communities of the soil (Lowery and Ursell 2019). If it gets altered, biogeochemical
cycle connected with mineralization of several trace elements required for plant
growth will also alter. It is Feng et al. (2013) who proved that the nanoplastics will
impact as a toxic physical component in mycorrhizal functioning.
There are several reports to prove the impact of microplastics on soil biodiversity
and function. Machado et al. (2018a, 2018b) conducted a thorough research for
5-weeks in a garden experiment where in loamy sand soil is exposed to polyethylene
fragments, polyacrylic fibers, polyester fibers, and polyamide beads up to 2%
concentration. After the exposure the bulk density, hydraulic conductivity, water
holding capacity, soil aggregation, and overall microbial activity were recorded.
They observed that microplastic affected the bulk density, water holding capacity
and even they observed the alteration in functional relationship between water stable
aggregates and microbial activity. They have a final saying to conclude that these
changes in due course of time will alter the terrestrial ecosystems homeostasis and
plastic will serve as a long term anthropogenic stressors.
Even though plastic pollution is increasing day by day, its impact on terrestrial
ecosystem is not completely worked out. Earthworms are used as a test organism to
assess the plastic pollution in soil and its adverse effect on soil fauna, similar
extended study on other organisms including human beings, invertebrates, plant
associated microflora, and insects needs to be thoroughly reviewed. This will
provide the information on overall effect of plastic in agriculture related ecosystem
(Chae and An 2018).
7.5
Plastic Degrading Soil Microflora
Microorganisms show inherent capacity to adapt to the environment they come
across during its multiplication. Since they are naturally exposed to the diverse
environmental conditions it is obvious that they should possess mechanism to use
one or the other carbon or energy source available in such situations. Due to this they
have the potential to transform variety of raw materials and if it is continuously
exposed to plastic rich environment, they do adjust its physiology to make use of
these plastics as source of nutrition through complete mineralization or partial
degradation. Hence in connection with this, numerous scientific studies are carried
out to isolate microorganisms associated with plastic polluted environment especially soil and water. Microbial flora associated with utilization of plastic polymers
and its degradation remains as a better alternative to clean up the plastic polluted
agricultural soil.
Research carried out on biodegradation associated plastic clean up using
microorganisms (Premraj and Doble 2005; Raaman et al. 2012; Alshehrei 2017;
Ru et al. 2020), it is observed that in the beginning microbes adhere to the polymer
surface leading to its further colonization. After successful colonization microbes are
known to produce array of enzymes which are generally extracellular, these enzymes
lead to hydrolytic breakdown of the surface. Dang et al. (2018) reported that Bacillus
sp. produced several hydrolytic enzymes such as CMCase, lipase, chitinase,
7 Microbe-Mediated Mitigation of Abiotic Stress in Plants
239
cycle connected with mineralization of several trace elements required for plant
growth will also alter. It is Feng et al. (2013) who proved that the nanoplastics will
impact as a toxic physical component in mycorrhizal functioning.
There are several reports to prove the impact of microplastics on soil biodiversity
and function. Machado et al. (2018a, 2018b) conducted a thorough research for
5-weeks in a garden experiment where in loamy sand soil is exposed to polyethylene
fragments, polyacrylic fibers, polyester fibers, and polyamide beads up to 2%
concentration. After the exposure the bulk density, hydraulic conductivity, water
holding capacity, soil aggregation, and overall microbial activity were recorded.
They observed that microplastic affected the bulk density, water holding capacity
and even they observed the alteration in functional relationship between water stable
aggregates and microbial activity. They have a final saying to conclude that these
changes in due course of time will alter the terrestrial ecosystems homeostasis and
plastic will serve as a long term anthropogenic stressors.
Even though plastic pollution is increasing day by day, its impact on terrestrial
ecosystem is not completely worked out. Earthworms are used as a test organism to
assess the plastic pollution in soil and its adverse effect on soil fauna, similar
extended study on other organisms including human beings, invertebrates, plant
associated microflora, and insects needs to be thoroughly reviewed. This will
provide the information on overall effect of plastic in agriculture related ecosystem
(Chae and An 2018).
7.5
Plastic Degrading Soil Microflora
Microorganisms show inherent capacity to adapt to the environment they come
across during its multiplication. Since they are naturally exposed to the diverse
environmental conditions it is obvious that they should possess mechanism to use
one or the other carbon or energy source available in such situations. Due to this they
have the potential to transform variety of raw materials and if it is continuously
exposed to plastic rich environment, they do adjust its physiology to make use of
these plastics as source of nutrition through complete mineralization or partial
degradation. Hence in connection with this, numerous scientific studies are carried
out to isolate microorganisms associated with plastic polluted environment especially soil and water. Microbial flora associated with utilization of plastic polymers
and its degradation remains as a better alternative to clean up the plastic polluted
agricultural soil.
Research carried out on biodegradation associated plastic clean up using
microorganisms (Premraj and Doble 2005; Raaman et al. 2012; Alshehrei 2017;
Ru et al. 2020), it is observed that in the beginning microbes adhere to the polymer
surface leading to its further colonization. After successful colonization microbes are
known to produce array of enzymes which are generally extracellular, these enzymes
lead to hydrolytic breakdown of the surface. Dang et al. (2018) reported that Bacillus
sp. produced several hydrolytic enzymes such as CMCase, lipase, chitinase,
7 Microbe-Mediated Mitigation of Abiotic Stress in Plants
239