Critical Reviews in Biotechnology最新文献

In recent years, pectinase, a vital enzyme in diverse manufacturing sectors, including: food and beverage industries, bioenergy, textile and paper industries, etc., has inspired the scientific community to delve its: sustainable, eco-friendly, efficient, and sufficient production. Pectinase demand is perpetually rising, requiring effective mass production solutions. This study examines the various sources and improvements made in the recent years at large-scale pectinase production. The article highlighted various fermentation strategies, agro-wastes, and types of bioreactor technology utilized for pectinase production. Further: statistical tools, research designs and optimization approaches, immobilization techniques, and purification and molecular engineering approaches were also explored, accounting pectinase production. The current work aims to provide the valuable insights for: researchers, academicians, industry stakeholders, and regulatory bodies, in advancing sustainable and efficient large-scale production of pectinase, thus, broadening and boosting pectinase production for the targeted applications.

Prodigiosin is an alkaloid, cell-associated, red pigment extensively produced as a secondary metabolite by Gram negative bacterium, Serratia marcescens. The red pigment holds immense recognition for multifunctional tri-pyrrole structure and as a promising candidate for wide array of industrial applications. The biosynthesis and regulation of prodigiosin in S. marcescens is a complex process, manifesting biological information at multiple cellular levels as genomics, transcriptomics and proteomics. The current review delves into molecular biology of S. marcescens highlighting it as a prolific producer of prodigiosin. This review also highlights crucial aspects of regulatory mechanisms for prodigiosin production in S. marcescens, along with recent advancements in strain improvement and heterologous production of pigment in industrially compliant host. In addition, this review integrates current knowledge on molecular biology and regulation of prodigiosin, addressing the approaches employed for high level of prodigiosin production, potential applications, challenges and future perspective for harnessing industrial potential of prodigiosin in future.

The adage "Food is the God of the people" underscores the profound interconnectedness between agriculture and the food industry. Agriculture forms the backbone of the food industry, while evolving consumer preferences continuously shape its progress. The balance between saturated and unsaturated fatty acids (SFAs and UFAs) in vegetable oils is critical to human health. As health awareness grows, UFAs have gained significant market traction, prompting extensive research into their biosynthesis, regulation, and improvement. This review focuses on oilseed crops, offering a comprehensive analysis of: fatty acid composition, biosynthesis pathways, gene regulation, and breeding strategies to enhance quality. By integrating theoretical and practical insights, our work aims to provide guidance for promoting sustainable agriculture and advancing the food industry.

Microalgae are desirable candidates for performing about half of the World's organic carbon fixation and its conversion to essential metabolites of human metabolism, including polyunsaturated fatty acids (PUFAs). However, the yields of microalgal FAs produced naturally are typically insufficient to cover the expenses of their commercial utilization. To overcome this problem, gene engineering techniques have been used to change the activity of endogenous enzymes. This review aims to find knowledge about the mechanism of regulation of fatty acid (FA) biosynthesis and CO₂ fixation in microalgae. Firstly, this study discusses molecular strategies toward accelerating FA biosynthesis with a main emphasis on a critical review of transcriptional engineering. Some transcription factors (TFs) are known to increase FA content and related gene expression. However, a research gap is revealed toward understanding their regulatory mechanism and finding their role in regulating CO₂ fixation. Secondly, a critical review of studies on CO₂ fixation regulated by Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCo) and RuBisCo activase (RCA) disclosed that no studies have yet been reported about their transcriptional control. Thirdly, prospects are given on the genetic basis of parallel transcriptional regulation of genes involved in FA biosynthesis and CO₂ fixation in microalgae. This study should potentially provide considerable knowledge on developing eco-friendly and sustainable microalgae genetic resources to maximize the yield of value-added FAs using TF engineering.

Docosahexaenoic acid (DHA, 22:6n-3) is an essential omega-3 polyunsaturated fatty acid, abundant in the brain and eyes. DHA is crucial for maintaining the structural integrity and physiological functions of these vital organs. Within the brain, DHA is concentrated in the gray matter, synaptic membranes, and hippocampus. Likewise, in the eyes, substantial quantities can be found in the retina, with lower levels in the cornea and lens. Previous studies have outlined the potential for culturing marine heterotrophic protists in ways that provide cost-effective and sustainable DHA biosynthesis. Similarly, our previous work on repurposing slaughterhouse waste has highlighted this underutilized source of brain and ocular tissue, which can support the extraction of valuable nutrients such as DHA. In this review, we will examine the current state of the art related to DHA production from these two sources, explore potential applications, and outline the possible benefits that may be generated from our approaches, with an emphasis on ocular diseases.

The global accumulation of keratin-rich waste, primarily from poultry and livestock industries, presents significant environmental and economic challenges. This review explores the potential of Bacillus-derived keratinases as a sustainable solution for keratin waste valorization and prospects of value-addition. Keratinases, the keratin hydrolyzing proteases produced predominantly by various Bacillus species, exhibit exceptional capability in degrading keratin, a highly stable and recalcitrant protein. This degradation process not only mitigates the environmental impact of keratin waste, but also converts it into valuable by-products with potential industrial applications. We systematically review various aspects, including: the production, properties and the mechanism of keratin degradation by Bacillus keratinases, highlighting their enzymatic properties, substrate specificity, and efficiency in valorizing keratin into peptides and amino acids. Biomolecular aspects and catalytic behavior relevant to the activity and stability of Bacillus keratinases are visited via in silico modeling. The economic and environmental benefits of utilizing keratinases for waste valorization are assessed, including reductions in waste disposal costs, greenhouse gas emissions, and the potential for creating new economic opportunities through the utilization of keratin-derived products. The recent advancements in keratin waste enzyme treatment and their utilization in developing circular bioeconomy are highlighted in the present article.

β-glucosidases are a well-characterized, diverse group of hydrolytic enzymes that act on various substrates. They are extensively used in different sectors, including: bioethanol, food, flavor, nutraceutical, and pharmaceutical industries. Immobilization improves the operational stability, reusability and catalytic efficiency of β-glucosidase compared to the free enzyme. The nanoscale dimensions, high surface area of the nanomaterial, and strong enzyme-nanosupport interactions prevent denaturation and leaching of β-glucosidase. This boosts enzyme stability, reduces the need for replenishment, and allows for easy recovery and reuse, minimizing enzyme waste and energy consumption in industrial biocatalysis. Nanosupport materials, including: inorganic materials, carbon, biopolymer-based, and magnetic nanoparticles, have gained popularity as immobilization matrices for generating either β-glucosidase immobilization or co-immobilization systems for various applications. The present review focuses on the current trends in immobilization strategies of β-glucosidase for improving operational stability and recyclability of the enzyme. Additionally, this review provides deeper insights into various surface modifications of magnetic and non-magnetic nanosupport matrices employed for immobilization and their impact on the catalytic efficiency of β-glucosidase. Moreover, the review thoroughly investigates the challenges encountered in immobilizing β-glucosidases on various nanosupport matrices. It concludes with insightful remarks that encourage future researchers to conduct studies dedicated to the development of a highly efficient, industrially adapted nanobiocatalytic system to achieve sustainable biotransformation aligning with United Nations Sustainable Development Goals (SDG): SDG 2 (Sustainable Food System), SDG 7 (Affordable and Clean Energy), SDG 9 (Sustainable Industry), SDG 12 (Responsible Consumption), and SDG 13 (Climate Action: Reducing Carbon Emissions).

Antimicrobial peptides (AMPs) play a crucial defensive role in living organisms, capable of rapidly responding to and eliminating invading microorganisms. Their mechanisms of action are diverse, primarily involving the disruption of microbial cell membranes. The interest in AMPs stems from their potential to address antibiotic resistance and improve human health. AMPs exhibit: broad-spectrum antimicrobial activity, low toxicity, thermal stability, and high specificity, making them promising candidates for new antimicrobial drugs with applications in medicine, food preservation, and agriculture. This review provides a comprehensive summary of the historical development and classification of AMPs. It details their: classification, mechanisms of action, application fields, and processes involved in the isolation, purification, and structural identification of microbial-derived AMPs. Additionally, it introduces a novel green extraction method using deep eutectic solvents (DESs) for peptide extraction.

Viral outbreaks are a topic of worldwide concern, resulting in a significant impact in health systems, a large number of deaths, and huge economical losses. The damage caused by Covid-19 has further highlighted the importance of prospecting for new molecules that can be applied in the prevention and treatment of viral infections. Many studies describe the remarkable antimicrobial activity of lipopeptides produced by Bacillus spp., especially against fungi and bacteria. However, research regarding the antagonistic effects on viruses is less frequent. Despite that, the antiviral activity of lipopeptides produced by Bacillus spp. has been demonstrated, indicating that these molecules could be potential candidates to control viral diseases. In this article, a compilation of reports with consistent data regarding the antiviral effect of Bacillus lipopeptides and the mechanisms involved in this process are presented. Moreover, the immunomodulatory role and toxicity profile of these molecules are discussed. Bacillus lipopeptides may exert an indirect antiviral effect, since they are able to positively induce humoral and cell-mediated immune responses. Moreover, their antiviral effect was observed in vitro and in vivo at nontoxic concentrations, offering a safe perspective for possible clinical application of these molecules. Finally, the challenges related to optimization and increasing production yield are addressed. This is the first critical review dedicated exclusively to antiviral activity of Bacillus lipopeptides.

Bacterial extracellular vesicles (EVs) are produced by both Gram-negative and Gram-positive bacteria. These EVs are composed of lipid bilayers and various components derived from parent bacteria, including proteins, lipids, and nucleic acids. Previous studies have indicated the significant role of bacterial EVs in interactions between bacteria and between bacteria and hosts. Moreover, bacterial EVs are emerging as promising delivery vectors capable of transporting drug molecules over long distances to tissues. Therefore, understanding the biogenesis of bacterial EVs and how to regulate their production holds great importance for expanding their applications. In this review, we provide an overview of bacterial EVs, especially focusing on the distinct mechanisms of EVs biogenesis and the regulation of EVs production in both Gram-negative and Gram-positive bacteria. Additionally, we discuss various methods for cargos loading into bacteria EVs, as well as their diverse applications in vaccines, cancer therapy, and drug delivery. We anticipate that this review will advance the field of bacterial EVs, contributing to both the enhancement of existing applications and the emergence of novel applications.