eChapters

Summary

Over the past several decades, the exponential population and social civilization expansion have been accompanied by rapid industrialization. As such, there has also been a proportionate expansion in the global energy demand. Till date, crude oil has been the only source to meet the increasing energy demand. Nowadays ethanol is the most acceptable product in the fuel market. The importance of ethanol is increasing due to a number of reasons such as global warming and climate change, limited reserves of fossil fuel and reduction on imports of transport fuel. Lignocellulosic biomass is an abundant renewable source for commercial alternative fuel. Maximum bioethanol production depends on the whole process and optimum process parameters itself. Bioethanol from lignocellulosics is a type of second generation biofuel. Many researchers have been focused on bioethanol production from renewable sources. This chapter highlights the processing steps for second generation bioethanol production from lignocellulosics.

Summary

The huge accumulation of agro-industrial waste-materials generated by the milling, brewing and various agriculture and food based industries which in total amount to be about 500 million tones per year in India. Most of these by-products contain three major structural polymers such as cellulose, hemicellulose and lignin. These are also the main source of feed for domestic animals. A high proportion of this waste material is carbohydrate and phenolic compounds. Accumulation of this kind of biomass not only results in the deterioration of the environment, but also loss of potentially important materials. Biological degradation, now-a-days, has become an increasingly popular alternative for the treatment of agricultural, industrial, organic as well as toxic wastes. Cellulose and hemicellulose being the major constituents of these materials can be referred to as valuable resources for a number of reasons, mainly due to the fact that they can be bio-converted easily into valuable products. These wastes can be processed to yield a number of value added products, such as biofuels like biohydrogen, bioethanol along with a variety of chemicals. Various treatment methods such as physical, chemical, biological are employed for the production of value-added compounds. Various phenolics like ferulic acid and vanillin are world’s most prized flavor compound mostly obtained through microbial treatment of agro-wastes.

Summary
 
Although the concept of IPM, with emphasis on minimum use of pesticides: is well established and widely practiced in India, pest population still continue to be unabated, often reaching to alarming levels .Development of non chemical methods of pest control  as component of IPM tactics is a priority area of research today. Development of multiple resistance in larval stages against recommended insecticides ,spoiling of crop ecosystem with toxic chemicals and consequences of health hazards is the best alternative to control the pest in adult stage before they reproduce. Use of light trap is one such potential methods of control for the species known to be positively phototropic in adult stage. Rice is one of the most important cereal crop grown in different parts of world , serving as staple diet for millions of people . The losses due to insect pests in rice are very high and the pesticidal use in this crop is second highest after cotton in world .The positive feature of using light trap as IPM tool for survey ,monitoring , detection and control tool is that most of the insect pest species of rice are phototropic in nature and collected in sufficient numbers in light trap .Therefore use of light trap for imparting eco-integrity  by minimizing indiscriminate use of chemicals ,reduction of pest management cost and enhancement of farm income can be very useful for achieving the ultimate goal of sustainability in rice cultivation. 

Summary

Molecular farming is the large scale production of pharmaceutically important and commercially valuable proteins in plants and animals. Molecular farming in plants has the potential to provide an inexpensive and convenient system in the production of unlimited quantities of recombinant proteins for use as therapeutics, diagnostics, vaccines, antibodies, plasma proteins, cytokines and growth factors. Plants are also being used for the production of oils, starches, plastics, enzymes for food processing and other uses and spider silk etc. However, quality and safety of the final product and wider effects of molecular farming on health and environment need to be addressed. The benefits of molecular farming should not be outweighed by risks to human health and environment.

Summary

Genetic engineering can be used to introduce specific traits into plants. It may not replace conventional breeding but can add to the efficiency of crop improvement. It is possible due to the fact that plants are totipotent, enabling regeneration of a new plant from an isolated cell. Transformation of dicots is usually carried out using the bacterium, Agrobacterium tumefaciens. Genes are cloned into plant expression vectors that carry the 25-bp repeat sequences at the borders of the onc region, known as the left and right borders (LB and RB) and the virulence genes (vir) of the Ti plasmid.

Summary

Expressed sequence tags are small pieces of DNA sequence (usually 200 to 500 nucleotides long) that are generated by sequencing either one or both ends of an expressed gene. Currently various EST sequencing projects are underway for numerous organisms, generating millions of short, single-pass nucleotide sequence reads, accumulating in EST databases. Extensive computational strategies and various databases have been developed to organize and analyse both small- and large-scale EST data for gene discovery, functional annotation of putative gene products as well as transcript and single nucleotide polymorphism analysis. Present chapter provides an overview of the significance of ESTs, their properties, databases, analysis software and the applications of ESTs.

Summary

Genes are discrete elements that govern the appearance of specific traits. Morgan Sturtevant and their coworkers demonstrated that genes have specific address. They reside at particular locations on particular chromosomes and these addresses remain constant from one individual of the species to the next. Transcription is the first step leading to gene expression. It is the process of creating a complementary RNA copy of a sequence of DNA. Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes. During transcription, a DNA sequence is read by RNA polymerase, which produces a complementary, antiparallel RNA strand. translation is the second stage of protein biosynthesis (part of the overall process of gene expression). In translation, messenger RNA (mRNA) produced by transcription is decoded by the ribosome to produce a specific amino acid chain, or polypeptide, that will later fold into an active protein.

Summary

Metagenomics is a rapidly developing field of research that enables the study of microbes that have not been cultured or cannot be cultured easily. It has greatly advanced the understanding of ecology and diversity of natural microbial communities and has led to the discovery of many new genes and geneproducts. The various aspects of metagenomics – history, techniques for identification, different approaches of data analysis, comparative and functional genomics, applications in the areas of medicine, agriculture, biotechnology, ecology, bioprospecting, bioremediation, future advances and challenges and issues related to intellectual property, have been discussed.

Summary

This review addresses various defense strategies evolved by plants to resist pathogen attack.Of the different defensive strategies, pathogen attack either induces or enhances constitutively the synthesis of a spectrum of diverse chemical compounds in various plant species. These chemical compounds also called secondary metabolites are classified broadly as nitrogen compounds, terpenoids and phenolics and have been documented to possess broad range antifungal, antimicrobial and pesticidal activities. Such defensive compounds could be extracted and developed as eco-friendly biopesticides/microbicides because of their natural occurrence, ephemeral nature and biodegradability. These will be favorable alternative strategies compared to chemical pesticides that are fraught with various harmful side effects.

Summary

Plant cell culture systems produce myriads of valuable compounds which cannot be synthesized by microbial cells or chemical synthesis. Many of the drugs sold today are simple synthetic modifications or copies of the naturally obtained substances. The burgeoning demand for secondary metabolites in recent years as therapeutic agent has resulted in a great interest, in secondary metabolism, and particularly in the possibility to alter the production of bioactive compounds using cell culture technology. Various strategies such as cell line selection, use of precursors and elicitors, mass culture in bioreactors and others have proved effective in enhancing the production of these metabolites so as to meet the market demand but space for improvement still exists. In order to stretch the boundary, recent advances, new directions and opportunities in plant cell based processes are being examined in this section.

Summary

Synthetic seed technology is an alternative to traditional micropropagation for the production and delivery of cloned plantlets. Several aspects of the technique are still underdeveloped and hinder its commercial application. This technology may be of greater value in breeding programs and allows the propagation of many elite genotype-derived plants in a short time and would provide an easy and novel propagation system for the elite as well as difficult to root species. Also, encapsulation of propagules that were produced in vitro could reduce the cost of micropropagation of plantlets for commercialization and final delivery to the farmer field. This technology also employed for germplasm storage and exchange purposes.

Summary

Human activities involving rapid industrialization and urbanization without concomitant environmental planning have resulted in a situation where substantial parts of our land and water resources have been polluted with organic and inorganic toxicants.  Environmental engineering principles have been utilized to detoxify polluted areas; however, the efforts, adopting predominantly physico-chemical methods, have addressed the issue to a restricted extent, focusing on solutions for specific categories of pollutants and applicable for limited areas, in addition to being expensive. Hence cost-effective sustainable alternatives in the form of bioremediation (involving microorganisms) and phytoremediation (involving plants alone or along with associated rhizospheric microorganisms) are gaining public acceptance. Considerable scientific evidence has proved that many plant species can detoxify the pollutants utilizing various mechanisms. In this background, in vitro plant cultures have served as invaluable tools in identifying appropriate plant species for phytoremediation. Better understanding of the complex interactions underlying phytoremediation has been facilitated using in vitro cultures where the only variable is the pollutant, in contrast to field experiments where there are many confounding variables. While straightforward extrapolation of in vitro data can be erroneous, these systems provide the basic framework for translating laboratory-scale experiments to field-scale technologies.

Summary

Tropical forests are declining sharply and continuously growing demand of wood leads to removal of trees from their natural habitats. Clonal propagation of superior trees is must for further exploration and conservation of these genetic resource. Tissue culture technique offers rapid and large scale propagation of desired traits. However, micropropagation of adult trees is difficult; many problems are associated like- maturity, contamination, phenolic leaching, season, variants, long life cycle, etc. Shoot bud culture is the easiest and successful tissue culture technique for the toughest material to clone- mature trees. The chapter deals with the bud culture method of heartwoods and associated problems at different stages – explant establishment, shoot multiplication, rooting and acclimatization. Also the possible solutions of the problems are discussed on the basis of previous reports.

Summary

Plant tissue culture is the technique of growing plant cells, tissues or organs in isolated from the mother plant on artificial media. It has opened up unprecedented opportunities in many areas of basic and applied biological research. This includes techniques and methods used to research into many botanical disciplines and has several practical objectives of plant tissue culture and micropropagation for sustainable development. Indeed, the landmark publication by Gottlieb Haberlandt who is arguably referred to as the “Father of Tissue Culture”, is often cited as the origin and emergence of plant tissue culture and its subsequent applications. Success of biotechnological approaches is dependent on regeneration of intact plants following genetic modification, generally by micropropagation. Potential uses of plant tissue culture in biotechnology to further our understanding of plant physiology, how plants function, resolution and expression of use full characters form in vitro to in vivo condition. Agro bacterium-mediated genetic transformation along with other modes of transformation such as microprojectile bombardment has been accomplished mainly through plant tissue culture.

Microbial inoculants in agriculture, horticulture and forestry can be defined as preparations containing strains of microorganisms which can augment the microbiological process such as nitrogen fixation, phosphate mobilization, excretion of growth promoting substances, decomposition of organic wastes, biocontrol of insect pests and diseases etc. Thus they become an important component of sustainable agriculture. Microbial inoculants are based on renewable sources available in soil and nature and are low cost input and eco-friendly. These inoculants carrying the microorganisms when applied to soil/plant promote plant growth and productivity.

Sustainable agriculture or organic farming wherein biological inputs are maximum and chemical inputs are minimal, is drawing the attention of farmers across the world including India. For replacing chemical fertilizers, which supply plant nutrients by organic manure, the basic requirement is the availability of raw material i.e. the organic matter or biomass that can be decomposed to organic manure. The question that is often asked is what are the different sources of available biomass and how much of it is available? Different sources of biomass can be categorized as

Herbicides are the chemical substances used to kill weeds, i.e., unwanted plants that compete with crop plants for soil nutrients. Chemical herbicides are the most effective immediate solution to most weed problems. Use of chemicals, however, can be harmful to wildlife, to the environment and to humans. Chemicals are also expensive, and weeds develop resistance to the chemicals. For these reasons, there is now a move toward alternative methods of controlling the weeds. One of the most promising is biological weed control, which involves using one living organism to control the activities of another organism.

The adoption of modern agricultural technologies has culminated into serious problems of pesticide resistance in major pests, resurgence in minor pests, elimination of populations of natural parasites, predators and pollinators, environmental pollution, pesticide residues in food chain and health hazards. World Health Organization (WHO) estimates one million pesticides poisoning cases and 20,000 deaths every year globally. This is due to high pesticide residues in food chain including cereals, pulses, vegetables, fruits, milk and milk products (including mother’s milk), fishes, poultry, meat products and water. Twenty five per cent of Indian food products contain pesticide residues above tolerance level compared to only 1.2% globally.

Emphasis of present day agriculture is to produce more with lesser land, water and man power. Apart from natural calamities like drought, flood etc., biotic stresses like pests, diseases and weeds also influence the crop productivity greatly. Sixty to eighty per cent of the total crop losses are attributed to the devastations caused by pests and diseases. Farmer’s income in recent years is decreasing gradually due to increased cost of inputs particularly in plant protection. The excessive dependence on chemical pesticides leads to the development of resistance in insect pests and pathogens, out breaks of secondary pests and pathogens / biotypes and occurrence of residues in food chain. To avoid this situation the concept of Integrated Pest Management (IPM)/ Integrated Disease Management (IDM) approach should be considered on top priority.

The rhizosphere is the narrow zone of soil surrounding the root that is under the immediate influence of the root system. This zone is rich in nutrients when compared with the bulk soil, due to the accumulation of a variety of organic compounds released from roots by exudation, secretion and deposition. Organic compounds released by plant roots include amino acids, fatty acids, nucleotides, organic acids, phenolics, plant growth regulators, putrescine, sterols, sugars and vitamins. Because these organic compounds can be used as carbon and energy source by microorganisms, microbial growth and activity is particularly intense in the rhizosphere.