Response of Cyanobacteria to Herbicides: A Biochemical and Molecular Approach

by Prof. Dr. Nirmal Kumar, J.I., Dr. Manmeet Kaur Amb, Dr. Rita N. Kumar, Dr. Hiren B. Soni

Cyanobacteria, formerly called blue-green algae, are the most primitive form of algae under plant kingdom. These are called blue-green algae because they contain the photosynthetic pigments-phycocyanin (dominant pigment), phycoerythryin and chlorophyll a, which are responsible for their characteristic blue-green colour. They are known by different names such as, Blue-Green Algae or Cyanobacteria, Schizobacteria or Myxobacteria, Myxophyceae and Cyanophyceae. These are the first plant forms, which got the power of chlorophyll in their thylakoids and started the life supporting process of photosynthesis on the earth. Inoculation of crop plants with nitrogen fixing microbes (in the form of biofertilizers) has become an accepted biotechnology in US, Germany, Brazil, Israel, Egypt, China, India and some other parts of the world also. The paddy field ecosystem provides a favorable environment for the growth of cyanobacteria (blue green algae) with respect to their requirements for light, water, high temperature, and nutrient availability. Cyanobacteria produce and secrete a variety of biological substances such as auxins (Indole Acetic Acid, Indole Butyric Acid, Naphthalene Acetic Acid), gibberellins (GA1 to GA3) and vitamins, which promote the crop growth. Cyanobacteria can also reduce the oxidizable matter of the soil, remove soil compaction, narrow the C:N ratio and facilitate the aeration in the rhizosphere zone. Environmental stresses influence a plethora of physiological activities in living organisms. Cellular adaptation to environmental stress is the major process that protects organism from deleterious effects of various stresses like pesticide, salt, temperature, heavy metals etc. Being cosmopolitan in distribution, cyanobacteria are thought to have been exposed to different levels and types of stressors during their development, thus providing a suitable system for analyzing the adaptive mechanisms developed in response to changing stress conditions. Looking into the enormous potentiality of cyabobacteria, the authors have presented their intensive investigation in the form of a book Response of Cyanobacteria to Herbicides: A Biochemical and Molecular Approach to explore morphological changes such as color of the cells, cell shape and heterocyst frequency of herbicide-treated cyanobacterial species such as Anabaena fertilissima Rao, Aulosira fertilissima Ghose and Westiellopsis prolifica Janet., variations in pigment contents like chlorophyll a, total carotenoids, phycobilin pigments - phycocyanin, phycoerythrin and allophycocyanin of herbicide-treated cyanobacterial species, response of metabolites like carbohydrates, amino acids, proteins, phenols and activity of enzymes like nitrate reductase, glutamine synthatase and succinate dehydrogenase of herbicide-treated cyanobacterial species, functional group variation and detoxicants of herbicide-treated cyanobacterial species, protein profiling by Soduim Dodecyl Sulfate - Polyacrylamide Gel Electrophoresis (SDS-PAGE), genomic DNA profiling by Random Amplified Polymorphic DNA (RAPD), and molecular characterization by 16S rDNA amplification of all three selected species of cyanobacteria. The present book would be helpful in enriching the knowledge of readers about herbicidal toxicology, biochemical response, and molecular aspects of cyanobacteria at lab scale as well as field studies.

Chemical Nature of Groundwater and its Bioremediation

by Dr. Rita N. Kumar, Dr. Rashmi M. Thakkar, Prof. Dr. Nirmal Kumar, J.I., Dr. Hiren B. Soni

Water and land are precious natural resources for the agricultural activities, which are prerequisite for any civilization. Rapid industrialization and urbanization exploit and severely pollute these resources. The organic and inorganic pollutants generate an unfavourable environment for the survival of aquatic flora and fauna by affecting the aquatic ecosystems. The increasing urbanization, industrial revolution, advancement of technologies, etc. are the reasons for increased pollution level. Pollution is the discharge of the contaminating substances that have adverse effects on the environment. It reduces the quality of the environment by contaminating it with impurities. Smoke and dust particles pollute the air, solid waste pollutes the land, and in the same way industrial discharge, municipal sewage, and domestic wastewater pollute the water resources (streams, lakes, oceans, groundwater). Pollutants, thereby, present in wastewater, take the entry into food chain and food web. Heavy metals are outlined as substances with comparatively high density, high atomic weights, and high atomic numbers. They naturally occur within the earth’s crust but presently due to several manmade activities, they pool-up at certain places and hamper the natural constitution and function of natural resources they invade. The natural sources of heavy metal intrusion are weathering of minerals, volcanic eruptions, overexploitation of underground resources, etc., which cause heavy metals of underlying rocks to leach into the groundwater, whereas man-made sources are smelting, mining, industries, sludge selling, agricultural use of serious metals in fertilizers and pesticides and many more. Some of the heavy metals like Lead, Mercury, Arsenic, and Chromium are one of the culprits for global warming and destroying the atmospheric ozone with atmospheric methane, nitrous oxide, and sulphur dioxide. Environmental contamination by heavy metals is a serious problem throughout the world. The addition of toxic heavy metals in the ecosystem may lead to its bioaccumulation, geo-accumulation, and biomagnification. The heavy metals can be removed by using some common conventional treatment processes. Physicochemical removal processes such as adsorption, ion exchange, membrane filtration, reverse osmosis etc. are used to remove heavy metals. Biological treatments using microorganisms include methods such as activated sludge, trickling filters, stabilization ponds etc. Biosorption and phytoremediation are promising, low cost, eco-friendly best solution for removal of heavy metals. The phytoremediation applications can be classified based on contaminant fate: degradation, extraction, containment or combination of these. Phytoremediation applications can be classified based on mechanisms involved. Such mechanisms include extraction of contaminant from soil or groundwater; concentration of contaminants in plant tissue, degradation of contaminants by various biotic and abiotic processes; volatilization or transpiration of volatile contaminants from plants into air, immobilization of contaminants in root zone etc. The present book Chemical Nature of Groundwater and its Bioremediation focuses on preliminary screening of aquatic macrophytes having phytoremediation potential, selection of two specific hyperaccumulator species for phytoremediation, screening of heavy metals accumulation potential and biochemical constituents of selected plant species involving heavy metal treatment, assessing heavy metal accumulation potential, physio-chemical and phytochemical parameters with a treatment of electroplating industry effluent, measuring the phytoremediation efficiency of two selected plant species by in situ experiments, assessing the physico-chemical characteristics of contaminated water treated with two selected plant species, and heavy metal accumulation in biomass by both the species.

Eutrophic Status of Narmada and Tapi Tropical Estuaries of Gujarat, India

by Prof. Dr. Nirmal Kumar, J.I., Dr. Shailendrasinh V. Viyol, Dr. Rita N. Kumar , Dr. Hiren B. Soni

Estuaries are among the most complex and complicated ecosystems in the biosphere because they are at the interface of terrestrial, freshwater, and marine systems. Estuaries and the lands surrounding them are places of transition from land to sea and from fresh to salt water. Although influenced by the tides, estuaries are protected from the full force of ocean waves, winds, and storms by the reefs, barrier island or fingers of land, mud or sand that define an estuary's seaward boundary. In India, estuaries have been a focal point of activities for human settlement, for development of port and harbors. The health status and the biological diversity of the Indian estuarine ecosystem are deteriorating day-by-day through man-made activities and dumping of enormous quantities of sewage and industrial effluent. Estuaries are ecologically very important because it provides vital habitats for thousands of marine species. They are "nurseries of the sea", as it is an ideal location for fish, shellfish, and other marine animals to reproduce in protected environment and availability of abundant food. Besides, estuaries are important for the health of the oceans as it can filter sediment and pollutants from the water before it flows into the oceans. Estuaries are vulnerable to excessive loading of nutrients by runoff containing fertilizer and other pollutants. In recent decades, population growth and related activities (agricultural practices, wastewater treatment plants, urban run-off, and the burning of fossil fuels) have increased nutrient inputs by many folds than the levels that occur naturally. The present book Eutrophic Status of Narmada and Tapi Tropical Estuaries of Gujarat, India point-out an intensive study at two major estuaries (Narmada, Tapi) of Gujarat, India. The authors have investigated hydrochemistry, geochemistry, phytoplankton, zooplankton, and benthic community, along with site-specific problems and their suggestions in both the estuarine environs. This book will certainly be a ready reference guide to the students, researchers, academicians, scientists, and riverine and marine authorities of Gujarat and India, to enrich their knowledge in cutting edge of research in the field of estuarine ecology, biodiversity, conservation, restoration, and management.