eChapters

Deliberate use of natural enemies to control invasive pest in an ecosystem is known as biocontrol. To control invasive weed species, selective pathogens and weed seed predators are employed to reduce the population of the weed to non competitive numbers rather than total eradication of the weed species (Appleby, 2005) These can be insects, herbivorous fish, other animals, disease causing organisms or even competitive plants. This method is comparatively safer to the ecosystem, is cheaper and has long lasting impact. Difficulty in f inding host specific bio-agent with minimum adverse effect on other crop and the environment is a challenge.

Abstract

Since the first oil well drilled successfully in 1859, crude oil has been a serious problem around world, including Indonesia. As a source of all petroleum products, crude oil is very complex component and divided into aliphatic, aromatic, resin and asphaltene. Petroleum products have been used for daily life and created large amounts of pollutants in environment and ecosystems around the globe. The pollutants should be treated by certain method; among them, bioremediation has several advantages to resolve the problem. In 2003, Ministry of Environmental (MoE) – Republic Indonesia was endorsed with a new regulation about biological treatment or bioremediation for crude oil contaminated soil (MoE regulation No. 128/2003). The most important to be noted in bioremediation process is the presence of microbes with certain metabolite capabilities. The degradation rate also can be improved and sustained by ensuring the adequate required factors. This article describes the removal of crude oil by utilization of microbial potentials, factors affecting biodegradation, and how they are applied in Indonesia.

The increasing concerns about dwindling biological resources globally led to the Convention on Biological Diversity in 1992. This convention for the first time, recognized sovereign rights of States over their biological resources and emphasized that access to genetic resources should be only for environmentally sound purposes and should be subject to national legislations. The access has to be on mutually agreed terms which inter-alia would include recognition of associated Traditional Knowledge of indigenous communities and equitable benefit sharing arrangements.

Taking cognizance of the provisions of the CBD, and to deal with extensive pressure on our biological resources, India has enacted an umbrella legislation called Biological Diversity Act-2002 (No. 18 of 2003), and also notified the Biological Diversity Rules-2004 for guidance and compliance by various stakeholders, including the Union and State Governments, Non-state sectors, and individuals. The Act aims at conservation of biological resources as well as facilitating access to them in a sustainable manner and through a just process. The salient features of this act are as follows (NBA, 2004).

The increasing concerns about dwindling biological resources globally led to the Convention on Biological Diversity in 1992. This convention for the first time, recognized sovereign rights of States over their biological resources and emphasized that access to genetic resources should be only for environmentally sound purposes and should be subject to national legislations. The access has to be on mutually agreed terms which inter-alia would include recognition of associated Traditional Knowledge of indigenous communities and equitable benefit sharing arrangements.

Plant nutrients are drawn up from soil for growth and development. There are more than 90 elements present in the soil. According to the criteria of Essentiality of Nutrients for plant growth, proposed by Arnon and Stout in 1952, only 16 are considered to be essential for plant growth. Out of these, C (Carbon), H (Hydrogen), O (Oxgen), N (Nitrogen), P (Phosphorus), K (Potassium), Ca (Calcium), Mg (Magnesium) and S (Sulfur) are called Macronutrients (required in large quantities) and the remaining 7 elements - Fe (Iron), Mn (Manganese), Cu (Copper), Zn (Zinc), B (Boran), Mo and Cl are called Micronutrients or trace elements (required only in very small quantities). Among the macro elements - N, P and K are called Fertiliser elements or primary nutrients as they are most often applied in the form of synthetic or mineral fertilisers, and Ca, Mg and S are called secondary elements which are applied in smaller quantities than primary nutrients and required subsequent to primary nutrients.

Definition

Garret (1970) defined biological control as any condition under which or practice whereby survival or activity of a pathogen is reduced through the agency of any other living organism (except man) with the result that there is a reduction in the incidence of the disease caused by that pathogen.

Baker and Cook (1974) stated that the biological control is the reduction of inoculum density or disease producing activities of a pathogen or parasite in its active or dormant stage, by one or more organisms, accomplished naturally or through manipulation of the environment, host or antagonists, or by mass introduction of one or more antagonists.

Biocontrol can be simply defined as the application of living organism to control diseases.

Plant diseases need to be controlled to maintain the quality and abundance of food, feed, and fiber produced by growers around the world. Different approaches may be used to prevent, mitigate or control plant diseases. Beyond good agronomic and horticultural practices, growers often rely heavily on chemical fertilizers and pesticides. Such inputs to agriculture have contributed significantly to the spectacular improvements in crop productivity and quality over the past 100 years. However, the environmental pollution caused by excessive use and misuse of agrochemicals, as well as fear-mongering by some opponents of pesticides, has led to considerable changes in people’s attitudes towards the use of pesticides in agriculture. Today, there are strict regulations on chemical pesticide use, and there is political pressure to remove the most hazardous chemicals from the market. Additionally, the spread of plant diseases in natural ecosystems may preclude successful application of chemicals, because of the scale to which such applications might have to be applied. Consequently, some pest management researchers have focused their efforts on developing alternative inputs to synthetic chemicals for controlling pests and diseases. Among these alternatives are those referred to as biological controls.

Managing plant diseases is necessary to preserve the quantity and quality of food, feed, and fiber that producers worldwide produce. To avoid, lessen, or manage plant diseases, several strategies may be employed. Aside from using effective horticultural and agronomic techniques, growers frequently largely depend on chemical pesticides and fertilizers. The remarkable increases in crop productivity and quality over the past 100 years have been largely attributed to such agricultural inputs. However, fear-mongering by certain opponents of pesticides and environmental degradation from excessive and improper use of agrochemicals have prompted significant shifts in public perceptions toward pesticide usage in agriculture. Political pressure is present to remove the most dangerous chemicals from the market, and there are stringent limits on the use of chemical pesticides today. Furthermore, because of the potential scale at which such applications could need to be made, the proliferation of plant diseases in natural ecosystems may make the successful application of pesticides impossible. As a result, several researchers studying pest management have concentrated on creating substitutes for artificial chemicals in the management of diseases and pests. Biological controls are one type of alternative among them.

COMMON FEATURES OF BIOLOGICAL MEMBRANES

Membranes are sheetlike, just a few molecules thick and form closed boundaries between cell compartments.

Membranes contain lipids and proteins, with small amounts of carbohydrayes linked to the lipids and proteins.

Lipids in membranes are small with hydrophobic and hydrophilic portions. Lipid bilayers provide a barrier to the diffusion of polar molecules.

Characteristic functions of membranes are mediated by specific proteins, serving as pumps, channels, receptors, energy transducers and enzymes.

Membrane components associate through noncovalent interactions.

Membranes are asymmetrical, with two sides of the membrane differing from each other.

Lipid and protein molecules often diffuse rapidly in the plane of the membrane.

Central transport of ions and molecules into and out of the cell.

Generate proton gradients for ATP production by oxidative phosphorylation.

Receptors bind extracellular signals and transduce the signal to cell interior.

Biological control in plant pathology refers to the use of living organisms to suppress or control plant pathogens, pests, and diseases, thereby reducing the need for chemical pesticides. These living organisms, known as biological control agents (BCAs), can be naturally occurring or introduced, and they act by various mechanisms to inhibit or eliminate the pathogen. These methods harness natural enemies of pathogens such as antagonistic fungi, bacteria, or other beneficial organisms to reduce the population of harmful pathogens in the environment. Biological control is an important component of sustainable agriculture, offering an eco-friendly alternative to chemical pesticides and contributing to integrated disease management (IDM).
Key Mechanisms of Biological Control
1. Predation: Certain organisms, like Trichoderma species or predatory mites, directly attack and consume plant pathogens, reducing their population.
2. Parasitism: Some fungi, like Ampelomyces quisqualis, parasitize plant pathogens, such as powdery mildew, thereby suppressing their growth and reproduction.
3. Antibiosis: Microorganisms like Bacillus subtilis and Pseudomonas fluorescens produce antibiotics that inhibit the growth or kill plant pathogens. For example, Bacillus subtilis produces iturin, which suppresses fungal growth.

Nanoparticles synthesis is done by two major routes, which include classical synthesis and green synthesis. The green synthesis techniques generally utilize relatively non-toxic chemicals non-toxic solvents, biological extracts and systems. Biological methods are considered safe and ecologically sound forthe nanomaterial fabrication asan alternative to conventional physical and chemical methods

Nanoparticles

Gold, silver, and copper have been used mostly for the synthesis of stable dispersions of nanoparticles, which are useful in areas of photography, catalysis, biological labeling, photonics, optoelectronics and surface-enhanced Raman scattering (SERS) detection

The need for biosynthesis of nanoparticles rose as the physical and chemical processes were costly. So in the search of cheaper pathways for nanoparticle synthesis, scientists used microorganisms and then plant extracts for synthesis. Nature has devised various processes for the synthesis of nano- and micro- length scaled inorganic materials which have contributed tothedevelopment of relatively newandlargely unexplored area of research based on the biosynthesis of nanomaterials.

17.1 Introduction

Bioenergy is an array of energy produced by biomass (organic matter) including liquid, solid, and gaseous fuels, electricity, heat, steam, biochemicals and materials. Biofuel is any plant derived organic matter available on a renewable basis, including dedicated energy crops and trees, agricultural food and feed crops, agricultural crop wastes and residues, wood wastes and residues, aquatic plants, animal wastes, municipal wastes, and other waste materials. An organic matter such as wood, plants, residues from agriculture or forestry, and the organic component of municipal and industrial wastes that can now be used as an energy source. Today, many bioenergy resources are replenished through the cultivation of energy crops, such as fast-growing trees and grasses, called bioenergy feedstocks.

6.1 Introduction

Nanotechnology is the study of manipulating matter on an atomic or a molecular scale that deals with particle sizes between 1 and 100 nano meters at least in one dimension. Particles reduced to the nanoscale show some unusual properties which are different from what they exhibit on a macro scale, enabling unique systematic applications Tarafdar et al. (2012). The unexpected properties of nanoparticles are broadly due to the large surface area of the material, which dominates the contributions made by the very small quantities of the material. Nanoparticles, thus, take advantage of their dramatically increased surface area to volume ratio.

Nanotechnology has the potential to revolutionize the agricultural and food industry with new tools for the molecular treatment of diseases, rapid disease detection, nanofertilizer, enhancing the ability of plants to absorb nutrients etc. Nanotechnology opened doors to new ways of identifying and quantifying biomolecules through use of nanosensors and nanoprobes.

Introduction

After water, nitrogen is the most critical nutritive element for crop productivity and human efforts to produce food and energy have greatly changed the nitrogen cycle of the earth. Sustainable cropping systems throughout history and across the world have relied on the combination of a cereal with an N-fixing legume. In recent history, cereals have dominated global agriculture, while legume areas and productivity have stagnated or even declined. An atmosphere around us contains nearly 78% nitrogen, which is in free form. Hence it is not available to plants. At present, India produces around 206 million metric tones of foodgrains for its growing population, increased foodgrain cannot be produced unless we carefully make use of biological nitrogen. Biological nitrogen fixation is the key to sustain agricultural productivity through the application of biofertilizers in the field. However, there is an urgent need to transfer this technology on the field to farmers and industry by producing these fertilizers on large scale.

Abstract

Nitrogen (N₂) is an essential nutrient for every organisms. It is the building block of many biological molecules. Atmosphere contains 79% of N₂ gas which cannot be used by plants directly as it is chemically inert. Many diazotrophs like bacteria and cyanobacteria have the capability to convert atmospheric dinitrogen into a usable form by means of Biological nitrogen fixation (BNF). N₂ fixation is generally three types i.e. Asymbiotic, Associative and Symbiotic. Asymbiotic N₂-fixation also known as free living N₂-fixation is under taken by some bacteria and cyanobacteria. In associative N₂-fixation, some bacteria fix nitrogen in association with root of some grasses and cereal plants. In symbiotic nitrogen fixation, Rhizobium form root nodule in legumes and fix atmospheric N₂ and convert it into the ammonia (NH₃) by the help of Nitrogenase enzyme. This oxygen sensitive enzyme consist of two components i.e. di-nitrogenase (MoFe protein) and di-nitrogenase reductase (Fe protein) which are highly conserve in sequence and structure. The N₂ fixing genes e.g. nod gene (nodulation gene) and the nif gene (nitrogen-fixing gene) are located in the plasmid which is also called mega plasmid. Symbiotic association between legume and rhizobium have agronomic importantance and reduce the use of N-fertilizers or even avoided. The long term use of the nitrogenous biofertilizer in the agricultural field is a promising approach to develop and fulfil N₂ demand of the growing crop without causing any environmental hazard.

Abstract
Biological nitrogen fixation (BNF) is a critical ecological process carried out by grain legumes, which form symbiotic associations with nitrogen-fixing bacteria, primarily Rhizobium species. This natural mechanism converts atmospheric nitrogen (N2) into ammonia, a form that plants can readily utilize, significantly enhancing soil fertility and reducing the need for synthetic nitrogen fertilizers. The process begins with the recognition and infection of the legume roots by rhizobia, leading to the formation of specialized structures called nodules, where the bacteria convert atmospheric nitrogen into ammonia through the enzymatic action of nitrogenase. The symbiosis between legumes and rhizobia is tightly regulated by various genetic and environmental factors, including plant signalling molecules, soil conditions, and nutrient availability. Grain legumes, such as soybeans, chickpeas, and lentils, play a vital role in sustainable agriculture by improving soil health, promoting biodiversity, and providing a protein-rich food source. This overview explores the molecular mechanisms underlying BNF, the factors influencing the efficiency of this process, and its potential to enhance sustainable agricultural practices. Understanding the intricacies of BNF in grain legumes can inform breeding programs and management strategies aimed at maximizing the benefits of this natural process for agricultural productivity and environmental sustainability.
Keywords: Nitrogenase, Biological Nitrogen Fixation, Environmental sustainability, Soil fertility

Fixation of elemental nitrogen in the atmosphere by the microorganisms through a reductive process into ammonia is called biological nitrogen fixation (BNF). Molecular nitrogen (N₂) is the major component (approximately 80%) of the earth’s atmosphere. The element nitrogen is an essential part of many of the chemical compounds, such as proteins and nucleic acids, which are the basis of all life forms. However, N₂ cannot be used directly by biological systems to build the chemicals required for growth and reproduction. Before its incorporation into a living system, N₂ must first be combined with the element hydrogen. This process of reduction of N₂ commonly referred to as nitrogen fixation (N-fixation).

N₂is transformed into reactive N via lightning discharge (5 teragrams (Tg) N / year; 1 Tg equals 1012 g) and by biological N fixation (100 -140 Tg N /year ). Conversion of dinitrogen to ammonia in the industrial process requires temperatures of 400 - 500^o C and high pressures (Haber-Bosch process). Biological nitrogen fixation is much more important as it contributes to more than 70 % of the input in to the world’s soil and water nitrogen. It has been estimated that 100 to 175 million tones of nitrogen are fixed annually by the process of biological nitrogen fixation.

The process of N₂ fixation is mediated by the enzyme, called nitrogenase (which reduces N₂ to ammonia). The overall reaction is as follows.

The biochemical oxygen demand is a chemical procedure for determining the amount of dissolved oxygen needed by aerobic organisms in a water body to break the organic materials present in the given water sample at certain temperature over a specific period of time. BOD of water or polluted water is the amount of oxygen required for the biological decomposition of dissolved organic matter to occur under standard condition at a standardized time and temperature. Usually, the time is taken as 5 days and the temperature is 20°C. microbes
C6H12O6 + 6O2 ¾¾¾¾®CO2 + H2O
Principle
The test measures the molecular oxygen utilized during a specified incubation period for the biochemical degradation of organic material (carbonaceous demand) and the oxygen used to oxidize inorganic material such as sulfides and ferrous ion. It also may measure the amount of oxygen used to oxidize reduced forms of nitrogen (nitrogenous demand).
Procedure
Fill two BOD bottles with sample (or diluted sample); the bottles should be completely filled.