Aafreen Fathima | Central leather research Institute (original) (raw)
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Papers by Aafreen Fathima
Clean Technologies and Environmental Policy, Dec 17, 2011
Abstract Discharge of untreated industrial effluents containing heavy metals is hazardous to the ... more Abstract Discharge of untreated industrial effluents containing heavy metals is hazardous to the environment as they are highly toxic and accumulates throughout the food chain. This study reports the removal of trivalent chromium from aqueous solution using Bacillus ...
Environmental Engineering and Management Journal, 2016
Archives of Microbiology, 2017
Applied Microbiology and Biotechnology, 2016
Catechin is a plant polyphenol composed of epicatechin (EC), epigallocatechin (EGC), epicatechin ... more Catechin is a plant polyphenol composed of epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG), and epigallocatechin gallate (EGCG) as diastereoisomers. Among the various classes of flavonoids, catechin was found to be the most powerful free radical scavenger, scavenging the reactive oxygen species (ROS) generated due to oxidative damage with antibacterial and anti-inflammatory activity. The toxicity of catechin towards bacteria was studied using gram-positive bacteria (B. subtilis) and gram-negative bacteria (E. coli) as model organisms and was found to be more toxic towards gram-positive bacteria. From the results, catechin was found to be beneficial as well as toxic (inhibitory) to the bacteria at a selective concentration behaving as double-edged swords with an IC50 value of 9 ppm for both the bacteria. The inhibitory mechanism of catechin was by oxidative damage through membrane permeabilization which was confirmed by the formation and treatment of bacterial liposomes. SEM images of the control and treated bacteria reveals membrane damage with morphological changes.
Clean Technologies and Environmental Policy, 2014
RSC Adv., 2014
[Cu(bitpy)2]2+ showed better antistaphylococcal activity than [Cu(bitpy)(dmp)]2+. SEM and confoca... more [Cu(bitpy)2]2+ showed better antistaphylococcal activity than [Cu(bitpy)(dmp)]2+. SEM and confocal microscopy showed the damage caused by complex 2 is more effective than 1. Complex 2 can be better used as an anti-biofouling agent.
Polyhedron, 2016
Abstract X-ray structural analyses of two newly synthesized Schiff base-complexes, [Co(L)3] (1) a... more Abstract X-ray structural analyses of two newly synthesized Schiff base-complexes, [Co(L)3] (1) and [Ni(L)2] (2) [HL = 2-((E)-(2-pyridine-2-pyridin-2-ylthio)ethylimino)methyl)phenol], reveal the bidentate chelation behavior of the ligand HL with octahedral and square planar geometries at the metal centers in 1 and 2, respectively. Both the compounds show antibacterial activity as well as catecholase activity. The antibacterial activities of the compounds were investigated on gram positive and gram negative bacteria; compound 2 was found to be better in terms of antibacterial activity than 1 against both the bacteria. Moreover, both compounds catalyse the oxidation of 3,5-ditertiarybutylcatechol in methanol in the presence of molecular oxygen with first order reaction kinetics and turn over numbers 3.48 × 103 h−1 (1) and 2.68 × 103 h−1 (2).
Chrome tanning wastewater generated during leather processing is one of the major source of aquat... more Chrome tanning wastewater generated during
leather processing is one of the major source of aquatic
contamination which has deleterious effect on the environment.
To deal this problem, many types of biosorbents
have been used so far. In this study, fugal biomass of
Termitomyces clypeatus, a byproduct of enzyme, and fermentation
industry have been employed for Cr(III) removal
from chrome tanning effluent. The maximum metal uptake
(qe) of 24.84 mg g-1 was obtained with an optimum pH
and temperature of 4 and 60 C for an initial metal concentration
of 100 ppm at an adsorbent dosage of 2 g L-1.
Adsorption process was best fitted by pseudo-second-order
kinetic model. Sorption process obeys Freundlich adsorption
isotherm model, rather than Langmuir. The presence
of functional groups and morphological changes on the
biomass responsible for metal uptake was confirmed by
FT-IR and scanning electron microscopy–energy dispersive
X-ray spectroscopy analyses.
Biofilm formation on medical implants is very difficult to overcome, since the bacteria in this f... more Biofilm formation on medical implants is very difficult to overcome, since the bacteria in this form resist the
host defense mechanism and antibiotic therapy. What is needed is the development of an anti-biofouling
agent which will prevent the formation of a biofilm especially on periprosthetic implants. In this study,
the antibiofilm forming potential of two copper(II) complexes namely, [Cu(bitpy)(dmp)](NO3)2 (1) and
[Cu(bitpy)2](ClO4)2 (2) was studied against Staphylococcus aureus MTCC – 7443, a soil isolate. From the
preliminary investigations, it became clear that the anti-staphylococcal activity of complex 2 was better
than complex 1 because of the damage the complex caused at the membrane level by inhibiting the
expression of some extracellular proteins responsible for biofilm formation. Further, the antibiofilm
forming nature of complex 2 was confirmed by biofilm susceptibility tests, SDS – PAGE and microscopic
imaging techniques. Complex 2 can therefore be used as one of the antibiofilm forming agents to curb
the formation of biofilms on medical implants.
1. Introduction
Staphylococcus aureus, a gram positive cocci occurring in grapelike
clusters is ubiquitous and is the most common causative
agent of localized suppurative lesions in humans. Most strains
of Staphylococcus possess resistance to b-lactam drugs such as
Methicillin, which enhances their importance as human pathogens
especially in a hospital environment. The cocci causes
major problems in the food sector by contaminating food
products;1 also it is responsible for indwelling device associated
infections with biolm formation on solid supports.2,3 Bacterial
biolm is a group of bacterial cells colonizing a surface or
substratum with the help of self-produced matrix of extracellular
polymeric substances (EPS)4 which consists of macromolecules
such as polysaccharides, proteins, humic substances
and uronic acid, collectively known as exopolysaccharides or
extracellular polymeric substances (EPS).5 Bacteria growing in
biolm escape host immune defense mechanism and are more
resistant to antimicrobial agents than their planktonic counterparts.
2 Bacterial anchorage to a suitable surface or
substratum is
Journal Of The American Leather Chemists Association, Nov 17, 2010
Journal of Chemical Technology and Biotechnology, Aug 30, 2011
BACKGROUND: Bacterial strains belonging to the genus Bacillus, isolated from Cr- polluted soil (t... more BACKGROUND: Bacterial strains belonging to the genus Bacillus, isolated from Cr- polluted soil (tannery sludge)were employed
as consortium for Cr(III) removal from tannery effluents. Kaolin clay, a natural adsorbent, was used as supporting material for
bacterial biofilm formation. The use of clay-supported bacterial biofilm has not previously been employed for the treatment of
tannery effluents containing Cr(III) salt.
RESULTS: Commercial tannery effluent containing 1000 ppm initial metal ion concentration was treated in stages. The initial
Cr(III) concentration of 1000 ppm was brought down to 2 ppm, a permissible level for discharge, after the fourth stage. The
bacterial isolates were found to be Bacillus subtilis VITSCCr01 and Bacillus cereus VITSCCr02 by 16s rRNA gene sequencing. Batch
assay and confocal laser scanning microscopy results revealed the role of kaolin as a support material in biofilm formation.
Best fit was obtained with the Freundlich adsorption isotherm. Themechanism of sorption was confirmed by Fourier transform
infrared (FT-IR) spectroscopy and scanning electronmicroscopy–energy dispersive X-ray spectroscopy (SEM-EDS).
CONCLUSION: Cr(III) removal from tannery effluent using low cost adsorbents such as kaolin and bacteria proved to be effective
for metal concentrations ≤1000 ppm; this is normally not possible using conventional treatment methods. This work has
demonstrated feasible sorption of Cr(III), especially during post-tanning operations.
Clean Technologies and Environmental Policy, Dec 17, 2011
Abstract Discharge of untreated industrial effluents containing heavy metals is hazardous to the ... more Abstract Discharge of untreated industrial effluents containing heavy metals is hazardous to the environment as they are highly toxic and accumulates throughout the food chain. This study reports the removal of trivalent chromium from aqueous solution using Bacillus ...
Environmental Engineering and Management Journal, 2016
Archives of Microbiology, 2017
Applied Microbiology and Biotechnology, 2016
Catechin is a plant polyphenol composed of epicatechin (EC), epigallocatechin (EGC), epicatechin ... more Catechin is a plant polyphenol composed of epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG), and epigallocatechin gallate (EGCG) as diastereoisomers. Among the various classes of flavonoids, catechin was found to be the most powerful free radical scavenger, scavenging the reactive oxygen species (ROS) generated due to oxidative damage with antibacterial and anti-inflammatory activity. The toxicity of catechin towards bacteria was studied using gram-positive bacteria (B. subtilis) and gram-negative bacteria (E. coli) as model organisms and was found to be more toxic towards gram-positive bacteria. From the results, catechin was found to be beneficial as well as toxic (inhibitory) to the bacteria at a selective concentration behaving as double-edged swords with an IC50 value of 9 ppm for both the bacteria. The inhibitory mechanism of catechin was by oxidative damage through membrane permeabilization which was confirmed by the formation and treatment of bacterial liposomes. SEM images of the control and treated bacteria reveals membrane damage with morphological changes.
Clean Technologies and Environmental Policy, 2014
RSC Adv., 2014
[Cu(bitpy)2]2+ showed better antistaphylococcal activity than [Cu(bitpy)(dmp)]2+. SEM and confoca... more [Cu(bitpy)2]2+ showed better antistaphylococcal activity than [Cu(bitpy)(dmp)]2+. SEM and confocal microscopy showed the damage caused by complex 2 is more effective than 1. Complex 2 can be better used as an anti-biofouling agent.
Polyhedron, 2016
Abstract X-ray structural analyses of two newly synthesized Schiff base-complexes, [Co(L)3] (1) a... more Abstract X-ray structural analyses of two newly synthesized Schiff base-complexes, [Co(L)3] (1) and [Ni(L)2] (2) [HL = 2-((E)-(2-pyridine-2-pyridin-2-ylthio)ethylimino)methyl)phenol], reveal the bidentate chelation behavior of the ligand HL with octahedral and square planar geometries at the metal centers in 1 and 2, respectively. Both the compounds show antibacterial activity as well as catecholase activity. The antibacterial activities of the compounds were investigated on gram positive and gram negative bacteria; compound 2 was found to be better in terms of antibacterial activity than 1 against both the bacteria. Moreover, both compounds catalyse the oxidation of 3,5-ditertiarybutylcatechol in methanol in the presence of molecular oxygen with first order reaction kinetics and turn over numbers 3.48 × 103 h−1 (1) and 2.68 × 103 h−1 (2).
Chrome tanning wastewater generated during leather processing is one of the major source of aquat... more Chrome tanning wastewater generated during
leather processing is one of the major source of aquatic
contamination which has deleterious effect on the environment.
To deal this problem, many types of biosorbents
have been used so far. In this study, fugal biomass of
Termitomyces clypeatus, a byproduct of enzyme, and fermentation
industry have been employed for Cr(III) removal
from chrome tanning effluent. The maximum metal uptake
(qe) of 24.84 mg g-1 was obtained with an optimum pH
and temperature of 4 and 60 C for an initial metal concentration
of 100 ppm at an adsorbent dosage of 2 g L-1.
Adsorption process was best fitted by pseudo-second-order
kinetic model. Sorption process obeys Freundlich adsorption
isotherm model, rather than Langmuir. The presence
of functional groups and morphological changes on the
biomass responsible for metal uptake was confirmed by
FT-IR and scanning electron microscopy–energy dispersive
X-ray spectroscopy analyses.
Biofilm formation on medical implants is very difficult to overcome, since the bacteria in this f... more Biofilm formation on medical implants is very difficult to overcome, since the bacteria in this form resist the
host defense mechanism and antibiotic therapy. What is needed is the development of an anti-biofouling
agent which will prevent the formation of a biofilm especially on periprosthetic implants. In this study,
the antibiofilm forming potential of two copper(II) complexes namely, [Cu(bitpy)(dmp)](NO3)2 (1) and
[Cu(bitpy)2](ClO4)2 (2) was studied against Staphylococcus aureus MTCC – 7443, a soil isolate. From the
preliminary investigations, it became clear that the anti-staphylococcal activity of complex 2 was better
than complex 1 because of the damage the complex caused at the membrane level by inhibiting the
expression of some extracellular proteins responsible for biofilm formation. Further, the antibiofilm
forming nature of complex 2 was confirmed by biofilm susceptibility tests, SDS – PAGE and microscopic
imaging techniques. Complex 2 can therefore be used as one of the antibiofilm forming agents to curb
the formation of biofilms on medical implants.
1. Introduction
Staphylococcus aureus, a gram positive cocci occurring in grapelike
clusters is ubiquitous and is the most common causative
agent of localized suppurative lesions in humans. Most strains
of Staphylococcus possess resistance to b-lactam drugs such as
Methicillin, which enhances their importance as human pathogens
especially in a hospital environment. The cocci causes
major problems in the food sector by contaminating food
products;1 also it is responsible for indwelling device associated
infections with biolm formation on solid supports.2,3 Bacterial
biolm is a group of bacterial cells colonizing a surface or
substratum with the help of self-produced matrix of extracellular
polymeric substances (EPS)4 which consists of macromolecules
such as polysaccharides, proteins, humic substances
and uronic acid, collectively known as exopolysaccharides or
extracellular polymeric substances (EPS).5 Bacteria growing in
biolm escape host immune defense mechanism and are more
resistant to antimicrobial agents than their planktonic counterparts.
2 Bacterial anchorage to a suitable surface or
substratum is
Journal Of The American Leather Chemists Association, Nov 17, 2010
Journal of Chemical Technology and Biotechnology, Aug 30, 2011
BACKGROUND: Bacterial strains belonging to the genus Bacillus, isolated from Cr- polluted soil (t... more BACKGROUND: Bacterial strains belonging to the genus Bacillus, isolated from Cr- polluted soil (tannery sludge)were employed
as consortium for Cr(III) removal from tannery effluents. Kaolin clay, a natural adsorbent, was used as supporting material for
bacterial biofilm formation. The use of clay-supported bacterial biofilm has not previously been employed for the treatment of
tannery effluents containing Cr(III) salt.
RESULTS: Commercial tannery effluent containing 1000 ppm initial metal ion concentration was treated in stages. The initial
Cr(III) concentration of 1000 ppm was brought down to 2 ppm, a permissible level for discharge, after the fourth stage. The
bacterial isolates were found to be Bacillus subtilis VITSCCr01 and Bacillus cereus VITSCCr02 by 16s rRNA gene sequencing. Batch
assay and confocal laser scanning microscopy results revealed the role of kaolin as a support material in biofilm formation.
Best fit was obtained with the Freundlich adsorption isotherm. Themechanism of sorption was confirmed by Fourier transform
infrared (FT-IR) spectroscopy and scanning electronmicroscopy–energy dispersive X-ray spectroscopy (SEM-EDS).
CONCLUSION: Cr(III) removal from tannery effluent using low cost adsorbents such as kaolin and bacteria proved to be effective
for metal concentrations ≤1000 ppm; this is normally not possible using conventional treatment methods. This work has
demonstrated feasible sorption of Cr(III), especially during post-tanning operations.