Critical Reviews in Biotechnology最新文献

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.

The rise of chronic and acute infections has increased reliance on antimicrobial agents. However, conventional antimicrobials often fail to deliver optimal therapeutic outcomes due to limitations such as low bioavailability, poor biocompatibility, nonspecific targeting, drug-induced toxicity, and the growing issue of antimicrobial resistance. Therefore, the concept of a resistance-proof antimicrobial agent (RPAA) and its smart delivery was introduced to overcome the existing problem and a targeted delivery due to the specific properties, such as: high bioavailability, biocompatibility, low drug-induced toxicity, biodegradability, high binding capacity with the pathogen, multiple targeting delivery, etc. This system generates a positive impact and could quash the multidrug resistance problem. In this review, we discuss: the rationale for developing a nanoengineering-based smart-delivery system for RPAA, the advantageous properties of such a system, the possible mechanism of delivery, and challenges in the development of a nano-drug delivery therapeutics tool for RPAA delivery as a solution to combat the global problem of drug resistance. We emphasize the urgent need for the development of such a next-generation drug delivery system and discuss the opportunities/hurdles as well as the questions that remain to be addressed. The article is important because it sheds light on the properties of nanoengineered drug delivery that could initiate new ways of thinking about the development of future-generation delivery systems. The article shares a promising idea that would be an essential foundation for opening a new window in the field of drug discovery and development of the smart delivery system for RPAA.

Upon pathogen attack, cytosolic Ca²⁺ levels increase in plant cells. The first innate immune response is activated by detecting microbe/pathogen-associated molecular patterns (MAMPs/PAMPs) and is called PAMPs-triggered immunity (PTI). The second immune response is triggered by recognizing pathogens' effector proteins named effectors-triggered immunity (ETI). Calcium-dependent protein kinases (CDPKs or CPKs) are well-known calcium sensors that have a mediator role both in PTI and ETI. Calcium can bind to the elongation factor (EF)-hand domain at the C-terminus of CDPKs, which then phosphorylates substrates at the N-terminal catalytic kinase domain to transfer calcium signals directly. Improving the stress resilience of crops is a critical strategy in attaining global food security. In plants, when a stimulus is seen, there is an increase in Ca²⁺ concentration, which activates CDPKs which are in charge of sending out the immunological signals needed for disease tolerance. During the immune response, CDPKs are subject to numerous levels of regulation, including Ca²⁺ dependency to decipher various Ca²⁺ signals. Furthermore, salicylic acid (SA) regulation by CDPKs provides a comprehensive overview of CDPKs-mediated SA signaling during immune response in plants under pathogen attack. The critical part of CDPKs in SA biosynthesis, from the regulation of SA biosynthesis to how NPR1 perceives SA upon biotic stress, is comprehensively reviewed in this paper with the latest advancements in research. However, more research about CDPKs-mediated SA signaling under pathogen attack is mandatory to further dissect their co-role in crop protection against various diseases to achieve sustainable production goals in the future.

Global warming caused by CO₂ emissions has been considered as one of the major challenges of this century. In an endeavor to control and reduce CO₂ emissions, a series of Carbon dioxide Capture, Utilization, and Storage (CCUS) technologies have been developed specifically for the sequestration of CO₂ from atmospheric air. Microalgae, as versatile and universal photosynthetic microorganisms, represent a promising avenue for biological CO₂ sequestration. Nevertheless, further advancements are necessary to optimize microalgae-based carbon sequestration technology in terms of light reaction and dark reaction. This review discusses the current status of microalgae-based artificial CO₂ sequestration technique, with a particular focus on the selection of CO₂-resistant species, optimization of cultivation for CO₂ sequestration, design of carbon concentration reactor, and the potential of synthetic biology to enhance CO₂ solubility and biofixation efficiency. Furthermore, a discussion of Life cycle assessment and Techno-economic analysis regarding microalgae-based carbon capture was performed. The aim of this comprehensive review is to stimulate further research into microalgae-based CO₂ sequestration, addressing challenges and opportunities for future development.

Reporter systems are gaining increasing popularity in modern molecular biology as they provide reliable and clear readouts for various types of assays, both in cellulo and in vivo. The generation of reporter cell lines is instrumental for screening activators and inhibitors of signaling pathways to develop new therapeutic approaches. Reporter cell lines are those with stably integrated reporter constructs containing signaling genes (often luciferase or fluorescent proteins), enabling the visualization and tracking of protein expression. Although seemingly harmless and straightforward, untargeted genomic integration of reporter genes may severely affect the expression of neighboring genes, causing unwanted and unpredictable effects. Unlike the untargeted approach, the CRISPR/Cas9 system provides a more precise method of reporter integration, especially when reporters are integrated into Safe Harbor loci. This ensures minimal influence on neighboring genomic regions. This review discusses recent advancements in creating reporter lines using the CRISPR/Cas9 system and experimental approaches for identifying suitable Safe Harbor loci.