eChapters

7.1 Introduction
In chapter 5, the cluster sampling has been discussed in which clusters were considered as sampling units and all the elements in the selected clusters were enumerated completely. It has been stated there that the cluster sampling is economical under certain circumstance but the method restricts the spread of sample over the population which results generally in increased sampling variance of the estimator under consideration. It is, therefore, logical to expect that the efficiency of the estimator will be increased by distributing the elements over a large numbers of clusters. Hence instead of observing all the units in the selected clusters, one may like to observe only few elements of the selected clusters. This will involve the sampling work to be done also within the selected clusters. If we do so, the process of selection will involve sampling work to be done at two stage, one for selecting the clusters where sampling units are the clusters and the second for selecting the units (elements) within the selected clusters where sampling units are the elements.
The process of sampling can be done at more than two stages. In this case the first stage unit will be larger than the second stage units and the second stage units will be larger than the third stage units and so on. Due to process of sampling in stages, such sampling is called “Multistage sampling.”

6.1 Introduction
So far we have considered the methods of sampling in which the successive units (elements or clusters) were selected with the help of random numbers. Now, we shall consider a new method of sample selection in which only the first unit of the sample is selected with the help of random number, the rest being selected automatically according to a predetermined pattern. The method is known as systematic sampling. It is operationally more convenient than simple random sampling and which at the same time ensures for each unit, equal probability of inclusion in the sample. The systematic sampling can also be termed as systematic random sampling because of the first unit of the sample being chosen randomly. The pattern usually followed in selecting a systematic sample is a simple pattern involving regular spacing of units.
Thus, suppose a population consists of N units and is serially numbered from 1 to N. Suppose further that N is expressable as the product of two integers k and n so that N=nk. Draw a random number i such that 1 < i < k and select the unit with the corresponding serial number and every kth unit in the population there after i.e. the sample consists the units bearing the serial numbers as

5.1 Introduction
In random sampling it is assumed in prior that the population is divisible into a finite number of distinct and identifiable units and these units are known as sampling units. The smallest unit into which the population can be divide, is called an elementary unit (element) of the population. A group of such units is known as cluster. When such cluster is treated as sampling unit, then the sampling procedure adopted is known as cluster sampling. If the entire area containing the population under study is divided into smaller area segments and each element in the population belongs to one and only one such area segment, the sampling is sometimes known as area sampling.
Generally, identification and location of an element requires considerable time. However, once an element is located, the time taken for surveying a few neighbouring elements is small. Thus, the main function in cluster sampling is to specify clusters or to divide the population into appropriate number of clusters. Clusters are generally made up of neighbouring elements and hence elements within a cluster happen to be of similar nature. As a matter of fact, the number of elements in a cluster should be small and the number of clusters should be large. The required number of clusters can be selected either by equal or unequal probabilities of selection. All the units in the selected clusters are enumerated completely i.e. complete enumeration is made in all the selected clusters.

4.1 Introduction
In many surveys, information on an auxiliary (supplementary, ancillary or apriori) variable x, which is highly (positively or negatively)correlated with the variable y under study, is readily available and can be used for improving the sampling design. Stratified sampling and probability proportional to size (p.p.s) schemes are two examples of improved sampling designs, in which the use of data on auxiliary variable has been made. However in both the schemes, it implies that the information on auxiliary variable on individual sampling units is available prior to presentation of sampling design. In case, data on auxiliary variable for individual sampling units are not available but only the aggregate value for all units of auxiliary variable is available, the two schemes can not be used. In such a situation, the aggregate data on auxiliary variable can still be used at the time of estimation of parameters under consideration, provided the data on auxiliary variable for the sampled units can be easily obtained at the time of recording the values of the study variable. Such types of estimation are based on ratio, product, difference and regression methods of estimation.

3.1 Introduction
Out of all methods of sampling, the most commonly used procedure in surveys is the stratified random sampling. When population units are of heterogeneous nature and if we select a sample using SRSWOR scheme then the sample selected may not be the representative sample and the estimate worked out from that sample will not be the reliable estimate of the population parameter. The estimate of sampling variance of the sample estimator obtained from that sampling scheme may happen to be very high leading to get a less precise estimate of the parameter. In such type of population, to overcome these draw backs, we use another sampling scheme known as stratified random sampling which is defined as follows.

2.1 Simple Random Sampling
The simplest and common most method of sampling is simple random sampling. In this procedure, the sample is drawn unit by unit with equal probability of selection for each unit at each draw. It is sometimes referred to as unrestricted random sampling.

The use of sampling in making decisions about an aggregate (or population) is possibly as old as civilization itself. Sampling is first broadly classified into two categories known as subjective and objective. Any type of sampling which depends upon the personal judgement or discretion of the sampler himself, is called subjective sampling. But the sampling method which is governed by a sampling rule or is independent of the sampler’s own judgement is known as objective sampling. The main difficulty with subjective sampling is that the sampler is ignorant of the degree of representativeness of his sample or the accuracy of the final estimates of the population values obtained.

Objective sampling is further subdivided as non-probabilistic, probabilistic and mixed. In non-probabilistic objective sampling, there is a fixed sampling rule but there is no selection probability attached to the sampling unit e.g. selection of every 10th individual from a list, starting with the first, or selecting every 10th line in a paddy field. If however, the selection of the first individual is made in such a manner that each of the first 10 gets an equal chance of being selected, it becomes a case of mixed sampling, partly probabilistic and partly non-probabilistic). On the other hand, if for each individual unit there is a definite pre-assigned probability of being selected, the sampling is said to be probabilistic sampling.

22.1 Introduction

Nanotechnology has proved to have infinite potential in increasing the quality of life of the human population. There is however, a growing realization regarding the potential health and safety risks of associated with development, production and application of these nanoparticles. Nanoscale particles are produced from a variety of different processes. Nanoparticles are the end product of a wide variety of physical, chemical and biological processes, some of which are novel and radically different, others of which are quite commonplace. Nanometer sized particles are also found in the atmosphere where they originate from combustion sources (traffic, forest fires), volcanic activity, and from atmospheric gas to particle conversion processes such as photochemically driven nucleation. A large quantity of nanoscale particles are also produced during the various human activities, Welding can generate large quantities of nanoparticles usually in the form of a well defined plume of aggregated nanoparticles.

21.1 Introduction

Nanotechnology is an emerging field of science which is being highly exploited in the sphere of medicine where “nano” plays a vital role in delivery of drugs or chemical molecules to the point it is required in précised quantities in right proportions. Nanoscience infuses intelligence to the truck load of chemical constituents that are to be delivered at appropriate locations and cleave from the site after the task is complete. Such process will likely to reduce the cost besides ensuring environmental safety. Nanoscale devices with its unique properties make the agricultural system more smart and effective; such devices are capable of responding to different situations by themselves, thus taking appropriate remedial action with the need of external directions from humans. In short, these devices act as a detectors and if need arises serve as a solution/remedy for the particular issue. These smart delivery systems of chemicals in controlled and targeted manner can be considered synonymous to the proposed nano-drug delivery system in human (Patolsky et al., 2006). 

20.1 Introduction
  
Fertilizers play an important role in improving soil fertility and productivity of crops regardless of nature of cropping sequence or environmental conditions. It has been unequivocally demonstrated that one third of crop productivity is dictated by fertilizers besides influencing use efficiencies of other agri-inputs. In the past four decades, nutrient use efficiency (NUE) of crops had hardly exceeded 35-50%, 18-20% and 30-35 % for N, P and K, respectively, despite our relentless efforts. The remaining nutrients stay in soil or enter into the aquatic environment causing eutrophication. In addition to the low nutrient efficiencies, Indian agriculture is facing a problem of low organic matter, imbalanced fertilization and low fertilizer response that eventually caused crop yield stagnation (Biswas and sharma, 2008).The fertilizer response ratio in the irrigated areas of the country  has dcreased from 13.4 kg grain / kg nutrient applied in 1970’s to just 3.7 kg in 2005. In other words, more amounts of fertilizers is required to produce the same quantity of grain output. For instance, 27 kg NPK ha-1 was required to produce one tonne of grain in 1970 while the same level of production can be achieved by 109 kg NPK ha-1 in 2008. 

19.1 Introduction

Nano technology or Nano Science is a new branch of research though nano materials or Nano Structures are not new. In nature nano particles or nano materials are abundant .The idea of manipulation, production, controlling size and physico - chemical properties and application as well as making devices out of these nano materials is the subject of Nano Science & Nano Technology. As the name suggests, the domain of Nano starts from 10-9 m but especially the effect of nano structures exists mostly in the 1-100 nm regime where quantum - mechanical behiviour is prevalent. Molecules with more than 10 atoms fall into the nanometer range  and scientists were not able to visualize individual molecules and nano scale objects until the invention of some very powerful microscopes. Working in Nano domain requires two basic facilities -

18.1 Introduction

Nano – Science & Technology is design, fabrication and application of nanostructures or nanomaterials, and the fundamental understanding of the relationships between physical properties or phenomena and material dimensions at nano meter scales.

17.1 Introduction

In industrialized nations the air is filled with numerous pollutants caused by human activity or industrial processes, such as carbon monoxide (CO), chlorofluorocarbons (CFC), heavy metals (arsenic, chromium, lead, cadmium, mercury, zinc), hydrocarbons, nitrogen oxides, organic chemicals (volatile organic compounds, known as VOCs, and dioxins), sulphur and other particulates. The presence of nitrogen and sulphur oxide in the air generates acid rain that infiltrates and contaminates the soil. The high levels of nitrogen and sulphur oxide in the atmosphere are mainly due to human activities, particularly burning of oil, coal and gas. Only a small portion comes from natural processes such as volcanic action and decay of soil bacteria. Water pollution is caused by numerous factors, including sewage, oil spills, leaking of fertilisers, herbicides and pesticides from land, by-products from manufacturing and extracted or burned fossil fuels.

16.1 Introduction

The stabilization of ultra fine as nano-particles in suspension is very important for both controlling the particle size and for developing process based application of these suspensions to achieve a desired result. Generally, two approaches, namely, Top Down and Bottom-Up approaches are followed for the preparation of ultra fine or nano particles. In the Top-Down method, production starts from the micro-scale and the particles size is reduced to nano-size through repeated impact and collision in high-energy ball mills. However, controlling of size, morphology, surface properties and electrostatic charge is often difficult. In the Bottom-up approach, production of nano-particles starts with the individual atoms and building up to a nano-structure by chemical processes.

15.1 Introduction

It is important that we understand some terms like clay, mineral, clay mineral, activated clay, and nanocomposite clearly. In fact, “clay” is a soil separate consisting of particles of <2 µm (equivalent to <0.002 mm) in equivalent diameter (Brady & Weil, 2002; pages 18-19) in both USDA and International systems. While in nanotechnology, uniqueness of micro- and nana- aggregates is of crucial consideration. (In Chapter 8: The Colloidal Fraction (Brady & Weil, 2002) size dimensions of minerals are given eliminating any chance of confusion.) Now let us look at some definitions provided in the Glossary of the Clay Minerals Society (CMS) Nomenclature Committee – Clay Science Project (www.clay.org; August 2011).

14.1 Introduction

The fast growing field of nanotechnology presents great potential to influence various sectors in the areas of energy, environment, agriculture, health care and consumer goods. To overcome the demanding need of nano-based applications, various strategies to synthesize nanoparticles have been attempted. The major focus is to synthesize nanoparticles of desirable properties such as shape, size and compositions. Various strategies have been employed to synthesize nanoparticles. Foremost among these are physical and chemical methods which include sol-gel technique, solvothermal synthesis, chemical reduction, laser ablation and inert gas condensation. But altogether they suffer from process limitations like difficulty in controlling experimental conditions, feeble reproducibility, polydispersity, costly instrumentation and recovery as well as energy intensive and eco-hazardous processes. However, various factors like cost, speed, efficiency, biocompatibility etc. are still not concerned. Thus, finding a balance between scalability, price and applicability is still a true challenge. These limitations can be potentially overcome by using biological methods for nanoparticle synthesis.

13.1 Introduction and Physical Principles

A microscope is a tool that enables the user to see objects at a magnification greater than the actual specimen. Resolution and magnifying power are the two integral aspects of microscopy. Resolution is a measure of capability of an image forming system to separate images of adjacent objects. The resolving power (8) is numerically defined as d = 0.61l/n sin a, where,  l is the wavelength of the light, n is the index of refraction of the medium between the specimen and lens, a is half the angle of the cone of light from the specimen plane accepted by the front surface of lens and n sin a is the numerical aperture (NA). The NA represents the light gathering power of the lens aperture or in other words, the measure of obliquity of rays which the lens can accept and utlilize and is limited by blurring of image due to spherical aberration of the lens.

12.1 Introduction

“Precision farming,” also known as site-specific management, describes a bundle of new information technologies applied to the management of large-scale, commercial agriculture. Precision farming technologies include, for example: personal computers, satellite-positioning systems, geographic information systems, automated machine guidance, remote sensing devices and telecommunications. If they function as designed, ubiquitous wireless sensors will become an essential tool for bringing this vision of precision farming to maturity.

11.1 Introduction

Nanotechnology is the manipulation or self-assembly of individual atoms, molecules, or molecular clusters into structures to create materials and devices with new or vastly different properties. Nanotechnology can work from the top down (which means reducing the size of the smallest structures to the nanoscale e.g. photonics applications in nanoelectronics and nanoengineering) or the bottom up (which involves manipulating individual atoms and molecules into nanostructures and more closely resembles chemistry or biology). The definition of nanotechnology is based on the prefix “nano” which is from the Greek word meaning “dwarf”. In more technical terms, the word “nano” means 10-9, or one billionth of something. It is a very promising new branch of small-scale technology named for the unit of measure at which it operates: the nanometer. Nanotechnology enables us to create functional materials, devices, and systems by controlling matter at the atomic and molecular scales, and to exploit novel properties and phenomena. Consider that most chemical and biological sensors, as well as many physical sensors, depend on interactions occurring at these levels and you’ll get an idea of the effect nanotechnology will have on the sensor world.

10.1 Introduction

A single-walled carbon nanotube (SW-CNT) is a nano scale tube formed by a cylindrical shell of single atomic layer of carbon atoms. Nanotubes have diameter of a few nm and length up to 100 nm so that they form extremely thin wires. The atomic structure of SWCNT can be formed by wrapping a stripe of single atomic layer of graphite sheet al.,ong a certain direction, and this direction determines the diameter and chirality of the nanotubes. Experimental and theoretical studies have found that these nano-meter sized CNTs have novel electronic properties, which can be metallic or semiconducting, depending on their radius or chiralities (Mintmire 1992, Hamada 1992, Saito et. al., 1992, Rao 1997, Wildoer 1998 and Odom et al., 1998).

9.1 Introduction

Nanoparticles (NPs) are particulate matter with at least one dimension less than 100 nm (Christian et al., 2008). Although NPs are naturally present in the environment, manufactured NPs may have distinctive surface properties and chemistry in comparison with natural NPs (Handy et al., 2008). Manufactured NPs have a large area-to-volume ratio and size-dependent properties, which impart novel properties and behaviors that make them suitable for nanotechnology applications (Auffan et al., 2009). Range of applications for NPs has brought about a rapid development of the nanotechnology industry.

8.1 Introduction

Nanotechnology is the manoeuvring or self-assembly of individual atoms, molecules, or molecular clusters into structures to craft materials with new properties. The definition of nanotechnology is based on the prefix “nano” which is from the Greek word meaning “dwarf”. In more technical terms, the word “nano” means 10^-9, or one billionth of something. The word nanotechnology is generally used when referring to materials with the size of 1 to 100 nanometres, which is true for metallic nano-material. In case of polymeric nano-material, size may reach 600 nm, as polymeric materials are larger in size compression to metallic material. Nano-materials have different properties from bulk materials as a result of their size. These differences include physical strength, chemical reactivity, electrical conductance, magnetism, and optical effects (Schmid, 2006).

7.1 Introduction

Organic polymers can play important role in ecosystems by accumulating biologically important elements and also by retaining soil moisture after aggregating soil particles. Extracellular polymeric substances (EPS) play an important role in cell aggregation, cell adhesion, and biofilm formation that subsequently protect cells from a hostile environment. Furthermore, certain polysaccharides from microbial sources are surface active, and thus attempts have been made to use them as metal chelaters, emulsifiers and flocculants in industrial and environmental fields/domain. Such use of microbial polysaccharides has infused renewed interest in its production and characteristics.

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.

5.1 Introduction

Phosphorus fertilization is a problem in acid soils due to the high fixation characteristics of these soils. Soluble phosphorus carriers such as triple super phosphate tend to get reverted into insoluble and slowly soluble forms, for e.g. iron and aluminium phosphates.  Some soils in Mauritius have been shown to fix up to 90% of applied phosphorus. The fixation characteristics as related to soil properties have been studied for some soils of Mauritius. Rock phosphate offers a good alternative or complement to triple super phosphate.  In volcanic soils of Chile it is recommended to apply rock phosphate in combination with triple super phosphate because of the high phosphorus-retention capacity of these soils.  However, in Western Australia it has been shown that rock phosphate response is low. Possible explanations are slow dissolution of rock phosphate due to the moderately acid pH (5.5 -6.5), low pH-buffering capacity, low calcium absorption in soil, which increases concentration of calcium in soil solution, and poor water holding capacity of these soils.

4.1 Introduction

More and more industrial applications require self cleaned surfaces, water repellent, anti-dirt pickup and many other specific surface requirements. Introduction of nanotechnology has changed the coating scenario drastically. Hard, anti-scratch, hydrophobic coatings are achieved by the addition of small amounts of nano-pigments which help in creating hydrophobic surface. It is also possible to grow certain nano-fibers which on chemical treatment give surfaces which can either attract water or repel it. It is also possible now to create self healing coatings which can repair surface once they are damaged by scratch. Capacitance coupler pads have been devised to reach those corroding areas which are not covered by other corrosion protection methods. Stringent requirements of many modern industrial application resulted in developing coatings which can give special surface properties such as high hardness, scratch resistance, hydrophobicity, anti-dirt pickup etc.  This brief article presents a few new researches which provide one or more special properties to the surface.

3.1 Introduction

The concept of nanoscience was first described in 1959 by physicist Richard P. Feynman in a lecture to the American Physical Society and it was Japanese researcher Norio Taniguchi who coined the term nanotechnology in 1974 to describe precision engineering with tolerances of a micron or less. Eric Drexler in 1986 in his book Engines of Creation, brought nanotechnology into the public domain.

2.1 Introduction

The word Nanotechnology has originated from a Greek word which means “dwarf” and nanometer is one billionth of a meter (1 nm = 10^-9 meter). The nano-scale is not just another step toward miniaturization but a qualitatively new scale. The new behiviour of matter at nano-scale is dominated by quantum mechanics, material confinement, large interfacial volume fraction and other unique properties, phenomenon and processes. At nano-scale, physics, chemistry and biology converge towards the same principles and tools. Nanotechnology cannot be considered as a discipline in science or technology but it is domain in science and technology. Nanotechnology is a multidisciplinary area, any scientist, engineer, medical doctor can do research on nanotechnology. Presently, it is more of a science and less of a technology because of a lack of proper tools for studying the properties of nano-material. There is an immediate need to convert this science into technology and get out of this transition stage.

1.1 Introduction

With the rise in the global population, the demand for increased supply of food has motivated scientists and engineers to design new methods to boost agricultural production. With limited availability of land and water resources, growth in agriculture can be achieved only by increasing productivity through good agronomy and supported with an effective use of modern technology. Advanced agronomical methods lay stress not only on boosting agricultural produce through use of more effective fertilizers and pesticides, but also on the hygienic storage of agricultural produce. The detrimental effects of modern agricultural methods on the ecosystem have raised serious concerns amongst environmentalists. The widespread use of persistent pesticides globally over the last six decades has contaminated groundwater and soil, resulting in diseases and hardships in non-target species such as humans and animals. The first step in the removal of disease causing microbes from food products or harmful contaminants from soil and groundwater is the effective detection of these damaging elements. Nanotechnology can augment agricultural production and boost food processing industry through applications of these unique properties.

1    Introduction to Patent Laws    540

2.    An Overview of the Patenting Process    541

    2.1.    Inventor’s disclosure, 542
    2.2.    Patentability search, 542
    2.3.    Patent application preparation, 542
    2.4.    Patent application amendment, 542
    2.5.    Patent application examination, 543
    2.6    Main parts of a patent, 543
    2.7.    Granting of patent, 544
    2.8.    Date and term of patent, 544
    2.9.    Provisional specification, 544
    2.10.    Complete specification, 545
    2.11.      Cost of patenting, 545

1.    Introduction    496

2.    Strain Development Technologies    496

    2.1.    Screening of natural variants of microorganisms, 496
    2.2.    Genetic manipulation of microorganisms, 498
        2.2.1.    Random mutagenesis and selection, 498
        2.2.2.    Conjugation, 504
        2.2.3.    Transduction, 504
        2.2.4.    Transposition, 506
        2.2.5.      Hybridization, 507
        2.2.6.    Rare Mating, 509
        2.2.7.    Cytoduction, 510
        2.2.8.    Protoplast fusion, 511
        2.2.9.    Transformation, 511
        2.2.10.    Gene cloning and transformation (Recombinant DNA technology), 513

1.    Introduction    468

2.    Biofuel Cell    470

    2.1.    Microbial-based Biofuel Cells, 471
        2.1.1.    Microbial bioreactors producing H2 for conventional fuel  cells, 475
        2.1.2.    Microbial fuel cells producing electrochemically active metabolites in  
                the anodic compartment, 476
        2.1.3.    Microbial fuel cells operating in the presence of artificial electron relays, 477
        2.1.4.    Microbial fuel cells producing electricity during wastewater treatment, 483
        2.1.5.    Microbial fuel cell producing  electricity from acetate or butyrate, 484

1.     Introduction    424

2.    Conventional Methods of Hydrogen Production    426

3.    Biological Methods of Hydrogen Production    429

    3.1.    Hydrogen production by biophotolysis of water, 430
        3.1.1. Photolysis by cyanobacteria (Blue green algae), 430
            3.1.1.1. Nitrogenase dependent hydrogen production, 434
            3.1.1.2.  Hydrogenase-dependent hydrogen production, 437
            3.1.1.3.  Factors affecting  hydrogen production by cyanobacteria, 440
            3.1.1.4.   Bioreactors for cyanobacterial hydrogen production, 443
            3.1.1.5. Future prospects for cyanobacterial hydrogen production, 446

1.    Introduction    392

2.    Landfill Gas    393

3.    Biogas    394

    3.1.    Benefits of biogas, 394
    3.2.    Potential of biogas, 395
    3.3.    Biogas production system, 396
        3.3.1.    Raw materials, 396
        3.3.2.    Biogas technology, 398
        3.3.3.    Process of anaerobic fermentation for methane generation, 400
        3.3.4.    Conditions for anaerobic fermentation, 404
        3.3.5.    Sludge-algae-methane system, 407
        3.3.6.    Biogas plant, 408

1.    Introduction    360
2.    Feedstocks for Biodiesel Production    361

    2.1.    Fats and oils, 362
    2.2.    Alcohols, 363
    2.3.    Catalysts and neutralizers, 367

1.    Introduction    302
2.    Raw Materials for Alcohol Production    304

    2.1.    Sugary substrates, 306
    2.2.    Starchy residues (cereal grains), 309
    2.3.    Cellulosic materials (crop residues), 314

3.    Microorganisms for Alcohol Production    316

    3.1.    Comparision of ethanol production by bacteria and yeasts, 318

1.    Introduction    272
2.    Alcohols    273

    2.1.    Methanol, 274
    2.2.    Ethanol, 277
    2.3.        Butanol, 283

3.    Biodiesel    284
4.    P-series fuels

1.    Introduction    232
2.    Photosynthesis and Biomass Yields    232
3.    Biomass Properties    233
    3.1.     Polymeric and chemical composition, 233
    3.2.     Fuels analysis, 235
    3.3.     Physical properties, 236

1.    Introduction    174
2.    The Thermodynamic and Mechanistic basis of Cellular Metabolism    174

    2.1.      Adenosine triphosphate, 175
    2.2.    Coenzyme A, 176
    2.3.    Modes of ATP synthesis, 177

3.      Components of Electron Transport Chain    181

    3.1.    Electron carriers in ETC, 182
    3.2.    Complex I - NADH dehydrogenase (NADH coenzyme Q reductase), 185
    3.3.    Complex II - Succinate - coenzyme Q reductase, 187
    3.4.    Complex III - Coenzyme Q - cytochrome c reductase, 187
    3.5.    Complex IV - Cytochrome c oxidase, 188
    3.6.    ATP synthese, 188

1.    Introduction    129
2.    Soil Microbiology    129

    2.1.    Bacteria, 130
    2.2.    Fungi, 132
    2.3.    Algae and Cyanobacteria, 132
    2.4.    Protozoa, 132
    2.5.    Viruses, 135

3.    Water Microbiology    133
4.    Microbial Associations    133

    4.1.    Neutral interactions, 133
    4.2.    Positive interactions, 133
    4.3.    Negative interactions, 133

1.    Introduction    71
2.    Microorganisms in Food Industry    72
    2.1.    Microorganisms as the agents of fermentation in  
        traditional fermented foods, 73
    2.2.    Microorganisms as the source of food, 83
    2.3.    Microorganisms as a source of food supplements, 86

3.    Microorganisms in Pharmaceutical Industry    92

    3.1.    Antimicrobial agents from microorganisms, 92
    3.2.     Microorganisms as probiotics, 97
    3.3.    Microbial enzymes in  pharmaceuticals, 98
    3.4.    Mushroom nutriceuticals, 98

1.    Introduction    3
2.    History and Scope of Microbiology    4
    2.1.    Controversy over the origin of microorganisms, 5
    2.2.    Germ theory of fermentation, 6
    2.3.    Germ theory of disease, 6
    2.4.    Development of laboratory techniques and pure cultures, 7
    2.5.    Discovery of immunization, 7
    2.6.    Discovery of protection against infection, 8
    2.7.    Discovery of chemotherapeutic agents, 8
    2.8.    Microorganisms as geochemical agents, 9

Aconites, the tuberous roots of which contain highly toxic alkaloids, are deadly poisons. In small doses, aconites are beneficial in nasal catarrh, sore throat, gibbous, paralysis and chronic fevers. Aconitum is a genus of perennial, erect or rarely twining herbs distributed over North temperate regions of world. The mountains of Eastern Asia form the primary centre, presenting the greatest diversity of genus. About 28 species are reported from India, mostly confined to alpine and subalpine belts of Himalayas. Of the Aconitum spp. occurring in India, roots of nine species are obtained in Indian market. In fact, aconite sold in Indian market is a mixture of 304 species. Still, A. ferox, known as Indian Aconite, is considered the most important.

A. ferox is a perennial herb with tuberous roots. Roots are paired, daughter tuber, ovoid oblong to ellipsoid, with filiform root fibres. Leaves are scattered, orbicular-cordate to reniform, palmately 5 lobed, resembling melon leaves. Petioles are pubescent. Flowers are pale dirty blue, borne in a dense terminal raceme, 10-25 cm long. Follicles are oblong with long, obovoid winged seeds.

Aloe, known for laxative property is one of the old natural remedies that have emerged as modern miracle drug. Popularly known as ‘nature’s sun screen’ has growing use as skin tonic in cosmetic industry and as a nutraceutical. Aloes are also quite popular among succulent ornamental plants because of their stiff, harsh and rugged habit and are commonly grown in deserts and other dry situations. Genus Aloe is indigenous to African continent and Mediterranean countries such as Greece and Southern Italy, and got naturalized in arid tracts of India. In India, Aloe barbadensis is cultivated on a small scale in Rajastan, Andhra Pradesh and Gujarat (CSIR, 1998).

Botany

Genus Aloe belonging to Liliaceae comprises 275 species distributed in Africa, Asia and America. Forty-two species belong to Madagascar region, 12-15 to Arabian Peninsula and rest are distributed over tropical South Africa. Aloe barbadensis, A. ferox and A. arborescens are used as herbal drugs. In India, only four species occur and of these, Aloe barbadensis is the most widely naturalized species. These taxa comprise several varieties viz., officinalis, chinensis, littoralis and they cross freely and several intermediary forms occur in semi wild state.

Good Agricultural Practices

Guidelines for Good Agricultural Practices of Medicinal and Aromatic Plants is intended to apply to the growing and primary processing of all such plants traded and used in food, feed, pharmaceutical, flavouring and perfume industries. The main aim is to ensure that the raw material meets the demands of the consumer and maintains standards of the highest purity. Important aspects are that, these are produced hygienically, in order to reduce microbial load to a minimum, and are produced with care, so that the negative impacts affecting plant during cultivation, processing and storage can be minimised. The guidelines provide guidance for producers to reduce raw material contamination to the lowest level. This document can be used in bilateral relationship between the supplier and the customer and the products documentation is regarded confidentiall (EUROPAM).

Medicinal plants and their various products are extensively utilized not only in traditional systems of medicine but also in modern medicine throughout the world. In recent times, they have also attracted attention of scientists encompassing various disciplines of medicine and biotechnology for search of new drug molecules and modern drug development. Although several research strategies are followed for drug development only the traditional, empirical and molecular methods/strategies are mostly applied. There is also need of scientific validation for safety, efficacy and rational use of traditional form of medicine along with development of standards for identity, purity and strength (Singh and Bagchi, 2002).

Approaches of Drug Developement

Following approaches are generally employed to discover and invent new therapeutic agents from plants viz. screening of plant materials, identification of active constituents, pharmacological and clinical evaluation and drug design.

Phytochemistry

Pytochemistry is concerned with enormous variety of organic substances that are elaborated and accumulated by plants and deals with chemical structures of these substances and biosynthesis, and their natural distribution and biological function. Chemical constituents of plants can be classified in different ways. Based on biosynthetic origin, solubility properties and presence of certain key functional groups, it is classified as phenolic compounds, substances that are readily recognized by their hydrophilic nature and by their common origin from aromatic precursor shikimic acid. Terpenoids share lipid properties and a biosynthetic origin from isopentenyl pyrophosphate (Fig. 1). Organic acids, lipids, alkenes and related hydrocarbons, polyacetylenes and sulphur compounds are derived biosynthetically from acetate. Nitrogen compounds of plants like amino acids, amines, alkaloids, cynogenic glycosides, indoles, purines, pyramidines and cytokinins and chlorophyll are basic substances recognized by their positive responses to either ninhydrin or Dragendorff reagent. Monosaccharides, oligosaccharides, sugar alcohols and cyclitols are water-soluble carbohydrates and their derivatives. Macromolecules of plants such as nucleic acids, proteins and polysaccharides are easily separated from other constituents by their high molecular weights (Harborne, 1984). Some of the therapeutically active compounds are discussed below:

Plants have been a major source of therapeutic agents since time immemorial. The increasing acceptance of traditional herbal systems of medicine, like Ayurveda, within India and outside has resulted in the revival of ancient traditions of medicine. Medicinal plants and their derivatives are thus looked upon not only as a source of affordable healthcare but also as an important commodity item of international trade and commerce. As per World Health Organization estimates, traditional medicines, mostly plant drugs, cater to the health needs of nearly 80% of the world population. The medicinal plant related trade is growing rapidly every year due to the growing recognition of natural products being non-narcotic, with relatively less side effects and being easily available at affordable costs.

In India, medicinal plant sector has traditionally occupied an important position in the socio-economic, cultural and spiritual arena of rural and tribal lives. About 8000 flowering plants, 650 lichens, 650 algae, 200 pteridophytes and 150 bryophytes are attributed with medicinal properties. The Indian coded systems encompasses a large number of treaties on recognized systems of medicine viz. Ayurveda, Unani and Siddha. The Ayurvedic system of medicine, which cater to the health needs of a major segment of population currently utilizes as many as 1000 single drugs and over 8000 compound formulations of recognized merit. Other systems of medicine viz. Siddha, Unani and Amchi (Tibetan) systems of medicine together utilize about 1800-1900 medicinal species. Many medicinal plants are the source of clinically useful prescription drugs being used in modern systems of medicine. Also incredible knowledge on phyto medicine is acquired in non-coded form by tribals and rural community, as is clear from evidences related to folklore medicine. Recognizing their importance, medicinal plant sector has been identified as one of the key areas by the Government of India and the Department of Indian System of Medicine and Homeopathy.

Management of paddy straw is one of the important problems being faced by the farmers. Burning of rice straw in the field is the traditional method being practiced by most of the farmers, which causes atmospheric pollution and nutrient loss. There are three options available to manage the straw viz. i) burning the straw in the field, ii) collecting/baling the straw from the field, and incorporation of straw in the field. If rice straw is not burnt then baling may provide an attractive economic environmentally safe option. Manual collection of paddy straw is a laborious job and also storing the large volume of straw is another problem. As for as paddy straw is concerned, it has higher silica content so animals do not prefer it.

Harvesting and threshing are the key most important operations in the entire range of field operations required in any crop production system. Both of these operations remain still the most important operations as fruit of labour depends upon them. Crops are harvested after normal maturity with the objective to take out grain, straw, tubers etc without much loss.  It involves cutting / digging/ picking, laying, gathering, curing, transport and stacking of the crop.  Harvesting of major cereals, pulse and oilseed crops are done by using sickle whereas tuber crops are harvested by country plough or spade (Fig. 8.1).