Combined pretreatment methods for improving sugar yield as well as the economic aspects of lignoe... more Combined pretreatment methods for improving sugar yield as well as the economic aspects of lignoethanol production processes have gained a great deal of interest. However, most investigations involving such methods have been conducted under optimum conditions. Such fully-optimized combinations although improve enzymatic digestion, they could also degrade cellulose structure resulting in reduced sugar yield in some cases. The present study was set to prepare rice straw for the 1-ethyl-3-methylimidazolium acetate pretreatment step (2 h, 120 °C), by mild alkaline extraction (30 min, 80 °C, 0.3 % NaOH) with a focus on only 30 % lignin removal to minimize the hemicelluloses degradation. Moreover, the effect of size reduction (\0.42 mm and \2 cm) was also investigated. The results showed that the novel combination method based on only 30 % lignin removal led to an increased sugar yield by 17 %. Unexpectedly, although IL pretreatment needs material to be ground (\0.42 mm), the difference in sugar yields for the two sized tested was negligible. Graphical Abstract The overall lignocellolusic bioetha-nol production pathway including the combined AE–IL process proposed in the present study based on 30 % lignin removal through the first AE step.
The role of exogenous methyl jasmonate (MJ; 100 μM) application (24 and 72 hours after the treatm... more The role of exogenous methyl jasmonate (MJ; 100 μM) application (24 and 72 hours after the treatment) was investigated in drought stress conditions in the two leaves stage of two barley (Hordeum vulgare L.) cultivars (Yousef as drought-tolerant and Morocco as drought-susceptible). Dry weight, leaf surface, total protein content, H 2 O 2 , malondialdehyde, ascorbate and antioxidant enzymes peroxidase, catalase and ascorbate peroxidase were studied. In both the genotypes, no significant effect was observed on morphological traits in MJ-sprayed plants, or on the total protein reduced in water stress. Drought stress increased H 2 O 2 , membrane-lipid peroxidation as expressed by malondialdehyde and ascorbate contents (both total and reduced ascorbate). As well as the increased activity of enzymatic antioxidants (peroxidase, catalase and ascorbate peroxidase), a simultaneous increase was observed in methyl jasmonate-treated plants under drought. Catalase activity was enhanced in drought but alleviated with the exogenous application of MJ. These results suggest the involvement of methyl jasmonate in improving the drought tolerance of barley.
Combined pretreatment methods for improving sugar yield as well as the economic aspects of lignoe... more Combined pretreatment methods for improving sugar yield as well as the economic aspects of lignoethanol production processes have gained a great deal of interest. However, most investigations involving such methods have been conducted under optimum conditions. Such fully-optimized combinations although improve enzymatic digestion, they could also degrade cellulose structure resulting in reduced sugar yield in some cases. The present study was set to prepare rice straw for the 1-ethyl-3-methylimidazolium acetate pretreatment step (2 h, 120 °C), by mild alkaline extraction (30 min, 80 °C, 0.3 % NaOH) with a focus on only 30 % lignin removal to minimize the hemicelluloses degradation. Moreover, the effect of size reduction (\0.42 mm and \2 cm) was also investigated. The results showed that the novel combination method based on only 30 % lignin removal led to an increased sugar yield by 17 %. Unexpectedly, although IL pretreatment needs material to be ground (\0.42 mm), the difference in sugar yields for the two sized tested was negligible. Graphical Abstract The overall lignocellolusic bioetha-nol production pathway including the combined AE–IL process proposed in the present study based on 30 % lignin removal through the first AE step.
The goal of this study was to determine micropropagation system for a mass production of Tuna (Op... more The goal of this study was to determine micropropagation system for a mass production of Tuna (Opuntia ficus – indica). For this reason, explants dissected from strilled young cladodes successfully established on Murashige and Skoog (MS) medium supplemented with 5 mg l-1 Benzyl amino purine (BAP). MS medium containing different combinations of BAP (5 mg l-1) and Indole acetic acid (IAA) (0, 0.25, 0.5, 1, 2 mg l-1) , BAP (5 mg l-1) and Naphtalene acetic acid (NAA) ( 0, 0.25, 0.5, 1, 2 mg l-1) and BAP (0.5 and 1 mg l-1) and Kinetin ( 0.5 and 1 mg l- 1) were tested for shoot development . The best results for shoot development and elongation were obtained in media containing 5 mg l-1 and 0.25 mg l-1 NAA. The highest multiplication rate (3.9) was observed in media supplemented with 5 mg l-1 BAP and 2 mg l-1 of NAA. Satisfactory rooting was achieved in MS Basal medium (5-6 cm length) without callus formation. The percentage of rooting was 100% and Plants were successfully established in ...
Salinity is one of the major environmental limiting factors that affects growth and productivity ... more Salinity is one of the major environmental limiting factors that affects growth and productivity of rice (Oryza sativa L.) worldwide. Rice is among the most sensitive crops to salinity, especially at early vegetative stages. In order to get a better understanding of molecular pathways affected in rice mutants showing contrasting responses to salinity, we exploited the power of 2-DE based proteomics to explore the proteome changes associated with salt stress response. Our physiological observations showed that standard evaluation system (SES) scores, Na+ and K+ concentrations in shoots and Na+/K+ ratio were significantly different in contrasting mutants under salt stress condition. Proteomics analysis showed that, out of 854 protein spots which were reproducibly detected, 67 protein spots showed significant responses to salt stress. The tandem mass spectrometry analysis of these significantly differentially accumulated proteins resulted in identification of 34 unique proteins. These proteins are involved in various molecular processes including defense to oxidative stresses, metabolisms, photosynthesis, protein synthesis and processing, signal transduction. Several of the identified proteins were emerged as key participants in salt stress tolerance. The possible implication of salt responsive proteins in plant adaptation to salt stress is discussed.
Combined pretreatment methods for improving sugar yield as well as the economic aspects of lignoe... more Combined pretreatment methods for improving sugar yield as well as the economic aspects of lignoethanol production processes have gained a great deal of interest. However, most investigations involving such methods have been conducted under optimum conditions. Such fully-optimized combinations although improve enzymatic digestion, they could also degrade cellulose structure resulting in reduced sugar yield in some cases. The present study was set to prepare rice straw for the 1-ethyl-3-methylimidazolium acetate pretreatment step (2 h, 120 °C), by mild alkaline extraction (30 min, 80 °C, 0.3 % NaOH) with a focus on only 30 % lignin removal to minimize the hemicelluloses degradation. Moreover, the effect of size reduction (\0.42 mm and \2 cm) was also investigated. The results showed that the novel combination method based on only 30 % lignin removal led to an increased sugar yield by 17 %. Unexpectedly, although IL pretreatment needs material to be ground (\0.42 mm), the difference in sugar yields for the two sized tested was negligible. Graphical Abstract The overall lignocellolusic bioetha-nol production pathway including the combined AE–IL process proposed in the present study based on 30 % lignin removal through the first AE step.
The role of exogenous methyl jasmonate (MJ; 100 μM) application (24 and 72 hours after the treatm... more The role of exogenous methyl jasmonate (MJ; 100 μM) application (24 and 72 hours after the treatment) was investigated in drought stress conditions in the two leaves stage of two barley (Hordeum vulgare L.) cultivars (Yousef as drought-tolerant and Morocco as drought-susceptible). Dry weight, leaf surface, total protein content, H 2 O 2 , malondialdehyde, ascorbate and antioxidant enzymes peroxidase, catalase and ascorbate peroxidase were studied. In both the genotypes, no significant effect was observed on morphological traits in MJ-sprayed plants, or on the total protein reduced in water stress. Drought stress increased H 2 O 2 , membrane-lipid peroxidation as expressed by malondialdehyde and ascorbate contents (both total and reduced ascorbate). As well as the increased activity of enzymatic antioxidants (peroxidase, catalase and ascorbate peroxidase), a simultaneous increase was observed in methyl jasmonate-treated plants under drought. Catalase activity was enhanced in drought but alleviated with the exogenous application of MJ. These results suggest the involvement of methyl jasmonate in improving the drought tolerance of barley.
Combined pretreatment methods for improving sugar yield as well as the economic aspects of lignoe... more Combined pretreatment methods for improving sugar yield as well as the economic aspects of lignoethanol production processes have gained a great deal of interest. However, most investigations involving such methods have been conducted under optimum conditions. Such fully-optimized combinations although improve enzymatic digestion, they could also degrade cellulose structure resulting in reduced sugar yield in some cases. The present study was set to prepare rice straw for the 1-ethyl-3-methylimidazolium acetate pretreatment step (2 h, 120 °C), by mild alkaline extraction (30 min, 80 °C, 0.3 % NaOH) with a focus on only 30 % lignin removal to minimize the hemicelluloses degradation. Moreover, the effect of size reduction (\0.42 mm and \2 cm) was also investigated. The results showed that the novel combination method based on only 30 % lignin removal led to an increased sugar yield by 17 %. Unexpectedly, although IL pretreatment needs material to be ground (\0.42 mm), the difference in sugar yields for the two sized tested was negligible. Graphical Abstract The overall lignocellolusic bioetha-nol production pathway including the combined AE–IL process proposed in the present study based on 30 % lignin removal through the first AE step.
The goal of this study was to determine micropropagation system for a mass production of Tuna (Op... more The goal of this study was to determine micropropagation system for a mass production of Tuna (Opuntia ficus – indica). For this reason, explants dissected from strilled young cladodes successfully established on Murashige and Skoog (MS) medium supplemented with 5 mg l-1 Benzyl amino purine (BAP). MS medium containing different combinations of BAP (5 mg l-1) and Indole acetic acid (IAA) (0, 0.25, 0.5, 1, 2 mg l-1) , BAP (5 mg l-1) and Naphtalene acetic acid (NAA) ( 0, 0.25, 0.5, 1, 2 mg l-1) and BAP (0.5 and 1 mg l-1) and Kinetin ( 0.5 and 1 mg l- 1) were tested for shoot development . The best results for shoot development and elongation were obtained in media containing 5 mg l-1 and 0.25 mg l-1 NAA. The highest multiplication rate (3.9) was observed in media supplemented with 5 mg l-1 BAP and 2 mg l-1 of NAA. Satisfactory rooting was achieved in MS Basal medium (5-6 cm length) without callus formation. The percentage of rooting was 100% and Plants were successfully established in ...
Salinity is one of the major environmental limiting factors that affects growth and productivity ... more Salinity is one of the major environmental limiting factors that affects growth and productivity of rice (Oryza sativa L.) worldwide. Rice is among the most sensitive crops to salinity, especially at early vegetative stages. In order to get a better understanding of molecular pathways affected in rice mutants showing contrasting responses to salinity, we exploited the power of 2-DE based proteomics to explore the proteome changes associated with salt stress response. Our physiological observations showed that standard evaluation system (SES) scores, Na+ and K+ concentrations in shoots and Na+/K+ ratio were significantly different in contrasting mutants under salt stress condition. Proteomics analysis showed that, out of 854 protein spots which were reproducibly detected, 67 protein spots showed significant responses to salt stress. The tandem mass spectrometry analysis of these significantly differentially accumulated proteins resulted in identification of 34 unique proteins. These proteins are involved in various molecular processes including defense to oxidative stresses, metabolisms, photosynthesis, protein synthesis and processing, signal transduction. Several of the identified proteins were emerged as key participants in salt stress tolerance. The possible implication of salt responsive proteins in plant adaptation to salt stress is discussed.
Uploads
Papers by Akram Ghaffari