Biotechnology is increasingly being used as a tool to replace traditional production methods due to concerns about the increasing damage caused by global warming. Bacteria, yeasts, fungi, and microalgae are microorganisms able to transform residues into value-added bioproducts. They produce microbial biomass that can result in the production of several products, such as biofuels, microbial proteins, fatty acids, bioactive polysaccharides, carotenoids, industrial enzymes, polyhydroxyalkanoates, and biofertilizers, among others. To improve microbial biomass and lipid yield, modern genetic engineering techniques can be applied as a way of optimizing processes and conditions. This review aims to explore the latest trends and technological advances in microbial biomass and lipid production, including optimization strategies for cultivation conditions and the use of genetic engineering to enhance yields and efficiency. It also discusses the challenges and future prospects for scaling up production for industrial applications. The potential of microbial lipids to contribute to a sustainable bioeconomy, as well as their applications in renewable energy and food industries, underscores their importance in a world increasingly seeking alternatives to fossil fuel dependence and unsustainable agricultural practices.

Cocoa fermentation is a critical step in chocolate production, influencing the flavor, aroma, and overall quality of the final product. This review focuses on the microbial dynamics of cocoa fermentation, emphasizing the roles of yeasts, lactic acid bacteria (LAB), and acetic acid bacteria (AAB). These microorganisms interact in a well-defined succession, producing organoleptic compounds such as alcohols, organic acids, and esters, which are key to the sensory profile of cocoa. This article examines the impact of different fermentation methods, including spontaneous fermentation and the use of starter cultures, on microbial communities and flavor development. Advances in starter culture technology are highlighted, demonstrating how microbial control can enhance fermentation efficiency, reduce fermentation time, and improve the consistency of chocolate flavor. Patents related to cocoa fermentation further emphasize the growing interest in microbial management to meet market demands for high-quality, distinct chocolate. This review also outlines future research directions, including the identification of new microbial strains, optimization of fermentation conditions, and the potential of biotechnological advancements to improve the fermentation process. Understanding microbial dynamics in cocoa fermentation offers significant potential for enhancing chocolate quality, sustainability, and the development of new, region-specific flavor profiles.

Renewable energy sources, such as biofuels, represent promising alternatives to reduce dependence on fossil fuels and mitigate climate change. Their production through enzymatic hydrolysis has gained relevance by converting agro-industrial waste into fermentable sugars and residual oils, which are essential for the generation of bioethanol and biodiesel. The fungus Aspergillus stands out as a key source of enzymes, including cellulases, xylanases, amylases, and lipases, which are crucial for the breakdown of biomass and oils to produce bioethanol and fatty acid methyl esters (FAME). This review examines the current state of these technologies, highlighting the significance of Aspergillus in the conversion of energy-rich waste materials. While the process holds significant potential, it faces challenges such as the high costs associated with enzymatic production and final processing stages. Agro-industrial waste is proposed as an energy resource to support a circular economy, thereby eliminating reliance on non-renewable resources in these processes. Furthermore, advanced pretreatment technologies—including biological, physical, and physicochemical methods, as well as the use of ionic liquids—are explored to enhance process efficiency. Innovative technologies, such as genetic engineering of Aspergillus strains and enzyme encapsulation, promise to optimize sustainable biofuel production by addressing key challenges and advancing this technology towards large-scale implementation.