Gurpreet Singh Dhillon

Triclosan: Current Status, Occurrence, Environmental Risks and Bioaccumulation Potential

Triclosan (TCS) is a multi-purpose antimicrobial agent used as a common ingredient in everyday household personal care and consumer products. The expanded use of TCS provides a number of pathways for the compound to enter the environment and it has been detected in sewage treatment plant effluents; surface; ground and drinking water. The physico-chemical properties indicate the bioaccumulation and persistence potential of TCS in the environment. Hence, there is an increasing concern about the presence of TCS in the environment and its potential negative effects on human and animal health. Nevertheless, scarce monitoring data could be one reason for not prioritizing TCS as emerging contaminant. Conventional water and wastewater treatment processes are unable to completely remove the TCS and even form toxic intermediates. Considering the worldwide application of personal care products containing TCS and inefficient removal and its toxic effects on aquatic organisms, the compound should be considered on the priority list of emerging contaminants and its utilization in all products should be regulated.

Recent trends in biological extraction of chitin from marine shell wastes: a review

Abstract The natural biopolymer chitin and its deacetylated product chitosan are widely used in innumerable applications ranging from biomedicine, pharmaceuticals, food, agriculture and personal care products to environmental sector. The abundant and renewable marine processing wastes are commercially exploited for the extraction of chitin. However, the traditional chitin extraction processes employ harsh chemicals at elevated temperatures for a prolonged time which can harm its physico-chemical properties and are also held responsible for the deterioration of environmental health. In view of this, green extraction methods are increasingly gaining popularity due to their environmentally friendly nature. The bioextraction of chitin from crustacean shell wastes has been increasingly researched at the laboratory scale. However, the bioextraction of chitin is not currently exploited to its maximum potential on the commercial level. Bioextraction of chitin is emerging as a green, cleaner, eco-friendly and economical process. Specifically in the chitin extraction, microorganisms-mediated fermentation processes are highly desirable due to easy handling, simplicity, rapidity, controllability through optimization of process parameters, ambient temperature and negligible solvent consumption, thus reducing environmental impact and costs. Although, chitin production from crustacean shell waste through biological means is still at its early stage of development, it is undergoing rapid progress in recent years and showing a promising prospect. Driven by reduced energy, wastewater or solvent, advances in biological extraction of chitin along with valuable by-products will have high economic and environmental impact.

The versatile biopolymer chitosan: potential sources, evaluation of extraction methods and applications.

Abstract Among the biopolymers, chitin and its derivative chitosan (CTS) have been receiving increasing attention. Both are composed of randomly distributed β-(1-4)-linked d-glucosamine and N-acetyl glucosamine units. On commercial scale, CTS is mainly obtained from the crustacean shells. The chemical methods employed for extraction of CTS from crustacean shells are laden with many disadvantages. Waste fungal biomass represents a potential biological source of CTS, in fact with superior physico-chemical properties, such as high degree of deacetylation, low molecular weight, devoid of protein contamination and high bioactivity. Researchers around the globe are attempting to commercialize CTS production and extraction from fungal sources. Fungi are promising and environmentally benign source of CTS and they have the potential to completely replace crustacean-derived CTS. Waste fungal biomass resulting from various pharmaceutical and biotechnological industries is grown on inexpensive agro-industrial wastes and its by-products are a rich and inexpensive source of CTS. CTS is emerging as an important natural polymer having broad range of applications in different fields. In this context, the present review discusses the potential sources of CTS and their advantages and disadvantages. This review also deals with potential applications of CTS in different fields. Finally, the various attributes of CTS sought in different applications are discussed.

Biotransformation of Waste Biomass into High Value Biochemicals.

These texts by Samir Amin have been selected for the purpose of encouraging readers to learn more about his work to trace the historical trajectory of capitalism, which has consistently produced polarization at the global level. Thus the dominated peripheries cannot hope to catch up with the social organization prevailing in the dominant centres and the impossibility of global capitalism becoming stabilized in its peripheries has resulted in the long decline of capitalism, coinciding with successive waves of active involvement by the peoples of the South to shape a new world, potentially embarking on the long journey to socialism.

Flocculation and haze removal from crude beer using in-house produced laccase from Trametes versicolor cultured on brewer's spent grain.

The potential of brewers spent grain (BSG), a common waste from the brewing industry, as a support-substrate for laccase production by the well-known laccase producer Trametes versicolor ATCC 20869 under solid-state fermentation conditions was assessed. An attempt was made to improve the laccase production by T. versicolor through supplementing the cultures with inducers, such as 2,2-azino bis(3-ethylbenzthiazoline-6-sulfonic acid), copper sulfate, ethanol, gallic acid, veratryl alcohol, and phenol. A higher laccase activity of 13506.2 ± 138.2 IU/gds (gram dry substrate) was obtained with a phenol concentration of 10 mg/kg substrate in a tray bioreactor after 12 days of incubation time. The flocculation properties of the laccase treated crude beer samples have been studied by using various parameters, such as viscosity, turbidity, ζ potential, total polyphenols, and total protein content. The present results indicated that laccase (25 IU/L) showed promising results as a good flocculating agent. The laccase treatment showed better flocculation capacity compared to the industrial flocculation process using stabifix as a flocculant. The laccase treatments (25 IU/L) at 4 ± 1 °C and room temperature have shown almost similar flocculation properties without much variability. The study demonstrated the potential of in-house produced laccase using brewers spent grain for the clarification and flocculation of crude beer as a sustainable alternative to traditional flocculants, such as stabifix and bentonite.

Facile fabrication and characterization of chitosan-based zinc oxide nanoparticles and evaluation of their antimicrobial and antibiofilm activity

The present investigation deals with the facile synthesis and characterization of chitosan (CTS)-based zinc oxide (ZnO) nanoparticles (NPs) and their antimicrobial activities against pathogenic microorganisms. ZnO–CTS NPs were synthesized through two different methods: nano spray drying and precipitation, using various organic compounds (citric acid, glycerol, starch and whey powder) as stabilizers. Both the synthesis methods were simple and were devoid of any chemical usage. The detailed characterization of the NPs was carried out using UV–Vis spectroscopy, dynamic light scattering particle size analysis, zeta potential measurements and scanning electron microscopy, which confirmed the fabrication of NPs with different shapes and sizes. Antimicrobial assay of synthesized ZnO–CTS NPs was carried out against different pathogenic microbial strains (Candida albicans, Micrococcus luteus and Staphylococcus aureus). The significant (pxa0<xa00.05) inhibition of growth was observed for both M. luteus and S. aureus with ZnO–CTS NPs (with a concentration ranging from 0.625 to 0.156xa0mg/ml) as compared to control treatment. ZnO–CTS NPs also showed significant biofilm inhibition activity (pxa0<xa00.05) against M. luteus and S. aureus. The study demonstrated the potential of ZnO–CTS NPs as antimicrobial and antibiofilm agents.

Waste Biomass: A Prospective Renewable Resource for Development of Bio-Based Economy/Processes

Although industrial revolution is an important factor governing the development of a country’s economy, but at the same time, the industrial activities have been also accompanied by problem of waste biomass. This commensurate with the increase in industrialization, urbanization, and population growth is leading to production of enormous quantities of industrial waste biomass that may cause environmental and health hazards. However, the increased awareness and desire for a healthy environment among people leads to the need for better ways of waste minimization and pollution prevention and better use of resources in achieving the required industrial and environmental standards. The present book deals specifically with the valorization of waste biomass to small-volume high-value biochemicals only. The products which are produced in bulk quantities, such as biofuels, some organic acids, hydrolytic enzymes, biogas, and other traditional products from waste biomass, are not discussed. In this context, the current chapter discusses the different sources, types, and nature of waste biomass. The chapter also provides overview of the different management strategies applied for the value addition of different types of waste biomass. The chapter will provide insights into the role of waste biomass resources for developing bio-based economy/processes for industrial biotechnology and renewable energy in supporting sustainable development and economic competitiveness.

Agricultural-Based Protein By-Products: Characterization and Applications

Abstract After carbohydrates and fats, proteins are one of the main components of agricultural products. Because of their limited supply, proteins are considered the most valuable agricultural product. The recent increased consumption of fats and carbohydrates for the production of biofuels and the resulting surplus supply of protein by-products has greatly altered the balance of agricultural supply and demand. Proteinaceous by-products from the production of bioenergy or agricultural postharvest and processing industries are generally used for xa0animal feed and other low-value applications. However, considering the abundance of protein by-product resources, it is mandatory to find pragmatic ways to explore new high-value applications for excess protein materials in non-feed and nonfood applications. Recently, proteins have been viewed as a substrate for the production of various high-value-added applications. This chapter primarily focuses on the plant- and animal-based protein by-products, their physicochemical and biological characterization, and finally their high-value applications.

Utilization of Agro-industrial Waste for the Production of Aroma Compounds and Fragrances

Agro-industrial wastes are unavoidable waste materials continuously generated in bulk quantity. Most of these materials can be used as nutrient source for industrial fermentation. However, commercial fermentation of low-value high-volume products generally suffer financial crisis. Alternatively, sustainable biotransformation of agro-industrial waste into fine biochemical, such as aroma compounds and fragrances, has been widely investigated. Significant variation of substrate quality imparts great variations in the production methodology of these processes. Further, a range of microorganisms are known to be used and different genetic engineering strategies have been applied for improved bioconversion. Moreover, novel strategies for detection, identification, and purification of the final products have been developed, and in some particular cases, successful commercialization has also been achieved. To have, however, further benefit from this potential strategy, a systematic study of the type and nature of the feedstock and their abundance should be evaluated. Similarly, presently used processes and their scale-up potential should be determined and different options for their economic competitiveness should be identified. The goal of this chapter, therefore, is to improve the basic understanding of the interesting strategy and to summarize the recent advancements in production of aroma compounds and fragrances.