Biotransformation of (-)-a-pinene by Botrytis cinerea

(-)-alpha-Pinene (1), a major constituent of many aromatic plants was biotransformed by the plant pathogenic fungus, Botrytis cinerea to afford three new metabolites, characterized as 3beta-hydroxy-(-)-beta-pinene (10%) (3), 9-hydroxy-(-)-a-pinene (12%) (4), 4beta-hydroxy-(-)-alpha-pinene-6-one (16%) (5) by physical and spectroscopic methods. A known metabolite verbenone (2) was also obtained.     

Ethanol production by Saccharomyces cerevisiae in biofilm reactors

Biofilms are natural forms of cell immobilization in which microorganisms attach to solid supports. At ISU, we have developed plastic composite-supports (PCS) (agricultural material (soybean hulls or oat hulls), complex nutrients, and polypropylene) which stimulate biofilm formation and which supply nutrients to the attached microorganisms. Various PCS blends were initially evaluated in repeated-batch culture-tube fermentation with Saccharomyces cerevisiae (ATCC 24859) in low organic nitrogen medium. The selected PCS (40% soybean hull, 5% soybean flour, 5% yeast extract-salt and 50% polypropylene) was then used in continuous and repeated-batch fermentation in various media containing lowered nitrogen content with selected PCS. During continuous fermentation, S. cerevisiae demonstrated two to 10 times higher ethanol production in PCS bioreactors than polypropylene-alone support (PPS) control. S. cerevisiae produced 30 g L⁻¹ ethanol on PCS with ammonium sulfate medium in repeated batch fermentation, whereas PPS-control produced 5 g L⁻¹ ethanol. Overall, increased productivity in low cost medium can be achieved beyond conventional fermentations using this novel bioreactor design. Received 20 May 1997/ Accepted in revised form 29 August 1997     

Chemical Characterization and Multidirectional Biological Effects of Different Solvent Extracts of Arum elongatum: in Vitro and in Silico Approaches

Arum elongatum (Araceae) is widely used traditionally for the treatment of abdominal pain, arterial hypertension, diabetes mellitus, rheumatism and hemorrhoids. This study investigated the antioxidant properties, individual phenolic compounds, total phenolic and total flavonoid contents (HPLC/MS analysis), reducing power and metal chelating effects of four extracts obtained from A. elongatum (ethyl acetate (EA), methanol (MeOH), methanol/water (MeOH/water) and infusion). The inhibitory activity of the extracts were also determined against acetylcholinesterase, butyrylcholinesterase, tyrosinase, amylase and glucosidase enzymes. The MeOH/water extracts contained the highest amount of phenolic contents (28.85 mg GAE/g) while the highest total flavonoid content was obtained with MeOH extract (36.77 mg RE/g). MeOH/water demonstrated highest antioxidant activity against DPPH⋅ radical at 38.90 mg Trolox equivalent per gram. The infusion extract was the most active against ABTS⁺⋅ (133.08 mg TE/g). MeOH/water extract showed the highest reducing abilities with the CUPRAC value of 102.22 mg TE/g and the FRAP value of 68.50 mg TE/g. A strong metal chelating effect was observed with MeOH/water extract (35.72 mg EDTAE/g). The PBD values of the extracts ranged from 1.01 to 2.17 mmol TE/g. EA extract displayed the highest inhibitory activity against AChE (2.32 mg GALAE/g), BChE (3.80 mg GALAE/g), α-amylase (0.56 mmol ACAE/g) and α-glucosidase (9.16 mmol ACAE/g) enzymes. Infusion extract was the most active against tyrosinase enzyme with a value of 83.33 mg KAE/g. A total of 28 compounds were identified from the different extracts. The compounds present in the highest concentration were chlorogenic acids, 4-hydroxybenzoic acid, caffeic acid, p-coumaric acid, ferulic acid, isoquercitrin, delphindin 3,5-diglucoside, kaempferol-3-glucoside and hyperoside. The biological activities of A. elongatum extracts could be due to the presence of compounds such as gallic acid, chlorogenic acids, ellagic acid, epicatechin, catechin, kaempferol, 4-hydroxybenzoic acid, caffeic acid, p-coumaric acid, ferulic acid, quercetin, isoquercitrin, and hyperoside. Extracts of A. elongatum showed promising biological activities which warrants further investigations in an endeavor to develop biopharmaceuticals.     

Chemical Profile and Cytotoxicity Evaluation of Aerial Parts of Marrubium vulgare L. From Different Locations in Turkey

Marrubium vulgare L. (Lamiaceae) is used for respiratory and gastrointestinal system disorders in folk medicine. According to European Pharmacopoeia criteria, standardization of the plant is defined by its marrubiin content. In present study, phenolics, marrubiin and essential oil compositions of M. vulgare from different locations in Turkey were analyzed quantitatively by UPLC, GC and GC/MS. Besides, their cytotoxic potentials were evaluated. In the samples, forsythoside B (77–400 mg/100 g dw), arenarioside (forsythoside F) (0–241 mg/100 g dw), verbascoside (acteoside) (171–416 mg/100 g dw) and apigenin-7-O-glucoside (0–17 mg/100 g dw) were determined in different ranges. Marrubiin contents (0.58–1.46 %) of some samples were two times higher than European Pharmacopoeia standards (0.7 %). β-Caryophyllene (7.24–20.34 %), (Z)-β-farnesene (1.58–34.85 %), germacrene D (9.8–13.37 %), bicyclogermacrene (1.71–8.63 %) and β-bisabolene (0–16.68 %) were detected as major compounds in essential oils. The sample from the west of Aegean Region showed cytotoxicity against human neuroblastoma (SH-SY5Y) cell lines (IC₅₀: 59.80 μg/mL) although it has no effect on non-cancerous NIH-3T3cell lines. This is the first report on phenolic profiles of M. vulgare populations from Turkey. Their potential as marrubiin source for pharmaceutical industry should be considered.     

DNA sequence and shape are predictive for meiotic crossovers throughout the plant kingdom

A better understanding of genomic features influencing the location of meiotic crossovers (CO s) in plant species is both of fundamental importance and of practical relevance for plant breeding. Using CO positions with sufficiently high resolution from four plant species [Arabidopsis thaliana , Solanum lycopersicum (tomato), Zea mays (maize) and Oryza sativa (rice)] we have trained machine‐learning models to predict the susceptibility to CO formation. Our results show that CO occurrence within various plant genomes can be predicted by DNA sequence and shape features. Several features related to genome content and to genomic accessibility were consistently either positively or negatively related to CO s in all four species. Other features were found as predictive only in specific species. Gene annotation‐related features were especially predictive for maize, whereas in tomato and Arabidopsis propeller twist and helical twist (DNA shape features) and AT /TA dinucleotides were found to be the most important. In rice, high roll (another DNA shape feature) and low CA dinucleotide frequency in particular were found to be associated with CO occurrence. The accuracy of our models was sufficient for Arabidopsis and rice (area under receiver operating characteristic curve, AUROC  > 0.5), and was high for tomato and maize (AUROC  ? 0.5), demonstrating that DNA sequence and shape are predictive for meiotic CO s throughout the plant kingdom.     

Follicular growth in vitro: detection of growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) during in vitro culture of ovine cortical slices

Primordial follicles from different mammal species can survive and enter the growth phase in vitro but do not develop beyond the primary stage. The hypothesis was that, in sheep, in vitro follicular growth is arrested because of a lack of secretion of GDF9 and/or BMP15. Cortical slices of 0.3-0.5 mm thickness issued from 5- to 6-month-old lambs were cultured for 15 days. The pieces were fixed on days 0, 2, 4, 7, 10, and 15 of culture. Follicle morphology, RT-PCR exploration of GDF9 and BMP15 mRNA, immunohistochemical location of their proteins and their receptor BMPRIB and BMPRII were assessed at different time of culture. The mean percentage of primordial follicles decreased from 58.6% (day 0) to 13.4% (day 15) (P<0.01), whereas that of primary follicles increased from 3.2% (day 0) to 31.5% on day 4 (P<0.01), then remained stable until day 15 (35.6%). The percentage of atretic follicles increased from 14.7% (day 0) to 27.1% (day 15) (P<0.05). A few secondary follicles were observed on days 4 and 10, representing 1.0%, and 2.1% of the total number of follicles. GDF9 and BMP15 mRNAs were detected from harvesting (day 0) up to day 15 following culture. At the same time, positive immunoreactions for GDF9, BMP15 and for BMPRIB and BMPRII were also found in oocyte cytoplasm. In conclusion, expression of GDF9, BMP15 and their receptors BMPRIB and BMPRII are detected during in vitro culture of ovine cortical slices.     

Effects of medium components in a glycerol-based medium on vitamin K (menaquinone-7) production by Bacillus subtilis natto in biofilm reactors

Bioprocess and Biosystems Engineering - Menaquinone-7 (MK-7) as the most important form of Vitamin K has been reported to have miraculous benefits such as preventing cardiovascular diseases and...     

Investigating the effect of Zn doping and temperature on the photoluminescence behaviour of CuLaSe2 quantum dots

In this study, CuLaSe₂ and ZnCuLaSe₂ quantum dots (QDs) with a mean size of ~4 nm were synthesized and characterized, and their temperature-dependent photoluminescence (PL) properties were studied in the temperature range from 90 to 300 K for the first time. The results show that the obtained QDs were spherical and revealed excitonic band gaps. The PL intensity for both types of materials decreased when increasing the temperature to 300 K, which was attributed to the nonradiative relaxation and thermal escape mechanisms. As the temperature was increased, the PL linewidths broadened, and PL peak energies were red shifted for both types of QDs due to the exciton–phonon coupling and lattice deformation potential mechanisms. In addition, we found that as the temperature was decreased, the PL spectrum of ZnCuLaSe₂ QDs contained two extra components, which could be attributed to the shallow defect sites (low energy peak) and the crystal phase transition process (high energy peak). The spectrum of CuLaSe₂ QDs contained one extra component, which could be attributed to the crystal phase transition process.     

Online recovery of nisin during fermentation and its effect on nisin production in biofilm reactor

An online removal of nisin by silicic acid coupled with a micro-filter module was proposed as an alternative to reduce detrimental effects caused by adsorption of nisin onto producer, enzymatic degradation by protease, and product inhibition during fermentation. In this study, silicic acid was successfully used to recover nisin from the fermentation broth of Lactococcus lactis subsp. lactis NIZO 22186. The effect of pH (at 6.8 and 3.0) during adsorption process and several eluents (deionized water, 20% ethanol, 1 M NaCl, and 1 M NaCl + 20% ethanol) for desorption were evaluated in a small batch scale. Higher nisin adsorption onto silicic acid was achieved when the adsorption was carried out at pH 6.8 (67% adsorption) than at pH 3.0 (54% adsorption). The maximum recovery was achieved (47% of nisin was harvested) when the adsorption was carried out at pH 6.8 and 1 M NaCl + 20% ethanol was used as an eluent for desorption. Most importantly, nisin production was significantly enhanced (7,445 IU/ml) when compared with the batch fermentation without the online recovery (1,897 IU/ml). This may possibly be attributed to preventing the loss of nisin due the detrimental effects and a higher biomass density achieved during online recovery process, which stimulated production of nisin during fermentation.