The Internet Journal of Microbiology ISSN: 1937-8289
Biotechnology: Role Of Microbes In Sustainable Agriculture And
Suraiya Binte Mosttafiz Department of Agricultural Sciences, Faculty of Agriculture and Forestry,
University of Helsinki
Mizanur Rahman Department of Energy Technology, Energy Economics Group, Aalto University School
of Engineering Espoo Finland
Mostafizur Rahman De partment of Medical Microbiology & Immunology, Faculty of Medicine, The
National University of Malaysia C heras Kuala Lumpur
Citation: S..B. Mosttafiz , M. Rahman , M. Rahman : Biotechnology: Role Of Microbes In Sustainable
Agriculture And Environmental Health. The Internet Journal of Microbiology . 2012 Volume 10 Number 1
Biotechnology is the rapidly growing segment in biological sciences. It has diversified applications in
sustainable agriculture. The review deals with microbes in biotechnology and their diversified
applications in agriculture as biofertilizers, bio-pesticides, bio-herbicides, bioinsecticides, fungal based
bioinsecticides and viral based bioinsecticides. Further, precise descriptions have been made on
Microbiology Ecology Biotechnology and Sustainable agriculture in the later part of the rev iew. Finally, a
brief highlight has be en given on the role of Microbial Biotechnology on Environmental Health
Biotechnology is the branch of biological science, which deals with the manipulation through genetic
engineering of living organisms or their components to produce useful products for various applications
in biological sciences.
The world's population is estimated to be double by the end of 2033. Food demand in Asia is expected
to exceed the need by the end of 2010. This poses a great challenge to agricultural sy stems.
Traditional farming equipment and practices are reaching their limits of effectiveness in increasing
agricultural productivity. As countries develop, people are also demanding more and better food. These
pressures are multiplied by shrinking farmland, rising labour costs and shortage of farm workers.
Biotechnology offers an additional me thod to improve the sustainability of existing system to produce
more and better quality of our agricultural products.. The potential benefits of plant biotechnology are
numerous and include providing resistance to crop pests, increasing crop yield and reducing chemical
pesticide usage. The processing of food and food ingredients using biotechnology provides a wide
variety of fermented foods and food ingredients that are extensively used. Agricultural technologies
that e nsured a ‘green revolution’ in the middle of 20th century, causing now high ecological cost and
contributing global pollution, unfavourable climate change and loss of biodiversity (Vance, 1998). The
broad application of microbes in sustainable agriculture is due to the genetic dependency of plants on
the beneficial functions provided by sy mbiotic cohabitants (Noble & Ruaysoongnern, 2010).Therefore,
microbial biotechnology and its applications in sustainable development of agriculture and
environmental he alth are getting better attention. The purpose of the rev iew is to further prioritize the
importance in the scientific community as well as stakeholders.
Microbes and biotechnology
Microbes / micro-organisms are mostly micropsic small creatures are placed in different groups such
bacteria, fungi, protozoa, micro-algae and viruses. These organisms live in soil, water, food, animal
intestines and other different environments. Various microbial habitats reflect an enormous diversity of
biochemical and metabolic traits that hav e arisen by genetic variation and natural selection in microbial
Men used some of microbial diversity in the production of fermented foods such as bread, yogurt, and
cheese. Some soil microbes release nitrogen that plants need for growth and emit gases that maintain
the critical composition of the Earth's atmosphere.
Other microbes challenge the food supply by causing yield-reducing diseases in food-producing plants
and animals. In our bodies, different microbes help to digest food, ward off invasive organisms, and
engage in skirmishes and pitched battles with the human immune system in the give-and-take of the
natural disease process.
A genome is the totality of genetic material in the DNA of a particular organism. Genomes differ greatly
in size and sequence across different organisms. Obtaining the complete genome sequence of a
microbe provides crucial information about its biology, but it is only the first step toward understanding
a microbe's biological capabilities and modifying them, if needed, for agricultural purposes.
Microbial biotechnology, enabled by genome studies, will lead to breakthroughs such as improved
vaccines and better disease-diagnostic tools, improved microbial agents for biological control of plant
and animal pests, modifications of plant and animal pathogens for reduced virulence, development of
new industrial catalysts and fermentation organisms, and development of new microbial agents for
bioremediation of soil and water contaminated by agricultural runoff
Microbial biotechnology is an important area that promotes for advances in food safety, food security,
value -added products, human nutrition and functional foods, plant and animal protection, and overall
fundamental research in the agricultural sciences.
Microbial biotechnology and its applications in agriculture
Micro-organisms found in the soil to improve agricultural productivity. Men use naturally occurring
organisms to develop biofertilizers and bio-pesticides to assist plant growth and control wee ds, pests,
Micro-organisms that live in the soil actually help plants to absorb more nutrients. Plants and these
friendly microbes are involved in “nutrient recycling”. The microbes help the plant to “take up” essential
energy sources. In return, plants donate their waste by-products for the microbes to use for food.
Scientists use these friendly micro-organisms to develop biofertilizers.
Phosphate and nitrogen are important for the growth of plants. These compounds exist naturally in the
environment but plants have a limited ability to extract them. Phosphate plays an important role in crop
stress tolerance, maturity, quality and directly or indirectly, in nitrogen fixation. A fungus, Penicillium
bilaii helps to unlock phosphate from the soil. It make s an organic acid, which dissolves the phosphate
in the soil so that the roots can use it. Biofertilizer made from this organism is applied by either coating
seeds with the fungus as inoculation, or putting it directly into the ground. Rhizobium is a bacteria used
to make biofertilizers. This bacterium lives on the plant's roots in cell collections called nodules. The
nodules are biological factories that can tak e nitrogen out of the air and convert it into an organic form
that the plant can use.
This fertilization method has been designed by nature. With a large population of the friendly bacteria
on its roots, the legume can use naturally-occurring nitrogen instead of the expensive traditional
Biofe rtilizers help plants use all of the food available in the soil and air, thus allowing farmers to reduce
the amount of chemical fertilizers they use. This helps preserve the environment for the generations to
Microorganisms found in the soil are all not so friendly to plants. These pathogens can cause disease or
damage the plant. As scientists developed biological “tools,” which use these disease-causing microbe s
to control weeds and pests naturally.
Weeds are the problem for farmers. They not only compete with crops for water, nutrients, sunlight,
and space but also harbor insect and disease pests; clog irrigation and drainage systems; undermine
crop quality; and deposit weed seeds into crop harvests.
Bio-herbicides are another way of controlling wee ds without environmental hazards posed by sy nthetic
herbicides. The microbes posse ss invasive genes that can attack the defence genes of the wee ds,
thereby killing it.
The benefit of using bioherbicides is that it can surv ive in the environment long enough for the next
growing season whe re there will be more weeds to infect. It is cheaper than synthetic pesticides thus
could essentially reduce farming expenses if managed properly. Further, it is not harmful to the
environment compared to conventional herbicides and will not affect non-target organisms.
Biotechnology can also help in developing alternative controls to synthetic insecticides to fight against
insect pests. Micro-organisms in the soil that will attack fungi, viruses or bacteria, which cause root
diseases. Formulas for coatings on the seed (inoculants) which carry these beneficial organisms can be
developed to protect the plant during the critical seedling stage.
Bioinsecticides do not persist long in the environment and have shorter shelf lives; they are effective in
small quantities, safer to humans and animals compared to synthetic insecticides; they are very
specific, often affecting only a single species of insect and have a very specific mode of action; slow in
action and the timing of their application is relatively critical.
Fungi cause diseases in some 200 different insects and this disease producing traits of fungi is being
used as bioinsecticides.
Fermentation technology is used to mass production of fungi. Spores are harvested and packaged so
these are applied to insect-ridden fields. When the spores are applied, they use enzymes to break
through the outer surface of the insects' bodies. Once inside, they begin to grow and eventually cause
Fungal agents are recommended by some researche rs as having the best potential for long-term insect
control. This is because these bioinsecticides attack in a variety of way s at once, making it very difficult
for insects to develop resistance.
Baculoviruses affect insect pests like corn borers, potato beetles, flea beetles and aphids. One
particular strain is being use d as a control agent for bertha army worms, which attack canola, flax, and
vegetable crops. Traditional insecticides do not affect the worm until after it has reached this stage and
by then much of the damage has been done.
Microbiology Ecology Biotechnology and Sustainable Agriculture
Now increasing attention has been paid to the dev elopment of sustainable agriculture in which the high
productivities of plants and animals are ensured using their natural adaptive potentials, with a minimal
disturbance of the environment (Noble & Ruaysoongnern, 2010). It is our view that the most promising
strategy to reach this goal is to substitute hazardous agrochemicals (mineral fertilizers, pe sticides) with
environment-friendly preparations of symbiotic microbes, which could improve the nutrition of crops
and livestock, as well as their protection from biotic (pathogens, pests) and abiotic (including pollution
and climatic change) stresses (Yang et al., 2009).
Therefore, agricultural microbiology is the present paramount research field responsible for the
transfer of knowledge from general microbiology and microbial ecology to the agricultural
biotechnologies. The present review is focussed on plants, but also emphasises the importance of
micro-organisms in relation to agriculture and environmental health (Wang et al., 2009) and to the
biocontrol of phy tophagans (Mohammed et al., 2008).
The broad application of microbes in sustainable agriculture is due to the genetic dependency of plants
on the beneficial functions provided by symbiotic cohabitants (Noble & Ruaysoongnern, 2010). The
agronomic potential of plant–microbial symbioses proceeds from the analysis of their ecological
impacts, which have been best studied for N2 fixing (Franche et al., 2009). This analysis has been
based on ‘applied co-evolutionary research’ (Arnold et al., 2010), addressing the ecological and
molecular mechanisms for mutual adaptation and parallel speciation of plant and microbial partners.
For plant–fungal interactions, it has been demonstrated that the host genotype represents the leading
factor in the biogeographic distribution of mycobionts and for their evolution within the
mutualist↔antagonist and specialist↔generalist continua (Peay et al., 2010).
The major impact of agricultural microbiology on sustainable agriculture would be to substitute
agrochemicals (mineral fertilizers, pesticides) with microbial preparations. However, this substitution is
usually partial and only sometimes may be complete, e .g. in recently dome sticated leguminous crops,
which retain a high potential for symbiotrophic N nutrition, typical for many wild legumes (Provorov &
Tikhonovich, 2003). The application of nutritional symbionts could be base d on plant mixotrophy, e.g.
on a simultaneous symbiotrophic and combined N nutrition. This is why the max imal productivity of the
majority of crops is reached using an optimal (species- and genotype-specific) combination of both
nutritional types because of which a high sustainability of legume production may be achieved
(Provorov et al., 1998). Moreover, the energy costs for N2 fixation and for assimilation of combined N
differ by less than 10% (Andrews et al., 2009). The balance between symbiotrophic and combined N
nutrition may be improved by a rapid removal of N-compounds from the actively N2-fixing symbiose s,
as has been suggested for tropical forest ecosystems (Hedin et al., 2009).
This approach is most promising in legume–rhizobia symbioses where the strong correlations between
the ecological efficiency of mutualism and its genotypic specificity are evide nt (Provorov & Vorobyov,
At present, a wide spectrum of preparations of diverse microbial species may be used to enhance crop
production (Andrews et al., 2010). However, different approaches for improving the nutritional and
defensive types of microbial mutualists need to be developed. For the nutritional types, an effective
colonisation of plants in a host-specific manner is optimal and the impacts of beneficial symbionts are
increased in parallel with their host specificity (Provorov & Vorobyov, 2009).
The application of microbial symbiotic signals or their derivatives for remodelling plant deve lopmental
or de fensiv e functions may represent a promising field for agricultural biotechnology.
The prospects for a future development of agricultural microbiology may involve the construction of
novel multipartite endo- and e cto-symbiotic communities based on extended genetic and molecular
(metagenomic) analyses. The primary approach for such construction is to create composite inoculants,
which simulate the natural plant-associated microbial communities. For balancing the host plant
metabolism, a combination of N- and P-providing symbionts would appear promising, including the
endosymbiotic rhizobia + VAM-fungi (Shtark et al., 2010),
The further development of agricultural microbiology faces several important ecological and genetic
challenges imposed by the broad application of symbiotic microbes. Some of these challenges are
associated with opportunistic or ev en regular human pathogens, which are frequently found in
endophytic communities, including Bacillus, Burkholderia, Enterobacter, Escherichia, Klebsiella,
Salmonella and Staphylococcus species ( Ryan et al., 2008).
An increased knowledge of microbe-based symbioses in plants could provide effective ways of
developing sustainable agriculture in order to ensure human and animal food production with a minimal
disturbance of the environment. The effective management of symbiotic microbial communities is
possible using molecular approaches based on the continuity of microbial pools which are circulating
regularly between soil-, plant- and animal-provided niches in natural and agricultural ecosystems
(Kupriy anov et al., 2010; Analysis of this circulation could enable the creation of highly productive
microbe-based sustainable agricultural system, whilst addressing the ecological and genetic
conse quence s of the broad application of microbes in agricultural practice
Environmental health and Microbial biotechnology
Bruce Rittmann, director of the Center for Environmental Biotechnology in the Biodesign Institute at
ASU, addressed the challenges and solution of environmental health by manipulation of
Their solution: a synergistic marriage of two distinct disciplines, microbial ecology and environmental
biotechnology. “Together, they offer much promise for helping society deal with some of its greatest
challenges in environmental quality, sustainability, security, and human health,” Rittmann stated in an
excerpt from the paper(http//:www.biodesign.asu.edu)
Leading the marriage are revolutionary changes in compiling vast amounts of genetic information on
microbial organisms through state-of-the-art DNA-based technique s. Identifying just a single microbial
specimen is a daunting task, considering, that there may be trillions of bacteria in ev ery litre of water.
To aid in the identification and function of indiv idual micro-organisms and communities, the first use of
modern molecular biology tools began in the early 1980s, with the advent of poly merase chain reaction
(PC R) amplification of microbial DNA and a new view of the ev olution of organisms based on their
These technologies have advanced into high-throughput genomic and proteomic protocols that can
detect specific genes and their metabolic functions with great precision and detail. Other methods can
now reconstruct entire genomes of what were once “uncultivable” microbes.
With recent advances in biology, materials, computing, and engineering, environmental
biotechnologists now are able to use microbial communities for a wealth of services to society. These
include detoxifying contaminated water, wastewater, sludge, sediment, or soil; capturing renewable
energy from biomass; sensing contaminants or pathogens; and protecting the public from dangerous
exposure to pathogens.
“Scientifically, it might be easiest to let the microbes convert the energy is organic wastes directly to
electricity. Howeve r, they also can generate useful fuels, such as methane and hy drogen, and we are
pursuing research on all of these renewable-energy forms.”
Rittman hoped the success in capturing the energy out of waste materials, this would be a world-
transforming technology and a real step forward to using more re newable forms of energy and much
less reliance on fossil fuel.”
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