Showing papers on "Protoplast published in 2014"

A simple improved-throughput xylem protoplast system for studying wood formation

Abstract: Isolated protoplasts serve as a transient expression system that is highly representative of stable transgenics in terms of transcriptome responses. They can also be used as a cellular system to study gene transactivation and nucleocytoplasmic protein trafficking. They are particularly useful for systems studies in which stable transgenics and mutants are unavailable. We present a protocol for the isolation and transfection of protoplasts from wood-forming tissue, the stem-differentiating xylem (SDX), in the model woody plant Populus trichocarpa. The method involves tissue preparation, digestion of SDX cell walls, protoplast isolation and DNA transfection. Our approach is markedly faster and provides better yields than previous protocols; small (milligrams)- to large (20 g)-scale SDX preparations can be achieved in ~60 s, with isolation of protoplasts and their subsequent transfection taking ~50 min. Up to ten different samples can be processed simultaneously in this time scale. Our protocol gives a high yield (~2.5 × 10(7) protoplasts per g of SDX) of protoplasts sharing 96% transcriptome identity with intact SDX.

Isolation, culture, and transient transformation of plant protoplasts.

Abstract: Transient gene expression in protoplasts, which has been used in several plant species, is an important and versatile tool for rapid functional gene analysis, protein subcellular localization, and biochemical manipulations. This unit describes transient gene expression by electroporation of DNA into protoplasts of Arabidopsis or tobacco suspension-cultured cells and by polyethylene glycol (PEG)-mediated DNA transformation into protoplasts derived from rice leaf sheaths. PEG-mediated DNA transformation for transient gene expression in rice protoplasts in suspension culture is also described as an alternative technique. Methods for collecting intracellular and secreted proteins are also provided.

A Novel Co-immunoprecipitation Protocol Based on Protoplast Transient Gene Expression for Studying Protein–protein Interactions in Rice

Abstract: Protein–protein interactions constitute the regulatory network that coordinates diverse cellular functions. Co-immunoprecipitation (co-IP) is a widely used and effective technique to study protein–protein interactions in living cells. However, the time and cost for the preparation of a highly specific antibody is the major disadvantage associated with this technique. In the present study, a co-IP system was developed to detect protein–protein interactions based on an improved protoplast transient expression system by using commercially available antibodies. This co-IP system eliminates the need for specific antibody preparation and transgenic plant production. Leaf sheaths of rice green seedlings were used for the protoplast transient expression system which demonstrated high transformation and co-transformation efficiencies of plasmids. The transient expression system developed by this study is suitable for subcellular localization and protein detection. This work provides a rapid, reliable, and cost-effective system to study transient gene expression, protein subcellular localization, and characterization of protein–protein interactions in vivo.

Plant regeneration from leaf-derived protoplasts within the Daucus genus: effect of different conditions in alginate embedding and phytosulfokine application

Abstract: Protoplasts of four Daucus carota subspecies and three wild Daucus species were isolated from 2-week-old shoot cultures during overnight incubation in an enzyme mixture composed of 1 % (w/v) cellulase Onozuka R-10 and 0.1 % (w/v) pectolyase Y-23. Before the culture, they were embedded in autoclave- or filter-sterilized alginate solution. Modified thin alginate layer (TAL) and extra thin alginate film (ETAF) techniques were applied for protoplast immobilization. A rich mineral-organic medium based on the formulation of Kao and Michayluk supplemented with 0.1 mg l−1 2,4-dichlorophenoxyacetic acid, 0.2 mg l−1 zeatin, and optionally 100 nM phytosulfokine (PSK), a peptidyl plant growth factor, was used for protoplast culture. Plating efficiency was genotype-dependent and in 40-day-old cultures, it varied from 10 % for Daucus pusillus to 73 % for D. carota subsp. sativus. A considerably higher ability in colony formation was observed in the modified TAL culture system using filter-sterilized alginate and in the presence of PSK in the protoplast culture medium. Plant regeneration through somatic embryogenesis stimulated by PSK application occurred for five out of the seven Daucus accessions used in the present study. We believe our data may facilitate the use of wild Daucus in somatic hybridization with cultivated carrot.

A Lallzyme MMX-based rapid method for fission yeast protoplast preparation

Abstract: Fungal cells including yeasts are surrounded by cell wall that counteracts turgor pressure and prevents cell lysis. Many yeast experiments, including genetic manipulation of sterile strains, morphogenesis studies, nucleic acid isolation and many others, require mechanical breakage or enzymatic removal of the cell wall. Some of these experiments require the generation of live cells lacking cell walls, called protoplasts, that can be maintained in osmostabilized medium. Enzymatic digestion of cell wall proteoglycans is a commonly used method of protoplast preparation. Currently existing protocols for fission yeast cell wall digestion are time consuming and not very efficient. We developed a new rapid method for fission yeast protoplast preparation that relies on digesting cell walls with Lallzyme MMX commercial enzyme mix, which produces protoplasts from all cells in less than 10 min. We demonstrate that these protoplasts can be utilized in three commonly used fission yeast protocols. Thus, we provide the fission yeast community with a robust and efficient plasmid extraction method, a new protocol for diploid generation and an assay for protoplast recovery that should be useful for studies of morphogenesis. Our method is potentially applicable to other yeasts and fungi. Copyright © 2013 John Wiley & Sons, Ltd.

A transient gene expression system using barley protoplasts to evaluate microRNAs for post-transcriptional regulation of their target genes

Abstract: Transient gene expression assays using protoplasts have been frequently used in high-throughput screening and functional characterization of plant genes. In barley, however, very few studies have explored the use of protoplasts isolated from green tissues. In this study, a reliable and efficient transient gene expression system has been established using barley green tissue protoplasts. Due to the importance of osmolarity in maintaining protoplast viability and transfection efficiency, different mannitol concentrations were tested to determine the optimal osmolarity suitable for barley protoplast preparation. The method and conditions were also described for efficient isolation of protoplasts from barley leaf and stem tissues and transient expression of exogenous gene constructs. This transient expression system has been successfully demonstrated for protein immunoblot analysis, subcellular protein localization and quantitative analysis of gene expression. Furthermore, a simplified method has been described to quickly evaluate microRNAs for post-transcriptional regulation of their target genes in barley protoplasts.

Comparative analysis of MAMP-induced calcium influx in Arabidopsis seedlings and protoplasts.

Abstract: Rapid transient elevation of cytoplasmic calcium (Ca(2+)) levels in plant cells is an early signaling event triggered by many environmental cues including abiotic and biotic stresses. Cellular Ca(2+) levels and their alterations can be monitored by genetically encoded reporter systems such as the bioluminescent protein, aequorin. Employment of proteinaceous Ca(2+) sensors is usually performed in transgenic lines that constitutively express the reporter construct. Such settings limit the usage of these Ca(2+) biosensors to particular reporter variants and plant genetic backgrounds, which can be a severe constraint in genetic pathway analysis. Here we systematically explored the potential of Arabidopsis thaliana leaf mesophyll protoplasts, either derived from a transgenic apoaequorin-expressing line or transfected with apoaequorin reporter constructs, as a complementary biological resource to monitor cytoplasmic changes of Ca(2+) levels in response to various biotic stress elicitors. We tested a range of endogenous and pathogen-derived elicitors in seedlings and protoplasts of the corresponding apoaequorin-expressing reporter line. We found that the protoplast system largely reflects the Ca(2+) signatures seen in intact transgenic seedlings. Results of inhibitor experiments including the calculation of IC50 values indicated that the protoplast system is also suitable for pharmacological studies. Moreover, analyses of Ca(2+)signatures in mutant backgrounds, genetic complementation of the mutant phenotypes and expression of sensor variants targeted to different subcellular localizations can be readily performed. Thus, in addition to the prevalent use of seedlings, the leaf mesophyll protoplast setup represents a versatile and convenient tool for the analysis of Ca(2+) signaling pathways in plant cells.

Influence of protoplast fusion between two Trichoderma spp. on extracellular enzymes production and antagonistic activity.

Abstract: Biological control plays a crucial role in grapevine pathogens disease management. The cell-wall degrading enzymes chitinase, cellulase and β-glucanase have been suggested to be essential for the mycoparasitism activity of Trichoderma species against grapevine fungal pathogens. In order to develop a useful strain as a single source of these vital enzymes, it was intended to incorporate the characteristics of two parental fungicides tolerant mutants of Trichoderma belonging to the high chitinase producing species T. harzianum and the high cellulase producing species T. viride, by fusing their protoplasts. The phylogeny of the parental strains was carried out using a sequence of the 5.8S-ITS region. The BLAST of the obtained sequence identified these isolates as T. harzianum and T. viride. Protoplasts were isolated using lysing enzymes and were fused using polyethylene glycol. The fused protoplasts have been regenerated on protoplast regeneration minimal medium supplemented with two selective fungicides. Among the 40 fast growing fusants, 17 fusants were selected based on their enhanced growth on selective media for further studies. The fusant strains were growing 60%-70% faster than the parents up to third generation. All the 17 selected fusants exhibited morphological variations. Some fusant strains displayed threefold increased chitinase enzyme activity and twofold increase in β-glucanase enzyme activity compared to the parent strains. Most fusants showed powerful antagonistic activity against Macrophomin aphaseolina, Pythium ultimum and Sclerotium rolfsii pathogens. Fusant number 15 showed the highest inhibition percentage (92.8%) against M. phaseolina and P. ultimum, while fusant number 9 showed the highest inhibition percentage (98.2%) against the growth of S. rolfsii. A hyphal intertwining and degradation phenomenon was observed by scanning electron microscope. The Trichoderma antagonistic effect against pathogenic fungal mycelia was due to the mycoparasitism effect of the extracellular enzymes.

Genetic transformation of Knufia petricola A95 - a model organism for biofilm-material interactions

Abstract: We established a protoplast-based system to transfer DNA to Knufia petricola strain A95, a melanised rock-inhabiting microcolonial fungus that is also a component of a model sub-aerial biofilm (SAB) system. To test whether the desiccation resistant, highly melanised cell walls would hinder protoplast formation, we treated a melanin-minus mutant of A95 as well as the type-strain with a variety of cell-degrading enzymes. Of the different enzymes tested, lysing enzymes from Trichoderma harzianum were most effective in producing protoplasts. This mixture was equally effective on the melanin-minus mutant and the type-strain. Protoplasts produced using lysing enzymes were mixed with polyethyleneglycol (PEG) and plasmid pCB1004 which contains the hygromycin B (HmB) phosphotransferase (hph) gene under the control of the Aspergillus nidulans trp C. Integration and expression of hph into the A95 genome conferred hygromycin resistance upon the transformants. Two weeks after plating out on selective agar containing HmB, the protoplasts developed cell-walls and formed colonies. Transformation frequencies were in the range 36 to 87 transformants per 10 μg of vector DNA and 106 protoplasts. Stability of transformation was confirmed by sub-culturing the putative transformants on selective agar containing HmB as well as by PCR-detection of the hph gene in the colonies. The hph gene was stably integrated as shown by five subsequent passages with and without selection pressure.

Isolation of hyphomonas strains that induce normal morphogenesis in protoplasts of the marine red alga Pyropia yezoensis.

Abstract: Marine macroalgae cannot develop normal morphology under axenic conditions although normal morphogenesis can be sustained when certain bacteria are present. In this study, bacteria that induced normal morphogenesis in the red alga Pyropia yezoensis (Nori) were identified. The bacteria were isolated from algal media, thalli, tissue debris, and purified protoplasts during protoplast isolation from P. yezoensis laboratory cultures. 16S rRNA gene sequence analysis showed these bacterial isolates belonged to α-Proteobacteria (12 groups), γ-Proteobacteria (3 groups), and Flavobacteria (2 groups). Axenic protoplasts of P. yezoensis generated by removing epiphytic bacteria were co-cultured along with the bacterial isolates. Most axenic protoplasts showed irregular morphogenetic and anaplastic cells; cells with normal morphology were scarce. However, inoculation with 11 strains of Hyphomonas (α-Proteobacteria) led to significantly higher normal morphogenetic rates (4.5–7.3 %, P < 0.01 or 0.05) compared to axenic protoplasts (0.06 %). These Hyphomonas strains were recovered from all experiments; thus, certain Hyphomonas strains can induce normal morphogenesis in P. yezoensis protoplasts. Direct inoculation of the Hyphomonas strain exhibited higher morphogenetic activity than inoculation of its extracellular and intracellular products. This is the first study demonstrating the influence of specific bacteria on protoplast morphology in marine macroalgae.

Construction of new GFP-tagged fusants for Trichoderma harzianum with enhanced biocontrol activity

Abstract: Trichoderma is one of the most exploited biocontrol agents for the management of plant diseases. In biocontrol ecology, the critical factors are detection, and the monitoring and recovery of specific biocontrol agents either naturally present or deliberately released into the environment. Protoplast fusion is an appropriate tool for the improvement of biocontrol Trichoderma strains. Proto- plast isolation from Trichoderma harzianum was achieved using 24 h culture age, 6.6 mg/ml Novazym L 1412 at 30°C which resulted the maximum protoplast yield of 5 × 108/ml. The self-fused protoplasts were regenerated and 12 fusants were selected based on their growth rate on 2% colloidal chitin medium. Next, a comparison was done for chitinase and antagonistic activity. Transcriptomic analysis based on quantitative real-time RT-PCR, demonstrated that T8-05 fusant expressed 1.5 fold of chit42 transcript as compared with the parental line. This fusant with 7.02±0.15U chitinase activity showed a higher growth inhibition rate (100%) than the parent strain, against Rhizoctonia solani. To obtain a genetically marked fusant that can be used as a biomonitor, the fusant was cotransformed with the gfp and amdS genes. The morphology and viability of selected cotransformant (FT8-7MK-05-2) was similar to the parent. Green fluorescing conidia were observed within the first 2 days of incubation in the soil, and this was followed by the formation of chlamydopores after 60 days. The colonisation of the gfp-tagged fusant was also monitored visually on R. solani sclerotia by scanning electron microscopy. Production of gfp-tagged fusant of Trichoderma spp. provides a potentially useful tool for monitoring hyphal growth patterns and the population of biocontrol agent isolates introduced into environmental systems.

Functional analyses of a putative plasma membrane Na+/H+ antiporter gene isolated from salt tolerant Helianthus tuberosus

Abstract: Jerusalem artichokes (Helianthus tuberosus L.) can tolerate relatively higher salinity, drought and heat stress. In this paper, we report the cloning of a Salt Overly Sensitive 1 (SOS1) gene encoding a plasma membrane Na+/H+ antiporter from a highly salt-tolerant genotype of H. tuberosus, NY1, named HtSOS1 and characterization of its function in yeast and rice. The amino acid sequence of HtSOS1 showed 83.4 % identity with the previously isolated SOS1 gene from the Chrysanthemum crassum. The mRNA level in the leaves of H. tuberosus was significantly up-regulated by presence of high concentrations of NaCl. Localization analysis using rice protoplast expression showed that the protein encoded by HtSOS1 was located in the plasma membrane. HtSOS1 partially suppressed the salt sensitive phenotypes of a salt sensitive yeast strain. In comparison with wild type (Oryza sativa L., ssp. Japonica. cv. Nipponbare), the transgenic rice expressed with HtSOS1 could exclude more Na+ and accumulate more K+. Expression of HtSOS1 decreased Na+ content much larger in the shoot than in the roots, resulting in more water content in the transgenic rice than WT. These data suggested that HtSOS1 may be useful in transgenic approaches to improving the salinity tolerance of glycophyte.

An inverse relationship between allelopathic activity and salt tolerance in suspension cultures of three mangrove species, Sonneratia alba, S. caseolaris and S. ovata: development of a bioassay method for allelopathy, the protoplast co-culture method

Abstract: A bioassay method for allelopathy, the ‘protoplast co-culture method’ was developed to study the relationship between salt tolerance and allelopathy of three mangrove species, Sonneratia alba, S. caseolaris, and S. ovata. Plants of S. alba grow in the seaward-side high salinity region and plants of the latter two species grow in upstream-side regions of a mangrove forest, respectively. Effects of five sea salts (NaCl, KCl, MgCl2, MgSO4 and CaCl2) on the growth of the suspension cells of the latter two species were first investigated by a small-scale method using 24-well culture plates. S. ovata cells showed higher tolerance than S. caseolaris cells to NaCl and other salts, but were not as halophilic as S. alba cells. Protoplasts isolated from suspension cells were co-cultured with lettuce protoplasts in Murashige and Skoog’s (MS) basal medium containing 1 μM 2,4-dichlorophenoxyacetic acid, 0.1 μM benzyladenine, 3 % sucrose and 0.6–0.8 M osmoticum. S. caseolaris protoplasts had a higher inhibitory effect on lettuce protoplast cell divisions than S. alba protoplasts at any lettuce protoplast density, and the effect of S. ovata was intermediate between the two. These results were similar to those obtained from a different in vitro bioassay method for allelopathy, the ‘sandwich method’ with dried leaves. The inverse relationship between allelopathic activity and salt tolerance in suspension cells of Sonneratia mangroves is discussed.

Formation, regeneration, and transformation of protoplasts of Streptomyces diastatochromogenes 1628

Abstract: Toyocamycin exhibits effective biological activities for use against plant pathogenic fungi thanks to its structural similarity to nucleoside. It has been recognized as a promising agricultural antibiotic utilized in controlling the occurrence of plant diseases. In our previous study, a strain that was isolated was identified and designated as Streptomyces diastatochromogenes whose major secondary metabolite was toyocamycin, but the production was largely limited. Protoplast transformation is a useful technique in the improvement of streptomycete. In this study, we optimized some key factors necessary for protoplast formation, regeneration, and transformation of S. diastatochromogenes. When mycelium was cultivated in CP medium with 1 % glycine, harvested at 48 h old, and then treated with 3 mg lysozyme/mL in P buffer for 1 h, the greatest regeneration frequency (42.5 %) of protoplasts was obtained. By using 1 × 109/mL protoplasts with polyethylene glycol 1000 at a concentration of 30 % (w/v), the best performance of protoplast transformation efficiency was 4.8 × 103/μg DNA transformants.

The phosphoproteome in regenerating protoplasts from Physcomitrella patens protonemata shows changes paralleling postembryonic development in higher plants

Abstract: The moss Physcomitrella patens is an ideal model plant to study plant developmental processes. To better understand the mechanism of protoplast regeneration, a phosphoproteome analysis was performed. Protoplasts were prepared from protonemata. By 4 d of protoplast regeneration, the first cell divisions had ensued. Through a highly selective titanium dioxide (TiO2)-based phosphopeptide enrichment method and mass spectrometric technology, more than 300 phosphoproteins were identified as protoplast regeneration responsive. Of these, 108 phosphoproteins were present on day 4 but not in fresh protoplasts or those cultured for 2 d. These proteins are catalogued here. They were involved in cell-wall metabolism, transcription, signal transduction, cell growth/division, and cell structure. These protein functions are related to cell morphogenesis, organogenesis, and development adjustment. This study presents a comprehensive analysis of phosphoproteome involved in protoplast regeneration and indicates that the mechanism of plant protoplast regeneration is similar to that of postembryonic development.

Plant regeneration from protoplasts in Indian local Coriandrum sativum L.: scanning electron microscopy and histological evidences for somatic embryogenesis

Abstract: Coriandrum sativum L. is an annual herb belonging to the family Umbelliferae. It is used as a spice plant in Indian subcontinent and it has several medicinal applications as well. In this present article, an efficient plant regeneration protocol from protoplasts via somatic embryogenesis was established and is reported. This is the first ever protoplast isolation study in Indian local coriander in which plant regeneration was achieved. Hypocotyl-derived embryogenic callus was used as a source of protoplast. The embryogenic callus suspension was prepared by transferring tissues onto rotary-agitated liquid Murashige and Skoog, added with 1.0 mg l−1 2,4-Dichlorophenoxyacetic acid (2,4-D) and 1.0 mg l−1 KIN (6-furfurylaminopurine). The suspension was digested with enzymatic solutions and a combination of cellulase (2.0 %), pectinase (1.0 %), macerozyme (0.02 %) and driselase (0.50 %) induced maximum yield of protoplasts (34.25 × 105). In 1.0 mg l−1 2,4-D + 1.0 mg l−1 KIN containing medium, protoplasts divided well and formed maximum number of microcolonies (14.30/test tube). The protoplast callus (PC) biomass grew well in solid medium. The protoplast embryogenic callus was rich in protein, proline and sugar compared to non-embryogenic PC. The protoplast originated callus later differentiated into somatic embryos. The somatic embryo morphology, scanning electron microscopy and histology of embryo origin and development were investigated and discussed in details in this present communication. In 1.0 mg l−1 2,4-D + 0.5 mg l−1 BA (6-Benzyladenine), maximum number of embryos were formed on microcallus (26.6/callus mass). The embryo matured and germinated into plantlets at a low to moderate rate, highest (31.3 %) embryo germination was observed in 1.0 mg l−1 BA + 0.5 mg l−1 α-Naphthalene acetic acid added medium. The entire process of regeneration took about 4–5 months’ time for recovering plantlets from protoplasts.

Studies on the isolation and culture of protoplasts from Kappaphycus alvarezii

Abstract: In this study, protoplasts were successfully isolated from Kappaphycus alvarezii using snail enzymes, abalone enzymes and cellulase. The optimum enzymic ratio was fixed to be 20% of abalone enzyme, 12% of cellulase and the osmotic stabilizer was 2.0 mol/L glucose. The optimum enzymic hydrolysis conditions were found to be dark enzymolysis at 30°C continuing for 4.0 h. The resultant density and yield of protoplasts achieved 32.60×104 mL−1, 65.20×104 g−1 tissue for Kappaphycus alvarezii. Finally, under the temperature of 20°C, light intensity of 1 500–2 000 lx and photoperiod of 12 h/d, two developmental pathways were investigated: (1) callus-like cell mass and regenerated plantlet occurred on protoplast; (2) young shoots and callus-like cell mass occurred in tissue blocks after enzymolysis.

Intraspecific protoplast fusion of Brettanomyces anomalus for improved production of an extracellular β-glucosidase.

Abstract: Improvement of production of an extracellular β-glucosidase with high activity by Brettanomyces anomalus PSY-001 was performed by using recursive protoplast fusion in a genome-shuffling format. The initial population was generated by ultraviolet irradiation, ultrasonic mutagenesis and, then, subjected to recursive protoplast fusion. Mutant strains exhibiting significantly higher β-glucosidase activities in liquid media were isolated. The best mutant strain showed increased cell growth in a flask culture, as well as increased β-glucosidase production. A recombinant strain, F3-25, was obtained after three rounds of genome shuffling and its production of β-glucosidase activity reached 4790 U L−1, which was a nearly eightfold increase compared to the original strain B. anomalus PSY-001. The subculture experiments indicated that F3-25 was genetically stable.

Development of SCAR Markers to Determine the Mating Types of Lepista nuda Protoplast Monokaryons

Abstract: Lepista nuda (Bull. ex Fr.) Cooke belongs to Tricholomataceae and is an edible fungus with both economic and medical value. Mycelia were isolated from the fruiting bodies of L. nuda and were used to prepare the protoplast monokaryons. One hundred and fifteen monokaryons were obtained and their mating types were determined using somatic incompatibility tests. Protoplast monokaryons segregated into either the A1B1 or the A2B2 mating types. Inter-simple sequence repeats and sequence-related amplified polymorphism fingerprinting were used to analyse the mating types of these protoplast monokaryons and 16 sequence-characterised amplified region primers were developed to efficiently differentiate between the monokaryon mating types. Multiplex PCR analyses were also established. The data presented here outline a method for the precise and rapid identification of protoplast monokaryon mating types, which has the promise to shorten the period required for conventional crossbreeding.

Construction and analysis of high-ethanol-producing fusants with co-fermentation ability through protoplast fusion and double labeling technology.

Abstract: Double labeling of resistance markers and report genes can be used to breed engineered Saccharomyces cerevisiae strains that can assimilate xylose and glucose as a mixed carbon source for ethanol fermentation and increased ethanol production. In this study Saccharomyces cerevisiae W5 and Candida shehatae 20335 were used as parent strains to conduct protoplast fusion and the resulting fusants were screened by double labeling. High performance liquid chromatography (HPLC) was used to assess the ethanol yield following the fermentation of xylose and glucose, as both single and mixed carbon sources, by the fusants. Interestingly, one fusant (ZLYRHZ7) was demonstrated to have an excellent fermentation performance, with an ethanol yield using the mixed carbon source of 0.424 g g−1, which compares with 0.240 g g−1 (W5) and 0.353 g g−1 (20335) for the parent strains. This indicates an improvement in the ethanol yield of 43.4% and 16.7%, respectively.

A xylose-fermenting yeast hybridized by intergeneric fusion between Saccharomyces cerevisiae and Candida intermedia mutants for ethanol production

Abstract: Bioethanol production from lignocellulosic biomass, in particular xylose, is currently of great concern, given the abundance of this sugar in the world, because Saccharomyces cerevisiae, which is widely used for bioethanol production, is unable to naturally ferment xylose. The aim of this study was to obtain a novel yeast capable of stably producing ethanol from biomass containing xylose by protoplast fusion between S. cerevisiae and xylose-utilizing yeast. We describe a novel xylose-fermenting yeast strain, FSC1, developed for ethanol production by intergeneric hybridization between S. cerevisiae and Candida intermedia mutants by using a protoplast fusion technique. The characteristics of the FSC1 strain are reported with respect to xylose fermentation, morphology, gene, and protein expression. Mutation of the parental strains prior to protoplast fusion endowed the FSC1 strain with the ability to convert xylose to ethanol. Microscopic analysis confirmed that the parental and FSC1 strains produced spores in the potassium acetate medium. The FSC1 strain is uninucleate diploid, has a stable metabolism, and expresses proteins at a higher level than the parental strains. We found that FSC1 strain could stably achieve an ethanol yield of 0.38 g/g-substrate in fermentation of a mixture of glucose and xylose. In addition, the fermentation ability of FSC1was improved by successive chemical mutation, resulting in a higher ethanol yield of 0.42 g/g-substrate, corresponding to 82% theoretical yield. The mutation-fusion technique we have described here is very useful for the development of intergeneric hybrids capable of xylose fermentation, and the FSC strains generated using this technique have the potential for industrial use in ethanol production from lignocellulosic biomass.

Optimization and Stability of Total Pigments Production of Fusan from Protoplast Fusion of Microalgae Dunaliella and Chlorella in vivo: Attempts on Production of Sustainable Aquaculture Natural Food

Abstract: Diversification of feed rich in natural carotenoids is needed in aquaculture because they will increase survival and body weight of animal farming. Different types of important carotenoids such as β-carotene, zeaxanthine can be combined through a process of protoplast fusion making it cheaper and faster. Crustaceans can not synthetize carotenoid de novo and they need it to provide nutrition and possibly disease resistance, pigmentation and esthetic value. Green microalgae produce carotenoids and can be manipulated easily by protoplast fusion. The research was conducted to obtain some fusants from interspesies protoplast fusion of D . salina and C. vulgaris . Interspecies protoplas fusion was carried out by protoplast isolation, protoplast fusion and protoplast regeneration. Microscopic and cell analysis will used to confirm positive regenerate protoplast. Analysis of the obtained fusants is limited to morphological description due to the complexity and variability of fusant. The stabilities of fusants obtained were examined by successive subcultures. The result revealed that the fusant from D . salina and C. vulgaris maintain their stability in growth and increased carotenoid production during four periods of subculturing. This result suggesting the potency of fusant to be used as food supplement. Key words: Carotenoid , Protoplast fusion , Dunaliella, Chlorella

Protoplast fusion enhances lignocellulolytic enzyme activities in Trichoderma reesei

Abstract: Protoplast fusion was used to obtain a higher production of lignocellulolytic enzymes with protoplast fusion in Trichoderma reesei. The fusant strain T. reesei JL6 was obtained from protoplast fusion from T. reesei strains QM9414, MCG77, and Rut C-30. Filter paper activity of T. reesei JL6 increased by 18 % compared with that of Rut C-30. β-Glucosidase, hemicellulase and pectinase activities of T. reesei JL6 were also higher. The former activity was 0.39 Uml−1, while those of QM9414, MCG77, and Rut C-30 were 0.13, 0.11, and 0.16 Uml−1, respectively. Pectinase and hemicellulase activities of JL6 were 5.4 and 15.6 Uml−1, respectively, which were slightly higher than those of the parents. The effects of corn stover and wheat bran carbon sources on the cellulase production and growth curve of T. reesei JL6 were also investigated.

Optimal conditions for high-yield protoplast isolations of Jatropha curcas L. and Ricinus communis L.

Abstract: The purpose of this study was to investigate the optimal conditions for high-yield protoplast isolation of Jatropha curcas L. and Ricinus communis L. for producing an intergeneric somatic hybrid. To isolate a large amount of protoplasts from J. curcas L. and R. communis L., several factors that affect protoplast isolation, such as the source of the plant tissue, type of cellulase, enzyme combination, incubation time and osmoticum were investigated. Our results indicated that in vitro leaves yielded a higher number of protoplasts than calli. Cellulase onozuka R10 highly affected protoplast isolation. In addition, 14 enzyme combinations of cellulase (Aspergillus sp.), cellulase onozuka R10, pectinase and pectolyase Y23 yielded various amounts of protoplasts. The greatest yield (94.5 ± 4.5 × 10 protoplasts/gFW) and viability (77.8 ± 3.1%) of J. curcas L. protoplasts was obtained from cellulase 5

Progress towards sugar beet improvement through somatic hybridization I. Inactivation of nuclei and cytoplasm in donor and recipient protoplasts

Abstract: The isolation and culture of suspension-derived protoplasts from two sugar beet ( Beta vulgaris L.) genotypes are described. Immobilization of protoplasts in agarose resulted in high frequency divisions and microcallus regeneration, with plating efficiency (PE) being clearly genotype-dependent. In further studies towards asymmetric fusion experiments, the effect of different doses of ultraviolet radiation (UV) and iodoacetic acid (IA) on protoplast physiology was assessed. Viability of both treated (UV, IA) and untreated protoplasts (control) was determined by FDA staining, and the biological effect was evaluated by testing the ability of protoplasts to divide and to form calli. The results are discussed in terms of the applicability of the methods for the production of asymmetric protoplasts suitable for somatic hybridization within the genus Beta .