Intergeneric Protoplast Fusion Research Articles

Nutritional analysis and molecular characterization of hybrid mushrooms developed through intergeneric protoplast fusion between Pleurotus sajor-caju and Calocybe indica with the purpose to achieve improved strains.

Two edible mushrooms Calocybe indica and Pleurotus sajor-caju were chosen as parent strains in this study to approach the concept of hybridization through theprotoplast fusion technique. Protoplast fusion in presence of polyethylene glycol (PEG) was conducted between the parent strains and by further double selection screening method, six somatic hybrid lines were developed. Those fruit bodies of the hybrid lines showed phenotypic resemblance with Pleurotus sajor-caju when grown on paddy straw under favorable conditions. The hybridity of the newly developed somatic hybrid strains was established by barrage reaction, morphological traits, fruitbody parameter and, inter single sequence repeat (ISSR) profiling. One-way analysis of variance (ANOVA) was used for the analysis of phenotypic data of hybrid lines and parents. Five ISSR primers were used to generate 51 amplified DNA fragments ranged between 250 and 3000bp in size in six hybrids and two parents with 90.19% polymorphism. Some of the hybrids contain some non-parental bands whichindicate that recombination might happen in thehybrid genome hence confirming the hybridity of newly developed strains. The dendrogram was created using theAverage Linkage (Between Groups) method based on ISSR profiling and genetic distance between parent-hybrids and hybrid-hybrid was analyzed by Jaccard's proximity matrix. A definite improvement in nutritional properties and biological activity was observed in the study. Due to ease in their cultivation, it can play a significant role in the rural economic development.

Construction of engineering bacteria degrading residual polyacrylamide in coal slime water by protoplast fusion technique

Polyacrylamide (PAM) is widely used as flocculant in coal preparation. A protoplast fusant with enhanced degradation ability of PAM was obtained by intergeneric protoplast fusion between Rhodopseudomonas spheroids and Bacillus subtilis. The protoplast preparation was optimised and inactivation of both parents was performed in different ways. The degradation abilities of domesticated R. spheroides, B. subtilis and mixed bacteria (v/v, 1.00) were compared with protoplast fusant. The results showed that the optimal dosage for R. spheroides protoplast preparation was determined to be 20.00% sucrose, 1.00 mg/mL lysozyme, 0.20% EDTA and 60.00 min. Under such conditions, the protoplast formation rate and the protoplast regeneration rate were 63.70% and 8.90%, respectively. The optimal dosage for B. subtilis protoplast preparation was determined to be 20.00% sucrose, 1.50 mg/mL lysozyme and 60.00 min. Under such conditions, the protoplast formation rate and the protoplast regeneration rate were 58.50% and 9.45%, respectively. The protoplast inactivation of R. spheroides and B. subtilis were optimally conducted by ultraviolet radiation (70.00 s) and by heat at 55.00°C (50.00 min), respectively. The degradation ability of protoplast fusant was obviously improved. Furthermore, using microscopic observation, it was found that both parents form protoplasts by the way of apical release.

Construction of Potent Recombinant Strain Through Intergeneric Protoplast Fusion in Endophytic Fungi for Anticancerous Enzymes Production Using Rice Straw.

Among all fungal endophytes isolates derived from different ethno-medical plants, the hyper-yield L-asparaginase and L-glutaminase wild strains Trichoderma sp. Gen 9 and Cladosporium sp. Gen 20 using rice straw under solid-state fermentation (SSF) were selected. The selected strains were used as parents for the intergeneric protoplast fusion program to construct recombinant strain for prompt improvement production of these enzymes in one recombinant strain. Among 21 fusants obtained, the recombinant strain AYA 20-1, with 2.11-fold and 2.58-fold increase in L-asparaginase and L-glutaminase activities more than the parental isolates Trichoderma sp. Gen 9 and Cladosporium sp. Gen 20, respectively, was achieved using rice straw under SSF. Both therapeutic enzymes L-asparaginase and L-glutaminase were purified and characterized from the culture supernatant of the recombinant AYA 20-1 strain with molecular weights of 50.6 and 83.2kDa, respectively. Both enzymes were not metalloenzymes. Whereas thiol group blocking reagents such as p-chloromercurybenzoate and iodoacetamide totally inhibited L-asparaginase activity, which refer to sulfhydryl groups and cysteine residues involved in its catalytic activity, they have no effect toward L-glutaminase activity. Interestingly, potent anticancer, antioxidant, and antimicrobial activities were detected for both enzymes.

Molecular characterization of intergeneric hybrid between Aspergillus oryzae and Trichoderma harzianum by protoplast fusion.

Protoplast fusion between Aspergillus oryzae and Trichoderma harzianum and application of fusant in degradation of shellfish waste. The filamentous chitinolytic fungal strains A. oryzae NCIM 1272 and T. harzianum NCIM 1185 were selected as parents for protoplast fusion. Viable protoplasts were released from fungal mycelium using enzyme cocktail containing 5 mg ml(-1) lysing enzymes from T. harzianum, 0.06 mg ml(-1) β-glucuronidase from Helix pomatia and 1 mg ml(-1) purified Penicillium ochrochloron chitinase in 0.8 mol l(-1) sorbitol as an osmotic stabilizer. Intergeneric protoplast fusion was carried out using 60% polyethylene glycol as a fusogen. At optimum conditions, the regeneration frequency of the fused protoplasts on colloidal chitin medium and fusion frequency were calculated. Fusant showed higher rate of growth pattern, chitinase activity and protein content than parents. Fusant formation was confirmed by morphological markers, viz. colony morphology and spore size and denaturation gradient gel electrophoresis (DGGE). This study revealed protoplast fusion between A. oryzae and T. harzianum significantly enhanced chitinase activity which ultimately provides potential strain for degradation of shellfish waste. Consistency in the molecular characterization results using DGGE is the major outcome of this study which can be emerged as a fundamental step in fusant identification. Now it is need to provide attention over effective chitin degradation to manage shrimp processing issues. In this aspect, ability of fusant to degrade shellfish waste efficiently in short incubation time revealed discovery of potential strain in the reclamation of seafood processing crustacean bio-waste.

Biocatalyst development for lactic acid production at acidic pH using inter-generic protoplast fusion

Acid tolerance ofL. delbrueckiiMut Uc-3 has been improved using an inter-generic protoplast fusion approach. The fusant was further treated with UV mutagenesis which generated a mutant with improved lactic acid production in acidic environment.

Production and evaluation of antimycotic and antihepatitis C virus potential of fusant MERV6270 derived from mangrove endophytic fungi using novel substrates of agroindustrial wastes.

Among forty endophytic fungal isolates derived from the mangrove plant Avicennia marina, thirty-seven isolates (92.5 %) shown vary antimycotic activity against clinical Trichophyton, Microsporum, and Epidermophyton isolates. The hyperactive wild antagonistic strains Acremonium sp. MERV1 and Chaetomium sp. MERV7 were subjected to intergeneric protoplast fusion technique, and out of 20 fusants obtained, the fusant MERV6270 showed the highest antimycotic activity with the broadest spectrum against all dermatophytes under study. Solid-state fermentation (SSF) showed its superiority for antimycotic/antiviral metabolite production using cost-effective agroindustrial residues. Low-cost novel fermentation medium containing inexpensive substrate mixture of molokhia stalk, lemon peel, pomegranate peel, peanut peel (2:1:1:1) moistened with potato, and meat processing wastewaters (2:1, at moisture content of 60 %) provided a high antimycotic metabolite yield, 33.25 mg/gds, by the fusant MERV6270. The optimal parameters for antimycotic productivity under SSF were incubation period (4 days), incubation temperature (27.5-30 °C), initial pH (6), initial moisture level (60 %), substrate particle size (1.0 mm), and inoculum size (2 × 10(6) spores/gds), which elucidated antimycotic activity to 44.19 mg/gds. Interestingly, wild mangrove Acremonium sp. MERV1 and Chaetomium sp. MERV7 strains and their fusant MERV6270 showed significant inhibition of hepatitis C virus with viral knockdown percent of -82.48, -82.44, and -97.37 %, respectively, compared to the control (100 %), which open a new era in combat epidemic viral diseases.

Biodegradation of benzoate by protoplast fusant via intergeneric protoplast fusion between Pseudomonas putida and Bacillus subtili

Intergeneric protoplast fusion was performed between Pseudomonas putida, a strain with moderate benzoate tolerance and degradation ability (<2000 mg l−1) while slow growth rate (specific growth rate μ = 4.5 × 10−3 h−1) and Bacillus subtilis, a strain with fast growth rate while intolerance to benzoate. A stable fusant (F29) with enhanced benzoate tolerance (as high as 10 000 mg l−1) and degradation ability (μ = 30.9 × 10−3 h−1) was obtained. The fusant is similar to P. putida in terms of amplified 16S ribosomal DNA restriction analysis (16S-ARDRA) and 16S rDNA clone sequencing analysis while alike to B. subtilis according to Gram staining. Possible biodegradation pathway of benzoate by F29 is benzene ring cleavage between two hydroxyl groups (ortho cleavage) with catechol being intermediate metabolite. However, the verification of benzoate biodegradation mechanism by this fusant requires further investigation.

Structural characterization of an immunoenhancing heteroglycan of a hybrid mushroom (pfls1h) of Pleurotus florida and Lentinus squarrosulus (Mont.) Singer

An immunostimulating water-soluble heteroglycan (PS-II) was isolated from an aqueous extract of the fruit bodies of a hybrid mushroom, pfls1h produced by intergeneric protoplast fusion between Pleurotus florida and Lentinus squarrosulus (Mont.) Singer. Structural characterization of PS-II was carried out using sugar analysis, methylation experiment, periodate oxidation and 1D/2D NMR studies. Sugar analysis indicated the presence of glucose, mannose and galactose in a molar ratio of 1:1:2. Methylation analysis revealed that PS-II was composed of (1→6)- and (1→2,4,6)-α-d-galactopyranosyl, terminal β-d-mannopyranosyl and terminal β-d-glucopyranosyl residues in a relative proportion of approximately 1:1:1:1. On the basis of chemical analysis and NMR studies, the structure of the repeating unit of the heteroglycan was established to consist of a backbone chain of two (1→6)-α-d-galactopyranosyl residues, one of which is branched at O-2 with terminal β-d-Manp and at O-4 with terminal β-d-Glcp. This heteroglycan (PS-II) showed in vitro splenocyte, thymocyte and macrophage activations.

Cellulase production from agricultural residues by recombinant fusant strain of a fungal endophyte of the marine sponge Latrunculia corticata for production of ethanol

Several fungal endophytes of the Egyptian marine sponge Latrunculia corticata were isolated, including strains Trichoderma sp. Merv6, Penicillium sp. Merv2 and Aspergillus sp. Merv70. These fungi exhibited high cellulase activity using different lignocellulosic substrates in solid state fermentations (SSF). By applying mutagenesis and intergeneric protoplast fusion, we have obtained a recombinant strain (Tahrir-25) that overproduced cellulases (exo-β-1,4-glucanase, endo-β-1,4-glucanase and β-1,4-glucosidase) that facilitated complete cellulolysis of agricultural residues. The process parameters for cellulase production by strain Tahrir-25 were optimized in SSF. The highest cellulase recovery from fermentation slurries was achieved with 0.2% Tween 80 as leaching agent. Enzyme production was optimized under the following conditions: initial moisture content of 60% (v/w), inoculum size of 10(6) spores ml(-1), average substrate particle size of 1.0mm, mixture of sugarcane bagasse and corncob (2:1) as the carbon source supplemented with carboxymethyl cellulose (CMC) and corn steep solids, fermentation time of 7days, medium pH of 5.5 at 30°C. These optimized conditions yielded 450, 191, and 225units/gram dry substrate (Ugds(-1)) of carboxylmethyl cellulase, filter-paperase (FPase), and β-glucosidase, respectively. Subsequent fermentation by the yeast, Saccharomyces cerevisiae NRC2, using lignocellulose hydrolysates obtained from the optimized cellulase process produced the highest amount of ethanol (58gl(-1)). This study has revealed the potential of exploiting marine fungi for cost-effective production of cellulases for second generation bioethanol processes.

Biochemical and molecular characterization of wild-type and fused protoplasts of Beauveria bassiana and Metarhizium anisopliae

Protoplasts were isolated from two isolates each of Beauveria bassiana and Metarhizium anisopliae using lysing enzymes. Intra- and intergeneric protoplast fusion has been carried out using 40% polyethylene glycol. The fused protoplasts of B. bassiana and M. anisopliae have been regenerated on Czapek-Dox agar media, and a total of four fusants were selected for further studies. An increase in proteinase and chitinase enzyme activity was recorded with all fusants as compared to the wild-type isolates. To understand the nature of recombination process, random amplification of polymorphic DNA (RAPD) and restriction fragment length polymorphism (RFLP) were carried out on genomic DNA of fused and wild-type isolates. The present study demonstrates the scope and significance of the protoplast fusion technique as a rapid consistent method for identification of B. bassiana and M. anisopliae fused and wild-type isolates based on the banding pattern of RAPD and RFLP that can be reliably used ahead for further applications on these species.

Structural characterization and study of immunoenhancing and antioxidant property of a novel polysaccharide isolated from the aqueous extract of a somatic hybrid mushroom of Pleurotus florida and Calocybe indica variety APK2

A water-soluble polysaccharide was isolated from the aqueous extract of the fruit bodies of somatic hybrid PCH9FB, obtained through intergeneric protoplast fusion between the strains Pleurotus florida and Calocybe indica var. On the basis of total acid hydrolysis, the polysaccharide was found to contain galactose, fucose, and glucose in a molar ratio of nearly 2:1:2. Methylation analysis and NMR experiments ( 1H, 13C, DEPT-135, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC) showed that the structure of the repeating unit present in the polysaccharide was [Display omitted] This molecule showed macrophage, splenocyte, thymocyte activation as well as antioxidant property.

Intergeneric protoplast fusion between Calocybe indica (milky mushroom) and Pleurotus florida aids in the qualitative and quantitative improvement of sporophore of the milky mushroom

This article primarily focuses on the production of somatic hybrid sporophores through PEG-mediated protoplast fusion between Calocybe indica var. APK2 and Pleurotus florida. To screen the hybrid strains a selection strategy was followed based on the differential tolerance of NaCl level by the two parental genera. Basidiocarps could be successfully generated from eight out of fourteen hybrid lines that were maintained in culture. Hybridity of the fusant lines was established on the basis of their colony morphology, mycelial growth rate and hyphal traits, while the fruit-body-generating lines were demarcated on the basis of nature of sporophores, isozyme and RAPD markers. The degree to which the hybrid population differed among themselves and from their parents was assessed by analysing each of these morphological variables by one-way analysis of variance (ANOVA). RAPD bands of the fusant lines were similar to either parental bands or were new non-parental bands, which classified them into the microgenome and macrogenome insertion types. A dendrogram created with the help of UPGMA method of clustering and Euclidean distance exhibited three major clusters, in which the Pleurotus–Calocybe hybrids showed intra-cluster variations. Notably, P. florida was genetically distant from the hybrid lines, while C. indica was phylogenetically the dominant parent. Significant increase in bio-efficiency and γ-linoleic acid content in these hybrid lines indicated quantitative as well as qualitative improvement of the newly developed somatic hybrids.

Strain construction for enhanced production of spinosad via intergeneric protoplast fusion

Spinosad is a new class of insecticides produced by Saccharopolyspora spinosa. The aim of this study was to construct a starch-utilizing strain that overproduced spinosad by intergeneric fusion between S. spinosa and Streptomyces avermitilis. Protoplast fusion is an important technique for engineering microbial strains, especially for microorganisms with few available molecular genetic tools. Protoplast fusion was conducted with UV-irradiated protoplasts of S. spinosa and S. avermitilis. Among 76 recombinants screened by ESI-MS and HPLC, a starch-utilizing strain F17, identified as S. spinosa, was obtained. The yield of spinosad in F17 was increased by 447.22%, compared with the yield of the wild-type strain. This is the first report of intergeneric protoplast fusion between S. spinosa and S. avermilitis, which shows great potential for industrial applications.

Production and characterization of somatic hybrids raised through protoplast fusion between edible mushroom strains Volvariella volvacea and Pleurotus florida

Twelve somatic hybrid lines were raised through polyethylene glycol-mediated intergeneric protoplast fusion between Volvariella volvacea and Pleurotus florida using a double selection method. Four hybrid lines belonging to two distinct colony morphology types could be maintained in culture. Basidiocarps could be generated from two hybrid lines, one of which showed resemblance to the P. florida parent while the other showed intermediate parental morphology. Hybridity of the fusant lines was established on the basis of colony morphology, mycelial growth rate, hyphal traits, fruit body morphology, isozyme and RAPD analysis. Four isozyme activities were analyzed to provide biochemical criteria for detection of polymorphism among the hybrids and their parents. Using 20 random decamers a total of 203 RAPD bands ranging from 0.09 to 1.6 kb were observed. The UPGMA method of clustering exhibited two major phylogenetic clusters, the first of which comprised of the parents, two fruit body generating hybrid lines and their subsequent fruit body derived lines, while the two non-fruit body generating hybrid lines formed the out group of the first major cluster. Screening of a Pleurotus type hybrid line having high biological efficiency and generation of a temperature tolerant Pleurotus type line through backcross mating between a non-fruit body generating somatic hybrid and V. volvacea parent are the key achievements of this fusion programme.

Polyploid Formation Between Aspergillus niger and Trichoderma viride For Enhanced Citric Acid Production From Cellulose

The first-stage heterokaryons, obtaining from intergeneric protoplast fusion between Aspergillus niger (Y-b) and Trichoderma viride (M5S51), showed slow growth and mixed morphologies on minimal medium. The fusants were classified into heterokaryon and prototrophic haploid, showing the morphology as that of A. niger. The heterokaryon strains formed conidia with the same nutritional requirements as those of the original auxotrophic mutant strains. After several subcultivations on minimal medium containing d-camphor, some heterokaryon strains formed larger two to seven nuclei/conidium as compared to one nucleus/conidium of the auxotrophic mutant and prototrophic strains, indicating that the new hybrids were generated. Interestingly, three fusant strains AT 11-2-3, AT 11-2-10, and AT 11-2-14 produce 19.2, 6.1, and 10.5 g/l citric acid, respectively, in semisolid culture containing cellulose, whereas A. niger Yang no. 2 could not use carboxymethyl cellulose as the sole carbon source for citric acid production. In addition, the average maximum beta-glucosidase and carboxymethylcellulase productions from AT 11-2-3, AT 11-2-10, and AT 11-2-14 were about 16- and 4-folds higher than those of A. niger, respectively.

Enchancement of monacolin K production via intergeneric protoplast fusion between Aspergillus terreus and Monascus anka

Abstract Intergenic protoplast fusion between Aspergillus terreus CA99 and Monascus anka M-3, the high and low producers of monacolin K respectively, was performed for enahancement of monacolin K production. The 24-hour-old mycelia of A. terreus CA99 and M. anka M-3 were treated with 0.5% lywallzyme, 0.3% snailase and 0.3% cellulase at 34°C for 5 h and at 30°C for 3.5 h, and their protplasts formation reached 1.76 × 107/mL and 1.68 × 107/mL respectively. Parental protoplasts were irradiated with a 30 W UV light away from 30 cm for 3 min and then mixed. The mixture was incubated with 30% PEG 6000 for 15 min. The reviving fusants were isolated on the regeneration plates. Of the 363 fusants isolated, over 100 showed enhanced monacolin K production compared with teh parental strain M. anka M-3. Ten of them produced monacolin K about 1.6-fold of that M. anka M-3 does and the monacolin K titer of two fusants (F49 and F104) increased by about 1-fold. The monacolin K yields of F49 and F104 were 460 µ g/mL and 457...

Gene Transfer Between Different Trichoderma Species and Aspergillus Niger Through Intergeneric Protoplast Fusion to Convert Ground Rice Straw to Citric Acid and Cellulases

Single-stage direct bioconversion of cellulosic materials to citric acid using intergeneric hybrids obtained from three different Trichoderma species and Aspergillus niger was carried out. The recent results were obtained on the basis of either resistance or sensitivity to one or more of five metal ions, two catabolite repressors, and five antifungal agents, which were used in this study at different concentrations. Sixty-six fusants were isolated after using the three intergeneric protoplast fusion experiments, belonging to two types of intergeneric fusants. Fusants of the first type are heterokaryons (35 fusants). On the other hand, those of the second type are haploids (31 fusants), i.e., they were stable. The present study can be successfully applied in the construction of 14 new genetic fusants, which produced at least 100% more citric acid than the citric acid producer strain A. niger. Out of the fusants, three (1/18, 2/13 and 2/15) showed about a threefold increase of citric acid production in comparison with the parent A. niger strain. Furthermore, studies on DNA content showed that this finding may be submitted on the evidence that citric acid and cellulases production was not correlated with DNA content; however, the productivity depends on specific DNA content.

Protoplast cultures and protoplast fusion focused on Brassicaceae: A review

The subjects of this article are protoplast isolations and protoplast fusions, in particular their history, a review of factors influencing the protoplasts isolation and fusion, selection of hybrid plants and utilization of somatic hybrids in plant breed-ing. Somatic hybridization through protoplast fusion can overcome sexual incompatibility among plant species or genera; transfer genes of resistance to diseases (viral, bacterial, fungal), pests, herbicides and others stress factors; obtain cybrid plants; transfer cytoplasmic male sterility or incease content of secondary metabolites in hybrid plants. The article is focussed mainly on the family Brassicaceae because among representatives are significant crops for the human population. Various successful combination of intraspecific, interspecific and intergeneric protoplast fusion were reported between representatives of the family Brassicaceae with the genus Brassica which belonged to the first agricultural crops used for the isolation of protoplast. &amp;nbsp;

A recombinant Saccharomyces cerevisiae strain for efficient conversion of lactose in salted and unsalted cheese whey into ethanol.

For utilization of lactose in salted and unsalted cheese whey, intergeneric protoplast fusion between lactose nonfermenting, salt-tolerant Saccharomyces cerevisiae ATCC4126 and lactose fermenting Kluyveromyces lactis CBS683 was carried out. The fusion process gave rise to new hybrid yeast strains that revealed higher significant DNA contents than parental strains. The recombinants showed growth on either lactose or sucrose. The ethanol yields by some recombinants were 5.55% from sweet whey and 4.66% from salted whey containing up to 6% sodium chloride compared to 4.15 and 2.86% for parental K. lactis CBS683, respectively.

Intergeneric protoplast fusion between Kluyveromyces and Saccharomyces cerevisiae - to produce sorbitol from Jerusalem artichokes

The construction of inulin-assimilating and sorbitol-producing fusants was achieved by intergeneric protoplast fusion between Kluyveromyces sp. Y-85 and Saccharomyces cerevisiae E-15. The cells of parental strains were pretreated with 0.1% EDTA (w/v) and 2-mercaptoethanol (0.1%, v/v) and then exposed to 2.0% (w/v) Zymolase at 30 °C for 30–40 min. The optimized fusion condition demonstrated that with the presence of 30% (w/v) polyethylene glycol 6000 (PEG-6000) and 10 mM CaCl2 for 30 min, the fusion frequency reached 2.64 fusants/106 parental cells. The fusants were screened by different characters between two parental strains and further identified by DNA contents, inulinase activity and sorbitol productivity. One of the genetically stable fusants, Strain F27, reached a maximal sorbitol production of 4.87 g/100 ml under optimal fermentation condition.