Electronic Journal of Biotechnology最新文献

Background

Walnut production (Juglans regia) generates a large amount of waste, mainly comprised of husk and shell. The two by-products have several bioactive compounds, mainly phenolic compounds with antioxidant activity. Given the above, this work seeks to establish productive and adequate conditions for the recovery of compounds with antioxidant activity (juglone among them) from such discards to use the extract as a bioherbicide.

Results

Temperature and extraction solvent (type of solvent and use of hydroalcoholic mixtures) are relevant factors on phenolic compounds’ (TPC, Folin-Ciocalteu method) recovery and antioxidant activity (AA, DPPH method), observing values from 2 to 17 mg GAE/g shell and 0.5 and 23 mg GAE/g husk, and 3 to 28 mg TE/g shell and 0.2–36 mg TE/g husk for TPC and AA, respectively. Using 50°C and ethanol as extraction solvent, 14,000 µmol TE/100 g of ORAC activity was obtained for both shell and husk. This value increased when a hydroalcoholic mixture was used. Juglone was recovered only from the husk at 166 mg/100 g. The bioherbicidal potential of the extract was evaluated; a phytotoxic effect and a lower plantar density when applying the product to broad-leaf weeds were observed.

Conclusions

In conclusion, the walnut process’s residues have a high potential to be used under the circular economy concept in the agri-food sector by obtaining products with high added value.

How to cite: Soto-Maldonado C, Caballero-Valdés E, Santis-Bernal J, et al. Potential of solid wastes from the walnut industry: Extraction conditions to evaluate the antioxidant and bioherbicidal activities. Electron J Biotechnol 2022;58. https://doi.org/10.1016/j.ejbt.2022.04.005

Background

Coral diseases are one of the serious threats embroiling in the imbalance of the coral holobiont integrity through disruption of the complex symbiotic relationship between endobiotic alga, coral animal, and a group of microorganisms. Such diseases are usually associated with many bacterial pathogens inflicting gross lesions in corals which show resistance against antibiotics. Therefore, this has led scientists to draw more attention towards the curative compounds from natural resources like herbal plants and seaweeds as substitutes for chemical antimicrobial agents. This study aimed to evaluate the antibacterial activity of the crude extracts (n-hexane, ethyl acetate, and ethanol), alkaloids, and flavonoids from Sargassum fusiforme through Well Diffusion Assay against different isolated bacterial coral pathogens such as (Vibrio owensii, Empedobacter brevis, Providencia vermicola, and Brevibacterium linens) which cause white band disease to coral reef Porites lutea. This study was also validated by bacterial growth kinetics using optical density, dry weight, and plate count method for the isolated coral bacterial pathogens.

Results

The results indicated that the crude extract with n-hexane and alkaloid extract showed prominent inhibiting activity against the tested bacterial pathogens compared to other extracts.

Conclusions

Here we report S. fusiforme extracts as a novel antibacterial agent against four Porites lutea bacterial pathogens and further investigation is recommended against other coral pathogens. Overall, S. fusiforme extracts might be able to improve the health status of commercially important coral species.

How to cite: Ahmed N, Mohamed HF, Xu C, et al. Novel antibacterial activity of Sargassum fusiforme extract against coral white band disease. Electron J Biotechnol 2022;57. https://doi.org/10.1016/j.ejbt.2022.03.002.

Background

Sound is a kind of mechanical stimulus and has various effects on the growth and metabolism of plants and animal cells. In previous studies, it was confirmed that sound stimulation promotes the neurodifferentiation process of mesenchymal stem cells. In this study, we examined the effect of sound on the maturation of neuroblastoma cells, SH-SY5Y cells, and investigated its effect on an ischemic mouse stroke model. In the in vitro study, SH-SY5Y cells were exposed to the sound for 3 days and then performed rt-PCR, FACS, and western blot for analysis. In the in vivo study, mesenchymal stem cells were injected into the injured area, and then rats were exposed to sound for 4 weeks. Then, immunohistochemical staining and western blotting were performed.

Results

Sound upregulated the expression of presynaptic proteins synaptophysin and postsynaptic density protein 95, as well as neuronal-related proteins such as NFL, Tau, and MAP2. T-type calcium channels such as CACNA1G and CACNA1I were also induced by sound. In an experiment using the brain of ischemic mice, the expression of proteins involved in neuronal differentiation such as MAP2, NF200, and S100 was increased, while the inflammation-related proteins IFNγ, MMP9, and TNFα were decreased. In this neuronal differentiation process, both ERK and CREB, which are proteins involved in the initial signal transduction process, were activated.

Conclusions

Our study demonstrates that sound, with the advantage of being non-invasive and easy to use, is an effective stimulus that induces neural differentiation and maturation on animal cells.

How to cite: Cho H, Park H-J, Choi J-H, et al. Sound affects the neuronal maturation of neuroblastoma cells and the repair of damaged tissues. Electron J Biotechnol 2022;57. https://doi.org/10.1016/j.ejbt.2022.03.001

Background

The consumption of antioxidant-rich foods can lower the risk of chronic diseases. In the present work, plain yogurt (control) and three kinds of herbal yogurts fortified with a polyphenol extract from nutmeg, black pepper, and white pepper were prepared. Post-acidification, proteolysis, total phenolic content (TPC), and antioxidant activity of yogurt samples were studied over 21 days. Additionally, all yogurt samples were subjected to sensory evaluations on the first day of storage.

Results

Higher production (p < 0.05) of lactic acids was observed in all herbal yogurts than in plain yogurt over 21 days of storage. Black pepper and nutmeg enhanced (p < 0.05) the proteolytic activity of yogurt as compared to control, with the maximum values at 21 days. All three herbal yogurts showed the highest TPC (48–55 µg GAE/ml) at day 14 of storage. The radical scavenging activity of yogurt was positively affected (p < 0.05) by the presence of the three kinds of herbal extracts (72–83%; day 0), with the highest values observed in nutmeg yogurt. Ferric reducing antioxidant potential (FRAP) value of nutmeg yogurt was the highest (p < 0.05) among the other samples at day 7 of storage. The ferrous ion chelating (FIC) ability of all the three herbal yogurts ranged from 80% to 83% during 2 weeks. The highest overall preference scores among the three kinds of herbal yogurts were recorded for black pepper yogurt.

Conclusions

Polyphenol compounds derived from nutmeg, black pepper, and white pepper extracts could enrich yogurt with antioxidant properties, with nutmeg yogurt showing the best effect.

How to cite: Shori AB. Storage quality and antioxidant properties of yogurt fortified with polyphenol extract from nutmeg, black pepper, and white pepper. Electron J Biotechnol 2022;57. https://doi.org/10.1016/j.ejbt.2022.03.003

Background

Juglone is a naphthoquinone currently obtained by chemical synthesis with biological activities including antitumor activity. Additionally, juglone is present in the green husk of walnut, which suggests evaluating the effect of GH extracts on carcinogenic cell lines.

Results

Walnut green husk ethanolic extract was obtained as 169.1 mg juglone/100 g Green Husk and antioxidant activity (ORAC) of 44,920 μmol Trolox Equivalent/100 g DW Green Husk. At 1 μM juglone in HL-60 cell culture, green husk extract showed an antiproliferative effect, but pure juglone did not; under these conditions, normal fibroblast cells were not affected. A dose-dependent effect on mitochondrial membrane potential loss was observed. Apoptosis of HL-60 was detected at 10 μM juglone. Despite high ORAC values, neither purified juglone nor the extract showed protective effects on HL-60 cells under oxidative conditions.

Conclusions

Green husk extract generates an antiproliferative effect in HL-60 cells, which is related to an induction of the early stages of apoptosis and a loss of mitochondrial membrane potential. The normal cells were not affected when juglone is present at concentrations of 1 μM, while at higher concentrations, there is loss of viability of both cancerous and healthy cells.

How to cite: Soto-Maldonado C, Vergara-Castro M, Jara-Quezada J, et al. Interactive 360° video to: Polyphenolic extracts of walnut (Juglans regia) green husk containing juglone inhibit the growth of HL-60 cells and induce apoptosis. Electron J Biotechnol 2022;57. https://doi.org/10.1016/j.ejbt.2022.04.002.

Background

Foods including probiotics are considered “functional foods.” As an alternative to dairy products, we investigated the behavior of Lactobacillus casei when exposed to low-pH fruit juice. Juices of fruits such as pineapple, raspberry, and orange were assessed. Free and microencapsulated forms of L. casei were compared, and the viability of the probiotic was evaluated under storage at 4°C for 28 d. Microbiological analyses were carried out to ensure a safe and healthy product for consumers who look for foods with probiotics from sources other than dairy.

Results

Low pH affected L. casei survival during storage depending on the type of fruit juice. In the case of pineapple juice, some microcapsules were broken, but microcapsules recovered at the end of the storage period had 100% viability (2.3 × 10⁷ CFU/g spheres). In the case of orange juice, more than 91% viability (5.5 × 10⁶ CFU/g spheres) was found. In raspberry juice, viability decreased rapidly, disappearing at the end of the storage period, which was caused by the absorption of high concentrations of anthocyanin inside microcapsules more than low pH.

Conclusions

Low pH affected the survival of L. casei under refrigeration; even when they were microencapsulated, acidic conditions impacted their viability. Although pH affects viability, its value is very sensitive and will depend on the type of fruit juice and its composition. Some fruit juices contain compounds used as substrates for Lactobacillus and other compounds with antimicrobial effects.

How to cite: Olivares A, Soto C, Caballero E, et al. Interactive 360° video to “Survival of microencapsulated Lactobacillus casei (prepared by vibration technology) in fruit juice during cold storage”. Electron J Biotechnol 2022;57. https://doi.org/10.1016/j.ejbt.2022.04.003.

Background

With a smaller environmental footprint and longer operation times, Microbial Fuel Cells (MFCs) are now preferred over other renewable technologies for powering small electronic devices in the field. Although with excellent performance in the laboratory, most of MFCs fail for not considering the real field conditions. The purpose of this study is the development of a compact, portable, and self-sustaining format of energy production based on MFC technologies. For this, three MFC configurations, soil MFC, plant MFC and a hybrid-MFC, where a plant and a soil MFC are combined, are assembled in portable power devices and compared.

Results

Plant MFCs provided lower performances (maximum power of 0.6 ± 0.4 µW·cm⁻²) resulting from a fast and sharp decrease in the anode potential by the flowing of oxygen from the aerenchyma of the plant roots. The performance of soil MFCs was much better (maximum power of 2.0 ± 0.02 µW·cm⁻²), but not sustained over time (20 days) by the depletion of organic matter. The combination of a soil MFC and a plant in separate compartments of a single container results in a hybrid-MFC with a good performance (maximum power of 2.7 µW·cm⁻²) which sustained over time for more than 1 month.

Conclusions

Therefore, the hybrid self-containing MFCs appears as an ideal alternative for the long-term power supply of low-power field electronic devices, from meteorological sensors or LED lights.

How to cite: Uria-Molto N, Costa RD, Nunziata C, et al. Self-contained and integral microbial fuel cells as portable and sustainable energy sources for low-power field devices. Electron J Biotechnol 2022;57. https://doi.org/10.1016/j.ejbt.2022.04.004

Background

In view of the increasing human life and the aging of the population, the search for safe anti-aging drugs has become a hot topic. Agaricus blazei Murrill is a rare edible fungus, with a variety of biological activities. The purpose of this study was to clarify the anti-aging effect and mechanism of ABM-A on the aging induced by D-Galactose in mice.

Results

The result showed that ABM-A contained 87.2% of glucose, 3.3% of galactose, 3.8% mannose and 5.7% gluconic acid. The behavior of mice in the treatment group was significantly improved after administration of ABM-A. And the activity of SOD and CAT and the level of T-AOC were increased (p < 0.05), the content of MDA and ROS was decreased (p < 0.05) in the serum of mice in ABM-A group. The results of mechanism research showed that nine genes were screened out by functional annotation and enrichment analysis for the verification by RT-qPCR, and the results of RT-qPCR were consistent with those of RNA-seq. Western Blot results showed that ABM-A upregulated the expression of Hmox1, Myd88, p-c-Jun, Apc, Bmil, Cox7a2l and Ndufv1, down-regulated the expression of Nfe2l2, Keap1, Apoe, Mapk1and Atp1a3, and decreased the phosphorylation of p38 and Jnk, suggesting that it may play an anti-aging effect by regulating Nrf2/ARE and MAPKs superfamily signal pathways.

Conclusions

ABM-A can reduce oxidation reaction and play an anti-aging role through Keap1-Nrf2/ARE and MAPKs signaling pathway.

How to cite: Guo, X, Ye Y, Liu X, et al. Effects of Agaricus blazei acidic polysaccharide on the aging of mice through keap1-Nrf2/ARE and MAPKs signal pathway. Electron J Biotechnol 2022;57. https://doi.org/10.1016/j.ejbt.2022.03.004

Background

Polyhydroxybutyrate (PHB) and polyhydroxybutyrate-co-hydroxyvalerate (PHBV) are the most common polyhydroxyalkanoates (PHAs). They are important candidates for biodegradable plastics that accumulate in the cytoplasm in the form of intracellular granules under unbalanced growth conditions. The present study focused on the production and optimization of PHAs from Paraburkholderia sp. PFN29 for the first time under submerged fermentation.

Results

Two hundred bacterial isolates were collected from soil samples in Thailand, six of which were found to accumulate PHB using the Nile red staining method. Six isolates were identified by 16S rDNA gene sequencing and were shown to be closely related to the genera Azotobacter, Sphingobium and Paraburkholderia. The best strain, Paraburkholderia sp. PFN29, showed the highest PHB concentration (5 ± 0.17 g/L). Optimization of PHB accumulation was achieved in modified medium containing 3% (w/v) glucose, and 0.1% (w/v) (NH₄)₂Fe(SO₄) with incubation at pH 7.0 and 35°C for 96 h with shaking at 200 rpm. In preliminary PHBV synthesis, PFN29 was utilized to synthesize PHBV from glucose and organic acids (levulinic acid and propionic acid). ¹H nuclear magnetic resonance (¹H NMR) spectroscopy and gas chromatography-mass spectrometry (GC/MS) analyses confirmed the extracted PHAs compared to standard PHB and PHBV.

Conclusions

PFN29 can be used for feasible PHB production with a PHB content of up to 97.3% of 5.14 ± 0.17 g/L CDW. The PHBV concentration can be further improved by optimizing the production parameters as cosubstrates. The present study provides useful data on PHA production by Paraburkholderia, which may be used as a candidate species for commercial PHA production.

How to cite

Sriyapai T, Chuarung T, Kimbara K, et al. Production and optimization of polyhydroxyalkanoates (PHAs) from Paraburkholderia sp. PFN 29 under submerged fermentation. Electron J Biotechnol 2022;56. https://doi.org/10.1016/j.ejbt.2021.12.003

Background

In the process of recombinant protein biosynthesis affinity tags are efficient tools to achieve the expected purity and yield during the purification steps. Nonetheless these tags might alter enzyme specificity and activity, therefore in functional assays it is recommended to use authentic or native proteins. Several ubiquitin fusion systems have been developed for E. coli-based recombinant protein expression that provide high levels of expression, with simple purification, and allow the production of various proteins with authentic N-terminus for subsequent applications.

Results

In the present research, we describe an ubiquitin fused bacterial biosynthetic system (pUbiq) for the production of the native Second mitochondria-derived activator of caspases (SMAC) recombinant protein. Using this system, the recombinant protein is expressed with an ubiquitin-decahistidine fusion partner, then purified from the cell-forming proteins by affinity chromatography. The fusion partner is then removed by proteolytic digestion, resulting the native structure of the recombinant protein without unnecessary amino acid residues. Following proteolysis, another affinity chromatography method is used to separate the native protein from the fusion partner and the proteolytic enzyme. The folding of the protein of interest was verified by a pull-down assay.

Conclusions

Based on our results, the presented pUbiq system was successfully applied in the production of native SMAC recombinant protein, where the affinity tag required for purification was completely removed. Our study suggests that the ubiquitin-fusion technology will be useful for enhancing expression and purification of native and authentic proteins for structural and functional studies as well as for therapeutic uses.

How to cite: Salamona P, Orbána CK, Molnár-Nagy K, et al. Exon based amplified polymorphism (EBAP): A novel and universal molecular marker for plants. Electron J Biotechnol 2022;56. https://doi.org/10.1016/j.ejbt.2022.01.002.