Warburgia ugandensis Sprague is a woody species in the family Canellaceae and an important source of medicines in Africa. Natural propagation of W. ugandensis is problematic due to its recalcitrant seeds and lack of an efficient in vitro regeneration system for this species. This study describes an efficient regeneration protocol. Petiole bases and shoot tips were used as explants. Callus tissue developed when the explants were cultured on Murashige and Skoog medium containing 30 g L−1 sucrose and 7 g L−1 agar (MS30 medium), supplemented with 1.0 mg L−1 indole-3-butyric acid (IBA), 1.6 mg L−1 6-benzylaminopurine (BA), and 0.1 mg L−1 thidiazuron (TDZ). Adventitious buds were efficiently induced from the callus when the MS30 medium was supplemented with 0.8 mg L−1 BA and 0.2 mg L−1 IBA. Root induction occurred within 7–10 d on half-strength MS30 medium supplemented with 0.8–1.0 mg L−1 1-napthalene acetic acid (NAA), 0.2 mg L−1 IBA, and 0.03% (w/v) activated charcoal (AC). Roots were followed by root elongation on the same medium but lacking NAA and IBA. Approximately 50% of the plantlets cultured produced roots, while more than 80% of the plantlets survived and successfully grew to maturity.
相似文献The importance of non-Saccharomyces yeast species in fermentation processes is widely acknowledged. Within this group, Pichia kudriavzevii ITV-S42 yeast strain shows particularly desirable characteristics for ethanol production. Despite this fact, a thorough study of the metabolic and kinetic characteristics of this strain is currently unavailable. The aim of this work is to study the nutritional requirements of Pichia kudriavzevii ITV-S42 strain and the effect of different carbon sources on the growth and ethanol production. Results showed that glucose and fructose were both assimilated and fermented, achieving biomass and ethanol yields of 0.37 and 0.32 gg−1, respectively. Glycerol was assimilated but not fermented; achieving a biomass yield of 0.88 gg−1. Xylose and sucrose were not metabolized by the yeast strain. Finally, the use of a culture medium enriched with salts and yeast extract favored glucose consumption both for growth and ethanol production, improving ethanol tolerance reported for this genre (35 g L−1) to 90 g L−1 maximum ethanol concentration (over 100%). Furthermore Pichia kudriavzevii ITV-S42 maintained its fermentative capacity up to 200 g L−1 initial glucose, demonstrating that this yeast is osmotolerant.
相似文献Effects of heavy metals on aerobic denitrification have been poorly understood compared with their impacts on anaerobic denitrification. This paper presented effects of four heavy metals (Cd(II), Cu(II), Ni(II), and Zn(II)) on aerobic denitrification by a novel aerobic denitrifying strain Pseudomonas stutzeri PCN-1. Results indicated that aerobic denitrifying activity decreased with increasing heavy metal concentrations due to their corresponding inhibition on the denitrifying gene expression characterized by a time lapse between the expression of the nosZ gene and that of the cnorB gene by PCN-1, which led to lower nitrate removal rate (1.67∼6.67 mg L−1 h−1), higher nitrite accumulation (47.3∼99.8 mg L−1), and higher N2O emission ratios (5∼283 mg L−1/mg L−1). Specially, promotion of the nosZ gene expression by increasing Cu(II) concentrations (0∼0.05 mg L−1) was found, and the absence of Cu resulted in massive N2O emission due to poor synthesis of N2O reductase. The inhibition effect for both aerobic denitrifying activity and denitrifying gene expression was as follows from strongest to least: Cd(II) (0.5∼2.5 mg L−1) > Cu(II) (0.5∼5 mg L−1) > Ni(II) (2∼10 mg L−1) > Zn(II) (25∼50 mg L−1). Furthermore, sensitivity of denitrifying gene to heavy metals was similar in order of nosZ > nirS ≈ cnorB > napA. This study is of significance in understanding the potential application of aerobic denitrifying bacteria in practical wastewater treatment.
相似文献The objective of this study was to set up a plant micropropagation facility to mass propagate sugarcane, energy cane, and related clonally propagated species. An efficient methodology for micropropagation of energy cane and perennial grasses using temporary immersion bioreactors was developed. Several different methods of tissue culture initiation, multiplication, and rooting were evaluated for several varieties of sugarcane (Saccharum officinarum L.) and sugarcane-related species such as Erianthus spp., Miscanthus spp., and Sorghum spp. × sugarcane hybrids, all from a germplasm collection. Apical meristem cultures were initiated for all genotypes that were micropropagated, when liquid or semisolid Murashige and Skoog (MS) medium was used, which was supplemented with 0.1–0.2 mg L−1 BAP, 0.1 mg L−1 kinetin, 0–0.1 mg L−1 NAA, and 0–0.2 μg L−1 giberellic acid. These cultures produced shoots between 4 and 8 wk after initiation. Shoot regeneration from leaf rolls or immature inflorescences was observed as early as 4 wk after initiation. Shoot multiplication was successful for all genotypes cultured in MS medium with 0.2 mg L−1 BAP and 0.1 mg L−1 kinetin. Energy cane had a significantly higher combined multiplication rate when grown under four or five LED lamps than when grown under three LED lamps, or under fluorescent lights in a growth chamber. The addition of 2 mg L−1 NAA produced faster and better rooting in all of the genotypes tested. Shoots produced well-developed roots after one cycle of 15–21 d in the bioreactors. The maximum number of plantlets produced per bioreactor was 1080. Plantlets developed a vigorous root system and were ready to be transplanted into the field after 2 mo. A protocol was standardized for different energy cane clones that were recommended for their biomass production and cell wall composition. Different tissues were used to speed up or facilitate tissue culture initiation. Visual assessment of micropropagated plants in the field did not show any off-types, based on gross morphological changes of plant morphology or disease reaction, compared to plants of the same genotype derived from a traditional propagation method (stem cuttings). This is the first report of energy cane and Miscanthus spp. micropropagation using the SETIS bioreactor.
相似文献The synergistic effect of plant growth regulators on axillary bud proliferation for mass clonal multiplication of Moringa oleifera Lam. (vern. drumstick) has been assessed for the first time. Treatment of decoated seeds with 1% (w/v) Bavistin for 60 min, 0.33% (w/v) streptocycline for 30 min, and 0.1% (w/v) HgCl2 for 3.5 min resulted in complete removal of the surface contaminants. Maximum seed germination (89.13%) was obtained on quarter-strength Murashige & Skoog (MS) medium. Culture of nodal segments on MS + 6-benzyladenine (BA) at 3 mg L−1 resulted in multiple shoot proliferation with ~ 18 shoots per explant. All combinations of indole-3-acetic acid (IAA) + kinetin (Kn) resulted in elongated shoots, while only lower concentrations of BA (0.5 mg L−1), along with IAA (0.5 to 2 mg L−1), or Kn (0.5 to 5 mg L−1), showed significant synergy in the shoot morphogenesis. In addition, the maximum (100%) rooting efficiency was attained on half-strength MS medium supplemented with different concentrations of IAA and indole-3-butyric acid (IBA). The rooted plants were successfully established in the greenhouse for acclimatization. Clonality of the raised plants was assessed using 15 random primers of Operon® technologies (OPT and OPF series), and eight primers resulted in significant amplification with distinct, identical, and reproducible bands that confirmed clonality of the micropropagated plants. The present study provides a comprehensive analysis of the synergistic effect of plant growth regulators (PGRs) on in vitro shoot regeneration and proliferation for clonal mass multiplication disease-free plantlets, which can be utilized to maximize the yield of healthy and genetically identical plants of drumstick tree, which is considered to be a miracle multipurpose tree.
相似文献Plant-derived smoke is a positive regulator of seed germination and growth with regard to many plant species. Of the several compounds present in plant-derived smoke, karrikinolide or KAR1 (3-methyl-2H-furo[2,3-c]pyran-2-one) is considered to be the major active growth-promoting compound. To test the efficacy of smoke-saturated water (SSW) and KAR1 on carrot (Daucus carota L.), two separate pot experiments were simultaneously conducted in the same environmental conditions. SSW and KAR1 treatments were applied to the plants in the form of aqueous solutions of variable concentrations. Prior to sowing, seeds were soaked in the solutions of SSW (25.8 µg L−1, 51.6 µg L−1,103.2 µg L−1 and 258.0 µg L−1) and KAR1 (0.015 µg L−1, 0.150 µg L−1, 1.501 µg L−1 and 15.013 µg L−1). Percent seed germination, vegetative growth, photosynthesis and nutritional values were the major parameters through which the plant response to the applied treatments was investigated. The results obtained indicated a significant improvement in all the plant attributes studied. In general, SSW (51.6 µg L−1) and KAR1 (1.501 µg L−1) proved optimum treatments for most the parameters. As compared to the control, 51.6 µg L−1 of SSW and 1.501 µg L−1 of KAR1 increased the percent seed germination by 58.0% and 54.4%, respectively. Over the control, the values of plant height and net photosynthetic rate were enhanced by 33.9% and 40.9%, respectively, due to 51.6 µg L−1 of SSW, while the values of these parameters were increased by 25.2% and 34.0%, respectively, due to 1.501 µg L−1 of KAR1. In comparison with the control, treatment 51.6 µg L−1 of SSW increased the contents of β-carotene and ascorbic acid by 32.7% and 37.9%, respectively, while the treatment 1.501 µg L−1 M of KAR1 enhanced these contents by 42.0% and 48.4%, respectively. This study provides an insight into an affordable and feasible method of crop improvement.
相似文献Phellodendron chinense Schneid is an important Chinese herb with berberine and phellodendrine in stems and leaves, but with little information available on in vitro culture of this species. Disinfection of explants in 75% alcohol for 45 s, sterilization in 0.1% HgCl2 for 20 min, and submersion in 1.0 mol L−1 gibberellin3 (GA3) solution for 24 h was the optimal condition for seed germination. Murashige and Skoog’s (MS) medium supplemented with 2.0 mg L−1 6-benzylaminopurine (6-BA) in combination with 1.5 mg L−1 1-naphthylacetic acid (NAA) was optimal for callus induction. MS medium supplemented with 2.0 mg L−1 6-BA was the appropriate medium for induction of adventitious shoots, and 1/2MS medium supplemented with 2.0 mg L−1 indole-3-butytric acid (IBA) and 0.5% active carbon was the optimal medium for root induction. The 15-d survival rate of regenerated plantlets after transplanting to basins containing perlite and peat moss (1:4) was greater than 80%, and the berberine and phellodendrine accumulation was lower in callus compared with regenerated plantlets. The establishment of highly efficient regeneration system provides technical support for genetic breeding of Phellodendron chinense Schneid.
相似文献Randia echinocarpa, an endemic plant to Northwest Mexico, is used as food and in traditional medicine, and several of its biological activities have been demonstrated (antioxidant, antimutagenic, antidiabetic, and immunomodulatory). Plant tissue culture is a safe and scalable system for plant propagation and production of bioactive compounds. Therefore, this study aims to establish protocols for seed germination and callus culture of R. echinocarpa and to evaluate the antioxidant activity of methanol extracts (ME) of plantlets and calli via the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) methods. Seeds were cultured in media with different concentrations of Murashige and Skoog (MS) salts and sucrose, and a higher germination rate and plantlet growth was observed in half-strength MS medium with 15 g L−1 of sucrose. Calli were obtained from cotyledon and hypocotyl explants cultured in MS media with different concentrations of benzyl aminopurine (BAP) and indole-3-acetic acid (IAA). All treatments induced callus formation in 100% of explants; however, the medium containing 1 mg L−1 BAP + 1 mg L−1 IAA was selected because it produced calli with higher biomass and friable texture. The ME of cotyledons showed the highest antioxidant activity values (μmol Trolox per 100 g dry weight) in DPPH (345.5) and ABTS (1166.4) assays, whereas the ME of calli from hypocotyls showed a higher antioxidant activity than the ME of calli from cotyledons in both antioxidant assays. The tissue culture protocols established here will be useful for R. echinocarpa germplasm conservation and propagation, as well as for the production of bioactive compounds.
相似文献Solanum viarum Dunal is an important medicinal plant with a high quantity of steroidal alkaloids used for the synthesis of contraceptives, corticosteroids, and sex hormones. It is also used by Indian tribal people for the treatment of leprosy, toothache, and diabetes. Therefore, to meet the existing needs for this plant, it is necessary to develop an efficient regeneration system useful for rapid and large-scale clonal propagation with ensured genetic fidelity. An efficient and improved regeneration protocol for prickly and prickleless genotypes of S. viarum has been developed using three explants, leaf, petiole, and internodes, under the influence of two plant growth regulators, thidiazuron (TDZ) and 6-benzyladenine (BA). Effects of genotype, explant type, and concentrations of TDZ and BA were studied. A higher percentage of shoot organogenesis (78.25% ± 2.53) and shoot number per explant (6.79 ± 1.04) were achieved in the leaf segments of prickly genotype cultured on modified Murashige and Skoog (MS) medium supplemented with TDZ (1.50 mg L−1). Furthermore, basal leaf segments showed 100% regeneration from the prickly genotype. A significantly higher content of total phenolics was quantified in prickleless (3.66 μg mg−1) than prickly genotypes (2.73 μg mg−1). The monomorphic banding pattern of random amplified polymorphic DNA (RAPD) and simple sequence repeats (SSR) analysis confirmed the genetic fidelity of the regenerated plants. Additionally, flow cytometric analysis of regenerants showed no variation in the ploidy levels when compared to the mother (control) plants. These results clearly depicted the efficiency of developed protocol that can be utilized for generating genetically stable population of S. viarum.
相似文献In this work, the effect of initial sugar concentration and temperature on the production of ethanol by Saccharomyces cerevisiae CCA008, a flocculent yeast, using cashew apple juice in a 1L-bioreactor was studied. The experimental results were used to develop a kinetic model relating biomass, ethanol production and total reducing sugar consumption. Monod, Andrews, Levenspiel and Ghose and Tyagi models were investigated to represent the specific growth rate without inhibition, with inhibition by substrate and with inhibition by product, respectively. Model validation was performed using a new set of experimental data obtained at 34 °C and using 100 g L−1 of initial substrate concentration. The model proposed by Ghose and Tyagi was able to accurately describe the dynamics of ethanol production by S. cerevisiae CCA008 growing on cashew apple juice, containing an initial reducing sugar concentration ranging from 70 to 170 g L−1 and temperature, from 26 to 42 °C. The model optimization was also accomplished based on the following parameters: percentage volume of ethanol per volume of solution (%V ethanol/V solution), efficiency and reaction productivity. The optimal operational conditions were determined using response surface graphs constructed with simulated data, reaching an efficiency and a productivity of 93.5% and 5.45 g L−1 h−1, respectively.
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