BioTechnologia最新文献

Bioactive peptides are short and specific fragments of proteins with a wide range of biological activities that provide health benefits to the host. These natural peptides are safe and nontoxic and do not show any side effects. Nowadays, the production and characterization of bioactive peptides have been a key area of research as they show great potential as nutraceuticals and functional foods. Thus, bioactive peptides are considered next-generation therapeutic agents that can replace pharmaceutical products with profound adverse effects in the near future. So far, proteolytic hydrolysis has been used as the method of choice for the large-scale production of bioactive peptides. Studies have reported that peptides with specific characteristics can be generated using a particular type of protease. Microbial proteases are the predominantly used ones because of the ease in their production and purification. However, recently, plant proteases have gained a renewed interest as they offer diversity and better specificity compared with other proteases. This review highlights the potential of plant proteases for the production of bioactive peptides and also describes the benefits of bioactive peptides as nutraceuticals.

The present study introduced an in vitro shoot organogenesis protocol for the medicinal plant Scutellaria araxensis (Lamiaceae). Stem, leaf, and petiole explants were cultured in half-strength Murashige and Skoog (MS) medium containing different concentrations of 6-benzylaminopurine (BAP) alone or in combination with thidiazuron (TDZ), indole-3-butyric acid (IBA), or α-naphthalene acetic acid. Callus formation occurred from stem and petiole explants in most cultures; however, in leaf explants, it was observed only in cultures containing 0.5 mg/l BAP supplemented with TDZ at all concentrations. The highest frequency of indirect shoot induction (100 and 90%) with an average of 20.33 and 12 shoots per explant was observed in stem-derived calli cultured on half-strength MS medium containing 2.0 mg/l BAP plus 0.5 and 1.5 mg/l TDZ, respectively. The best direct shoot organogenesis (40%) was observed in stem explants cultured on half-strength MS medium containing 0.5 mg/l BAP and 0.5 mg/l IBA with a mean of 18 shoots per stem explant. The regenerated micro-shoots were elongated on a medium fortified with 0.5 mg/l gibberellic acid and then successfully rooted in half-strength MS medium supplemented with 0.5 mg/l IBA. The obtained plantlets were acclimatized in a growth chamber with a survival rate of 100%. This study is the first report of a simple and efficient in vitro shoot organogenesis and regeneration protocol for S. araxensis by using stem explants, which could be useful for the conservation, genetic manipulation, and exploitation of biological molecules of this valuable genetic source.

The application of plant biotechnology to enhance beneficial traits in crops is now indispensable because of food insecurity due to increasing global population and climate change. The recent biotechnological development of the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated system 9 (Cas9) allows for a more simple and precise method of gene editing, which is now preferred compared to Zinc Finger Nucleases (ZFNs) and Transcription Activator-like Effector Nucleases (TALENs). In this review, recent progress in utilizing CRISPR/Cas9-mediated gene editing in plants to enhance certain traits in beneficial crops, including rice, soybean, and oilseed rape, is discussed. In addition, novel methods of applying the CRISPR/Cas9 system in live cell imaging are also extensively reviewed. Despite all the applications, the existing delivery methods of CRISPR/Cas9 fail to provide consistent results and are inefficient for in planta transformation. Hence, research should be focused on improving current delivery methods or developing novel ones to facilitate CRISPR/Cas9-based gene editing studies. Strict regulations on the sale and commercial growth of gene-edited crops have restricted more efforts in applying CRISPR/Cas9 technology in plant species. Therefore, a shift in public viewpoint toward gene editing would help to propel scientific progress rapidly.

In addition to their nutritional properties, mushrooms have emerged as a health supplement because of their medicinal potential. Many studies have shown that mushrooms exhibit important biological activities. Here, the antioxidant and antimicrobial activities of Hohenbuehelia myxotricha (Lév.) Singer mycelia cultivated on Sabouraud dextrose broth (SDB) and glucose peptone yeast (GPY) medium were studied. The total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) of ethanolic extracts of mycelia were measured using Rel Assay kits. The antioxidant and oxidant potentials of H. myxotricha mycelial extracts were determined for the first time in the present study. The highest TAS, TOS, and OSI values of H. myxotricha were 5.416 ± 0.150 mmol/l, 1.320 ± 0.156 μmol/l, and 0.024 ± 0.003, respectively. Ethanolic mycelial extracts of H. myxotricha showed antimicrobial activities at concentrations from 25 to 200 μg/ml against all the studied bacteria (Acinetobacter baumannii, Enterococcus faecalis, Escherichia coli, Staphylococcus aureus, methicillin-resistant S. aureus, and Pseudomonas aeruginosa ) and fungi (Candida albicans, C. glabrata, and Issatchenkia orientalis ) tested by the agar dilution method. The antifungal activity of the extract was more significant than its antibacterial activity. The antioxidant, oxidant, and antimicrobial potentials of H. myxotricha mycelia varied depending on the culture media used. GPY medium was more suitable for the synthesis of antibiotic compounds against E. coli, while SDB medium was more appropriate for producing metabolites with antioxidant and antifungal properties. Based on the results, ethanolic extract of H. myxotricha mycelia showed a significant pharmacological potential and could be used as a natural antioxidative and antimicrobial source for health benefit.

This study aimed to culture and screen salt-tolerant Plant growth promoting rhizobacteria (PGPRs) from Bougainvillea glabra rhizosphere to improve wheat HD-2687 and maize PSCL-4642 cultivars under saline conditions up to the seedling stage. Twenty-four rhizobacterial isolates were screened for salt tolerance at different NaCl levels. Indole acetic acid (IAA) production, phosphate solubilization, and siderophore and hydrogen cyanide (HCN) production of salinity-tolerant isolates were tested. Positive salt-tolerant PGPRs were further subjected to seedling studies to examine the improvement in the development of experimental crops under 50, 100, 150, and 200 mM NaCl concentrations with/without bacterial inoculant. Of the 24 isolates, BoGl123 was the most promising PGPR, which showed the maximum phosphate solubilization, and IAA, siderophore and HCN production. It was further subjected to seedling studies. In comparison with controls, BoGl123 resulted in a higher radicle length in maize (34 mm, 87.4%) and wheat (26.8 mm, 85.8%) at the 50 mM salinity level. At the 100 mM NaCl level, the radicle length of wheat and maize seedlings was increased by 82.5% and 78.6%, respectively, compared with controls. At different NaCl concentrations, BoGl123 improved the plumule length of seedlings in both crops. The stress tolerance attributes and plant growth promotion (PGP) indicate the potential of Pseudomonas fluorescens BoGl123 to be used as a microbial inoculant in the cultivation of wheat and maize under stressful conditions.

This study aimed to investigate controlled fermentation of cocoa beans with selected yeasts as starter cultures via integrating microbiological, biochemical, and chromatographic analyses. The steps involved in the yeast starter culture test were of the following order: 1) counting, isolation, purification, and biochemical identification of yeasts, 2) selection of ethanol-producing yeasts, 3) selection of thermotolerant yeasts, and 4) evaluation of physicochemical parameters of the selected yeasts in controlled fermentation of cocoa (F1 - Saccharomyces ssp. and Hanseniaspora ssp. and F2 - spontaneous fermentation - control). A total of 32 yeasts were isolated from three sampling points (M1, M2, and M3), which comprised 50% Candida ssp., 9.4% Rhodotorula ssp., 18.8% Saccharomyces ssp., and 18.8% Hanseniaspora ssp. The yeasts identified as Saccharomyces ssp. (n = 6) were subjected to the ethanol production test. Saccharomyces spp. CLV09 showed the highest concentration of ethanol in the simulated cocoa medium (3.5% v/v). Hanseniaspora spp. CVL20 and CVL19 strains showed the highest thermotolerance at 42°C after 72 h of growth. The starter cultures with Saccharomyces ssp. and Hanseniaspora ssp. showed a similar growth rate of the mesophilic aerobic population in both F1 and F2. Fermentation of the starter culture showed a higher production of organic acids than spontaneous fermentation (F2). Thus, Saccharomyces ssp. and Hanseniaspora ssp. can be used as a starter culture in cocoa fermentation.

Biofuel cells (BFCs) are an environmental friendly technology that can simultaneously perform wastewater treatment and generate electricity. Peculiarities that hinder the widespread introduction of this technology are the need to use artificial aeration and chemical catalysts, which make the technology expensive and cause secondary pollution. A possible solution to this issue is the use of biocathodes with microalgae and cyanobacteria. Microalgae in the biocathodic chamber produce oxygen as the terminal electron acceptor. Various BFC technologies with algal biocathode (microbial fuel cells, microbial desalination cells, and plant microbial fuel cells) can address a variety of issues such as wastewater treatment, desalination, and CO₂ capture. The main technological parameters that influence the performance of the biocathode are light, pH, and temperature. These technological parameters affect photosynthetic production of oxygen and organic compounds by microalgae or cyanobacteria, and hence affect the efficiency of electricity production, wastewater treatment and production of added-value compounds in microalgae biomass like lutein, violaxanthin, astaxanthin. The ability to remove carbon, nitrogen, and phosphorus compounds; antibiotics; and heavy metals by pure cultures of microalgae and cyanobacteria and by mixed cultures with bacteria in the cathode chamber can be used for wastewater treatment.

The ability of aqueous extracts of sclerotia of Pleurotus tuberregium and leaves of Cnidoscolus aconitifolius to regulate plasma markers of kidney and liver function/integrity was investigated in doxorubicin-treated Wistar rats. Doxorubicin (dissolved in normal saline) was injected intraperitoneally (15 mg/kg body weight) into the rats; metformin was daily administered orally at 250 mg/kg, while the extracts were daily administered orally at doses of 50, 75, and 100 mg/kg. Compared to the test control, in both the doxorubicin pre-treatment (or ameliorative) study and the extract pre-treatment (protective) studies, the extracts and metformin-treated groups had significantly lower (P < 0.05) plasma levels of alkaline phosphatase, alanine transaminase and aspartate transaminase, and concentrations of creatinine, urea, and blood urea nitrogen. However, the plasma globulin, albumin, and total protein concentrations and the albumin/globulin ratio of the extract and metformin-treated groups were significantly higher (P < 0.05). The extracts prevented (in the protective study) or attenuated (in the ameliorative study) doxorubicin-induced increase in the levels of plasma markers of kidney and liver function/integrity, and afforded protection or recovery towards near-normal values.

The present study aimed to isolate different pigment-producing bacteria from the mangrove rhizosphere habitat and to extract their pigments for evaluating their antioxidant and sun-protective properties. Three pigment-producing bacterial cultures were isolated from soil samples and were identified by morphological analysis and 16S rDNA sequencing. The pigments were isolated by the solvent extraction method and named as MZ (Pink), Orange, and Yellow. They were characterized by Fourier Transform Infrared (FTIR) and UV-Vis spectroscopy. The sun protection factor (SPF) values of these pigments were then determined using the Mansur equation. The total polyphenol content was estimated by the Folin-Ciocâlteu method, and the antioxidant activity of the pigments was determined using DPPH (2,2-diphenyl-1-picrylhydrazyl), FRAP (ferric reducing antioxidant power), and ABTS (2,2-azinobis-3-ethyl-enzothiazoline-6-sulfonic acid) assays. The in vitro antioxidant potential of the pigments in the presence of oxidative stress (H₂O₂) was confirmed in the mouse macrophage cell line RAW264.7 by using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. The pigment-producing bacterial isolates were identified as Bacillus infantis (MZ), Halomonas spp. (Orange), and Bacillus spp. (Yellow). The pigments were found to be carotenoid in nature, and the SPF values were in the range of 3.99 to 5.22. All three pigments had high polyphenol content (22 to 48 μg tannic acid equivalent) and showed significant antioxidant properties in both chemical and cell line-based studies. The results of this study indicate that these pigments have the potential to be used as an antioxidant agent and can be further developed as a pharmaceutical compound.