congo red binding. Interestingly, field emission scanning electron microscopy and energy-dispersive X-ray spectrometry analysis demonstrated that there was no MICP under glycerol-amended conditions. Although glycerol promoted exopolysaccharide capture of Ca2+ ions, Ca2+ embedded onto EPS did not participate in MICP formation. The pH was reduced in glycerol-added media, which led us to analyze high acetate production under our test conditions. Purified glycerol-induced exopolysaccharide showed a higher capacity of Ca2+ capture than the control. Quantitative RT-PCR analysis showed that three genes involved in exopolysaccharide production were highly upregulated by glycerol. The amounts of three detected monosaccharides (arabinose, glucose, and mannose) were altered by glycerol. Cell hydrophobicity measurements indicated that glycerol could confer more hydrophilic characteristics to cells, which might enhance Ca2+ binding onto EPS. Unexpectedly, our data demonstrated, for the first time, that glycerol could promote exopolysaccharide and acetate production under our test condition, which could inhibit MICP by reducing the availability of free Ca2+.

Journal

Applied Microbiology and BiotechnologySpringer Journals

Published: Jun 22, 2017

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off