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Jianxin Jiang - One of the best experts on this subject based on the ideXlab platform.
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Enzymatic degradation of steam-pretreated Lespedeza stalk (Lespedeza crytobotrya) by cellulosic-substrate induced cellulases
Bioprocess and biosystems engineering, 2010Co-Authors: Yue Feng, Hui-qin Liu, Jianxin JiangAbstract:The cellulase production by Trichoderma viride, cultivated on different substrates, namely steam-pretreated Lespedeza, filter paper, microcrystalline cellulose (MCC) or carboxymethyl cellulose (CMC), was studied. Different cellulase systems were secreted when cultivated on different substrates. The cellulolytic enzyme from steam-pretreated Lespedeza medium performed the highest filter paper activity, exoglucanase and endoglucanase activities, while the highest β-glucosidase activity was obtained from the enzyme produced on filter paper medium. The hydrolytic potential of the enzymes produced from different media was evaluated on steam-pretreated Lespedeza. The cellulase from steam-pretreated Lespedeza was found to have the most efficient hydrolysis capability to this specific substrate. The molecular weights of the cellulases produced on steam-pretreated Lespedeza, filter paper and MCC media were 33, 37 and 40 kDa, respectively, and the cellulase from CMC medium had molecular weights of 20 and 43 kDa. The degree of polymerization, crystallinity index and micro structure scanned by the scanning electron microscopy of degraded steam-pretreated Lespedeza residues were also studied.
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influence of steaming explosion time on the physic chemical properties of cellulose from Lespedeza stalks Lespedeza crytobotrya
Bioresource Technology, 2009Co-Authors: Kun Wang, Jianxin Jiang, Runcang SunAbstract:The synergistic effect of steam explosion pretreatment and sodium hydroxide post-treatment of Lespedeza stalks (Lespedeza crytobotrya) has been investigated in this study. In this case, Lespedeza stalks were firstly exploded at a fixed steam pressure (22.5 kg/m(2)) for 2-10 min. Then the steam-exploded Lespedeza stalks was extracted with 1 M NaOH at 50 degrees C for 3 h with a shrub to water ratio of 1:20 (g/ml), which yielded 57.3%, 53.1%, 55.4%, 52.8%, 53.2%, and 56.4% (% dry weight) cellulose rich fractions, comparing to 68.0% from non-steam-exploded material. The content of glucose in cellulose rich residues increased with increment of the steaming time and reached to 94.10% at the most severity. The similar increasing trend occurred during the dissolution of hemicelluloses. It is evident that at shorter steam explosion time, autohydrolysis mainly occurred on the hemicelluloses and the amorphous area of cellulose. The crystalline region of cellulose was depolymerized under a prolonged incubation time. The characteristics of the cellulose rich fractions in terms of FT-IR and CP/MAS (13)C NMR spectroscopy and thermal analysis were discussed, and the surface structure was also investigated by SEM.
Runcang Sun - One of the best experts on this subject based on the ideXlab platform.
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influence of steaming explosion time on the physic chemical properties of cellulose from Lespedeza stalks Lespedeza crytobotrya
Bioresource Technology, 2009Co-Authors: Kun Wang, Jianxin Jiang, Runcang SunAbstract:The synergistic effect of steam explosion pretreatment and sodium hydroxide post-treatment of Lespedeza stalks (Lespedeza crytobotrya) has been investigated in this study. In this case, Lespedeza stalks were firstly exploded at a fixed steam pressure (22.5 kg/m(2)) for 2-10 min. Then the steam-exploded Lespedeza stalks was extracted with 1 M NaOH at 50 degrees C for 3 h with a shrub to water ratio of 1:20 (g/ml), which yielded 57.3%, 53.1%, 55.4%, 52.8%, 53.2%, and 56.4% (% dry weight) cellulose rich fractions, comparing to 68.0% from non-steam-exploded material. The content of glucose in cellulose rich residues increased with increment of the steaming time and reached to 94.10% at the most severity. The similar increasing trend occurred during the dissolution of hemicelluloses. It is evident that at shorter steam explosion time, autohydrolysis mainly occurred on the hemicelluloses and the amorphous area of cellulose. The crystalline region of cellulose was depolymerized under a prolonged incubation time. The characteristics of the cellulose rich fractions in terms of FT-IR and CP/MAS (13)C NMR spectroscopy and thermal analysis were discussed, and the surface structure was also investigated by SEM.
J. A. Mosjidis - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of Lespedeza germplasm genetic diversity and its phylogenetic relationship with the genus Kummerowia.
Conservation Genetics, 2008Co-Authors: Ming Li Wang, J. A. Mosjidis, John Bradley Morris, Zhenbang Chen, Noelle A. Barkley, G. A. PedersonAbstract:The genetic diversity of the genus Lespedeza is not well known and the phylogenetic relationship of Lespedeza with the genus Kummerowia is unclear. We report the first study in which polymorphic expressed sequence tag-simple sequence repeat (EST-SSR) markers derived from Medicago, cowpea and soybean were used to assess the genetic diversity of the USDA Lespedeza germplasm collection and clarify its phylogenetic relationship with the genus Kummerowia. Phylogenetic analysis partitioned 44 Lespedeza accessions into three main groups some of which were species-specific and eight subgroups. This data set revealed some misidentified accessions, and indicated that the two species in the genus Kummerowia are closely related to the genus Lespedeza. Morphological reexamination was used to correct the misidentified accessions within the genus Lespedeza. Our results demonstrated that phylogenetic analysis with morphological reexamination provides a more complete approach to classify accessions in plant germplasm collection and conservation.
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Variability for biomass production and plant composition in Sericea Lespedeza
Biomass and Bioenergy, 1996Co-Authors: J. A. MosjidisAbstract:Abstract Sericea Lespedeza [ Lespedeza cuneata (Dumont de Courset) G. Don.] is a deep-rooted legume that is well adapted to the acid, eroded soils found throughout the southeastern region of the U.S.A. A field experiment aimed at measuring biomass yield and biomass composition of 81 genotypes of sericea Lespedeza harvested once every season was conducted. Results indicated substantial differences for biomass yield among sericea Lespedeza genotypes. However, dry matter percentage was the same. Genotype R194-79-290-9 had the highest mean biomass yield (9.0 Mg ha −1 ) and, consistently, ranked among the top four during the four years that this study was conducted. Other genotypes that also exhibited a good performance over the four years were the cultivar Serala (7.8 Mg ha −1 ) and the breeding line 75-2-3 (7.8 Mg ha −1 ). Differences in yield stability over time among genotypes were observed, hence, long term performance would need to be considered in a breeding program. These results suggested that sericea Lespedeza genotypes with a consistently high biomass yield can be selected. No significant differences were found among genotypes for crude protein concentration. Crude protein concentrations were about 25% lower than those previously reported. Significant differences among genotypes for neutral detergent fiber, hemicellulose, and holocellulose concentration were observed. However, no significant differences for acid detergent fiber, lignin, cellulose concentration, and holocellulose yield were measured. In summary, there is variability and potential to select for biomass yield and quality traits that are considered important for biofuel production.
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Variability for Temperature of Germination in Sericea Lespedeza Germplasm
Crop Science, 1995Co-Authors: J. Qiu, J. A. Mosjidis, J. C. WillliamsAbstract:Poor and slow seed germination are major problems in growing sericea Lespedeza [Lespedeza cuneata (Dumont de Courset) G. Don.]. Knowledge about the temperatures for optimum seed germination is vital to selecting the best seeding date for this forage legume. The objectives of this study were to determine the variability of sericea Lespedeza germplasm for germination under several temperatures and the effect of seed weight on percentage and rate of germination. Germination response to temperature of 54 breeding lines and 26 accessions were tested. Mechanically-scarified seed of each of the 80 genotypes were weighed and germinated in the dark in a germinator at constant temperatures of 10, 15, 20, 25, and 30°C. An additional temperature (35°C) was included to test the germinability of the 26 accessions. Germination counts were recorded daily for 14 d to calculate total percent germination (TPG) and Maguire germination rate index (GRI). Temperature had a significant effect on TPG and GRI. Optimum germination temperature for sericea Lespedeza ranged between 20 and 30°C. Thus, seeding time for this species for a particular location should be selected to match the optimum range of soil temperatures provided that adequate soil moisture is available. Mean TPG and GRI were significantly different among the genotypes at each temperature. However, genotypes with a consistently high TPG and GRI at a wide range of temperatures were found. Seed weight was correlated with TPG at 10 (r = 0.401) and 15°C (r = 0.459), and also with GRI (r = 0.388-0.475) at all temperatures for the breeding lines. However, seed weight was not correlated with TPG or GRI for the 26 accessions. THe TPG and GRI were highly interrelated, thus, measuring TPG alone should provide adequate information when describing response to environmental stresses in sericea Lespedeza
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Effects of sericea Lespedeza root exudates on some perennial grasses.
Journal of Range Management, 1993Co-Authors: K. L. Kalburtji, J. A. MosjidisAbstract:Root exudates are substances released into the surrounding medium by healthy and intact plant roots. Research on root exudates has shown that root exudates can reduce seed germination and plant growth. There is no information on the effect of sericea Lespedeza [Lespedeza cuneata (Dum. de Cours) G. Don.] root exudates on other plants. In a series of greenhouse experiments we studied (1) if sericea root exudates affect seed germination and seedling growth of the perennial grasses tall fescue (Festuca arundinacea Schreb.), bermudagrass [Cynodon dactylon (L.) Pers.], and bahiagrass (Paspalum notatum Flugge); and (2) if any such responses were cultivar dependent. The effects of the root exudates were measured in 2 experiments. In the first one, coarse perlite was used as a medium to measure seed germination and radicle and coleoptile growth. In the second experiment, soil was used as a medium to measure emergence and biomass. Root exudates from sericea Lespedeza had no effect on germination and emergence of tall fescue and bahiagrass but reduced their radicle and coleoptile length and biomass. Germination, radicle, and coleoptile length, and emergence of bermudagrass decreased when exposed to the root exudates; however, biomass was not affected. Cultivars of the grass species differed in their response to the root exudates of sericea Lespedeza. Thus, establishment of tall fescue in mixture with sericea Lespedeza is not likely to be affected; however, its growth is likely to be decreased. Therefore, tall fescue contribution to total yield will be reduced. Conversely, establishment of bermudagrass is likely to be affected, but once established, its growth is expected to be similar to its grown alone.
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effects of sericea Lespedeza residues on cool season grasses
Journal of Range Management, 1992Co-Authors: K. L. Kalburtji, J. A. MosjidisAbstract:Incorporation of crop residues into the soil prior to planting has been shown to reduce the growth of subsequent crops. Information is limited on the allelopathic effect of sericea Lespedeza [Lespedeza cuneata (Dum. Cours) G. Don.] residues on multiple cropping and rotational systems. Experiments were conducted to determine (1) if sericea Lespedeza residues affected seed germination and plant growth of rye (Secale cereale L.), ryegrass (Lolium multiflorum Lam.), and tall fescue (Festuca arundinacea Schreb.); (2) if cultivars of these species varied in response to phytotoxins from sericea Lespedeza residues; and (3) if N fertilization nullified the effects of residues. Germination experiments were conducted by using water extracts from low- or high-tannin sericea Lespedeza residues, distilled water (control), and topsoil and subsoil obtained from areas in which low- or high-tannin sericea Lespedeza plants had grown for 4 years. Greenhouse experiments showed that germination, emergence, seedling growth, above-ground biomass, and N concentration of rye and tall fescue were reduced by sericea Lespedeza residues. Although ryegrass germination was not affected by the residues, biomass and N concentration were reduced. Rye and tall fescue germination were not affected by soils where sericea Lespedeza previously had grown, but ryegrass germination and seedling growth of all 3 species were reduced. Immobilized N was the main factor limiting plant growth. Fertilizer-N more than compensated for the negative effects of the residues on all species. Establishment of rye and tall fescue in a sericea Lespedeza field is likely to require higher seeding rates than normal to compensate for reduced germination, whereas ryegrass would not be affected. Fertilizer-N may be needed to enhance growth of grasses that otherwise would be curtailed by sericea Lespedeza residues.
Yue Feng - One of the best experts on this subject based on the ideXlab platform.
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Enzymatic degradation of steam-pretreated Lespedeza stalk (Lespedeza crytobotrya) by cellulosic-substrate induced cellulases
Bioprocess and biosystems engineering, 2010Co-Authors: Yue Feng, Hui-qin Liu, Jianxin JiangAbstract:The cellulase production by Trichoderma viride, cultivated on different substrates, namely steam-pretreated Lespedeza, filter paper, microcrystalline cellulose (MCC) or carboxymethyl cellulose (CMC), was studied. Different cellulase systems were secreted when cultivated on different substrates. The cellulolytic enzyme from steam-pretreated Lespedeza medium performed the highest filter paper activity, exoglucanase and endoglucanase activities, while the highest β-glucosidase activity was obtained from the enzyme produced on filter paper medium. The hydrolytic potential of the enzymes produced from different media was evaluated on steam-pretreated Lespedeza. The cellulase from steam-pretreated Lespedeza was found to have the most efficient hydrolysis capability to this specific substrate. The molecular weights of the cellulases produced on steam-pretreated Lespedeza, filter paper and MCC media were 33, 37 and 40 kDa, respectively, and the cellulase from CMC medium had molecular weights of 20 and 43 kDa. The degree of polymerization, crystallinity index and micro structure scanned by the scanning electron microscopy of degraded steam-pretreated Lespedeza residues were also studied.
Kun Wang - One of the best experts on this subject based on the ideXlab platform.
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influence of steaming explosion time on the physic chemical properties of cellulose from Lespedeza stalks Lespedeza crytobotrya
Bioresource Technology, 2009Co-Authors: Kun Wang, Jianxin Jiang, Runcang SunAbstract:The synergistic effect of steam explosion pretreatment and sodium hydroxide post-treatment of Lespedeza stalks (Lespedeza crytobotrya) has been investigated in this study. In this case, Lespedeza stalks were firstly exploded at a fixed steam pressure (22.5 kg/m(2)) for 2-10 min. Then the steam-exploded Lespedeza stalks was extracted with 1 M NaOH at 50 degrees C for 3 h with a shrub to water ratio of 1:20 (g/ml), which yielded 57.3%, 53.1%, 55.4%, 52.8%, 53.2%, and 56.4% (% dry weight) cellulose rich fractions, comparing to 68.0% from non-steam-exploded material. The content of glucose in cellulose rich residues increased with increment of the steaming time and reached to 94.10% at the most severity. The similar increasing trend occurred during the dissolution of hemicelluloses. It is evident that at shorter steam explosion time, autohydrolysis mainly occurred on the hemicelluloses and the amorphous area of cellulose. The crystalline region of cellulose was depolymerized under a prolonged incubation time. The characteristics of the cellulose rich fractions in terms of FT-IR and CP/MAS (13)C NMR spectroscopy and thermal analysis were discussed, and the surface structure was also investigated by SEM.