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This study focuses on the bioelectricity production of Paracoccus homiensis strain DRR-3, a Gram-negative bacterium with Nafion117 and polymer membranes. Among the various electrodes used, carbon p...

Klebsiella oxytoca ADR 13 isolated from the gut of Poekilocerus pictus, which feeds on Calotropis gigantean, was studied for its oleic acid degradation capacity in microbial fuel cell (MFC). Both single-chamber MFC and double-chamber MFC were performed. Power density produced by MFC using oleic acid was 4.87 W/m2. Gas chromatography mass spectrometry results confirm that oleic acid has been degraded and the products were smaller-chain fatty acids such as lauric acid, myristoleic acid, linoelaidic acid, octadecenoic acid, hexadecanoic acid, vaccenic acid, dodecanoic acid, and palmitoleic acid after the course of 20 days. This study indicates the possibility for bioelectricity production along with the degradation of fatty acids by Klebsiella oxytoca ADR 13.

Resistance of microbes towards the antibiotics has agitated the scientific community to look for authentic compounds from plants and microbes. They also make sure that these metabolites are strong enough to fight back the diseases in the long run. Traditional medicines that were used during the ancient times remain as unsung heroes until today. Only few medicines are of plant origin, and their usage is limited due to efficacy, treatment time and toxicity factors. But still, it can be overcome by the modern methods. Due to the increasing health problems all over the world, people are now switching over to the pharmaceutical products from plants and microbes. Considering these facts, this chapter has been framed to give a deep understanding of the current and forthcoming antimicrobial compounds from indigenous plants and microbes. It also discusses about the modern methods that are employed in the processing of antimicrobial compounds and their effects against different groups of pathogens.

Nanotechnology is the field that deals with nano-sized structures of different shapes. Nanoparticles are generally synthesized using inorganic materials with restricted usages. However, there has been a great demand for nanoparticles in various medical applications. In the recent times, the usage of antibiotics has increased, which also has adverse effects to the immune system. Nanotechnology paves way to find the alternate resources for antibiotics. Eco-friendly nanoparticles are synthesized using biological organisms such as plants, bacteria, fungi, and algae. Algae are said to be the reservoir of nanoparticles, and hence, they are also called as nanofactories. Algae are used to produce metallic nanoparticles that can be used as antimicrobial agents. This chapter discusses the types of nanoparticles, synthesis of nanoparticles from algae, different kinds of algae that produce antimicrobial nanoparticles, and mechanism of nanoparticle as an antimicrobial agent.

This study focused on bioelectricity production by Pseudomonas fragi DRR-2, a psychrophilic Gram-negative bacterium isolated from rumen fluid. The experiments were conducted at four different temperatures, namely 4°C, 10°C, 20°C, and room temperature (around 30°C) at neutral pH. The maximum voltage of 510 mV was obtained on the 10th day at 20°C, 320 mV at 10°C, and 250 mV at 4°C, respectively. The redox potential from cyclic voltammograms confirmed that the bacterium is electrochemically active. Based on the results, it was observed that P. fragi produced more electricity at 20°C. This is the first-hand information of power production by P. fragi at low temperatures.

Microorganisms play a vital role in the electron transfer in the anodic chamber. These microbes achieve this via various mechanisms, namely, direct electron transfer and indirect electron transfer. Electricigens are the microbes that are capable of transferring electrons to the anode. Predominant microbes that are studied in the microbial fuel cell (MFC) are Geobacter sp. and Shewanella sp. because of their high-power output. There has been a steep increase in the number of research articles published in the recent years concentrating on different bacterial families in the MFC. Each microbe has been studied in detail, and their electron transfer mechanisms, power output and behaviour inside the anodic chamber have been explored. This has provided a pavement for the future researchers to work on different aspects of the microorganisms. Even the techniques for studying the biofilm nature, electrochemical activity and power output have developed much, and this has aided the scientists to do the investigation in a broader spectrum.

The critical demand of alternate energy sources, pollution issues related to the conservative energy sources made the researchers to find a novel technology without any environmental effects. The ability of electricity generation by the bacteria and the environmental crisis reinvigorate the researchers to pay much attention on microbial fuel cell (MFC). MFC is a promising technology for electricity generation without any emission of carbon. The fundamental is conversion of chemical energy into electric energy from organic and inorganic compounds by microbes. Various types of MFCs are constructed with different microbes for electricity production, waste water treatment and several other processes. However, the feasibility of this technology is limited by several limitations. The technological advancement will prevail over some limitation such as enhanced electricity production and cost reduction. The recent advancements in MFC provided a pavement to biohydrogen production, wastewater treatment, toxicity removal and various applications. However, the successful large scale construction is still a bottleneck. This chapter explores the fundamentals of this technology and a clear idea of factors and parameter used in this process and its role. Also, the recent advancements, different types or classifications, limitations and application of this technique are described in this chapter.

Microbes in the biofilm coordinate themselves for a proper electron transfer inside the microbial fuel cell. Certain microbes use external mediators for the effective electron transfer. There are few exoelectrogens which can directly transfer the electrons to the anode via cytochromes and others through an indirect electron transfer, where the mechanism either takes place by bacteria’s own mediators or by some chemical mediators added in the anode chamber. Bacteria in order to observe their population density, they use an autoinducer ligand and this process is so called quorum sensing.

Microbial desalination cell is one of the emerging technologies in the field of microbial fuel cell. The need for a good source of water in this world has turned up many researchers to treasure this innovative approach of treating marine or seawater. Though there are some conventional technologies involving physical and chemical means of separating salts from marine water, they have a drawback of using energy to drive the process. This energy consumption can be overcome by exploiting microorganisms in microbial fuel cell where these microbes play a major role of desalting the water with the synchronized power production. With the help of salt-tolerant microbes and an ideal ion-exchange membrane desalination process can be accomplished. This way of treating seawater will however be a boon to the future generation for the water availability. Though this technology has its own limitations, it is in the hands of researchers to make this as a sole source of water conversion for the upcoming generation.

The current need of energy in this automated world has made the researchers to search for alternative sources. One of such resource is microbial fuel cell (MFC) through which the microbes act upon the organic matter and help in the electron transfer. Exclusive studies have been made in this field using the industrial wastewater. However, there are very few reports pertaining to the bioenergy production from animal waste. Among the animal waste, rumen fluid which is collected from goat’s intestinal part (rumen) have been exclusively studied by few groups, and this chapter will surely help the reader in understanding the concepts of power production from the rumen waste and the microbes which have participated in the process.

Microbial fuel cell is a fast-growing technology and method for the energy recovery from wastewater treatment. The technology is so tempting that still researchers are carrying this out because of its potential benefits and other important resources. This chapter has attempted to focus on the production of energy from various sources such as domestic waste, industrial waste, animal waste and sewage waste. Though there are more sources that are widely exploited in the anodic chamber, usage of animal waste has been limited hitherto. Hence, a brief introduction of animal waste used in MFC in terms of renewable energy has been provided to the readers. The pros and cons of using animal waste have to be kept in mind before using them in the microbial fuel cell.

Environmental pollution and global warming are major threats to life on Earth. These drastic changes are caused by carbon dioxide emission, which has become a very serious problem worldwide. For the generation of useful sustainable and renewable energy in an efficient manner, the production of electricity using solar energy trapped by algae in combination with microbial fuel cells (MFCs) is a very attractive option. The use of different kinds of algae has become a recent research trend, especially because algae have great capacity to utilize carbon dioxide via photosynthesis, with the potential to convert it into a biomass. Integrating algae into MFCs has given rise to a new MFC model, that of photosynthetic MFCs. Algal MFCs play an extensive role in the treatment of organic contaminants that can be converted to bioelectricity and they also efficiently remove various by-products. This chapter provides- detailed descriptions of the basic experimental setup of MFCs, and the electrode materials used for anodes, cathodes, and membranes. Microbial fuel cells employing different types of algae as substrates under various conditions are described in detail. A brief description of special MFC designs that are integrated with PBR is given. Details of MFC models with algae-assisted anodes and cathodes are also supplied. The multiple bioreactor constructions that are employed to yield algal biomasses are discussed, along with the technologies that will have to be developed. Future challenges and perspectives are highlighted, and we describe research work that can be applied for the commercialization of algal MFCs.

Day by day the demand for petroleum products has been increasing greatly and the difficulty raised because it has given rise to different kinds of problem such as heavy pollution, thus leading to be a cause of global warming. This lays a strong reason for the researchers to find the alternative source of energy and reduce the risk associated with it by developing new technologies. In recent times, the biofuel cells have been trending as a source of bioenergy production. Many different kinds of small devices and large-scale industrial equipment have been designed and are applied in various industries. Yet, the permanent solution hasn’t been found. But the various researches in biofuels have given rise to many valuable results that are enormously applicable to various kinds of industries based on their production and utility. At the midst of microbial fuel cells, algal fuel cells, and combinatorial bacterial algal fuel cell, recently fungal cultures and strains have been used in the fuel cells giving rise to a new kind of fungal fuel cell with many advantages and challenges. This chapter will discuss about the different kinds of fungi species used in microbial fuel cells. The methods of fungi culturing and maintaining are discussed along with the incorporation of the fungal cultures in fuel cells that is applied in various industries for biodegradation, bioremediation and bioenergy production. The construction methods to imply the fungal cultures differ in the mode of application. So far, very few researchers have designed and constructed MFCs by altering the anodes and cathode by creating bio-anodes and bio-cathodes, with fungal biofilm around the anode electrodes and air-cathode electrodes. This chapter will give you a detailed vision in applying the fungal cultures in different forms in the MFC so that the upcoming researchers can optimise the standards even better than are achieved so far.