Critical Reviews in Biotechnology最新文献

Exploring the untapped potential of deep-sea microorganisms, particularly their cold-active enzymes, or psychrozymes, offers exciting possibilities for revolutionizing various aspects of the food processing industry. This review focuses on these enzymes, derived from the largely unexplored depths of the deep ocean, where microorganisms have developed unique adaptations to extreme conditions. Psychrozymes, as bioactive molecules, hold significant promise for food industry applications. However, despite their potential, the understanding and industrial utilization of psychrozymes remains limited. This review provides an in-depth analysis of how psychrozymes can: improve processing efficiency, enhance sensory qualities, extend product shelf life, and reduce energy consumption across the food production chain. We explore the cryodefense strategies and cold-adaptation mechanisms that support these enzymes, shedding light on the most extensively studied psychrozymes and assessing their journey from theoretical applications to practical use in food production. The key properties, such as stability, substrate specificity, and catalytic efficiency in cold environments, are also discussed. Although psychrozymes show considerable promise, their large-scale application in the food industry remains largely unexplored. This review emphasizes the need for further research to unlock the full potential of psychrozymes, encouraging their broader integration into the food sector to contribute to more sustainable food production processes.

Nicotinamide mononucleotide (NMN) presents significant therapeutic potential against aging-related conditions, such as Alzheimer's disease, due to its consistent and strong pharmacological effects. Aside from its anti-aging effect, NMN is also an emerging noncanonical cofactor for orthogonal metabolic pathways in the field of biomanufacturing. This has significant advantages in the field of metabolic engineering, allowing cells to produce unnatural chemicals without disrupting the natural cellular processes. NMN is produced through both the chemical and biological methods, with the latter being more environmentally sustainable. The primary biological production pathway centers on the enzyme nicotinamide phosphoribosyltransferase, which transforms nicotinamide and phosphoribosyl pyrophosphate to NMN. Efforts to increase NMN production have been explored in microorganisms, such as: Escherichia coli, Bacillus subtilis, and yeast, serving as biocatalysts, by rewiring their metabolic processes. Although most researchers are focusing on genetically and metabolically manipulating microorganisms to act as biocatalysts, a growing number of studies on cell-free synthesis are emerging as a promising strategy for producing NMN. This review explores the different biological production techniques of NMN employing microorganisms. This article, in particular, is essential to those who are working on NMN production using microbial strain engineering and cell-free systems.

Muconic acid (MA) is a valuable dicarboxylic acid with three isomers that are extensively utilized in textile and chemical industries. Traditionally, the chemical synthesis of MA consumes nonrenewable petrochemical raw materials and causes significant environmental problems. With the rapid increase in demand for MA, eco-friendly biosynthetic technologies with renewable sources are becoming ideal alternative solutions. This paper systematically reviews recent advances in the biosynthesis of MA isomers, describing not only the mechanism for MA biosynthesis in different microorganisms, including wild and engineered strains, but also focuses on MA production from various renewable resources, especially lignin hydrolysate and lignin-derived aromatics hydrocarbons, such as: benzoic acid, isoeugenol, vanillic acid and phenol. Moreover, cis,cis-muconic acid production from xylose, PET, methane, and glycerol are discussed in detail, providing a much broader substrate spectra and further possibilities for MA large scale industrialization economically. Challenges facing biosynthesis of cis, trans muconic acid and trans, trans muconic acid are discussed finally.

The C1 resource is widely considered because of its abundance and affordability. In the context of extensive utilization of C1 resources by methylotrophic microorganisms, especially for methanol, formaldehyde is an important intermediate metabolite that is at the crossroads of assimilation and dissimilation pathways. However, formaldehyde is an exceedingly reactive compound that can form covalent cross-linked complexes with amine and thiol groups in cells, which causes irreversible damage to the organism. Thus, it is important to balance the intensity of the assimilation and dissimilation pathways of formaldehyde, which can avoid formaldehyde toxicity and improve the full utilization of C1 resources. This review details the source of endogenous formaldehyde and its toxicity mechanism, explaining the harm of excessive accumulation of formaldehyde to metabolism. Importantly, the self-detoxification and various feasible strategies to mitigate formaldehyde toxicity are discussed and proposed. These strategies are meant to help appropriately handle formaldehyde toxicity and accelerate the effective use of C1 resources.

Fungal diseases threaten the forest ecosystem, impacting tree health, productivity, and biodiversity. Conventional approaches to combating diseases, such as biological control or fungicides, often reach limits regarding efficacy, resistance, non-target organisms, and environmental impact, enforcing alternative approaches. From an environmental and ecological standpoint, an RNA interference (RNAi) mediated double-stranded RNA (dsRNA)-based strategy can effectively manage forest fungal pathogens. The RNAi approach explicitly targets and suppresses gene expression through a conserved regulatory mechanism. Recently, it has evolved to be an effective tool in combating fungal diseases and promoting sustainable forest management approaches. RNAi bio-fungicides provide efficient and eco-friendly disease control alternatives using species-specific gene targeting, minimizing the off-target effects. With accessible data on fungal disease outbreaks, genomic resources, and effective delivery systems, RNAi-based biofungicides can be a promising tool for managing fungal pathogens in forests. However, concerns regarding the environmental fate of RNAi molecules and their potential impact on non-target organisms require an extensive investigation on a case-to-case basis. The current review critically evaluates the feasibility of RNAi bio-fungicides against forest pathogens by delving into the accessible delivery methods, environmental persistence, regulatory aspects, cost-effectiveness, community acceptance, and plausible future of RNAi-based forest protection products.

Plants, anchored throughout their life cycles, face a unique set of challenges from fluctuating environments and pathogenic assaults. Central to their adaptative mechanisms are transcription factors (TFs), particularly the AP2/ERF superfamily-one of the most extensive TF families unique to plants. This family plays instrumental roles in orchestrating diverse biological processes ranging from growth and development to secondary metabolism, and notably, responses to both biotic and abiotic stresses. Distinguished by the presence of the signature AP2 domain or its responsiveness to ethylene signals, the AP2/ERF superfamily has become a nexus of research focus, with increasing literature elucidating its multifaceted roles. This review provides a synoptic overview of the latest research advancements on the AP2/ERF family, spanning its taxonomy, structural nuances, prevalence in higher plants, transcriptional and post-transcriptional dynamics, and the intricate interplay in DNA-binding and target gene regulation. Special attention is accorded to the ethylene response factor B3 subgroup protein Pti5 and its role in stress response, with speculative insights into its functionalities and interaction matrix in tomatoes. The overarching goal is to pave the way for harnessing these TFs in the realms of plant genetic enhancement and novel germplasm development.

Natural fibers have garnered considerable attention owing to their desirable textile properties and advantageous effects on human health. Nevertheless, natural fibers lag behind synthetic fibers in terms of both quality and yield, as these attributes are largely genetically determined. In this article, a comprehensive overview of the natural and synthetic fiber production landscape over the last 10 years is presented, with a particular focus on the role of scientific breeding techniques in improving fiber quality traits in key crops like cotton, hemp, ramie, and flax. Additionally, the article delves into cutting-edge genomics-assisted breeding techniques, including QTL mapping, genome-wide association studies, transgenesis, and genome editing, and their potential role in enhancing fiber quality traits in these crops. A user-friendly compendium of 11226 available QTLs and significant marker-trait associations derived from 136 studies, associated with diverse fiber quality traits in these crops is furnished. Furthermore, the potential applications of transcriptomics in these pivotal crops, elucidating the distinct genes implicated in augmenting fiber quality attributes are investigated. Additionally, information on 11257 candidate/characterized or cloned genes sourced from various studies, emphasizing their key role in the development of high-quality fiber crops is collated. Additionally, the review sheds light on the current progress of marker-assisted selection for fiber quality traits in each crop, providing detailed insights into improved cultivars released for different fiber crops. In conclusion, it is asserted that the application of modern breeding tools holds tremendous potential in catalyzing a transformative shift in the textile industry.

The chloroplast and mitochondrion are semi-autonomous organelles that play essential roles in cell function. These two organelles are embellished with prokaryotic remnants and contain many new features emerging from the co-evolution of organelles and the nucleus. A typical plant chloroplast or mitochondrion genome encodes less than 100 genes, and the regulation of these genes' expression is remarkably complex. The regulation of chloroplast and mitochondrion gene expression can be achieved at multiple levels during development and in response to environmental cues, in which, RNA metabolism, including: RNA transcription, processing, translation, and degradation, plays an important role. RNA metabolism in plant chloroplasts and mitochondria combines bacterial-like traits with novel features evolved in the host cell and is regulated by a large number of nucleus-encoded proteins. Among these, pentatricopeptide repeat (PPR) proteins are deeply involved in multiple aspects of the RNA metabolism of organellar genes. Research over the past decades has revealed new insights into different RNA metabolic events in plant organelles, such as the composition of chloroplast and mitochondrion RNA editosomes. We summarize and discuss the most recent knowledge and biotechnological implications of various RNA metabolism processes in plant chloroplasts and mitochondria, with a focus on the nucleus-encoded factors supporting them, to gain a deeper understanding of the function and evolution of these two organelles in plant cells. Furthermore, a better understanding of the role of nucleus-encoded factors in chloroplast and mitochondrion RNA metabolism will motivate future studies on manipulating the plant gene expression machinery with engineered nucleus-encoded factors.

Every year, a huge amount of lethal compounds, such as synthetic dyes, pesticides, pharmaceuticals, hydrocarbons, etc. are mass produced worldwide, which negatively affect soil, air, and water quality. At present, pesticides are used very frequently to meet the requirements of modernized agriculture. The Food and Agriculture Organization of the United Nations (FAO) estimates that food production will increase by 80% by 2050 to keep up with the growing population, consequently pesticides will continue to play a role in agriculture. However, improper handling of these highly persistent chemicals leads to pollution of the environment and accumulation in food chain. These effects necessitate the development of technologies to eliminate or degrade these pollutants. Degradation of these compounds by physical and chemical processes is expensive and usually results in secondary compounds with higher toxicity. The biological strategies proposed for the degradation of these compounds are both cost-effective and eco-friendly. Microbes play an imperative role in the degradation of xenobiotic compounds that have toxic effects on the environment. This review on the fate of xenobiotic compounds in the environment presents cutting-edge insights and novel contributions in different fields. Microbial community dynamics in water bodies, genetic modification for enhanced pesticide degradation and the use of fungi for pharmaceutical removal, white-rot fungi's versatile ligninolytic enzymes and biodegradation potential are highlighted. Here we emphasize the factors influencing bioremediation, such as microbial interactions and carbon catabolism repression, along with a nuanced view of challenges and limitations. Overall, this review provides a comprehensive perspective on the bioremediation strategies.

Microalgae-based technology is widely utilized in wastewater treatment and resource recovery. However, the practical implementation of microalgae-based technology is hampered by the difficulty in separating microalgae from treated water due to the low density of microalgae. This review is designed to find the current status of the development and utilization of microalgae biogranulation technology for better and more cost-effective wastewater treatment. This review reveals that the current trend of research is geared toward developing microalgae-bacterial granules. Most previous works were focused on studying the effect of operating conditions to improve the efficiency of wastewater treatment using microalgae-bacterial granules. Limited studies have been directed toward optimizing operating conditions to induce the secretion of extracellular polymeric substances (EPSs), which promotes the development of denser microalgae granules with enhanced settling ability. Likewise, studies on the understanding of the EPS role and the interaction between microalgae cells in forming granules are scarce. Furthermore, the majority of current research has been on the cultivation of microalgae-bacteria granules, which limits their application only in wastewater treatment. Cultivation of microalgae granules without bacteria has greater potential because it does not require additional purification and can be used for border applications.