No abstract

No abstract

Plastic has become an indispensable part of our lives and cutting down plastic consumption entirely is difficult to achieve. The recalcitrant and non-biodegradable nature of plastic leads to accumulation of tons of plastic in landfills and water bodies which further risks marine life and human life too causing serious health issues. In recent years, several microbial enzymes have been discovered that have the ability to degrade plastic. The present review highlights the recent discovery and properties of the plastic-eating bacteria, Ideonella sakaiensis, that has potential to be used for plastic degradation and recycling. The bacteria possess unique enzymes that allow it to utilise Polyethylene terephthalate (PET) plastic, thereby degrading it to relatively safer monomeric forms that can be further degraded and purified to manufacture recycled plastics. The review focuses on the mechanism of PET hydrolysis, recent advances in the field to escalate enzymatic efficiency and development of new bacterial and enzymatic strains through genetic engineering which can enhance its catalytic competence and make the process time and cost-effective. The plastic metabolising bacteria can thus be a potential and efficient bio-alternative to degrade plastic in a biological and sustainable manner thereby helping scale the otherwise insurmountable plastic pollution crisis.

With an increase in the discharge of contaminated wastewater from point and non-point/diffuse sources, a great burden has been inflicted upon the environment. Although treatment systems are available for industry, due to the high cost, inadequate/untreated wastewater is discharged directly into near-by water sources. Major contaminants, such as heavy metals, dyes, pesticides, antibiotics, endocrine disrupting compounds and microplastics etc. are posing a risk to aquatic and human life. Studies have highlighted a decrease in the levels of dissolved oxygen, biomagnification of toxic components and increased nutrient content (leading to eutrophication) in receiving water bodies. Further, irrigation with contaminated water cause many negative effects, especially on soil properties i.e. low carbon mineralization, low microbial biomass, poor enzyme activities and change in soil pH and cation exchange capacity (CEC). In humans, severe side effects, including neurotoxicity, mutations, cancer and disruption of endocrine and reproductive systems has been reported. This chapter summarizes the detrimental effects of various contaminants on environment and human health.

Bacterial cellulose has come forth as a novel nano-material with an extensive range of distinct properties, making it an excellent industrial alternative to conventional plant cellulose, as the world moves toward a sustainable and cleaner phase. Bacterial cellulose is a biomaterial that breaks down naturally in the environment and is produced by natural mechanism in bacterial cells. It has been considered as a substitute to traditional biomaterials in numerous sectors, namely, textile, pharmaceutical, food industry, biotechnology, for its features enabling to achieve sustainable development goals. The present focus is on looking at developing an inexpensive substrate for the synthesis of bacterial cellulose from industrial waste as its commercialization is restricted due to social, economic, and environmental considerations. Upcoming research in biotechnological area of biotextiles and biocomposites aims to integrate basic knowledge of textiles with biological sciences thereby facilitating production of goods which are commercially more viable and also less harmful to the environment. The review discusses the data regarding the use of bacterial cellulose and its production over the years, notably in the textile sector, with an emphasis on advancement of research to enable its extensive production and in various other areas like cosmetology, food industry, biomedical and paper industry. In addition, potential benefits of bacterial cellulose development addressing many of the global sustainable development goals along with suggestions for its scale-up have also been discussed.