respective “antidote” genes immE3 and ecoRM (EcoRI methylase) were put into the
bacterial chromosome so that they are not transferred with the plasmid. This dual
control system exhibited higher control of gene transfer than the individual lethality
functions alone (Torres et al. 2003a; Davison 2005).
12.13 Future Directions
Detection of new genes and proteins which have the capacity for environmental
friendly cleaning will be of great help to attain increased bioremediation. Random
mutations may occur in those genes which are responsible for providing heavy metal
tolerance to microbes. These mutations generally have dangerous influences on the
organism but sometimes also have positive influences which create strains of higher
detoxification capacity. This event is known as gain-of-function mutation (Arora
et al. 2010). Complete genome analysis must be done through a microarray technique to recognize novel genes which may be induced under the presence of a
specific contaminant. Investigation of the expression of a variety of genes immediately is made possible through this technique by which it may become possible for
scientists to decide whether only a single gene or a group of genes is causing the
detoxification of a specific contaminant. Another simple procedure which can be
applied for investigating the presence of some target genes is fluorescence in situ
hybridization (FISH) (Pernthaler et al. 2002). FISH is usually utilized in medical
science to identify the existence of pathogens if infection occurs. But, its range may
be extended to other studies as well. Metagenomic analyses make possible to detect
and investigate several other unknown genomes which have the capacity to control
pollution. At last, once particular genes are detected, they may be moved to other
powerful strains and firmly induced for creating microbes which are more efficient
candidates for doing bioremediation. Microbes consist of several special traits like
production of biofilm, generation of biosurfactant, production of secondary
metabolites and various others to tolerate the stress environment. These
characteristics of metal resistant bacteria may be employed for their increased use
in bioremediation. Multispecies biofilm communities have been investigated for
their metal resistance as well as biomineralization characters recently (Golby et al.
2014) which exhibited the potential of using microbial population for bioremediation of metals and require further investigations (Das et al. 2016).
References
Abdel-Monem MO, Al-Zubeiry AH, Al-Gheethi AA (2010) Biosorption of nickel by Pseudomonas
cepacia 120S and Bacillus subtilis 117S. Water Sci Technol 61(12):2994–3007
Ackerley DF, Gonzalez CF, Keyhan M, Blake R, Matin A (2004) Mechanism of chromate
reduction by the Escherichia coli protein, NfsA, and the role of different chromate reductases
in minimizing oxidative stress during chromate reduction. Environ Microbiol 6:851–860
Adamis PD, Gomes DS, Pinto ML, Panek AD, Eleutherio EC (2004) The role of glutathione
transferases in cadmium stress. Toxicol Lett 154(1):281–288
352
N. Srivastava
bacterial chromosome so that they are not transferred with the plasmid. This dual
control system exhibited higher control of gene transfer than the individual lethality
functions alone (Torres et al. 2003a; Davison 2005).
12.13 Future Directions
Detection of new genes and proteins which have the capacity for environmental
friendly cleaning will be of great help to attain increased bioremediation. Random
mutations may occur in those genes which are responsible for providing heavy metal
tolerance to microbes. These mutations generally have dangerous influences on the
organism but sometimes also have positive influences which create strains of higher
detoxification capacity. This event is known as gain-of-function mutation (Arora
et al. 2010). Complete genome analysis must be done through a microarray technique to recognize novel genes which may be induced under the presence of a
specific contaminant. Investigation of the expression of a variety of genes immediately is made possible through this technique by which it may become possible for
scientists to decide whether only a single gene or a group of genes is causing the
detoxification of a specific contaminant. Another simple procedure which can be
applied for investigating the presence of some target genes is fluorescence in situ
hybridization (FISH) (Pernthaler et al. 2002). FISH is usually utilized in medical
science to identify the existence of pathogens if infection occurs. But, its range may
be extended to other studies as well. Metagenomic analyses make possible to detect
and investigate several other unknown genomes which have the capacity to control
pollution. At last, once particular genes are detected, they may be moved to other
powerful strains and firmly induced for creating microbes which are more efficient
candidates for doing bioremediation. Microbes consist of several special traits like
production of biofilm, generation of biosurfactant, production of secondary
metabolites and various others to tolerate the stress environment. These
characteristics of metal resistant bacteria may be employed for their increased use
in bioremediation. Multispecies biofilm communities have been investigated for
their metal resistance as well as biomineralization characters recently (Golby et al.
2014) which exhibited the potential of using microbial population for bioremediation of metals and require further investigations (Das et al. 2016).
References
Abdel-Monem MO, Al-Zubeiry AH, Al-Gheethi AA (2010) Biosorption of nickel by Pseudomonas
cepacia 120S and Bacillus subtilis 117S. Water Sci Technol 61(12):2994–3007
Ackerley DF, Gonzalez CF, Keyhan M, Blake R, Matin A (2004) Mechanism of chromate
reduction by the Escherichia coli protein, NfsA, and the role of different chromate reductases
in minimizing oxidative stress during chromate reduction. Environ Microbiol 6:851–860
Adamis PD, Gomes DS, Pinto ML, Panek AD, Eleutherio EC (2004) The role of glutathione
transferases in cadmium stress. Toxicol Lett 154(1):281–288
352
N. Srivastava