Table 3.5 is given which gives the names of some important bacterial strains that are
shown to degrade plastics (without concerning the fact that how efficient these
strains are in the process of degradation).
The microbial strains mentioned in Table 3.5 are a few examples where we can
use microbes to degrade plastics. One important thing to bear in mind that these
microbial strains that has been studied until are not available on commercial scale to
degrade large garbage dump sites in land, or to degrade plastic litter in oceans rather
these studies are just a hope that in near future we might discover some strains or
modify the existing strains using biotechnology, recombinant DNA technology or
our knowledge of protein and enzyme engineering. Scientists are working to
enhance the speed of catalytic activity of enzymes that degrade plastics so that
these modified enzymes can break the strong bonds between the synthetic polymer
chains of the plastics and convert them into simpler residues that might be less toxic
or can be used in making a diverse range of other useful products. Hence we can say
with confidence that in near future we can come up with new versions of plastic
degrading enzymes that will help us to counter plastic pollution not only in land but
also in ocean and other water bodies like rivers, lakes, and ponds.
O
O
O
HO
O
O
OH
OH
HO
HO
+
MHET
Ethylene glycol
(EG)
Terephthalic
acid (TPA)
O
OH
MHETase
H 2 O
(b)
Fig. 3.2b MHETase hydrolyzes MHET to Terephthalic acid and ethylene glycol
Table 3.5 Microbial degradation of synthetic plastics
Microbial strain
Type of plastic degraded
Reference(s)
Pseudomonas sp.
Polyethylene,
Polypropylene,
Polyvinyl chloride.
Wilkes and Aristilde (2017)
Aspergillus flavus,
Mucor circinilloides,
Low density polythene,
Polyvinyl chloride films
Urbanek et al. (2018)
Alcaligenes faecalis
Clostridium
botulinum
Polycaprolactone
Caruso (2015)
Micrococcus sp.
Polyvinyl chloride
Patil and Bagde (2012)
Ideonella sakaiensis
Flavobacterium sp.
Pseudomonas sp.
Polyethylene terephthalate,
Nylon
Ahmed et al. (2018) and Palm et al. (2019)
Thermophilic Bacillus Low-density polyethylene,
High density polyethylene
Dang et al. (2018)
Bacillus magaterium
Strain B1
Polyvinyl chloride
Luengo et al. (2003)
108
F. Muneer et al.
shown to degrade plastics (without concerning the fact that how efficient these
strains are in the process of degradation).
The microbial strains mentioned in Table 3.5 are a few examples where we can
use microbes to degrade plastics. One important thing to bear in mind that these
microbial strains that has been studied until are not available on commercial scale to
degrade large garbage dump sites in land, or to degrade plastic litter in oceans rather
these studies are just a hope that in near future we might discover some strains or
modify the existing strains using biotechnology, recombinant DNA technology or
our knowledge of protein and enzyme engineering. Scientists are working to
enhance the speed of catalytic activity of enzymes that degrade plastics so that
these modified enzymes can break the strong bonds between the synthetic polymer
chains of the plastics and convert them into simpler residues that might be less toxic
or can be used in making a diverse range of other useful products. Hence we can say
with confidence that in near future we can come up with new versions of plastic
degrading enzymes that will help us to counter plastic pollution not only in land but
also in ocean and other water bodies like rivers, lakes, and ponds.
O
O
O
HO
O
O
OH
OH
HO
HO
+
MHET
Ethylene glycol
(EG)
Terephthalic
acid (TPA)
O
OH
MHETase
H 2 O
(b)
Fig. 3.2b MHETase hydrolyzes MHET to Terephthalic acid and ethylene glycol
Table 3.5 Microbial degradation of synthetic plastics
Microbial strain
Type of plastic degraded
Reference(s)
Pseudomonas sp.
Polyethylene,
Polypropylene,
Polyvinyl chloride.
Wilkes and Aristilde (2017)
Aspergillus flavus,
Mucor circinilloides,
Low density polythene,
Polyvinyl chloride films
Urbanek et al. (2018)
Alcaligenes faecalis
Clostridium
botulinum
Polycaprolactone
Caruso (2015)
Micrococcus sp.
Polyvinyl chloride
Patil and Bagde (2012)
Ideonella sakaiensis
Flavobacterium sp.
Pseudomonas sp.
Polyethylene terephthalate,
Nylon
Ahmed et al. (2018) and Palm et al. (2019)
Thermophilic Bacillus Low-density polyethylene,
High density polyethylene
Dang et al. (2018)
Bacillus magaterium
Strain B1
Polyvinyl chloride
Luengo et al. (2003)
108
F. Muneer et al.