Preparative Biochemistry & Biotechnology最新文献

Melanogenesis is tightly regulated by tyrosinase, and its inhibition represents a key strategy in developing skin-whitening agents. In this study, p-hydroxyphenethyl anisate (HP) was identified as a potent melanogenesis inhibitor through a zebrafish-based screening without affecting embryo viability at concentrations up to 10 μM. The biological activity of HP was further validated in isobutyl-1-methylxanthine (IBMX)-stimulated B16-F1 murine melanoma cells. HP treatment significantly suppressed IBMX-induced melanin synthesis without reducing cell viability. Mechanistically, HP markedly inhibited tyrosinase activity and reduced tyrosinase protein levels. Furthermore, HP suppressed tyrosinase mRNA expression, as well as the expression of Mitf, a key transcriptional regulator of tyrosinase. These findings indicate that HP inhibits melanogenesis through transcriptional downregulation of Mitf, hence its downstream tyrosinase, leading to reduced protein expression and enzymatic activity. Seeking the source of HP, we applied the purification process guided by HPLC peak-tracing and successfully isolated HP from a concentrated Chinese medicine Qiang Huo. Starting from herbal powder, a methanol extract was fractionated by LH-20 column chromatography, and the target compound was purified using preparative C18 HPLC. Collectively, our study identifies HP as a promising natural compound with potent and nontoxic anti-melanogenic activity, supporting its potential application in cosmetic or therapeutic skin depigmentation.

A statistical method was utilized in this study to enhance Lentinus edodes (shiitake) secondary metabolites, thereby improving its anticancer properties. The importance of employing the statistical method in this study stemmed from the initial statistical optimization of the substrate in submerged conditions, and the subsequent transfer of that optimal setting to the solid-state culture medium. The Plackett-Burman (PB) screening indicated that wheat starch, meat peptone, and vitamin B₆ had a more pronounced impacted on polysaccharide production. The optimal substrates for polysaccharide production, identified using response surface methodology (RSM) after screening, was revealed to contain 48.56 g/L wheat starch, 15 g/L meat peptone, and 300 µg B₆ vitamins. Shiitake polysaccharide solutions exhibited shear-thinning behavior, enhanced viscosity, and gel-like properties at higher concentrations. Shiitake polysaccharide also demonstrated superior emulsifying capacity for oil-in-water emulsions, suggesting its potential as an effective stabilizer in food formulations. The fruit body of shiitake had the highest diversity in flavonoids and phenolic acids and anticancer activity against MDA-MB-231 breast cancer cell. The IC50 levels of extracted polysaccharide, fruiting body, fruit stipe, fruit pileus, mycelium from the control sample, and mycelium cultivated in MgO nanoparticles-enriched culture medium were 225, 182, 194, 244, 202, and 138 μg/mL, respectively. The statistical methods used in this study have successfully optimized the bioactive compound content in both the biomass and fruiting body of shiitake, yielding a promising natural source of polysaccharides and anticancer agents.

This study investigates the immobilization of Rhizomucor miehei lipase in organogel systems formulated with gelatin, chitosan, or alginate, incorporating different surfactants and organic solvents, both with and without glutaraldehyde activation. Among the systems tested, gelatin/SDS combinations demonstrated superior thermal stability, whereas chitosan-based matrices exhibited the highest catalytic performance, achieving up to 80% conversion in the esterification of oleic acid at a 1:1 molar ratio. When applied to the esterification of pequi and buriti oils, the biocatalyst performance was influenced by the oils' viscosity and lipid composition. The presence of sago starch in the reaction medium enhanced conversion rates, likely due to its role in modulating the interfacial environment and reducing water activity. This effect was less evident with pequi oil, possibly owing to its sensitivity to ethanol. Catalytic assays confirmed high initial activity, whereas reusability and operational stability tests revealed significant mass loss and limited activity retention during long-term operation, mainly due to physical disintegration of the chitosan-SDS matrix. Despite this limitation, the study provides mechanistic insight into the instability of ionically assembled organogels under real oil conditions. Overall, the findings highlight the complex interplay between support, solvent, substrate, and reaction conditions.

The study uses solid-state fermentation to explore the co-production of industrial enzymes (amylases, cellulases, xylanases, and phytases). The experiments examine the key cultivation parameters, such as fermentation time (2 to 7 days), incubation temperature (25 to 35 °C), medium components, and the effects of inducers. Maximum enzyme activities were observed at 30 °C after 6 days of incubation, using paddy straw as a primary substrate. Supplementing paddy straw with rice bran significantly enhanced the activities of amylase, CMCase, FPase, and xylanase by 1.94x, 1.36x, 1.45x, and 2.14x, respectively using fungal strain Lasiodiplodia theobromae strain RBEE-GCS103. Further, enzyme production in enamel-coated metallic trays increased enzyme activities by 20-35% compared to production in 250 ml flasks. The present study highlights L. theobromae strain RBEE-GCS103 as a novel and potential co-producer for the industrially important enzyme utilizing underutilized agro-waste.

The growing demand for biofuels and biochemicals, driven by the concerns over fossil fuel dependence, has led to significant interest in synthetic biology as a potential solution for biofuel production from alternative feedstocks. Synthetic biology offers innovative approaches by leveraging advances in DNA modeling, metabolic engineering, and microbial fermentation to optimize biofuel production, especially from non-food feedstocks like lignocellulosic biomass. These advancements allow for the creation of engineered potent microorganisms capable of producing biofuels/biochemicals more efficiently and sustainably. Among them, ethanol is the most widely produced biofuel, though challenges related to biomass recalcitrance and fermentation efficiency remain. Recent advancements in metabolic engineering of microorganisms such as Saccharomyces cerevisiae and Zymomonas mobilis aim to improve the production of ethanol from various lignocellulosic feedstock thriving on variety of sugars in presence of inhibitors. The biofuels and bioproducts industry is evolving rapidly, and the companies from various sectors-ranging from biotechnology to chemical engineering-investing in biofuel technologies. However, challenges related to biosafety, intellectual property, and regulation persist, with concerns over the potential misuse of synthetic biology for biosecurity and biopiracy. This review explores the role of synthetic biology in biofuel and green chemicals production, focusing on its applications in the development of renewable energy sources.

Silver nanoparticles are materials that exhibit good antimicrobial activity due to their unique properties. Silver nanoparticles obtained by using chemical synthesis techniques cause the formation of toxic products during and after the process. Therefore, there is a need for environmentally friendly, cheap, and fast synthesis. The green synthesis technique is developed as an alternative to chemical synthesis techniques, which enables the synthesis of silver nanoparticles in an environmentally friendly, cheap, and fast way. In this study, the potential of Glycyrrhiza glabra (G. glabra, licorice) roots for the synthesis of silver nanoparticles was determined. The obtained nanoparticles were characterized using various techniques. It was determined that the obtained nanoparticles exhibited maximum absorbance at 420 nm, with an average size of 36 nm. The 2,2-diphenyl-1-picrylhydrazyl (DPPH·) radical scavenging activity of the synthesized nanoparticles was 94 ± 1.18%, the iron-reducing capacity was 55 ± 0.84%, and the antimicrobial activity, determined by the disk diffusion method on Escherichia coli (E. coli), was found to be quite good.

Cyanobacteria, as vital photosynthetic microorganisms in soil ecosystems, contribute to soil stabilization, nutrient cycling, and water balance. They also produce bioactive compounds such as lipopeptides, carotenoids, and phytohormones. This study explored the plant growth-promoting potential of cyanobacterial strains isolated from native paddy field soils. A polyphasic approach, combining 16S rRNA gene sequencing, phylogenetic analysis, and morphological assessments was used to characterize the isolates. Microscopy revealed distinct traits, including barrel-shaped cells, intercalary and terminal heterocytes, solitary akinetes adjacent to heterocytes, and proakinetes occurring near heterocytes. The strain also displayed a fascicular thylakoid arrangement and contained distinct nutrient storage granules. Phylogenetic analysis placed the isolate in close relation to Neowollea manoromensis. The strain produced an auxin-like compound, identified as indole-3-acetic acid (IAA), under various tryptophan concentrations. IAA was confirmed through TLC, FT-IR, and HPLC. In vitro experiments with paddy seeds treated with cyanobacterial extract showed 95.55% germination, with significant root elongation (11.27 ± 0.09 cm) and shoot growth (6.46 ± 0.050 cm) by day 12. Chlorophyll content (3.18 μg/mL), fresh weight (0.69 ± 0.09 g), and dry weight (0.08 ± 0.00 g) also increased. These results underline the auxin-producing potential of the cyanobacterium and its effectiveness in enhancing seed germination and plant growth, offering a sustainable strategy for improving paddy cultivation.

Polyhydroxyalkanoate (PHA) is a sustainable bioplastic biomaterial primarily produced by microorganisms and has demonstrated the ability to produce PHA. This work aims to characterize PHA derived from the novel biosurfactant-producing bacterium isolated from an industrial site, Bacillus cereus ST001. A comprehensive investigation of the time-dependent degradation of PHA film by novel microorganisms isolated from contaminated industrial sites under natural soil conditions has received little attention. In this context, the environmental biodegradability of B. cereus ST001, which produces PHA films, in typical natural soil settings was also studied. Microscopic examination, employing dyes, confirmed the presence of PHA, and molecular analysis indicated the presence of the PHA synthase gene (phaC) and PHA depolymerase gene (phaZ) genes. The extracted PHA was analyzed using Fourier transform infrared spectroscopy (FTIR) and ¹H nuclear magnetic resonance (NMR) spectroscopy, revealing characteristics similar to those of a homopolymer of PHA, specifically polyhydroxybutyrate (PHB). The polymer was stable up to 150 °C and showcased 64% crystallinity. The polymeric film showed a degradation rate of 80% of the initial film biomass after 180 days of incubation in soil. These findings highlight the potential of B. cereus ST001 as a dual-purpose strain for PHB biosynthesis and degradation, shedding light on the future of bioplastics and sustainable waste management techniques. This aligns with the concept of a circular economy and sustainable production and consumption patterns.

High blood glucose levels are a hallmark of type 2 diabetes mellitus (T2DM), and managing it involves inhibiting carbohydrate-hydrolyzing enzymes such as α-amylase, α-glucosidase, and dipeptidyl peptidase-4 (DPP-4). The objective of this study was to optimize ultrasound-assisted extraction of Arctium lappa L. by varying parameters such as feed-to-solvent ratio, ethanol concentration, extraction temperature, and time to maximize total phenolic content (TPC), total flavonoid content (TFC), and extraction yield. The optimal conditions of 1:40 g/mL feed-to-solvent ratio, 70% ethanol, 50 °C, and 40 minutes resulted in 18.5 mg GAE/g dry extract (TPC), 7.3 mg QE/g dry extract (TFC), and 22.73% yield. Extraction kinetics were modeled effectively using the Power Law and Peleg models, with strong goodness-of-fit values (R² > 0.96). GC-MS analysis identified 160 bioactive compounds, with 25 major constituents including 9,12-octadecadienoic acid (Z,Z) (11.40%), n-hexadecanoic acid (11.54%), 9-octadecenoic acid (5.91%), octadecanoic acid (3.37%), and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (3.19%). Docking revealed strong binding of fatty acids and pyranone derivatives to carbohydrate-hydrolyzing enzymes. D-allose and vanillic acid, though less abundant, showed the strongest affinities, suggesting complementary inhibition. In vitro assays confirmed significant α-amylase and α-glucosidase inhibition by the extracts. These findings highlight burdock root extract's potential for functional food applications targeting T2DM management.

India is among the leading nations in global production of pomegranate and post their utilization in beverage manufacturing sectors, significant volumes of peel waste are generated annually, which is a grave issue from the standpoint of solid waste management. Extrapolating this matter in question in the backdrop of circular economy and sustainable development, this very agro-industrial residue has been valorized in this work, in an attempt to remediate yet another major planetary concern which is, the bio-deterioration of built environment by microbial invasion. The current study used aqueous ethanolic extract from peel waste of Punica granatum, as a reducing agent, to obtain prospective nano-additives for architectural coatings, which were subsequently evaluated using an array of characterization techniques, which confirmed their physicochemical attributes. These were assessed for their antimicrobial efficacy against predominant fungal and bacterial pathogens of the built environment. The highest inhibition of 77.41 ± 2.14% was noted against Cladosporium sphaerospermum and the molecular mechanism of action includes alteration of cell membrane permeability and inhibition of fungal protein synthesis, as confirmed through conductometric and spectrophotometric measurements, respectively. Thus, this study provides a proof of concept that this green synthesized nanomaterial holds a future prospect for nano-functionalization of architectural coatings.