Molecular Soil Biology (online), 2013, Vol. 4 No.1, 1-6
ISSN 1925-2005
http://msb.sophiapublisher.com
1
Research Report Open Access
Hexavalent
Chromium (Cr (VI)) Removal by Live Mycelium of a
Trichoderma harzianum
Strain
Soumik Sarkar
1
,
Annamalai Satheshkumar
2
,
Robert Premkumar
2
1.
Al-Ameen Arts Science and Commerce College, P.G. and Research Dept. of Microbiology and Biotechnology- Bangalore-560027
2.
UPASI Tea Research Foundation, Tea Research Institute, Nirar Dam BPO, Valparai-642 127, Tamil Nadu, India
Corresponding author email:
soumiksarkarmib@rediffmail.com
;
Authors
Molecular Soil Biology, 2013, Vol.4, No.1 doi: 10.5376/msb.2013.04.0001
Received: 20 Dec., 2012
Accepted: 09 Jan., 2013
Published: 17 Feb., 2013
This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction
in any medium, provided the original work is properly cited.
Preferred citation for this article:
Sarkar et al., 2012, Hexavalent Chromium (Cr (VI)) Removal by Live Mycelium of a
Trichoderma harzianum
Strain, Molecular Soil Biology, Vol.4, No.1 1
-6
(
doi: 10.5376/msb.2013.04.0001)
Abstract
In the present study, an attempt was made to investigate the metal removal capacity of
Trichoderma harzianum
strain to
different chromium concentrations. It was noticed that, the mycelial growth was inhibited up to 94% at 40 mg/L concentration
followed by 30 mg/L (91%) of chromium by poison food technique. The metal (Cr (VI)) biosorption ability of
Trichoderma
harzianum
was tested in-vitro. The organism was inoculated on Czapek Dox broth medium containing 30 mg/L of Cr (VI) salt. The
metal residues were analyzed at different day’s interval (4, 5, 6 and 7 days). The effect of different pH and temperature on metal
removal was also investigated. Results indicated that, at 7
th
day the metal removal reached the maximum level (90.2%). Further
incubation did not increase the metal uptake. A pH range of 4~5 and temperature of 30
?
was optimum for Cr (VI) removal by
T.
harzianum
in the present study.
Keywords
Chromium;
Trichoderma harzianum
;
Biosorptionl pHl Temperature
Introduction
One of the most common and abundant heavy metal in
the earth crust is chromium (IARC. 1973). This metal
is also widely used in several industrial processes like
metal cleaning, textile, dyes etc. (Sen and Ghosh
Dastidar, 2007; Morales-Barrera and Cristiani-Urbina,
2008).
Cr can occur in various oxidation states (
-
2
to +6), but commonly found in oxidation states of +3
and +6. The oxidation states have significant
consequences for toxicity, bioavailability and
enrichment by microbial biomass (Bartlett, 1991). The
trivalent Cr compounds are less noxious, less portable
and available for biological uptake, while hexavalent
Cr are more toxic due to its greater solubility in water,
rapid permeability and subsequent interaction with
cell components (Sultan and Hasnain, 2005). Cr (VI)
also represents health hazards to animals and humans
since they are reported to be toxic, mutagenic,
carcinogenic and teratogenic (McLean and Beveridge,
2001;
JECFA, 2005). Existing methods presently
employed to eliminate heavy metals are many like
precipitation, ion-exchange, electrodeposition, reverse
osmosis etc (Rodriguez
et al
., 2006;
Alluri et al.,
2007).
These techniques for metal removal are not
often suitable or not very cost effective (Al-Saraj et al.,
1999;
Vieira and Volesky, 2000) and often generate
other wastes that require further treatments (Rostami
and Joodaki, 2002). Due to these complications, an
alternative way of metal removal is of great
importance.
The ability of microorganisms to take up metals has
been confirmed for some time (Hussain et al., 2004;
Preetha and Viruthagiri, 2005). The possible use of
microorganisms in treatment of hazardous materials
and metals from aqueous environment by biosorption
is considered as a favoured means (Ma et al., 2004;
Viraraghavan and Yan, 2003). Fungi, with other
microbial groups can accumulate metals from external
environments by means of various ways like
physico-chemical and biological mechanisms (Cabuk
et al., 2005). This technique of metal removal has
attracted increased attention in recent years which
offers several advantages over conventional methods
(
Popuri et al., 2007). In several previous studies, metal
removal abilities of various fungi have been