Beneficial Relationships: Bacterial Partners Boost Mangrove Tolerance to Contaminants
- Date
- 2023/12/20
- Writer
- 사이트매니저
- Hit
- 1943
Boost Mangrove Tolerance to Contaminants
Scientists find that
mangrove seedlings inoculated with diesel-degrading bacteria are more tolerant
to diesel contamination.
Diesel
is an important driver of economic growth but also has negative impacts on
estuarine ecosystems that are hard to ignore. In this regard, the potential of
mangrove ecosystems for phytoremediation of diesel-contaminated soil remains
unknown. Scientists have now found that Bacillus safensis-SH10, Sphingomonas
sp.-LK11, Rhodococcus corynebacterioides-NZ1, and Bacillus
subtilis-EP1 can significantly improve mangrove seedling tolerance to
diesel contamination, opening the door for managing pollutants in estuarine
ecosystems with bacterial-enhanced phytoremediation
Image title: Soil bacteria can degrade diesel contaminants and mitigate
oxidative stress.
Image caption: Long-chain n-alkanes in diesel are damaging to
plant growth. Scientists have found that augmenting mangrove seedlings with a
bacterial inoculum can improve their tolerance to diesel contamination and
overall growth.
Image credit: In-Jung Lee from Kyungpook National University
License type: Original Content
Usage restrictions: Cannot be reused without permission.
Fostering beneficial
relationships can pay dividends in the long run. In plant-microbe associations,
relationships that impact ecosystems in the context of mitigating hydrocarbon
pollutants are receiving plenty of attention. Diesel has a prominent role in
propping up most economies. However, diesel contamination from spills poses a
significant threat to many estuarine ecosystems. As a result of these spills,
estuarine ecosystems face threats to soil aeration, infiltration, and
permeability. These spills also take a heavy toll on mangroves and the
ecosystem services they provide a habitat to live in and a sanctuary to breed
for a diverse group of marine organisms.
While plant species like
alfalfa harbor the capacity for hydrocarbon phytoremediation a process where
plants decontaminate and detoxify the affected environment the potential for
mangroves to do so remains untapped. However, research has shown that
detoxifying diesel contaminants using microbial species in tandem with natural
vegetation can be a viable approach to mitigating the effects of hydrocarbon
pollution.
Recently, a group of
researchers led by Professor In-Jung Lee from the Department of Applied
Biosciences at Kyungpook National University, South Korea, and Professor Abdul
Latif Khan from the Department of Engineering Technology at the University of
Houston, USA, has identified a microbial consortium that degrades diesel
components and improves mangrove growth in the presence of diesel
contamination. Their findings were made available online on August 28, 2021,
and published in the Journal of Hazardous Materials on February 05, 2022.
“The rhizosphere is the
region in the immediate periphery of the root, and a plethora of microbial
species reside here. We were keen to enhance the degradation of diesel
contaminants by engineering the rhizosphere with specific bacterial species
that could degrade the alkanes found in diesel and reprogram the host’s
metabolism to bolster tolerance to the contamination,” says Prof. Lee.
The team first set out to identify bacteria capable of degrading diesel
by isolating species from the rhizosphere and oil-contaminated soil. Following
this screening, they narrowed down their analyses to Bacillus safensis-SH10,
Sphingomonas sp.-LK11, Rhodococcus corynebacterioides-NZ1, and Bacillus
subtilis-EP1. These bacteria rapidly degraded diesel into less
harmful products. They also showed high expression of alkane monooxygenase, an
enzyme that catalyzes the breakdown of n-alkanes.
When mangrove seedlings were treated with the bacteria and grown in the
presence of diesel, SH10 was inherently more effective in improving the
morphology, anatomy, and growth of the seedlings compared to the other strains.
The mangrove seedling defenses also exhibited an unexpected effect upon
treatment with SH10-diesel inoculation. “On profiling the expression of
anti-oxidative stress response genes and enzyme activities in the leaf, stem,
and root, we found the mangrove seedlings had reprogrammed their metabolism.
The inoculum reduced the expression and activity of the enzymes. This suggested
that the hosts were exposed to less diesel-contamination-induced oxidative
stress,” explains Prof. Lee.
Following treatment with SH10 and diesel, the researchers found that
mangrove seedlings produced higher soil-enzyme activities and secreted
essential metabolites in the rhizosphere. This observation reflected the
positive effects of the plant-microbe association when challenging the host
with the contaminant.
Prof. Lee foresees a bright future for research that aims to demystify
such plant-microbe-contaminant interactions and believes it is the key to
understanding pollutant detoxification, stabilization, and transformation in
natural environments. In conclusion, he remarks, “In the not-too-distant future,
we could see the widespread application of rhizosphere bacteria to reprogram
host physiology in agriculture. With the extensive degradation of natural
habitats, this strategy can ensure food safety and safeguard important crops.”
Reference
Authors |
Abdul Latif Khana,b,
Muhammad Numanc, Saqib Bilalb, Sajjad Asafb,
Kerri Crafwordd, Muhammad Imrane, Ahmed Al-Harrasib,
Jamal Nasser Al-Sabahif, Najeeb ur Rehmanb, Ahmed
A-Rawahib, and In-Jung Leee,* |
Title of
original paper: |
Mangrove’s
rhizospheric engineering with bacterial inoculation improve degradation of
diesel contamination |
Journal: |
Journal
of Hazardous Materials |
DOI: |
|
Affiliations |
aNatural
& Medical Sciences Research Center, University of Nizwa, 616, Oman eSchool of
Applied Biosciences, Kyungpook National University, Daegu Korea, South Korea |
Corresponding author’s
email |
About Kyungpook National University
Kyungpook National University (KNU) is
a national university located in Daegu, South Korea.
Founded in 1946, it is committed to
becoming a leading global university based on its proud and lasting tradition
of truth, pride, and service. As a comprehensive national university
representing the regions of Daegu and Gyeongbuk Province, KNU has been striving
to lead Korea’s national and international development by fostering talented
graduates who can serve as global community leaders.
Website: https://en.knu.ac.kr/main/main.htm
About Prof. In-Jung Lee
Dr. In-Jung Lee is a senior Professor
in the Department of Applied Biosciences at Kyungpook National University,
South Korea. He earned his Ph.D. from Texas A&M University, USA. Prof. Lee
researches plant physiology, and his team focuses on pioneering approaches to
understand plant growth regulation, phytohormonal signaling, and plant-microbe
interactions, particularly under stressful conditions. Professor Lee's research
delves into the intricate roles of plant hormones in growth and development,
especially in response to changing environmental factors. A key focus of his
work is investigating how microorganisms can mitigate environmental stressors.
About Prof. Abdul Latif Khan
Dr. Abdul Latif Khan is an Assistant
Professor of Plant Physiology and Genomics in the Department of Engineering
Technology at the University of Houston, USA. He completed his postdoctoral
training and earned a Ph.D. from Kyungpook National University, South Korea.
Before coming to the University of Houston, he was an Assistant Professor at
the University of Nizwa, Oman, where he gained experience with plant-microbe
interactions and genomics. His group is developing approaches to studying
plant-microbe interactions, gas exchange, and genomics of plants under
stressful conditions.
About Prof. Ahmed
Al-Harrasi
Dr. Al-Harrasi is
a Professor at the Natural & Medical Sciences Research Center, University
of Nizwa, Oman. He has obtained an MSc. and Ph.D. in Chemistry from the Free
University of Berlin. He received the Fulbright award for postdoctoral research
in Chemistry at Cornell University. His research group at the University of
Nizwa, Oman, extensively works in plant and soil chemistry.