The current review is based on various reports that utilize a variety of kitchen waste & cafeteria leftovers like banana peels, orange peels, onion residues, and kiwi peels and their procedure of methane production under varied conditions. This review also covers the anaerobic digestion [AD] process which is reported to enhance biogas production under enhanced nitrogen supply such as ammonium chloride. We also covered an analysis of biogas production utilizing a mixture of cow dung slurry and kitchen refuse at various environmental conditions. Combining food waste and cow manure through anaerobic co-digestion can generate renewable biogas, reduce environmental impact and improve methane quality, making it a viable method for enhancing biogas production efficiency. Biogas derived from fruit waste and cow manure through anaerobic co-digestion shows increased production compared to processing fruit waste alone. Some factors affecting biogas production include temperature, pH levels and microbial activity. The study explores the dual functionality of fruit waste as an energy source and organic fertilizer. Combining fruit waste and cow manure under mesophilic conditions enhances biogas production. The study suggests that biogas production can improve agricultural practices, reduce environmental impact and serve as an alternative to traditional fuels like firewood.

Plastic pollution has escalated into a global environmental crisis, with millions of tons of synthetic polymers accumulating within ecosystems and posing significant threats to both biodiversity and human health. Conventional methods of plastic waste management, such as mechanical and chemical recycling, exhibit limitations in terms of sustainability, particularly for polymers such as polyethylene (PE) and polystyrene (PS), which demonstrate a pronounced resistance to degradation. Biotechnological approaches that exploit microbial enzymes and synthetic biology offer a promising alternative to tackle this pressing issue. Enzymes such as PETase and MHETase, which facilitate the degradation of polyethylene terephthalate (PET), in conjunction with laccases and lipases that target more recalcitrant plastics, have manifested considerable potential in deconstructing plastics at the molecular level. Notwithstanding these advancements, challenges persist regarding degradation efficiency, especially for non-PET plastics, as well as the economic viability of scaling these biotechnological processes. Furthermore, environmental parameters including temperature, pH, and oxygen levels significantly influence enzyme functionality, while regulatory and societal obstacles impede the utilization of genetically modified organisms (GMOs). Nevertheless, emerging technologies such as protein engineering, CRISPR-based gene editing, and industrial applications like bioreactors present avenues for surmounting these challenges. This article investigates the current landscape, challenges, and prospects associated with biotechnological plastic degradation, emphasizing its potential contribution to achieving global circular economy objectives and enhancing sustainable waste management strategies.

Bioplastics originating from waste biomass present a viable remedy to the environmental dilemmas associated with traditional plastics, thereby reducing dependency on fossil fuels and mitigating carbon emissions. This review investigates the utilization of diverse waste biomass sources, encompassing agricultural residues, food waste, industrial by-products, municipal solid waste, and forest biomass residues, in the synthesis of bioplastics. Technological innovations in feedstock pretreatment, bioconversion methodologies, and polymerization techniques have markedly enhanced the efficiency and material characteristics of bioplastics, establishing them as formidable alternatives to petroleum-derived plastics. Notwithstanding these advancements, obstacles such as feedstock inconsistency, scalability issues, technological limitations, and consumer acceptance persistently impede the extensive adoption of bioplastics. The ecological advantages of bioplastics, particularly concerning their diminished carbon footprint and potential for biodegradability, are underscored through life cycle assessments (LCAs). Government policies, the increasing market demand for sustainable products, and advancements in emerging technologies, including synthetic biology and AI-enhanced process optimization, are propelling the commercialization of bioplastics derived from waste biomass. The incorporation of bioplastics within a circular economy framework, coupled with considerations for long-term sustainability, positions them as a pivotal element in fostering a more sustainable and environmentally friendly future. This review offers a thorough examination of the present landscape, challenges, and future prospects of bioplastics production from waste biomass.

The depletion of fossil fuels and increased atmospheric CO₂ levels have precipitated a global energy and environmental crisis. The cultivation of microalgae offers a viable remedy by utilizing solar energy and assimilating CO₂ for biofuel production via photosynthesis. Microalgae demonstrate rapid growth in diverse environments, rendering them a dependable biomass source for large-scale biofuel generation. Furthermore, their biofuel production can be tailored through the manipulation of growth conditions or genetic engineering. This review aims to highlight the variety of biofuels produced from microalgae and the methodologies to optimize their yield. This review also explores the economic implications of algal biofuel production in both open ponds and closed photobioreactors. Various strategies for the photo-production of biohydrogen utilizing the hydrogenase enzyme from green algae are investigated. Additionally, certain microalgae species are recognized for their potential as biodiesel sources due to their high lipid content. The lipid profiles of leading oil-producing algal strains under optimal conditions are assessed. This review further examines the potential of microalgae in synthesizing petroleum-based chemicals and in generating bioethanol and biogas from algal biomass.

The depletion of fossil fuels and increased atmospheric CO2 levels have precipitated a global energy and environmental crisis. The cultivation of microalgae offers a viable remedy by utilizing solar energy and assimilating CO2 for biofuel production via photosynthesis. Microalgae demonstrate rapid growth in diverse environments, rendering them a dependable biomass source for large-scale biofuel generation. Furthermore, their biofuel production can be tailored through the manipulation of growth conditions or genetic engineering. This review aims to highlight the variety of biofuels produced from microalgae and the methodologies to optimize their yield. This review also explores the economic implications of algal biofuel production in both open ponds and closed photobioreactors. Various strategies for the photo-production of biohydrogen utilizing the hydrogenase enzyme from green algae are investigated. Additionally, certain microalgae species are recognized for their potential as biodiesel sources due to their high lipid content. The lipid profiles of leading oil-producing algal strains under optimal conditions are assessed. This review further examines the potential of microalgae in synthesizing petroleum-based chemicals and in generating bioethanol and biogas from algal biomass.

In the past few years, biodiesel has garnered considerable interest from researchers, government bodies, and industries as a sustainable, eco-friendly, and safe alternative fuel. Nonetheless, various feedstocks have been deemed impractical or unviable due to their exorbitant costs, primarily because they are utilized as food sources. Waste cooking oils (WCOs) and waste animal fats (WAFs) stand out as the most viable options for biodiesel feedstocks, despite their challenges, since treating such waste can be quite expensive due to stringent environmental regulations. A portion of these expenses might be mitigated through the production of bioenergy like biodiesel. This review article offers an extensive analysis of the pre-treatment processes and the application of WCOs and WAFs in biodiesel production. The predominant method for generating biodiesel is transesterification. Additionally, this paper emphasizes the purification and examination of the biodiesel produced, along with the latest innovations in biodiesel production from WCOs and WAFs. This review concludes that both WCOs and WAFs hold great potential as feedstocks for the production of biodiesel.