Electronic Journal of Biotechnology最新文献

Over the past two decades, interest in pollutant removal by yeasts has grown substantially. Yeasts can remove high amounts of pollutants at low production costs under non-sterile conditions. This work presents a compilation of the studies carried out regarding the potential application of yeasts in the treatment of wastewater. For example, a summary is presented on data about various yeast strains that are used to treat wastewater. The study will help the decision-making process for the selection of yeast for a type of wastewater and support research efforts by acquiring an overview of advancements in this area. Yeast treatment is versatile and has outstanding adaptability to varying treatment conditions. The effectiveness of yeast in treating wastewater is influenced by multiple factors. Yeast technology could potentially be retrofitted to existing activated sludge processes or be used instead of bacteria. Within its characteristics, we can observe tolerance to low pH (3.0–5.0), high salinity, high organic loads, antibiotics, and survive in up to 12% v/v alcohol mixtures. In fact, using low pH for yeast cultivation reduces bacterial contamination and supports yeast domination under non-sterile conditions. Laboratory-scale trials for yeast wastewater treatment have shown improvement over the past two decades; however, efficiencies differ according to the type of wastewater. In general, yeast offers several benefits compared to traditional microbial treatment methods, especially in its capacity to effectively process diverse organic carbon sources. However, it still must be proven to be an effective technology at an industrial scale.

How to cite: Mohiuddin O, Harvey A, Orta Ledesma MT, et al. Bioremediation of waste by yeast strains. Electron J Biotechnol 2024;69. https://doi.org/10.1016/j.ejbt.2024.01.005.

Background

Ferredoxin 1 (Fd1) is the main electron donor to hydrogenase (HydA) for generating molecular hydrogen (H₂) in green microalgae. In order to obtain an increased H₂ production, the Fd1 of Chlamydomonas reinhardtii (CrFd1, encoded by crfd1) was therefore overexpressed in Chlorella sp. DT (DT) in this study.

Results

The coding region of crfd1 was constructed into the p121-crfd1 plasmid, which was also constructed with a resistance gene to the antibiotic geneticin (G418) as a selection marker. The p121-crfd1 plasmid was transformed into DT cells by electroporation. Observation of the crfd1 gene fragment in the genomic DNA of DT-crfd1 mutants by PCR indicated that the transgene was successfully transformed. Using western blotting, the overexpressed CrFd1 protein, with a molecular weight of about 14 kDa, was found in DT-crfd1 mutants of DT-crfd1-4, DT-crfd1-22, and DT-crfd1-23. Using an in vitro assay, the H₂ production of DT-crfd1-4, DT-crfd1-22, and DT-crfd1-23 mutants was about 4.4-, 5.0-, and 3.8-fold higher, respectively, than the DT wild type (DT-WT). Using an in vivo assay, the H₂ production of DT-crfd1-4, DT-crfd1-22, and DT-crfd1-23 mutants was about 1.3-, 1.4-, and 1.2-fold higher, respectively, than the DT-WT.

Conclusions

The results suggested that heterologous overexpression of CrFd1 could enhance H₂ production in DT-crfd1 mutants even though in vitro H₂ production of DT-crfd1-22 mutant was up to 5-fold higher than the DT-WT.

How to cite: Lin YJ, Chien LF. Hydrogen production in the Chlorella sp. DT mutants carrying heterologous electron donor ferredoxin 1 of Chlamydomonas reinhardtii. Electron J Biotechnol 2024;69. https://doi.org/10.1016/j.ejbt.2024.03.001.

Background

Complex graft bioengineering is an actual topic in bone defects’ repair. For those, different scaffolds may be seeded with mesenchymal stromal cells and growth / differentiation factors. The natural role of platelet factors in reparative processes justifies the possibility of its usage for mesenchymal stromal cell proliferation and differentiation into osteoblasts in vitro in terms of the scaffold-based bioengineering. To develop and evaluate in vitro biocompatibility and osteoconductivity of a complex biograft based on a bioorganic scaffold seeded with human bone marrow mesenchymal stromal cells and saturated with growth and differentiation factors of allogeneic platelet-rich plasma.

Results

The properties of viability and adhesion of human bone marrow mesenchymal stromal cells in four types of bioorganic scaffolds were evaluated with biochemical and immunomorphological methods. Scaffold with the least cytotoxicity was used as a basis for complex biograft formation, so as a carrier for cells and platelet-derived factors. Then, cell proliferation activity and osteogenic differentiation were estimated with biochemical, morphological, histochemical and molecular-biological methods. The study showed high viability of cells in all bioorganic scaffolds but the least cytotoxicity was the one based on xenogeneic collagen sponge. We also found that allogeneic platelet-rich plasma positively affects the proliferation and osteogenic differentiation of bone marrow mesenchymal stromal cells in a complex biograft in vitro.

Conclusions

The properties of the developed complex biograft characterize its biocompatibility and osteoconductivity and make it potentially suitable for regenerative medicine, particularly for reconstructive surgery of bone defects.

How to cite: Danilkovich NN, Kosmacheva SM, Ionova AG, et al. Formation of osteoconductive biograft with bioorganic scaffold, human mesenchymal stromal cells, and platelet rich plasma with its evaluationin vitro. Electron J Biotechnol 2024;69. https://doi.org/10.1016/j.ejbt.2024.01.004.

Background

Targeted insertion of the repair template into the genome is a common strategy for high-precision base replacements; however, the main challenge likely remains regarding the limited efficiency of homologous-directed repair (HDR). A precise genome cut achieved by CRISPR-Cas9 system combining with a single-stranded oligodeoxynucleotide (ssODN), as the donor template, improves significantly the rate of HDR. It is well-established that the spatial availability of the donor template to the repair system effectively enhances knock-in events in CRISPR-Cas9. PolyPurine Reverse Hoogsteen hairpins (PPRHs), as an alternative repairing strategy, benefits from a Triplex-forming oligonucleotide (TFO) for the repair template providing the ease of access. The main objective of the study was to evaluate the HDR frequency as a result of improvement of the spatial accessibility of the donor template adjacent to the cutting site. Hence, a flanking purine-rich hairpin complementary to the genomic DNA adjacent to the repairing site was fused to the ssODN with the incorporated bases for the alteration of EGFP to EBFP.

Results

Results from the comparison between the donor templates, ssODN and TFO-tailed ssODN, demonstrated an increased rate of knock-in from 18.2% ± 1.09 to 38.3% ± 4.54, respectively. From another perspective, findings indicated that the targeted Cas9-mediated DNA cleavage improves the efficiency of the repair-PPRH approach four-fold, as well.

Conclusions

The present study provides a viewpoint that highlights the significance of the designing of the donor template in terms of the structural features and positional access for the HDR-based repairing CRISPR-Cas9 systems.

How to cite: Ebrahimi Z, Kazemi B, Salehi M, et al. Successful CRISPR/Cas9-mediated HDR at individual DNA breakpoints using TFO-based targeted template design. Electron J Biotechnol 2024, 68. https://doi.org/10.1016/j.ejbt.2024.01.001.

Background

Naringin is one of the main flavonoids in citrus fruits and byproducts. This flavanone has been shown to be a good antioxidant nutraceutical component, and it also has potential as a gut microbiome modulator, although its applications in final formulations represent a challenge due to its low solubility, both in water and in organic solvents. This work addresses this problem by functionalizing naringin through enzymatic acylation.

Results

The enzymatic acylation catalyzed by the lipase Novozym® 435 and using acyl donors of different chain lengths, acetate (C2), propionate (C3), and laurate (C12), yielded in conversions of 95% at 24 h and 100% at 48 h, generating a monoacylated product. Both the aqueous and solvent solubility of acylated naringin products were improved while maintaining or even increasing their antioxidant activity.

Conclusions

This acylation process significantly enhanced both the water and solvent solubility of the acylated naringin products while preserving or even enhancing their antioxidant activity. In addition to the gut-modulating properties of flavonoids, acylating them with short- and medium-chain fatty acids could enhance their potential applications in the emerging field of research dedicated to understanding and modulating gut health.

How to cite: Gutiérrez-Navarro E, Padilla-de la Rosa JD, Macías A, et al. Enzymatically acylated naringin with gut modulation potential. Electron J Biotechnol 2024; 68. https://doi.org/10.1016/j.ejbt.2023.12.003.

Background

High chitosanase-producing microorganisms from natural sources have extensive applications in food and agriculture. This study aimed to optimal conditions for high-activity chitosanase production. A named CGMCC21422 chitosanase-producing strain -2T-2 was isolated from soil and identified named as Aspergillus fumigatus chitosanase (A. fumigatus chitosanase). This enzymatic activity was validated in various culture conditions. It is stored in the China General Microbiological Culture Collection Center. The efficacy of A. fumigatus chitosanase in the degradation of chitosan was validated.

Results

In this study, we determined that the optimal fermentation conditions of stain-2T-2 were 1.0% powered chitosan, 0.8% ammonium nitrate, 37°C culture temperature, initial pH 5.0, culture time 6 d, bottle volume 50 mL, and 2% inoculation dosage. Under these culture conditions, the highest enzyme activity of fermentation broth in the shaker flask reached 827.53 U/mL. The optimal reactive conditions of A. fumigatus-produced chitosanase are 55–60°C and pH 4.5. When the reactive temperature was over 60°C, the A. fumigatus chitosanase was easily inactivated. The chitosanase catalyzed substrate chitosan to produced ≈20% chito-oligosaccharide and ≥80% glucosamine salt samples in a variety of acidic solutions. These reactive products are not cytotoxic or mild to MH7A cells.

Conclusions

A. fumigatus chitosanase strain -2T-2 is a strain with high chitosanase and can catalyze chitosan into chito-oligosaccharide in acidic solutions.

How to cite: Yang, H., Wang, L., Xu, C, et al. Screening for Aspergillus fumigatus strain-2T-2 with high chitosanase production activity and its application in chitosan degradation. Electron J Biotechnol 2024; 68. https://doi.org/10.1016/j.ejbt.2024.01.003.

Background

Alzheimer’s disease (AD) is the most common form of dementia and dementia constitutes the fifth leading cause of mortality across the globe. Available treatment modalities and drugs have abysmally failed to curtail AD. This study evaluated the mitigation of Aβ aggregation and anti-cholinesterase activities with the crude extracts of Ptaeroxylon obliquum and Bauhinia bowkeri. Computational studies of the most abundant phytochemicals from the crude extracts of both plants with proteins were investigated. The phytochemical composition of the different crude extracts (hexane, DCM, and ethanol) of the plants were analyzed with FTIR and GC-MS. The inhibitory potential of the extracts on BACE-1 and cholinesterase activities was determined with both computational molecular docking studies and in vitro enzyme assays. Their anti-aggregation properties were confirmed with Thioflavin-T assay and TEM.

Results

The in silico studies revealed that though thunbergol and cyclotetradecatriene (the major constituents of the extracts) inhibited all the proteins, the latter exhibited the best inhibitory potential. The in vitro results showed that while the dichloromethane (DCM) extract of P. obliquum had the highest butyrylcholinesterase (BuChE) inhibitory activity (1.77 µg/ml), the hexane and ethanol extract of B. bowkeri exhibited the highest β-site amyloid precursor cleaving enzymes-1 (BACE-1) (30.4 µg/ml) and acetylcholinesterase (AChE) (58.11 µg/ml) inhibitory efficacy, respectively. The ethanol extract (160 μg/ml) of B. bowkeri had the most efficacious anti-aggregation activity.

Conclusions

This study suggests that the plants could possess neuroprotective effects and could also be sources of anti-AD novel drugs.

How to cite: Ojo MC, Mosa RA, Osunsanmi FO, et al. In silico and in vitro assessment of the anti-β-amyloid aggregation and anti-cholinesterase activities of Ptaeroxylon obliquum and Bauhinia bowkeri extracts. Electron J Biotechnol 2024;68. https://doi.org/10.1016/j.ejbt.2023.11.004.

Background

Beer is the most consumed alcoholic beverage globally, and the demand for differentiated beers with peculiar characteristics has intensified among beer consumers, creating a significant market niche. In this study, we developed a low alcohol light craft beer enriched with olive leaf extract (Olea europaea L.). The cold mashing technique associated with interrupted fermentation was used in the mashing step. Different concentrations of olive leaf extract (0.5, 1.0 and 2.0%) were added at the maturation stage. The samples were characterized by physicochemical parameters, phenolic and polyphenolic content, bioactive compounds, antioxidant potential, and microbiological quality.

Results

The cold mash technique associated with interrupted fermentation provided a low-alcohol beer (≅1.3%). The bitterness dimension (19.0 to 23.2 IBU) and color (9–17 EBC) parameter were in accordance with the Beer Judge Certification Program (BJCP) for the American Blond Ale-style. The addition of the extract enriched the content of total phenolics (171.09 to 437.4 mg GAE/mL) and polyphenolic (221.4 to 729.0 mg/L). Coumaric, ferulic, and cinnamic phenolic acids were detected in appreciable amounts in the beers. Oleuropein was the major compound in the beverage and plant extract. After adding 2% extract, the ABTS and DPPH radical scavenging activity, as well as the ferric reduction power, increased in beers by 28.4%, 449.1%, and 120.5%, respectively.

Conclusions

The extract of O. europaea L. promoted the enrichment of low-alcohol beer samples with bioactive compounds and antioxidant potential. The results obtained indicated the potential use of O. europaea L. extract as a natural oxidant in other beverages and food products.

How to cite: Cappelin E, Meneguzzi D, Hendges DH, et al. Low-alcohol light beer enriched with olive leaves extract: Cold mashing technique associated with interrupted fermentation in the brewing process. Electron J Biotechnol 2024; 68. https://doi.org/10.1016/j.ejbt.2024.01.002.

Background

It has been reported that circular RNA formin 2 (circFMN2) can motivate colorectal cancer (CRC) proliferation. However, the effect of circFMN2 on the polarization of tumor-associated macrophages (TAMs) in the CRC tumor microenvironment remains unclear. The study was to figure out the latent mechanism by which circFMN2 impacts TAM polarization to motivate the malignant behavior of CRC cells.

Results

circFMN2 and PIK3R3 levels were reduced in M1 macrophages but elevated in M2 macrophages, whereas miR-150-5p level was the opposite. circFMN2 knockdown downregulated M2 macrophage markers CD163, CCL22 and CD206 and upregulated M1 macrophage markers CD86, TNF-α and IL-1β in M2 macrophages. Co-culture with M2 macrophage-conditioned medium with circFMN2 knockdown reduced CRC proliferation, invasion, and migration, while knockdown of miR-150-5p had the opposite effect. CircFMN2 adsorbed miR-150-5p to mediate PIK3R3 in M2 macrophages. Overexpression of miR-150-5p can reverse the promoting effects of overexpression of circFMN2 on M2 polarization, CRC cell proliferation, invasion, and migration. Elevation of PIK3R3 could turn around the repressive effect of circFMN2 knockdown on M2 polarization and CRC cell proliferation, invasion, and migration. In an in vivo model, M2 macrophages expressing low or high circFMN2 were co-transplanted with CRC cells into nude mice, resulting in inhibition and promotion of tumor growth, respectively.

Conclusions

All in all, circFMN2 mediates TAM polarization to M2 type by controlling the miR-150-5p/PIK3R3 axis to motivate CRC development and may offer a latent molecular target for CRC treatment.

How to cite: Cao Y, Cao D, Zhu T. Circular RNA FMN2 motivates colorectal cancer development by mediating tumor-associated macrophage polarization by controlling the microRNA-150-5p/PIK3R3 axis. Electron J Biotechnol 2024;68. https://doi.org/10.1016/j.ejbt.2023.12.002.

Background

Essential oil nanoemulsions have received much attention in the last period due to their ability to fight microbes and cancers. In the current study, clove and thyme essential oils CL+TH-emulsion and CL+TH-nanoemulsion were prepared through an eco-friendly method. The prepared CL+TH-nanoemulsion was characterized using DLS and TEM analyses.

Results

Results revealed that CL+TH-nanoemulsion droplets were spherical in shape and nanoform in size (68.6 nm) with PDI 0.281. MIC concentrations of CL+TH-nanoemulsion against tested bacteria were found to be between 6.25 and 25 mg/mL. After being exposed to MICs of CL+TH-emulsion and CL+TH-nanoemulsion, which additionally prompted 1.43 log and 3.12 log declines, accordingly, as opposed to untreated (Control), the number of cells grown in the generated biofilms decreased. Furthermore, CL+TH-nanoemulsion exhibited anticancer activity more than CL+TH-emulsion toward HepG2 and MCF-7. Also, the effect of CL+TH-nanoemulsion is more effective and significantly cytotoxic than taxol on MCF-7. Besides, both prepared emulsions increased the rate of apoptosis and decreased the cell viability % of MCF-7 by increasing the activity of caspases 8 and 9. Moreover, CL+TH-nano emulsion decreased the activity of VEGFR-2 in MCF-7 in a more pronounced manner than CL+TH-emulsion and taxol.

Conclusions

The prepared CL+TH-nanoemulsion had antibacterial, and antibiofilm as well as anticancer properties, which can be used in different biomedical applications after extensive studies in vivo.

How to cite: Hashem AH, Doghish AS, Ismail A, et al. A novel nanoemulsion based on clove and thyme essential oils: Characterization, antibacterial, antibiofilm and anticancer activities. Electron J Biotechnol 2024;68. https://doi.org/10.1016/j.ejbt.2023.12.001.