Preparative Biochemistry & Biotechnology最新文献

Finding new bioactive metabolites offers a powerful solution to combat antibiotic resistance. Under plastic-enriched high salinity fermentation environment, Streptazolin, Streptazone E/F, and clavulanic acid biosynthesis by Streptomyces clavuligerus KARE_KK2, an actinobacterial isolate from termite mound soil, was studied. The fermentation medium was modified with 12% NaCl, 2% UV pretreated polythene, 2% plastic powder and 0.5% urea to mimic osmotic and xenobiotic stress. Post-10-day incubation with aeration, ethyl acetate was used to extract and analyze extracellular metabolites by LC-MS/MS. Streptazolin (a nitrogenous azoline), Streptazone E/F (azabicyclic electrophilic compounds), and Clavulanic acid (a clinically important β-lactamase inhibitor) are found in the metabolic profile. Because of chemical and environmental stress signals activation of silent or cryptic biosynthetic gene clusters on the part of these compounds are induced. Urea provided nitrogen, while the other factors likely act as small-molecule signaling in secondary metabolites regulation. This research shows that humans can help unlock the potential of actinobacteria, which are important to the pharmaceutical industry. Based on in silico molecular docking studies of Streptazolin and Clavulanic acid, it was observed that these two drug molecules could interact with Staphylococcus aureus exfoliative toxins A and B (ETA and ETB) which are the causative agents for Staphylococcal Scalded Skin Syndrome (SSSS). Further, it was also seen that Streptazolin and Clavulanic acid possessed the ability to bind with the human epidermal desmoglein-1, and hence have tremendous potential to act as SSSS toxin inhibitors. The results suggest the pharmaceutical potential of these metabolites, as well as a new way to use plastic waste as a microbial inducer for antibiotic discovery in biotechnology.

In this study, Streptomyces pilosus was used to produce Desferrioxamine B (DFOB). To increase DFOB yield, the effects of-yeast extract, MgSO4·7H2O concentration, and different buffer molarities-were assessed using Response Surface Methodology (RSM). The Statistical analysis indicated that all factors significantly influenced DFOB production. Under optimal conditions-yeast extract 15 g/L, MgSO4·7H2O 0.6 g/L, and phosphate buffer 0.0215 M-a maximum yield of 1.55 g/L was achieved, with a productivity of 0.63 g/L·day, the highest DFOB productivity reported in a flask to date. Since oxygen transfer, pH, and medium composition are crucial for improving production, the effects of glucose, yeast extract concentration, and oxygen transfer were studied in a 2-L bioreactor using the Taguchi method (L₉ orthogonal array), with pH maintained at 7.3. Under optimal conditions-glucose 25 g/L, yeast extract 20 g/L, and agitation at 200 rpm with aeration-resulted in 2.35 g/L DFOB, and 0.235 g/L.h productivity, the highest reported in a bioreactor. Field emission scanning electron microscopy (FESEM) analysis revealed that higher agitation rates caused extensive fragmentation of S. pilosus mycelia, reducing DFOB production. This study demonstrates that combining medium optimization and process control can achieve the highest reported DFOB yields, providing insights for industrial-scale production.

This study investigates the effects of atmospheric room temperature plasma (ARTP) mutagenesis on the morphological and genetic modifications of the lipase-producing strain Bacillus licheniformis NCU CS-5. While traditional strain improvement methods often suffer from low mutation rates and uneven mutation distribution, ARTP mutagenesis offers a powerful and efficient alternative. The significance of this study lies in its potential to enhance lipase production, a key enzyme in various industrial applications, through the generation of high-performance mutant strains. The gap in existing literature pertains to the limited understanding of ARTP-induced mutations in B. licheniformis and their impact on enzyme production. The novelty of this study is to explore the morphological and genetic changes induced by ARTP and to identify key genetic determinants contributing to these changes. Key findings include significant morphological alterations, higher intracellular Ca²⁺ levels, and numerous single-nucleotide variants (SNVs) and insertions/deletions (InDels) in the mutant strain. These findings imply that ARTP mutagenesis can effectively enhance lipase production, paving the way for optimized industrial microbial strains.

The agricultural system is facing significant abiotic challenges, particularly salinity stress, which leads to reduced germination, poor seedling vigor, lower crop quality, and yield. The study aims to overcome the problem by employing green synthesized zinc oxide nanoparticles (ZnO NPs) using Eucalyptus globulus leaf extract. Nanoparticles were characterized using zeta sizer analysis, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and energy-dispersive X-ray spectroscopy (EDX), and. The green synthesized ZnO NPs were used to explore the impact of ZnO NPs as a seed priming agent at concentrations of 20, 40, and 60 ppm on the morphological, physio-biochemical, antioxidant enzyme activities, nanoparticle internalization and seed quality parameters of Zea mays under different salinity stress levels (0, 50, and 100 mM NaCl). The results indicate that the seed quality, morphological, physiological, biochemical and antioxidant enzyme parameters were improved in seeds primed with ZnO NP as compared to the control. Nanopriming with ZnO offers an innovative, easy way to boost salinity-stress germination and growth.

This work investigates the effects of two elicitors, yeast extract (YE) and methyl jasmonate (MeJA), on the growth, oleanolic acid (OA) biosynthesis, and biological activities (antioxidant and antibacterial) of Polyscias fruticosa suspension cells. The results showed that while both elicitors inhibited cell growth, with YE having a stronger inhibitory effect, they significantly increased both OA content and the overall biological activity of the cell extracts. The degree of growth inhibition was directly proportional to the elicitor concentration and inversely related to the time of addition. YE proved more effective than MeJA, leading to a higher OA accumulation (78.55 mg/flask) and superior antioxidant activity, as evidenced by a lower IC₅₀ (0.55 mg/mL) and a higher FRAP value (0.46 µmol Fe²⁺/g). Additionally, extracts from YE-treated cells showed stronger antibacterial activity against both Escherichia coli and Staphylococcus aureus compared to the MeJA-treated extracts. The study concludes that there is a tradeoff between cell growth and the biosynthesis of bioactive compounds. Optimizing both the type of elicitor and its application timing is crucial to balance biomass yield with the production of key compounds. YE proved to be a superior elicitor to MeJA in enhancing both OA content and the overall biological activity of the extracts, providing a scientific basis for the future production of highly potent bioactive compounds from P. fruticosa cell cultures.

Clitoria ternatea has a long history of traditional use in treating cardiovascular, neurological, and cancer-related ailments. To support its historical claims, this study aimed to compare the two varieties of C. ternatea whole flower, i.e., blue and white, to assess their chemical constituents for potential impact on medicinal properties. The major compounds detected in blue and white C. ternatea whole flower were trilinolein and ternatin A1, whereas in white flower: carda-4,20(22)-dienolide and trans-traumatic acid were detected by GC-MS. In blue variety, the calcium level was found to be 5.326 mg/Kg in ICP-OES. The levels of sodium and potassium were 4.78 and 12.62 weight % in EDAX, 9.57 and 16.05 mg/Kg in flame photometry of blue flower, respectively. FTIR spectra confirmed the presence of functional groups such as primary amines, carboxylic acid and alkanes in the blue color variety, whereas the white color variety contains only the alkane group. The XRD showed the presence of a brominated compound which could be responsible for forming the most stable complex with another organic compound. At 50 µg/mL, the methanol extract of the blue color variety exhibited higher antioxidant potential in all of the tests as compared to the white variety.

The Malaysian fish sausage (Keropok Lekor, KL) is a fish snack made mainly from fish, sago flour, and seasonings. In KL production, the fish bones, innards, skins, and heads are usually removed, and only the flesh is used. The by-products are normally discarded, causing disposal problems and environmental pollution. The by-products can however be converted into high-value antioxidative peptides (APs) by microbial or enzymatic processing. After the bioconversion, the complicated, lengthy, and expensive bioseparation including filtration, precipitation, dialysis, and chromatography are commonly employed in purifying the APs. Thus, researchers are interested in developing alternative bioseparation technology. In this study, the feasibility of using precipitation techniques and aqueous two-phase system (ATPS) to isolate the APs from the protein hydrolysate produced from KL by-products by Lactobacillus casei fermentation was evaluated. Four types of precipitation were evaluated: (1) salt precipitation using ammonium sulfate ((NH₄)₂SO₄) and sodium chloride (NaCl), (2) solvent precipitation using ethanol and acetone, and (3) combination of salts and solvent precipitation, and (4) pH-shift precipitation. Amongst the precipitation techniques investigated, the pH-shift precipitation (pH 7.5) gave the highest purification fold (P_F,181.1). Both solvent and salt-solvent precipitations gave the lowest P_F (1.5 and 1.6, respectively). The salt precipitation (60%, w/v (NH₄)₂SO₄) achieved 2.0 for P_F. Besides, exceptionally high P_F (3,140.4) was obtained using ATPS (bottom phase of 15% (w/w) PEG2000 with 10% (w/w) phosphate system). Overall, the ATPS showed superior performance in enriching the AP compared to the precipitation techniques. The effectiveness of the AP purification may be increased by combining the ATPS with precipitation techniques. The study laid the groundwork for developing an effective bioprocessing, which is important to valorize the KL by-products to the high-value APs.

Isothermal nucleic-acid testing is ideal for on-site diagnostics, but large-scale lyophilization of reagents is hindered by three bottlenecks: costly in-situ capping of vials or PCR tubes, activity loss during non-in-situ transfer/sealing caused by ambient humidity and exposure time, and wild-type T7 RNA polymerase inactivation due to lyophilization-induced structural changes. We overcame these obstacles by optimizing the freeze-drying protocol, screening for robust enzyme variants, and refining the protectant recipe. Sealing at 15% RH prior to stoppering proved optimal; a lyophilization-tolerant T7 RNA polymerase mutant termed V5 was isolated; and a blend of 3%(w/v) PEG8000 plus 0.5%(w/v) mannitol markedly enhanced stability. The resulting cake contains 3%(w/w) residual moisture, reconstitutes in <1 s, and retains full activity after 13 months at 4 °C and for approximately 2 months at 25 °C. These specifications enable short-term, cold-chain-independent field deployment of isothermal nucleic-acid detection reagents.

Environmental concerns over synthetic plastics highlight the need for sustainable alternatives, among which bacterial polyhydroxyalkanoates (PHAs) have emerged as promising. However, their commercialization is limited, owing to their higher production cost and lower applicability. Hence, this study employs ANN-GA-based optimization of a novel in-situ fed-batch process using a self-isolated Bacillus sp. PhNs9 utilizing untreated sugarcane molasses as a cost-effective substrate. The bioreactor scale production at optimized conditions resulted in a PHA production of 3.47 ± 0.11 g/L, whose GC-MS and DSC analysis revealed it to be Polyhydroxybutyrate-co-valerate (PHBV). This PHBV was successfully blended with in-situ extracted neem oil and threadlets to form a biocomposite, which was found to be antibacterial, non-cytotoxic, and biodegradable with significantly higher tensile strength. The HR-MS analysis of the extracted neem oil revealed the presence of bioactive compounds like nimbin, azadirachtin, and Salannin, providing medicinal properties. The techno-economic analysis of the whole process resulted in the cost of PHBV production and extraction as ₹1.03/g, extraction of neem oil as ₹5.75/mL, which further resulted in the biocomposite preparation cost to be ₹0.30 cm^-2. This accentuates the commercial feasibility of the developed biocomposite as an eco-friendly alternative to synthetic plastics.

The current study focuses on enhancing microbial dextran production using a renewable and cost-effective Saccharum officinarum juice medium (SOJM) feedstock and compares it with a chemically defined medium (CDM). The optimized medium variables using SOJM (sucrose: 200 g/L; yeast extract: 10 g/L; KH₂PO₄: 50 g/L; time: 2 d) and CDM (sucrose: 200 g/L; yeast extract: 40.5 g/L; KH₂PO₄: 50 g/L; time: 1 d) for predicting the dextran production were found to be 80 and 96 g/L, respectively. The economic productivity of produced dextran from SOJM and CDM was 0.06 and 0.18 $ dextran per $ nutrient per h, respectively. The functional, structural characteristics, and molecular mass distribution of the produced dextran using SOJM and CDM were analyzed using various characterization techniques. The average molecular mass of dextran using SOJM (before optimization: 2519.7 kDa; after optimization: 3474.3 kDa) is greater than that of CDM (before optimization: 2119.7 kDa; after optimization: 2884.2 kDa). These findings demonstrated that the optimization approach significantly enhanced both yield and average molecular mass using CDM and SOJM. Owing to its antioxidant activity, the produced dextran could be extensively employed in various healthcare applications. Furthermore, the produced dextran is involved in the preparation of an immobilization matrix with calcium alginate for the entrapment of cellulase. The prepared matrix (dex-cel-alg) exhibited greater immobilization efficiency (86.9%) than the alginate matrix (35.5%), illustrating its suitability for the hydrolysis of cellulose to fermentable sugars for biofuel applications.