Biotechnology Letters最新文献

Over the last few decades sulfonamides are being prescribed on a large scale for treating human beings and livestock. Contaminants of sulfonamide antibiotics are present in various environments and these residues can enter the food web, leading to health threat. The purpose of this study was to assess sulfamethoxazole degradation using a novel strain of Aspergillus sp. and demonstrates the degradation pathway of sulfamethoxazole. To the best of our knowledge, this marks the first detailed biodegradation pathway for Aspergillus sp. AJC4 proposed. The biodegradation pattern of sulfamethoxazole was assessed using High Performance Liquid Chromatography (UPLC) and validated through Gas Chromatography Mass Spectroscopy (GC-MS), Liquid Chromatography Mass Spectrometry (LC-MS) and Fourier Transform Infrared Spectroscopy (FTIR). The fungal isolate was able to degrade 99.42% of sulfamethoxazole at a concentration of 150 mg/l within 7 d. Three metabolic compounds were identified throughout the Sulfamethoxazole biodegradation process. The degradation pathway was shown to follow first order kinetics model according to the kinetics energy.

Biological control of plant diseases is recognized as an effective and environmental friendly alternative to chemical fungicides. We demonstrated the dual biocontrol strategy of Bacillus velezensis CE 100 through the hydrolytic activity of chitinase and β-1,3-glucanase and the elicitation of induced systemic resistance (ISR) against Colletotrichum gloeosporioides that causes anthracnose disease in walnut trees. B. velezensis CE 100 produced a maximum of 62.1 units mL^-1 (132.9 units mL^-1) chitinase and 5.2 units mL^-1 (9.4 units mL^-1) β-1,3-glucanase enzymes in the broth culture (crude enzyme fraction), and inhibited spore germination and mycelial growth of C. gloeosporioides by 81.6% and 22.6%, respectively, at 100 µl mL^-1 of crude enzyme fraction. The inoculation of B. velezensis CE 100 induced the production of pathogenesis-related (PR) chitinase in walnuts by 2.1-fold, and to a lesser extent PR β-1,3-glucanase, and reduced anthracnose disease severity by 3.0-fold compared to the control group. The bacterium produced a maximum of 11.4 µg mL^-1 indole-3-acetic acid (IAA) and improved the chlorophyll content, shoot length, and root collar diameter of walnut trees compared to the fungicide treatment and control groups. B. velezensis CE 100 demonstrated the prospect of controlling walnut anthracnose by direct antagonism and ISR against C. gloeosporioides, while simultaneously enhancing walnut growth through IAA production.

The work reported here aimed to enhance the reduction of the downstream intermediates 2-hydroxybiphenyl (2-HBP) and 2-(2'hydroxyphenyl ethan-1-al) produced by biodesulfurization of DBT (dibenzothiophene) and BT (benzothiophene) using Paenibacillus strains (32O-W and 32O-Y). Salicylaldehyde was used as a surrogate for 2-(2'hydroxybiphenyl ethan-1-al), as the two compounds are structurally very similar while the latter is not commercially available. Five strategies were tested using growth in media containing either 2-HBP or salicylaldehyde: use of single strain cultures, co-culturing, genetic engineering to express Vitreoscilla hemoglobin (VHb), cell immobilization, and nanoparticle coating of cells. Cell growth and reduction of 2-HBP and salicylaldehyde were measured during 96 h of culturing. Regarding 2-HBP reduction, 32O-Y was generally better than 32O-W (about 50% for free cells, and as much as 16% for immobilized cells, and 24% for coated cells); co-culturing did not provide any consistent advantage, while VHb expression increased utilization only for 32O-W (by about 50%). Immobilization and coating resulted in large improvements for both strains (as much as 3700%). Free, immobilized, and coated cells of 32O-Y all removed salicylaldehyde, while only immobilized 32O-W cells were able to do so. For 32O-Y, co-culturing and coating, but not VHb expression, resulted in improvements in salicylaldehyde reduction (of up to 31%). Thus, alginate immobilization or nanoparticle coating of bacterial cells may be useful approaches for enhancing the reduction of DBT or BT biodesulfurization end products, and thus the overall biodesulfurization process for petroleum and petroleum products.

Background: The study was designed to explore the enhanced impact of nano-hydroxyapatite and emdogain on the survival and osteogenic/odontogenic differentiation of human stem cells isolated from the apical papilla (hSCAPs).

Materials and methods: In this in vitro trial, hSCAPS obtained from intact impacted immature third molars were confirmed to have characteristic cell surface markers, then exposed to nanohydroxyapatite, emdogain, and nanohydroxyapatite coated with emdogain for durations of 1-3 days. The survival of apical papilla stem cells was measured using a methyl thiazolyl tetrazolium assay. The quantitative reverse transcription polymerase chain reaction, alkaline phosphatase activity (ALP) and Alizarin red staining were used to evaluate osteogenic-odontogenic differentiation. Analysis of the data was done using one-way ANOVA, t-test, and Mann-Whitney test (α = 0.05).

Results: At 1-3 days, emdogain exhibited no significant impact on the survival of human stem cells from the apical papilla. In contrast, nanohydroxyapatite (α > 0.05) and nanohydroxyapatite coated with emdogain demonstrated a notable reduction in cell survival compared to the control group (α < 0.05). The expression of dentin sialophosphoprotein, dentin matrix protein 1, and bone sialoprotein genes demonstrated a notable increase in the group treated with nanohydroxyapatite coated with emdogain compared to the other groups (α < 0.05), and furthermore, this group exhibited more pronounced mineralized nodules than the other experimental groups.

Conclusion: In contrast to nanohydroxyapatite, Emdogain did not demonstrate a detrimental effect on the survival of hSCAPs. Nanohydroxyapatite, emdogain, and nanohydroxyapatite coated with emdogain increased osteogenic/odontogenic differentiation of hSCAPs.

This article examines biochemical alterations and gene expression changes during tomato fruit physiology. The chroma index increases from mature green (41.27) to red ripe (48.36) stages, and the texture softens from mature green (43.56 N) to red ripe (24.75 N). Reducing sugar and total carotenoid levels rise at the red ripe stage. Free radical content was elevated in the early stages (7 nM) of ripening and declined at the later stages (4 nM). The specific activity of α-mannosidase and β-N-acetyl hexosaminidase was high at the breaker (0.077 & 0.075 U/mg, respectively) stages, while polygalacturonase activity was high at red ripe (1.173 U/mg) stage. qPCR experiments revealed that the α-mannosidase was upregulated during the breaker (1.2 fold) stages of tomato ripening, the β-N-acetyl Hexosaminidase was upregulated throughout the breaker (2 fold), and pink (1.2 fold) stages of tomato ripening, and the β-xylosidase was upregulated significantly during the breaker stage (3.9 fold) of tomato ripening. The current findings revealed that the α-Mannosidase (0.77), β-N-acetylhexosaminidase (0.99), xylosidase (0.85), ethylene-responsive factors (0.86), aminocylco propane carboxylic oxidase (0.90), and pectin methylesterase (0.83), were significantly associated with textural softening. Polygalacturonase (0.75) positively correlated to reducing sugar formation, aminocylco propane carboxylic synthase 4 (0.96) expression correlates with chroma changes during tomato fruit ripening. These correlations illustrate the complex interplay between gene expression and the physical and biochemical changes occurring during tomato fruit ripening.

Objectives: (1) To evaluate the potential of producing huperzine (Hup) and anticholinesterase (AChE) activities of nine native Lycopodiaceae species collected in Vietnam; (2) Isolation, identification and characterization of a novel fungus producing both HupA and HupB isolated from Lycopodium casuarinoides Spring.

Results: All methanolic extracts of nine plants showed AChE inhibition from 8.55 to 71.81%. Of note, Huperzia serrata (Thunb.) Trevis, L. casuarinoides, Lycopodium clavatum L., Phlegmariurus squarrosus (G. Forst.), and P. phlegmaria (L.) T. Sen & U. Sen were shown to biosynthesize both HupA and HupB by high-performance liquid chromatography (HPLC). Plants H. serrata, L. casuarinoides and L. clavatum showed the most potent AchE IC₅₀ inhibition. HupA and HupB concentrations from six plants were greater than those of previously reported Lycopodiaceae species. Sixty-four endophytic fungi were isolated from tissue of natural L. casuarinoides and then screened for HupA- and HupB-production by HPLC. Out of 64 fungal strains, only TTD2-2.7 extract could produce both HupA and HupB with the yields of 0.034 and 0.028 µg gdcw^-1, respectively. Moreover, TTD2-2.7 extract also had inhibitory effects on AChE with the IC₅₀ of 129.76 ± 4.13 µg ml^-1, which was lower than the extract of host plant L. casuarinoides (94.03 ± 4.13 µg ml^-1). The fungus was identified as Aspergillus sp. TTD2-2.7 by morphological characteristics and Internal Transcribed Spacer sequence analysis.

Conclusions: These are the first reports of (1) two species L. clavatum and L. casuarinoides producing both HupA and HupB, and (2) L. casuarinoides as novel sources of Hup-producing endophytic fungi as well as (3) fungus Aspergillus as a novel HupA- and HupB-producing endophyte isolated from L. casuarinoides.

Selenium is an essential element with various industrial and medical applications, hence the current considerable attention towards the genesis and utilization of SeNPs. SeNPs and other nanoparticles could be achieved via physical and chemical methods, but these methods would not only require expensive equipment and specific reagents but are also not always environment friendly. Biogenesis of SeNPs could therefore be considered as a less troublesome alternative, which opens an excellent window to the selenium and nanoparticles' world. bSeNPs have proved to exert higher bioavailability, lower toxicity, and broader utility as compared to their non-bio counterparts. Many researchers have reported promising features of bSeNP such as anti-oxidant and anti-inflammatory, in vitro and in vivo. Considering this, bSeNPs have been tried as effective agents for health disorders, especially as constituents of probiotics. This article briefly reviews selenium, selenium nanoparticles, Se-enriched probiotics, and bSeNPs' usage in an array of health disorders. Obviously, there are very many articles on bSeNPs, but we wanted to summarize studies on prominent bSeNPs features published in the twenty-first century. This review is hoped to give an outlook to researchers for their future investigations, ultimately serving better care of health disorders.

Purpose: Cartilage repair necessitates adjunct therapies such as cell-based approaches, which commonly use MSCs and chondrocytes but is limited by the formation of fibro-hyaline cartilage. Articular cartilage-derived chondroprogenitors(CPs) offer promise in overcoming this, as they exhibit higher chondrogenic and lower hypertrophic phenotypes. The study aimed to compare the efficacy of various cell types derived from adult and foetal cartilage suspended in platelet-rich plasma(PRP) in repairing chondral defects in an Ex-vivo Osteochondral Unit(OCU) model.

Methods: In-vitro characterization of the cells included growth kinetics, FACS, qRT-PCR, and multilineage differentiation potential using histology and GAG analysis. Ex-vivo human OCUs with chondral defects containing the different cells in PRP were cultured and subjected to analysis for matrix and collagen staining.

Results: The ex-vivo OCU analysis, in terms of defect repair, showed that adult chondrocytes, sorted-CPs, and foetal MCPs displayed better host integration and filling. The In-vitro analysis of adult chondrocytes displayed greater chondrogenic genes ACAN and COL2A1 expression, with sorted-CPs also showing higher levels of ACAN. In terms of accumulation of extracellular matrix uptake evident by Safranin O staining and collagen type II fibrillar uptake, the AD-MSCs, BM-MSCs, and sorted CPs outperformed the other groups. BM-MSCs also showed corroborative higher CD146 levels, however, the gene analysis of the AD-MSCs showed a high hypertrophic tendency in terms of its COL1A1 and RUNX2 expression.

Conclusion: Sorted chondroprogenitors outperformed both in terms of filling and hyaline-like repair, with AD-MSC and BM-MSC groups also achieving functional cartilage of a hyaline nature, warranting further evaluation using in-vivo and clinical studies.

Objective: Adeno-associated viruses (AAVs) are widely used as gene therapy vectors due to their safety, stability, and long-term expression characteristics. The objective of this work is to develop an aqueous two-phase system (ATPS) as a universal platform for the separation and purification of AAVs.

Results: This study utilized polyethylene glycol (PEG)/salt ATPSs to separate and purify various AAV serotypes, including AAV5, AAV8, and AAV9, which focusing on serotype-specific performance and partial empty capsid removal. The results showed that all the AAV serotypes were mainly enriched in the interphase of ATPS, with achieving high recovery (> 95%) and impurity removal (> 95%). The PEG/sodium citrate ATPS was serotype-independent, but the process optimization of component concentrations for each serotype was necessary to attain the best performance. Notably, a single-step aqueous two-phase extraction also demonstrated the ability to remove some amount of empty capsids from the crude cell lysate, with removal rate ranging from 4 to 25%.

Conclusions: The results demonstrated the practical applicability of PEG/sodium citrate ATPS in separating and purifying different AAV serotypes, which addressing key challenges in gene therapy vector production.

Recombineering (recombination-mediated genetic engineering) is a powerful strategy for bacterial genomic DNA and plasmid DNA modifications. CoS-MAGE improved over MAGE (multiplex automated genome engineering) by co-electroporation of an antibiotic resistance repair oligo along with the oligos for modification of the Escherichia coli chromosome. After several cycles of recombineering, the sub-population of mutants were selected among the antibiotic resistant colonies. However, a pre-generated strain with mutS deletion and multiple inactivated antibiotic resistance genes integration is required. Herein, CoS-MAGE was modified by employing a single copy BAC vector harboring a bla-mkan cassette and a Red helper vector cloned with dominant mutL E32K, thus bypassing the utilization of the pre-generated strain. The proof-of-concept of the new strategy, CoS-BAC-MAGE, was demonstrated via the mutation of non-essential genes, essential genes, and AT rich regions of the wild type strain E. coli MG1655. With this system, an editing efficiency of 60% was realized. Furthermore, by toggling between two antibiotic resistance genes (one active, the other defective) on the BAC, sequential mutations were achieved without the requirement of BAC vector elimination and re-transformation. Via CoS-BAC-MAGE, simultaneously mutations of three sites were obtained in a day. We envision that CoS-BAC-MAGE will be a practical improvement for the generation of chromosomal mutations using the Cos-MAGE approach.