Harnessing Microbial Potential for Multifarious Applications

Microorganisms, imperceptible to the unaided eyes, have played a crucial role in shaping all ecosystems globally. From the trailblazing work of scientists like Louis Pasteur to the state-of-the-art biotechnological developments, harnessing the tremendous potential of the microbiological community has led the world through applications spanning diverse scientific domains. This book provides an overview of the captivating world of microbes and their multitude of applications, while also guiding the reader’s comprehension of their versatility and capabilities. The book’s sections on microbial bioremediation, microbial bioplastics, waste-to-wealth, and metabolite applications span out in multiple directions from microplastic and heavy metal remediation, biodegradable plastics, zero-waste processes, and biofuels to applications of primary and secondary metabolites. Overall, this book underscores varying microbial innovations that can reduce pollution and the burden on nature along with the improvement of human health.

A gradual rise in the level of hazardous metal viz., arsenic, lead, cadmium, nickel, etc., concentrations in soil, sediments, and water has become one of the most severe problems in India and worldwide over the last few decades. Many studies have also revealed the fate, transport, bioaccumulation, ecotoxicity, and health risks of these metal contaminants in humans, animals, and soil biomass. Therefore, various conventional and modern in-situ and ex-situ technologies have been proposed and developed to control the increasing levels of hazardous metals. However, only a few studies have investigated microbial-based technologies and their processes for the remediation of these metal contaminants to prevent health hazards in plant, animal, and soil ecosystems. Further, technological breakthroughs in microbe-based bioremediation have pushed bioremediation as a promising alternative to standard approaches. Therefore, in this chapter, we aim to review all the recent advancements in the remediation of metals, address the status of hazardous metals in soil, sediments, and water, and discuss their impact on human and animal health. Furthermore, this chapter also discusses the microbial technologies currently available for removing metals from soil, sediments, and water, followed by their management.

Mining activities have significantly contributed to pollution and environmental degradation, generating vast amounts of waste that pose substantial risks to ecosystems. Conventional remediation methods often fail to address the complex nature of pollutants in mining wastes. Alternative approaches, such as microbial remediation, have emerged as promising solutions for sustainable remediation of contaminated sites. This chapter provides a detailed overview of microbial remediation technologies specifically tailored to mining and industrial waste. It explores the diversity of microorganisms capable of degrading various pollutants commonly found in these waste, including heavy metals, organic pollutants, and toxic chemicals. Additionally, it examines factors that affect microbial activity and the optimization of remediation processes. Furthermore, it highlights the advantages, limitations, and applicability of microbial remediation techniques for different types of mining and industrial waste. The chapter also discusses the challenges and considerations regarding the real-world implementation of microbial remediation. Additionally, it reviews the synergistic effects of combining different antimicrobial approaches to enhance overall efficacy and efficiency. Overall, this chapter presents a valuable resource for interested parties seeking to understand and apply microbial remediation technologies for mining and industrial waste. By harnessing the power of microbes, these techniques offer promising prospects for restoring contaminated sites, reducing environmental impacts, and promoting sustainable development.

Manganese is one of the most prevalent elements in the earth’s crust, deposited in the form of different oxides. Strategically, it is an important metal that has augmented industrial applications. Being a cofactor of multiple metabolic enzymes, the Mn (II) ion exhibits a crucial role as an essential trace element of all living organisms. Rapid industrialization, mining, mineral processing, and further anthropogenic activities imposed severe consequences on the generation of a large amount of manganese mining waste product. The inappropriate supervision and unprocessed dumping of these Mn waste products have caused a significant threat to the ecosystem and public health. Hence, remediation is required to avoid heavy metal mobilization into environmental segments and facilitate their extraction. At first, this chapter introduces the essentiality, toxicity, and regulation of Mn. Various Mn-solubilizing microorganisms mediated In-situ approaches to bioremediation, viz., microbially induced carbonate precipitation (MICP), biomineralization, biosorption, bioaccumulation, bio-oxidation, bioleaching, biomining, bioventing, disparaging, biostimulation, and bioaugmentation, are discussed in detail. To promote bioremediation efficiency, the combination of different techniques is preferred. Finally, we propose the cost-efficient and eco-friendly future approach of Mn bioremediation without producing any secondary pollutants and, conclusively, providing a scientific basis for the microbial remediation performance for Mn pollution.

Human activities have significantly contributed to environmental degradation, resulting in the emergence of diseases, and losses in health and the economy. Single-use plastic production grew exponentially during COVID times due to high demand for PPE kits, masks, gloves, etc. In India alone, an estimated 3.4 million tons of plastic waste is generated annually, with only 30 percent being recycled. Due to unmanaged recycling, the presence of microplastics has been reported in samples from human lungs, urine, blood, and even breast milk. The persistence of plastic waste has evolved from an environmental hazard to a medical threat. However, managing and disposing of plastic waste poses significant challenges, as it is classified as a major chemical waste requiring environmental clearance. Microorganisms such as bacteria, fungi, and algae have demonstrated the remarkable ability to degrade a wide range of plastic polymers through biofilm formation and the enzymes that aid in plastic breakdown. The discovery of plastic-degrading genes and enzymes in microbial genomes has opened doors for engineering microbial strains with enhanced plastic degradation capabilities. This chapter explores the diversity of microbial processes involved in plastic waste management and proposes eco-friendly alternatives to reduce the hazardous impact of plastic on the environment. By delving into these processes, the chapter aims to advance scientific understanding and promote the adoption of sustainable practices.

Plastic pollution is one of the most bothersome issues mankind is facing in the modern era because we cannot completely do away with the plastics, nor do we have enough solutions for the heaps of plastics littering our land and seas in microplastic (MP) and nanoplastic forms also. As methods for identification and measurement of microplastics in different ecosystems are developing, there is growing concern about its possible consequences on micro and macroflora, and fauna. The persistence of microplastics (MPs) and their possible negative effects on biota make MP pollution a serious environmental issue. However, as the plastic mounds increased and continued to accumulate in the environment, nature found its own way of fighting back. The so called “non-biodegradable” material was found to be broken down by none other than the tiniest creatures on earth. In response to the manmade plastic hazard, microbes have evolved the capacity to enzymatically degrade the recalcitrant polymers. Literature shows several strains of microorganisms can mineralize plastics but the diversity of microbes involved in this activity and the extent of mineralization is practically unknown. Majority of scientific investigations have focused on MP dispersion, ingestion, destiny, behaviour, quantity, and effects; but few studies report the techniques for MP removal and remediation. Therefore, in this chapter we propose to explore the practical possibility of microbial communities in the remediation of plastics in contaminated sites of land and water bodies, and report microbial strains/consortia that can degrade different types of microplastics like Polypropylene (PP), Polyethylene (PE), Polyetheylene Terepthalate (PETE), High Density Polyethylene (HDPE), and Low-Density Polyethylene (LDPE). The sources and effects of MPs, and its impact on human health are examined. The most recent research and developments in the enzymatic properties of microorganisms, and the mechanisms of biodegradation by bacteria and fungi, in consortia or biofilms, are discussed. The influence of temperature, pH, nutrient availability, and microbial competition, on the biodegradation; and finally the products of biodegradation and the molecular methods or other instrumental techniques of characterizations of plastic degradation are also elaborated. The plastic degradation by invertebrates is also covered because there are several reports of worms and insects that eat plastics. Unique methods for the biodegradation of microplastics must be developed to understand the various ways in which microbes react to these plastic contaminants, in order to lessen their negative effects on the environment. Still, a lot of microbial mechanisms involved in the enzymatic degradation pathway of plastics remain to be elucidated.

2,4,6-Trinitrotoluene (TNT) is a prominent environmental pollutant due to its widespread use in military, industrial, and mining activities. Numerous documented physical and chemical abiotic treatment technologies for its disposal exist, but microbial remediation emerged as a green substitute for TNT disposal administration proficiently and ecologically. This chapter systematically examines the biotic conversion and diminution of TNT through microbial degradation, focusing on bacterial breakdown and the synergistic interaction of microbes and TNT in this process. We analyze the biochemical pathways and mechanisms employed by various bacteria in TNT degradation, highlighting the role of enzymes and metabolic intermediates. This chapter aims to provide a detailed discussion of TNT attenuation through microbes in both aerobic and anaerobic environments in the aqueous and soil strata. Additionally, it comprehends the strength of microbial strains in isolation, consortium, and under immobilized conditions. Furthermore, the synergistic interaction of microbes is explored, emphasizing their potential for accelerating the biotransformation of TNT. Additionally, we discuss the factors influencing bacterial degradation. This chapter focuses on the comprehensive discussion of TNT attenuation through microbial remediation, covering degradation mechanisms, microbial strains, and treatment arrangements.

Elevating environmental issues and health hazards pertaining to plastic wastes utilization has attracted researchers to explore novel and sustainable alternatives to such traditional plastics from natural resources like petroleum and other fossil fuel. The frequently utilized conventional plastics create several ecological menaces primarily due to their non-biodegradable nature and unfathomable and rapid accumulation rate leading to several health hazards. A novel, cost effective and environmentally friendly plant based sustainable and biodegradable plastic such as Polylactic acid plastic can act as suitable substitute to fossil fuel-based plastic with similar functional potencies with nontoxic nature and biodegradable attributes. Many such plant products with enormous quality for utilization as bioplastic raw product can include starch, plant biomass, vegetable oils, etc. These bioplastics are not only eco-friendly and cost effective but also highly secured and promiscuous to be utilized in diverse sectors including food, agriculture, electronics, transport, constructions and many more with higher feasibility and durability. On this panorama the concerned review is a concrete compilation of different kinds of available nature-based plastics with higher efficacy and biodegradable attributes that can easily replace the conventional petroleum-based non-biodegradable plastics for frantic applications globally with a sustainable approach toward environmental feasibility.

The presence of plastic waste in the environment poses a serious threat to all living beings and their immediate environment. The presence of micro and nano plastics in the environment has further endangered the soil health and aquatic life. The robust nature of plastics makes it stay in the environment for several years. Moreover, the processes like landfills and chemical treatments are not enough to handle the plastic waste generated at present, globally. Biodegradable plastics can offer a solution to the plastic waste issue, and could be beneficial for the environment. The bioplastics produced from the microorganisms like bacteria, microalgae, and macroalgae are potential candidates to replace the petroleum plastics with the biodegradable plastics. The use of biodegradable plastics leads to reduction in fossil fuel usage and thus reduces the carbon dioxide emissions. It also reduces the waste generation and thus aids in the recycling and reuse process. The current chapter deals with the various sources from which the biodegradable plastics can be produced, and the impact of plastic waste on agricultural lands, fresh, and marine water bodies. The technological readiness levels (TRLs) of the current technologies necessary for the production of biodegradable plastics, as well as the techno-economical aspects of the production process are discussed in the current chapter. Manufacturing, marketing, and acceptability of biodegradable plastics will affect the future of human kind in many ways. Thus, it is crucial to understand its manufacturing process, and its bottlenecks to further improve the overall process.

Polyhydroxyalkanoates (PHAs) are the wonder polymers which are of biological origin with several application potential. Microbes involved in PHA accumulation are found in all types of environments from fresh water, saline and extreme environments. They have adapted various strategies to survive in various environments. These PHAs are accumulated as carbon reserves in the bacterial cells in the presence of excess carbon source. These potential PHAs have a wide range of applications which makes them attractive to the eyes of the researchers. The review focuses on the type of media, fermentation conditions and recovery methods adapted by several researchers to produce PHAs.

In modern times, the plastic industry is significantly responsible for the large quantities of plastic that end up in water bodies and land. Every year, tons of plastic waste are scattered into the oceans, causing widespread environmental pollution, and disrupting ecosystems. As the need to reduce the usage of petroleum-based plastics grows, researchers are exploring alternative sources of raw materials that possess plastic-like properties but are biodegradable and non-toxic to the environment and human health. The development of biodegradable and bio-based polymers is gaining traction in the market. Some seaweed-based packaging that has already been developed demonstrates excellent mechanical properties, such as tensile strength, elongation at break, thermal resistance, and water vapor permeability, comparable to traditional petroleum-based plastics. The addition of other biopolymers, nanoparticles, or natural active agents improves these features. Seaweed polysaccharides exhibit various biological activities, which open the possibility of creating “active packaging” with antioxidant, antimicrobial, anticarcinogenic, and photoprotective properties that can help preserve the freshness of packaged food or pharmaceuticals. This chapter aims to present the role of seaweeds and algal bioactive compounds in the production of bio-packaging biodegradable and plastic-free.

As environmental concerns and the need for sustainable waste management rise, zero-waste techniques have gained popularity. Microbes’ capacity to convert organic waste into useful resources, decrease waste quantities, and reduce environmental contamination makes them essential to zero-waste projects. Many waste management systems use microbes’ metabolic versatility to handle diverse kinds of waste. The study covers composting, anaerobic digestion, bioremediation, waste-to-chemical conversion, and microbial fuel cells. These provide eco-friendly and sustainable trash management methods. For instance, a consortium of bacteria and fungus breaks down organic waste to produce nutrient-rich compost that improves soil fertility and lowers artificial fertilizers. Anaerobic digestion generates biogas from organic waste using methane-producing bacteria, decreasing waste and providing sustainable energy. Bioconversion techniques use bacteria to make biodegradable polymers, lowering fossil fuel use. Microbial fuel cells generate power from organic waste, while bioremediation cleans contaminated areas. In this chapter, these zero-waste procedures demonstrate how bacteria promote sustainable waste management, a circular economy, and trash reduction.

The production of biofuels from microbial sources has emerged as a promising solution to address the energy crisis and environmental concerns associated with fossil fuels. The present chapter offers a thorough overview of the most recent developments and persistent challenges in this sector. It focuses on the considerable advancements in using microorganisms, such as bacteria, yeasts, and microalgae, to produce biofuels. It explores the utilization of various feedstocks, including lignocellulosic biomass and waste materials, to generate biofuels like biodiesel, bioethanol, and biogas. The chapter also covers applications of genetic and metabolic engineering methods to improve microbial biofuel production, including raising yields and enhancing substrate usage efficiency. Despite these efforts, various obstacles stand in the way of the widespread use of microbial-based biofuel generation. Critical issues such as the availability and sustainability of feedstocks, high production costs, and effective downstream processing are also discussed in detail. It also explores the environmental implications of biofuel production and the need for developing sustainable and eco-friendly processes. Further, this chapter sheds light on the life cycle assessment approach and its assessment methods in the field of biofuel production. The national biofuel policy of India is critically analyzed in the context of the policies from different developed countries. It also emphasizes the importance of continued research and development to overcome challenges, optimize production processes, and establish microbial biofuels as a viable and sustainable alternative to conventional fuels.

Wastewater remediation using microbes for biofuels and pollution mitigation is an innovative approach that combines wastewater treatment and biofuel production while addressing environmental pollution. This process involves the use of specific microbial organisms to break down organic matter in wastewater, converting it into valuable biofuels and reducing the pollutants present in the water. It is worth noting that the success and feasibility of this approach depend on various factors such as the composition of the wastewater, the selection and management of microbial cultures, and the infrastructure and technology used for treatment. Ongoing research and technological advancements are continually improving the efficiency and scalability of these processes, making them increasingly viable for widespread implementation. In the present book chapter, the basic concept of wastewater remediation using microbes along with the utilization of microbes to produce biofuels is discussed. The present chapter also emphasizes biofuel production and pollution mitigation through the lens of sustainability.

Microalgae, photosynthetic microorganisms found in aquatic environments, have gained attention as a potential sustainable source for therapeutic agents. Their diverse biochemical composition and ability to produce bioactive compounds make them particularly appealing for the development of vegan pharmaceuticals. The rise of veganism has created a demand for ethical and sustainable alternatives to traditional therapeutic agents, which often rely on animal-derived ingredients or animal testing. Microalgae have emerged as a fascinating area of research due to their unique biochemical composition and potential health benefits. Microalgae offer a solution by synthesizing a wide range of bioactive molecules, including antioxidants, antimicrobial agents, anticancer compounds, anti-inflammatory substances, and neuroprotective molecules. Bioprospecting microalgae involves screening and isolating these bioactive compounds, tapping into the vast diversity of microalgae species. Moreover, microalgae possess practical advantages, such as rapid growth, high biomass productivity, and the ability to utilize various carbon sources. This chapter explores the potential of microalgae as a sustainable source for vegan therapeutic compounds, discussing species diversity, bioprospecting methodologies, and the challenges and opportunities associated with their development and commercialization. By uncovering the untapped potential of microalgae, we aim to inspire further research and development in the field of vegan pharmaceuticals, aligning scientific progress with ethical and environmental values.

The world of microbial pigments is a very captivating one and the interest in microbial pigments is sparking due to increasing demand for alternatives to artificial colors. Microorganisms can produce a wide range of pigments with different chemical structures, and these offer several advantages compared to the conventional synthetic colorants. Firstly, they are obtained from renewable resources, secondly, these pigments are often biodegradable and environmentally friendly which can offer their sustainable usage. The diversity of microbial sources provides a wide color range from vibrant reds, oranges, and yellows to lush greens, deep blues, and regal purples. There are various well-known microbial pigments are available such as carotenoids, chlorophylls, melanin, anthocyanins, and phycobilins, each with unique chemical structures and functionalities. Different pigments also offer different pharmacological properties such as anti-inflammatory, antioxidant, anti-inflammatory, protective, etc. Beyond the therapeutic applications, microbial pigments have great potential in biosensors, environmental remediation, and nanomaterial synthesis. These are the components of choice for drug delivery and tissue engineering due to their biocompatibility. These pigments can be customized based on factors like pH, temperature, and light, allowing for tailored color formulations and these can be utilized in various food applications, including beverages, confectionery, and dairy products. Similarly, in the pharmaceutical industry, these pigments can be incorporated into capsules, tablets, and oral liquids, which may fulfill the demand for natural and sustainable pharmaceutical products. Microbial pigments have been reported to be compatible with most of the pharmaceutical excipients and offer stability under typical storage conditions. To summarize, microbial pigments offer a renewable and vegan-friendly approach for food and pharmaceutical sectors, but additional research is necessary to optimize production processes and ensure compliance with regulatory standards to harness their multifarious applications.

The environment is constantly polluted by xenobiotics emitted by anthropogenic activities, which puts ecosystem integrity at risk. Thus, monitoring and research on the harmful consequences of xenobiotics is of great importance. For its monitoring, rapid, consistent, cost-effective, and compact equipment is required. Microbial living cells have developed the ability to perceive a variety of environmental cues, providing a unique platform for the development of biosensing devices. A biosensor is an analytical tool with a transducer that is biologically integrated and produces a quantifiable signal that indicates the concentration of an analyte. Microbial-derived biosensors have the potential to be used in a variety of detection domains because of their usability, affordability, compatibility, portability, and simplicity in genetic alteration. Owing to their distinct structural and functional characteristics, they are ideal for detecting and monitoring a wide range of environmental contaminants. This chapter examines current trends and advancements in microbial-derived biosensors for monitoring environmental pollutants. A special emphasis is also placed on the development of genetically altered microbial biosensors and their use in the monitoring of environmental contaminants. Furthermore, the key difficulties and prospective results will be systematically addressed to highlight the use of microbial biosensors.

Air pollution poses an enormous threat to both human health and the environment. Aerosols play a vital role and affect human health and climate. They infect humans, plants, and animals and are estimated to be responsible for more than 15 million deaths worldwide each year. The biological components of aerosols are known as bioaerosols, which include microorganisms (like; bacteria, viruses, fungi, etc.), pollens, biofilms, etc. The present pandemic situation due to SARS-COVID-19 and the production of biological warfare agents has posed threats to the safety and security of human beings. The development of fast and accurate methods of detection and identification systems for biological components in the environment is of paramount importance in the current scenario of the infection and spread of pathogens. Hence, a thorough understanding of biosensors and their application in environmental management is the need of the time. This chapter deals with the present environmental conditions, prediction of growth of new epidemic, endemic and pandemic diseases due to microbial contamination of environment, mechanism of transmission of infection or disease, impacts on human health, different types of diseases, role of nanomaterials in detection and disinfection, biosensor, different types of biosensor, role of biosensor in diseases control and environmental management, and future implications of biosensor in formulation of policy.

The increasing demand for natural bioactive compounds has prompted researchers to explore novel sources of valuable metabolites. Gram-negative photosynthetic bacteria are class one cyanobacterial prokaryotes with the capacity to recycle organic materials. It has emerged as a hallmark resource to combat global warming, disease prevention agents, nutrition insecurity, and energy crises, and also as a biotherapeutic agent. More than 45–50% of cyanobacteria are cultivated on commercial platforms to extract active metabolites and bioactive compounds. In this review, we discuss the versatile and potential metabolic material applications of cyanobacteria and microalgae in various fields of modern biotechnology to deal with issues of nutrition, biofuel production, and pharmaceutical industry raw materials through engineering innovations.

Conventionally, fungi have been featured heavily in the production of food and beverages, biofertilizers, biopesticides, industrial enzymes, and antibiotics. However, with the advent of novel technologies with high-throughput capabilities, there is a boon in fungal biotechnology. With the developments in molecular life sciences, these technologies have been facilitated by new integrated “omics” approaches, which include parallel use of metagenomics, meta-transcriptomics, meta-proteomics, and metabolomics. These technologies have concurred some of the usual challenges such as identification of mixed and unculturable strains, genetic variants, understanding complex pathways, and signaling processes in inter-species interactions, which in turn have had a major impact on conventional fungal biotechnology as well as exploring hitherto uncharted territories. For instance, identifying a small yet significant group of fungi with higher lipid content has the potential of using fungi in the biodiesel industry, and the metagenomic-based identification of fungal microbiomes may pave the way for more efficient bioinoculants in mushroom culture and biofertilizers. In addition to these developments, the new sequencing technologies have resulted in exploring unusual fungal niches including caves, cold and saline environments including glaciers, saline microbial mats, salt flats, and salterns. Due to the unique conditions and stresses of these environments, such explorations have led to the identification of novel fungal strains, enzymes and metabolites which can be beneficial in fungal biotechnology. While most of the developments of fungal biotechnology discussed in this chapter are focused on the fields of medicine, food and agriculture, and industrial biotechnology, the recent developments in the service-based environmental biotechnology, such as air purification of hydrophobic volatile compounds and fungal-based removal of synthetic dyes in aquatic environments, are also considered.

Psychrophilic and psychrotrophic microorganisms are those that have the ability to grow at low temperatures and are widely distributed around the globe. They are catalytically active at 0–40 ˚C temperatures and a pH range of 4.5–7.0 and are found inhabiting soil, water, and food, which make up upto 86% of the total population. These microbes, when exposed to higher temperatures, disrupt transcription and translation processes and inactivate certain heat-sensitive enzymes, inhibiting cell division and causing distortion of cell morphology. Cold-adaptive cellulases derived from cold-adapted microorganisms, their catalytic mechanisms, molecular modification, and applications are of utmost importance in various fields. In addition, they have a beneficial role in bioconversion and also in the food and fermentation industries, which have an impact on sustainable agriculture. This chapter discusses cold-adaptation mechanisms in bacteria in terms of their cellular components, especially proteins and lipids, membrane fluidity, translation machinery, nutrient uptake, biodegrading enzymes, and adaptations at the molecular level, including changes in gene expression, the production of cold-adaptive enzymes, and the production of cryoprotectants, chaperones, and antifreeze proteins. Understanding all these mechanisms may offer greater insight into the proteins and enzymes that offer advantages as industrial candidates for commercial purposes.