Applied Biochemistry and Biotechnology最新文献

Diatoms are unicellular eukaryotic algae, renowned for their intricately patterned silica cell walls, which exhibit remarkable morphological precision and nanostructural complexity. They possess a unique and rich biochemical profile and are prolific producers of biologically active polysaccharides, broadly categorized as intracellular, extracellular (primarily sulfated), and cell wall-associated types. These polysaccharides play vital roles in biofilm formation, carbon cycling, nutrient storage, and ecosystem dynamics, while also holding substantial promises in commercial and biotechnological fields. This review provides an integrated overview of diatom polysaccharide chemotypes-storage β-glucans, cell-wall uronic- and sulfate-rich scaffolds, and extracellular exopolymers-and evaluates the conventional versus emerging extraction and purification techniques, discussing trade-offs in yield, selectivity, and polymer integrity. The diverse structural characterization methods for elucidating monosaccharide linkages and functional modifications have been reviewed. The genomic and metabolic insights into polysaccharide biosynthesis have been elaborated along with elucidation of the relationship between extracellular polymeric substances and bacterial community assembly. The multifaceted applications of diatom-derived polysaccharides in carbon sequestration, biomedicine (e.g., anticoagulant, antioxidant, antiviral, anticancer, immunomodulatory agents), materials science, and environmental remediation has been discussed along with the current challenges-species variability, efficient frustule disruption, and scalable processing. The-genomics-guided strain optimization and sustainable bioprocess design holds immense future potential for diatom derive polysaccharides.

The Amazon biome hosts a rich fungal biodiversity; however, the biotechnological potential of its macrofungi remains largely underexplored. This study evaluates and compares the mycelial growth and protease production of a wild Amazonian isolate of Pleurotus ostreatus (474) with two commercial strains (542 and 885) to identify unique biotechnological profiles. The strains were cultivated in nine different culture media, and their mycelial growth rates and major proteolytic activities were systematically measured. The wild Amazonian strain (474) exhibited significantly superior mycelial growth, reaching maximum growth on Oat Flakes Agar (OFA) within four days. In contrast, the commercial strains acted as specialized enzyme producers; strain 885 showed the highest cysteine protease activity (8.05 ± 0.15 UA/mL) on Malt Yeast Sucrose Agar (MYSA), while strain 542 exhibited the highest total protease (77.53 ± 0.67 UA/mL) and fibrinolytic activity (6.45 ± 0.00 mm²) on Malt Extract Agar (MEA). These results reveal a clear biotechnological trade-off, with the Amazonian isolate excelling in biomass accumulation and the commercial strains optimized for enzyme production. This study highlights the Amazonian strain as a promising candidate for rapid mycoprotein production and underscores the Amazon as a valuable source for expanding the functional diversity of P. ostreatus.

Breast cancer (BC) remains the most commonly diagnosed cancer among women worldwide and a leading cause of cancer-related mortality. Despite advances in early detection and treatment modalities, challenges such as recurrence, metastasis, and therapy resistance persist, necessitating the development of novel therapeutic strategies. Benzyl isothiocyanate (BITC), a naturally occurring isothiocyanate derived from cruciferous vegetables, has emerged as a promising anticancer agent due to its potent chemopreventive and therapeutic properties. This review comprehensively explores the investigational potential of BITC in the management of breast cancer, emphasizing both its molecular mechanisms and its targeted delivery through nanotechnological approaches. The chemistry and pharmacology of BITC are discussed, highlighting its ability to modulate key signaling pathways, induce apoptosis, inhibit metastasis, and arrest the cell cycle in breast cancer cells. Special attention is given to its pharmacokinetic profile, including bioavailability and metabolic stability, which are crucial for clinical translation. Furthermore, the review examines preclinical findings that demonstrate BITC's suppressive effects on tumor growth and its synergistic interactions with conventional therapies. Innovative strategies for BITC delivery, such as nanoparticle-based systems, are also evaluated for their potential to enhance therapeutic efficacy and reduce systemic toxicity. The safety profile and toxicity considerations of BITC are critically assessed based on current preclinical evidence. By synthesizing findings from a broad range of preclinical studies, this review underscores the multifaceted anticancer potential of BITC and its promise as a complementary or alternative approach in breast cancer treatment. Continued research into its mechanistic actions, delivery optimization, and translational applications is essential to harness BITC's full potential in improving patient outcomes.

Photosynthetic bacteria (PSB) are protein-rich and a high-quality producer of microbial proteins. In this study, PSB were cultivated using self-fermented kitchen waste fermentation broth under controlled light intensity and light cycle conditions. Biomass and protein concentrations were measured daily, and microbial community composition and functional succession were analyzed using high-throughput sequencing and bioinformatic tools to investigate the effects of photoperiod on PSB growth and protein synthesis. The results showed that PSB had the highest biomass and protein production of 1356.5 mg/L and 564.3 mg/L at 4000 lx and 24 h light/0 h dark, respectively. Organic pollutant removal was also the highest, with 89.7% chemical oxygen demand (COD) removal and 65.8% ammonia nitrogen removal. Microbiological analysis indicated that the selected light intensity and light/dark cycles were highly favorable for PSB growth. Under these conditions, the dominance of Rhodopseudomonas was further strengthened. During the cultivation process, PSB adjusted its metabolic pathway and shifted its metabolic focus from carbon metabolism to nitrogen metabolism. In addition, the activities of ribulose bisphosphate carboxylase (Rubisco), a key enzyme for photosynthesis, and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and succinate dehydrogenase (SDH), key enzymes of the tricarboxylic acid (TCA) cycle, were enhanced in PSB. These findings provide an important reference for an in-depth understanding of the growth characteristics, metabolic responses, and protein biosynthesis of PSB in the treatment of kitchen waste fermentation broth.

Silver nanoparticles (AgNPs) have surfaced as a potential agent for the augmented biosynthesis of secondary metabolites in vitro plant cultures. This research examines the impact of different concentrations of silver nanoparticles (2.0, 4.0, 6.0, 8.0, 10.0 and 12.0 mg/L) in combination with 6-Benzylaminopurine (BAP) (1.0 mg/L) and other supplementary compounds such as ascorbic acid (0.050 g/L), adenine sulfate (0.025 g/L), arginine (0.025 g/L) and citric acid (0.025 g/L) on callus growth and secondary metabolites synthesis. The findings demonstrated that different concentrations of AgNPs had a notable impact on callus proliferation and led to a considerable enhancement in callus biomass. The most significant accumulation of fresh (19.170 g/L) and dry (1.842 g/L) callus biomass was recorded in the in vitro cultures supplemented with 8 mg/L AgNPs. The phytochemical analysis of the callus cultures revealed a notable increase in the production of phenolics (35.40 mg/g of DW), flavonoids (15.0 mg/g of DW), total protein content (18.76 mg/g of DW), total antioxidant activity (73.33 µg/mg of DW) and total reducing power (93.36 µg/mg of DW) in the cultures established on MS media supplemented with 8 mg/L AgNPs. Additionally, the antioxidant activity reached an impressive 97.3% at a concentration of 10 mg/L AgNPs. It can be inferred that the AgNPs serve a significant role in augmenting bioactive antioxidants within the callus cultures of E. alba, a plant of considerable medicinal value and conservation concern. This protocol can be expanded for large-scale synthesis of plant biomass and therapeutic metabolites in E. alba.

β-(1,4)-Mannobiose is a functional oligosaccharide with multiple prebiotic properties. The limitation of existing production technologies has hindered its further development and applications. In this study, we developed an efficient and scalable method combining a three-step enzymatic hydrolysis process with microbial purification to produce high-purity mannobiose from locust bean gum (LBG). The enzymatic degradation was carried out using β-mannanases rManA and rMan113A, along with α-galactosidase rGal27A from the alkaliphilic Bacillus N16-5, sequentially breaking down the substrate into galactose, mannose, and mannobiose. Lactobacillus casei LH23 was then employed to selectively metabolize mannose and galactose, ensuring the exclusive production of mannobiose. In a 250 mL reaction system containing 5% LBG, mannobiose was obtained at a concentration of 25.99 g/L with a conversion efficiency of 51.98%, representing 98% of the total sugar yield. This study highlights the significance of understanding microbial polysaccharide utilization and engineering specialized enzymes to enhance enzymatic hydrolysis strategies for targeted oligosaccharide production.

Metagenomic approaches have revolutionised the discovery of novel enzymes with ecological and biotechnological significance from different environments. Here, we report the comprehensive characterisation of a novel salicylaldehyde dehydrogenase (SALD_AP) obtained from an alpine soil metagenome. Phylogenetic analysis revealed that SALD_AP is the first experimentally characterised Alphaproteobacterial SALD, forming a distinct evolutionary clade among known bacterial enzymes. The recombinant enzyme exhibited strict specificity for NAD⁺ and exceptional catalytic efficiency toward aromatic aldehydes, with benzaldehyde as the preferred substrate. Kinetic analyses showed catalytic efficiencies exceeding 10⁶ M⁻¹ s⁻¹ for aromatics, whereas aliphatics were oxidised with much lower efficiency, consistent with ecological specialisation for aromatic catabolism in alpine soils enriched in lignin-derived compounds. SALD_AP was most active under mildly alkaline conditions (optimum pH 8.0) and tolerated a range of chemical environments, though high concentrations of certain metals and solvents were inhibitory. Differential scanning fluorimetry demonstrated that the enzyme was stabilised by ligand binding, with maximal thermal stability observed when both substrate and cofactor were present. Structural alignment with Pseudomonas NahF and docking analyses revealed that SALD_AP employs a distinctive catalytic configuration involving ASN-137, ARG-145, GLU-238, and CYS-272, highlighting a non-canonical role for ASN-137 in substrate binding and stabilisation. Based on these findings, we propose a mechanistic model for SALD_AP that expands the catalytic diversity of the aldehyde dehydrogenase superfamily. This study establishes a new paradigm for aromatic aldehyde oxidation, underscores the ecological significance of SALD_AP in alpine soil microbiomes, and provides a foundation for engineering novel biocatalysts for bioremediation and synthetic biology applications.

Mastitis caused by multidrug-resistant Staphylococcus aureus and its robust biofilm formation poses a significant threat to dairy health. To address this, we developed a novel, eco-friendly therapeutic platform, Carthamus tinctorius L. extract-functionalized lignin nanoparticles (CTLe@LigNPs), using a one-pot ultrasound-assisted protocol. These nanoparticles demonstrated high colloidal stability (71.07 nm, ζ-potential of -21.7 mV), efficient drug loading, and sustained release in both gastric (~ 90%) and intestinal (~ 76%) environments over 24 h. The CTLe@LigNPs showed low cytotoxicity while effectively eradicating planktonic S. aureus (MIC = 125 µg/mL) and significantly disrupting pre-formed biofilms, achieving 71.38% inhibition at the highest concentration tested. In an oral gavage rat mastitis model, a single dose (100 mg/kg) for 7 days ameliorated mastitis symptoms and improved hematological parameters. Mechanistically, CTLe@LigNPs acted as a potent immunomodulator by downregulating TLR2/4, JNK, and MAPK signaling pathways, suppressing pro-inflammatory cytokines such as TNF-α and IL-1β by up to 50%, and elevating antioxidant enzymes (SOD, CAT, GPx) by over 30%. These findings establish CTLe@LigNPs as a promising multifunctional nano-antimicrobial and immunomodulatory platform for treating S. aureus mastitis, warranting further clinical translation.

Microbial fuel cells as bioelectricity generating devices have demonstrated poor energy density. Electrode surface modification has pronounced as an efficient strategy to boost power generation. This paper proposes the synthesis of a new nanostructure TiC@C-TiO₂/PANI for anode surface modification to improve power generation in MFCs. By incorporating aniline into the TiC@C-TiO₂ nanostructure, morphological and electrochemical characteristics of modified MFCs anodes are evaluated. FESEM, HRTEM, EDX, FTIR, XRD analyzes demonstrate the presence of PANI on the surface, formation of polymeric layer, the uniformity of coating, the aromatic nature and presence of amine groups, and the crystalline structure of the TiC@C-TiO₂ substrate, respectively. The polarization tests indicate that the addition of polyaniline up to 1.5% significantly improves power density to 435 mW.m^-2 that is 55% higher than unmodified anode (281 mW.m^-2) and 22% higher than TiC@C-TiO₂ (357 mW.m^-2). Cyclic voltammetry analysis revealed an anodic peak current of 33 mA, substantially higher than 21 mA observed in the bare anode. Electrochemical impedance spectroscopy tests demonstrated a remarkable reduction in charge transfer resistance (R_ct) to 0.04 Ω, which is 28 times lower than that of the control. These findings underscore the potential of TiC@C-TiO₂/PANI (1.5%) as a promising material for anode modification.