Critical Reviews in Biotechnology最新文献

Tyrosinase is a copper-containing monooxygenase that catalyzes the O-hydroxylation of tyrosine to 3,4-dihydroxyphenylalanine and subsequently to dopaquinone. The enzyme is essential for the formation of melanin in eukaryotes, and its over-activation is linked to hyperpigmentation, which is metabolically associated with severe clinical conditions. The most efficient way to regulate the overproduction of melanin and its harmful effects is to suppress tyrosinase. Endophytic fungi are of immense importance in producing the pharmacologically active and structurally diverse range of secondary metabolites with the host plant and even as sole producers. These fungi have been widely reported to produce a myriad of potent tyrosinase inhibitors, which can pave the path for discovering new treatment approaches, especially for melanin-induced hyperpigmentation. To utilize tyrosinase inhibitors as active pharmaceutical or cosmeceutical ingredients, however, extensive studies are required to evaluate them under in vivo conditions, and there is also a need to explore novel fungal endophytes from diverse sources.

Fungal natural products (FNPs) are an important class of natural medicines. Genome sequencing has uncovered an unexpectedly large number of silent biosynthetic gene clusters (BGCs) in fungi that hold potential for FNP production. However, activating silent BGCs in native hosts is hindered by undesirable traits, such as difficulty in genetic manipulation or exhibiting extremely low metabolite titers. With the development of synthetic biology, heterologous expression systems are increasingly becoming the preferred option to overcome these limitations. In this review, we first summarize the major structural classes of FNPs and the corresponding backbone enzymes. We then evaluate the key features of various microbial chassis and strategies employed for pathway refactoring to achieve efficient heterologous expression. Furthermore, we discuss optimization strategies that enhance pathway flux toward the target product and minimize by-product formation. These methodologies are essential for advancing heterologous platforms for FNP discovery and biosynthesis. Additionally, we analyze current challenges and propose solutions to further improve microbial chassis for more effective FNP production.

Fungi have emerged as powerful biological agents in the bioremediation of hydrocarbon-contaminated environments due to their robust enzymatic systems, adaptability, and ecological relevance. This review critically examines their potential, highlighting enzymatic mechanisms and technological innovations that underpin this sustainable approach. Case studies with: Aspergillus sp., Fusarium sp., Paecilomyces sp., Penicillium sp., and Trametes sp. demonstrate, through complex enzyme systems (laccases, lignin, manganese, and versatile peroxidases), the ability to degrade toxic compounds such as polycyclic aromatic hydrocarbons (PAHs) and BTEX, converting them into less harmful metabolites or even reusable by-products. Integrated strategies, including: biostimulation, bioaugmentation, microbial consortia, and the application of biosurfactants and bioemulsifiers, further enhance fungal efficiency in heterogeneous environments. Emerging innovations such as enzyme immobilization, myco-nanoremediation, and genetic engineering are discussed as promising solutions to overcome the inherent limitations of contaminant degradation under adverse conditions. Nevertheless, significant challenges remain, including the complexity of fungal metabolic pathways, gaps in proteomic regulation, and persistent obstacles in scaling and field reproducibility, which currently restrict large-scale commercial application. The alignment of fungal bioremediation with circular economy principles is emphasized, particularly the transformation of oil-derived pollutants into economically valuable bioproducts. Although fungal-based technologies remain underexplored commercially, especially in relation to regulatory frameworks and strategic partnerships, with this gap being especially evident in the Brazilian context, this review provides a robust foundation for advancing the application of fungi in sustainable environmental recovery. By integrating mechanistic insights with technological innovations and regulatory perspectives, it addresses a critical gap in the literature and outlines future directions for the field.

Sugarcane, a leading source of sugar and bio-energy around the globe stands at the cross-road of genome complexity and agricultural innovation, offering the immense potential to fuel a sustainable future. Functional genomics with its precise identification and manipulation of genes could enable researchers unlock this potential and accelerate the breeding efforts. However, the polyploid genome of sugarcane with: high heterozygosity, high-repetitive DNA content, multiple copies of homo(eo)logous gene, epistatic interaction of alleles, etc., challenges the gene annotation, genome sequencing, genome editing, and phenotypic characterization. Similarly long breeding cycle, low transformation efficiency, time-consuming, and labor-intensive transformation methods further complicates the genome editing. Recent advances of functional genomics are transforming this scenario, such as current availability of reference genome "R570," has provided a significant insight of genome architect and function. Genome wide association studies (GWAS)/genome selection (GS) are enhancing trait-mapping and prediction of breeding values to accelerate the breeding cycles. The current era of smart breeding with integrative bio-informatics, advance genome editing tools, i.e., CRISPR/Cas-systems (Cas-proteins, Cas-RNPs, d-Cas-RNPs, and CRISPRa/i), and high-throughput phenomics offers a significant approach to: overcome transformation bottlenecks, explore complex trait architect and address polyploidy challenges. Therefore, this review summarizes the key challenges and focuses on elaborating recent advances and suggests optimized strategies for future improvement in functional genomics of sugarcane breeding.

Adaptive laboratory evolution (ALE) is a powerful tool for understanding and controlling the evolutionary trajectories of microorganisms. The scope of applications extends widely, including areas such as: biotechnology, synthetic biology, microbial ecology, and fundamental evolutionary research. In this work, we systematically explore the implementation and advantages of mini-bioreactors, defined as reactors with working volumes below 0.5 L, in ALE experiments. Mini-bioreactors offer substantial improvements over traditional large-scale reactors, including: reduced costs, enhanced parallelization capabilities, customizable configurations, and ease of automation. Through the utilization of illustrative case studies, which facilitate a comparative and critical evaluation of: batch, chemostat, turbidostat, and morbidostat operational modes, this review underscores the distinct capabilities of mini-bioreactors in enabling precise, dynamic control of evolutionary pressures. The novelty of this review lies in its comprehensive synthesis of recent advancements in mini-bioreactor technologies and operational strategies, particularly emphasizing innovations, such as: integrated automation, advanced sensors, and novel control algorithms adapted or specially designed for ALE. The ultimate objective is to provide both novices and experienced researchers with an updated, in-depth resource that addresses current technological limitations and future directions of mini-bioreactors in ALE.

Fucoidan is a sulfate-containing polysaccharide present in the cell wall of brown algae. It ensures the survival of the algae in the marine environment by providing protection against desiccation and osmotic stress. This review explores the structural diversity, synthesis, extraction methods, and application potential of fucoidan of brown algae with a focus on its bio-stimulant activities in plants. The structural variation of fucoidan in brown algae depends on various parameters, and it is the key factor for determining its biological activities. The synthesis of this polysaccharide takes place in the Golgi bodies, and it involves several steps for the polymerization and further modifications. Extraction and purification of this polysaccharide from the algal biomass involve several steps, and choosing the appropriate method is crucial for achieving maximum yield. As a complex heterogeneous polysaccharide, fucoidan possesses diverse biological activities, such as: anticancer, anticoagulant, antioxidant, immunomodulatory effects. Nowadays fucoidan is a topic of intense research, and studies are ongoing to explore its potential applications. This review also focuses on explaining bio-stimulant application in plants along with its potential application in: cancer research, tissue engineering, drug delivery, food coating and as an edible film and storage material for fruits with a particular emphasis on its role in promoting plant growth and enhancing stress tolerance.

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.