eChapters

Principle

Apart from PCR for generating large amounts of DNA, the second method is to use bacteria to replicate the DNA and then purify the replicated DNA from the bacteria. Plasmid DNA is usually the DNA of interest for this method. A plasmid is a double stranded circular DNA molecule that will replicate in an organism. A typical plasmid contains four important features:

The plasmid must be circular, because bacteria generally will not replicate linear ? DNA.

The plasmid must contain a sequence that functions as an origin of replication (ori).

The plasmid must contain a selection mechanism that will force the bacteria to retain the DNA; the most common type of selection mechanism used in bacteria is a gene for resistance to an antibiotic such as ampicillin or tetracycline.

The plasmid must contain a region for the insertion of the experimental DNA. A generic plasmid exhibiting these features is shown at right.

An expression plasmid that allows expression of foreign DNA should have a strong promoter segment for transcription of inserted DNA.

Must have an effective ribosome binding site that will allow efficient translation of the transcribed RNA.

Must have high copy number, i.e., the host bacterium should have many copies (usually >100)

11.1 Introduction

Fermented foods are the result of the activity of a few specialized types of micro-organisms among the thousands of species known to mankind. Success of such processes is depended upon the control of environmental conditions ensuring the growth of the desired microbial species and inhibition of others. The fermentation can be broadly defined as the process in which the carbohydrate or like compounds are broken down, under anaerobic or aerobic conditions [171]. The basic role of micro-organisms is to breakdown the organic compounds to get energy for their metabolic activities. From ancient times, people all over the world have developed traditional processes for production of alcoholic beverages (wine) either from natural sugar such as in wine or by degrading the starchy materials (beer). Fruit wines referred to as ‘Soma’ in our ancient scriptures have been part of food of man and were used as medicine, might have originated accidentally (transformation of fruit juice beverages having exhilarating or stimulating properties). Wines are made principally from fruits like grape or extract of other fruits of various types (table wine, sparkling wine, dessert, aperitif or vermouth and pop wines) while the beers are prepared from grains like barley, rice and corn. The principal carbohydrate in grain is starch which can not be fermented directly. This process is brought about by starch splitting enzymes by germinating the grains followed by drying and storage until needed. Distillation of beer produces a variety of liquors (whisky, rum, gin, vodka), while that of wine produces the brandy. Besides, the improvement in the raw material selection, fermentation conditions and techniques, a lot of waste material is generated during fermentation process in the industries. Nevertheless, the food based industries are significant contributors to the economy of the many countries of the world (Fig 1). The global market value of food fermentation based industries is estimated to be around 250 million US dollars. Interestingly, more than 10% of this accounts for alcoholic beverages (Fig 2) with projected increase of US$ 27 billions in 1989 to 40 billions in 1990 [93,123,123,129].

1. INTRODUCTION

1.1. The Agriculture Sector of Zimbabwe

Zimbabwe has a total area of 390 580 square kilometers of which one per cent is made up of rivers and lakes, 38 per cent is arable land and the rest is suited for livestock and wildlife production. The country is bordered by South Africa, Botswana, Namibia, Zambia and Mozambique. It is located between latitudes 15,30 and 22,30 degrees south of the Equator and between longitudes 25 and 33,10 degrees east of the Greenwich Meridian (CSO, 2006).

The Agriculture sector forms the backbone of Zimbabwe’s economy and accounts for about 17 per cent of the GDP. Zimbabwe‘s agricultural sector comprises mostly smallholder farmers who include communal, resettlement and small-scale farmers. However, this sector is besieged by a plethora of issues, namely high stocking rates, sub-optimal climate, and deforestation and land degradation. The Land Reform and Resettlement Programme which commenced in 1980 resulted in hundreds of thousands of Zimbabweans being resettled on former white commercial farms, in either Model A1(communally owned) or A2 schemes (large scale commercial farms). Thus the challenge to policy makers was now to ensure that future agricultural production is not compromised by current practices. The new farming sector largely comprises resource poor farmers, academics, corporate leaders, high-level policy makers and traditional farmers. Most of the new farmers lack requisite Agricultural skills and knowledge needed in modern Agricultural practice. Land reform measures led to the exodus of some white farmers in the beginning of the 21st century which crippled the economy depriving it of technological know-how and causing shortages of basic commodities.

The modernization of agriculture therefore, among other intervention strategies, through the use of ICTs can contribute directly to food security at national and household levels, beneficiation of agricultural produce, effective land management and an increase of national wealth.

The essential nutrients and their function in microbial cells

3.1 Introduction

Different types of farm ponds with their characteristics features are discussed in this Chapter. It is observed that farm ponds can be constructed at different sites starting from the plain areas with relatively flat slopes to valley terrain having steep slopes. The choice of a particular type of pond largely depends on the kind of water supply available and on the existing topography of the site selected. In general for valleys with bottom width less than 100 m, barrage ponds may work well whereas valleys with bottom width more than 100 m, diversion ponds find suitable.

3.2 Collection of Basic Information

Basic information on different data relating to the soil, climate, plant, topography, groundwater table, catchment characteristics, and livestock populations are to be collected for the area where pond has to be constructed. Estimation of water supply from different sources and water demand form the pond for various purposes are to be done and a pond water balance study needs to be done before designing a pond in a particular place.

16.1 Introduction

Food safety is most important issue in today's global environment. To safeguard food supply is a very difficult and challenging responsibility, as a consequence of which the world's largest food companies, retailers, and manufacturers have placed very high food safety standards. Although the safety of food has improved exponentially but progress is uneven and food borne outbreaks due to microbial contamination, pesticides, antibiotics chemicals and toxins are common in many countries. International trade statistics (2007) by World Trade Organization (WTO) reported that Europe has accounted for 46% of world exports of agricultural products, where food represents 80% of agricultural exports. The trading of contaminated food among countries increases the risk for outbreaks and consequently, health risks due to microbial pathogens in food are of major concern to all governments.

Biosensors are an important option in the agricultural and food sectors to control production processes and ensure food quality and safety by dependable, fast and cost effective methods. Biosensors have plenty of advantages over conventional analytical tools since they offer advantages in size, cost, inherent specificity, selectivity, rapid response, accuracy and sensitivity. Food microbiologists are always in search of rapid and reliable automated systems for the detection of biological activity. Biosensors provide sensitive, miniaturized systems that can be used to detect unwanted microbial activity or the presence of a biologically active compound, such as glucose or a pesticide. Immunodiagnostics and enzyme biosensors are two of the leading technologies that have had the greatest impact on the food industry. The use of these two systems has reduced the time for detection of pathogens such as Salmonella to 24 hour and has provided detection of biological compounds such as cholesterol or chymotrypsin. The another useful application for biosensors, is detection of genetically modified organisms (GMO), since several countries have laws regulating the commercialization of GMO products and their derivatives. Biosensors are also useful in the implementation of hazard analysis and critical control points (HACCP) plans by verifying process developments and correcting errors in due time. There is joint application of Biosensor technologies and nanotechnologies in many food and agricultural applications such as the development of nano-scale tools for biosafety, nanoscale compounds for food packaging, and nano-sensors for pathogen detection in animals and plants. These are helpful tools in the detection and control of potential food contaminants by the agricultural and food industries.

Antibiotics are substances which are produced by micro-organisms and which act against micro-organisms. It is also defined as secondary metabolites produced by microorganism, which inhibits the growth of another microorganism. Most antibiotics known uptill now are products of actinomycetes and some are from fungi and bacteria. The use of the antibiotics in managing plant diseases, particlulaty the disease caused by bacteria, mycoplasma and ricketsia, is well demonstrated and are thought to be effective means because of their selective action directed towards causal agents not to the infected host. The mode of action of the antibiotics varies depending on site of action which in turn detrmines their specificity towards given target host (Table 12). Some time mixture of antibiotics are in practice in managing the diseases to reduce delay the chances of resistance development against a particular antibiotic by the causal agent. The most useful antibiotic mixture is streptocycline, which contains streptomycin and tetracycline.

ABSTRACT

Dysoxylum binectariferum (Roxb.) Hook. is an evergreen tree, indigenous to India and widely distributed in different parts of India. Primarily, this plant is used in the timber market for the preparation of furniture and other wooden goods. Apart from utility in timber market, it has tremendous medicinal properties because of its unique secondary metabolites. Its hydroalcoholic extracts possess a wide range of pharmacological activities including immunomodulatory, anti-inflammatory, anti-cancer, anti-leishmanial, etc. The chromone alkaloid rohitukine, the major constituent of the plant, possess anti-fertility, anti-leishmanial, anti-adipogenic, anti-ulcerogenic, anti-cancer and immunomodulatory activities. The most extensively studied and advanced therapeutic property of this chromone alkaloid is its cyclin-dependent kinase inhibition activity, which has a direct link with its anti-cancer effect. Inspired by this natural product, two clinical candidates (flavopiridol and riviciclib) are discovered and studied in human cancer patients for treating various types of cancer. Another preclinical lead IIIM-290, which is directly derived from rohitukine via synthetic modification, has demonstrated promising oral efficacy in animal models of various cancer types. The high-value medicinal applications of this plant have necessitated the need of bringing this tree under captive cultivation. The present chapter discusses the biology pharmacological and secondary metabolites present in Dysoxylum binectariferum. The preclinical and clinical leads derived or inspired from rohitukine are also discussed in this communication.

Abstract: Orchids, one of the largest commodities in international cut flowers and ornamental plant market, in which genera Cymbidium, Dendrobium, Phalaenopsis, and Vanda are most traded. Orchids occupy prime position among ornamental plants of the modern world. Both warm and cool temperature cultivars are grown in vitro germinated seeds or clones. Breeders have created polyploid cultivars (amphidiploids, triploids) which have greater flower number/raceme, large flowers and other valuable traits. Numerous genes have been identified in the genus with some sequenced genes being used to create genetic transformants. Genome breeding and wide crosses are routinely used to create new genetic variability. Future crop ideotypes are proposed to continue transformation of this crop during the next millennium.

ABSTRACT

Vanilla planifolia Andrews - the high value, exotic spice crop has recently gained wide acceptance in the southern and northeastern states of the country. Being an orchid, germination of naked embryo is limited and this favours genetic uniformity. An attempt was made to induce genetic variability in Vanilla through biotechnology tools for its exploitation in crop improvement programmes. In vitro embryo culture and mutagenesis were applied for the purpose. Plantlets were multiplied, hardened, planted out and evaluated for morphological, biochemical and molecular markers. Great interclonal variability was observed in the in vitro derived plantlets. The intraclonal variability was very low in tissue culture derived regenerants. Isozyme and RAPD assay confirmed genotypic variation. Six superior clones were identified and distributed to farmers for further evaluation.

Introduction

Spatial datasets always exhibit two common features (i) the occurrence of a few very large concentrations (hot-spots) and (ii) the presence of data below the detection limit (black spots). Extreme values can strongly affect the characterization of spatial patterns, and subsequently the prediction. Several approaches exist to handle strongly positively skewed histograms (Saito and Goovaerts 2000). One common approach is to first transform the data (e.g. normal, Box Cox or lognormal), perform the analysis in the transformed space, and back-transform the resulting estimates. Such transform, however, does not solve problems created by the presence of numerous black spot data, since either it yields a spike of similar transformed values or, in the case of the normal-score transform, it requires a necessarily subjective ordering of all equally-valued observations. Moreover, except for the normal score transform (Deutsch and Journel 1998), it does not guarantee the normality of the transformed histogram, which is required to compute confidence intervals for the estimates. Last, the back-transform of estimated moments is not straightforward and can introduce bias if not done properly (Saito and Goovaerts 2000); for example, lognormal kriging estimates cannot simply be exponentiated. Another way to attenuate the impact of extreme values is to use more robust statistics and estimators. The non-parametric approach of indicator kriging (IK) falls within that category (Journel 1983, Goovaerts 2001). The basic idea is to discretize the range of variation of the environmental attribute by a set of thresholds (e.g. deciles of sample histogram, detection limit, regulatory threshold) and to transform each observation into a vector of indicators of non-exceedence of each threshold. Kriging is then applied to the set of indicators and estimated values are assembled to form a conditional cumulative distribution function (ccdf). The mean or median of the probability distribution can be used as an estimate of the concentration of the material in question (Barabas et al. 2001, Cattle et al. 2002, Goovaerts et al. 2005).

Seedling Blight

Phytophthora parasitica

Economic Importance

• Seedling blight is wide spread in Africa, India and other Asian countries.
• The average economic loss due to the disease has been 10%.

1. Introduction

India is an exquisite example of biodiversity. From time immemorial scholars like Charaka, Barathwaj, Athreyan, Agnivesha, Dhanyandhari, Shushruthan, Wakbadan and Bharathduja etc. have studied and explored the possibility of such a diversity for human welfare and the most conspicuous exploration in this field has lead to the discovery of so many indigenous medicinal plants that were scripted mainly in Vedas (1500 BC) that contain rich materials on herbal lore of that time. Charaka in his medical treatise – Charaka samhita delt with innumerable medicinal plants, their usage and descriptions. Besides the two above said texts, treatise like Sushruth samhita and Ashtangha hridaya samhita are a few among other precious ancient texts. Thus the gradual accumulation of practical and systematic medical knowledge lead to the formation of Ayurveda.

Ayurveda - the science of life, prevention and longevity, is the oldest and most holistic or comprehensive medical system available. It was placed in written form over 2000 years ago. Ayurveda is said to have been first complied as a text by Agnivesha (Agniveshtantra). This text was later revised by Charaka and renamed as Charaka samhita (completed by Dhridhabala). The concept of medicines envisaged in the Ayurveda comes from the monumental scripture called Ashtanga hridaya and Sahasrayoga.

Abstract

Malaria is a widespread disease in the developing world, known to mankind since primeval times. It exists over hundreds countries of the world. Malaria is caused by the Plasmodium parasite and cause disease in over 30 crores people annually and kills approximately 10 lakhs people worldwide. Plasmodium protozoan species which causes malaria can be differentiated into four species viz. P. malariae, P. falciparum, P. vivax, and P. ovale. Among all these four species P. falciparum parasite has got resistance to all common antimalarial drugs available in the market; therefore it is a devastating strain of Plasmodium causing of serious disease and death. The rising resistance of existing remedy based on quinoline is a key provider to the re-emergence of malaria as a main public health difficulty and its widen to fresh locations and populations. Therefore, In this compilation, an effort is made to compile clinical features of malaria, life cycle of Plasmodium sp., different classes of antimalarial drugs and their mechanism of actions and recent advances in target based discovery and recent development in artemisinin research especially different kinds of artemisinin derivatives and new structural classes of antimalarial agents. We have also reviewed new leads discovered as antimalarial from natural products where we have possible to see new lead in near future.

Cardiovascular system consists of heart and blood vessels which include both arteries and veins. Blood vessels formation occurs in two stages i.e vasculogenesis and angiogenesis. Splanchnic mesodermal cells lining the yolk sac form clusters, referred to as blood islands. Vasculogenesis, the formation of blood vessels from blood islands of of Pander, commences during the third week of gestation in domestic animals first in yolk sac and later in the allantois.Development of blood vessels involves a complex series of events during which endothelial cells differentiate, proliferate, migrate and become organized into vascular network. Angiogenesis describes budding and sprouting of new vessels from existing vessels. This process a fundamental requirement for embryological development, continues postnatally.

Three types of water movement within the soil are recognized. They are

1. Saturated flow
2. Unsaturated flow
3. Water vapour movement

Saturated flow

This occurs when the soil pores are completely filled with water. This water moves at water potentials larger than 33 kPa. Saturated flow is water flow caused by gravity’s pull. It begins with infiltration, which is water movement into soil when rain or irrigation water is on the soil surface. When the soil profile is wetted, the movement of more water flowing through the wetted soil is termed percolation.

Hydraulic conductivity can be expressed mathematically as

A branch of anatomy that deals with joints or articulations in the body is termed as arthrology or syndesmology. A joint is an articulation or union formed by two or more bones or cartilages with the help of connective tissue. To form a joint, the long bones meet at their extremities e.g. joints of fore limb and hind limb. Joints of flat bones are formed by their borders or edges e.g. joint of bones of skull, the cranial and facial bones. The short bones and irregular bones form a joint by uniting at any of their parts or surfaces e.g. intervertebral joints.

Classification of joints

Joints are classified on the basis of their structure i.e. the kind of tissue material by which the bones are united, the other constituent parts that help in uniting the bones and the kind of movement performed at that joint. On this basis, the following three major types of joints exist in the skeleton of animal body.

Black Pepper

Black pepper (Piper nigrum) is indigenous to the tropical forests of Western Ghats of South India. The crop is grown in Kerala, Karnataka, Tamil Nadu, Andra Pradesh and Assam.

The root-knot nematode, Meloidogyne incognita and the burrowing nematode, Radopholus similis are important pests of this crop. The root-knot nematode infested vines show yellowing of lower leaves and the leaves loose natural luster. The yellowing of leaves gradually progresses upwards. The affected vine leaves become flaccid and wither. The infested plant root show root galls of varying sizes.

The burrowing nematode also causes serious damage to the vine. Var der Vecht (1950) first reported slow wilt in this crop due to R.similis infestation in Indonesia. The nematode in association with Fusarium and Rhizoctonia causes serious damage to the crop.