Species specific shoot regeneration response of cotyledonary explants of Brassicas

A study of shoot regeneration from cotyledons of three basic diploid species of Brassica, B. campestris (AA), B. nigra (BB), B. oleracea (CC) and their amphidiploids B. juncea (AABB), B. napus (AACC) and B. carinata (BBCC) showed species-specific responses for in vitro shoot regeneration. Analysis of the species mean shoot regeneration response over a range of growth regulator combinations revealed that i) B. campestris is the lowest regenerating species, ii) B. nigra and B. oleracea regenerate with high frequencies, iii) In amphidiploids, the presence of B. campestris component brings down shoot regeneration frequency below the value of B. oleracea in B. napus combination and is additive of the combining genomes in B. juncea combination. In B. carinata regeneration frequencies are less than the parental diploid species, iv) Significant intraspecific genotypic differences were observed for B. nigra and B. oleracea among diploids and B. juncea and B. carinata among amphidiploids, when cotyledons of eighteen genotypes were tested in one growth regulator combination.Abbreviations MS Murashige and Skoog (1962) - NAA -naphthalene acetic acid - IAA Indole 3-acetic acid - BA 6-Benzyl aminopurine     

Microbial transformation of sterols

Summary Arthrobacter simplex, Serratia marcescens, Fusarium and Mycobacterium were tested for their ability to transform phytosterol to Androsta 1, 4 diene 3, 17 dione (ADD). Arthrobacter simplex ATCC 6946 was found to be more efficient than the other species tested.     

Production of citric acid from sugars present in wood hemicellulose usingAspergillus niger andSaccharomycopsis lipolytica

Summary One strain each of the fungus,Aspergillus niger, and the yeast,Saccharomycopsis lipolytica, were investigated for their ability to produce citric acid from the sugars present in hemicellulose hydrolysates.S. lipolytica produced citric acid as efficiently from mannose as from glucose, but failed to assimilate xylose, arabinose or galactose.A. niger readily assimilated mannose, xylose and arabinose, and produced citric acid from these sugars although the yields were lower than from glucose. A possible inhibitory effect of arabinose on citric acid production from other sugars was observed usingA. niger.     

A high molecular weight plasmid ofZymomonas mobilis harbours genes for HgCl2 resistance

Summary Plasmids fromZ. mobilis could be stably maintained inE. coli HB101 in which the expression of various drug resistance markers could be monitored. A large molecular weight plasmid (5.2 kbp) ofZ. mobilis was found to harbour the genes for mercuric chloride degradation and to confer uponE. coli, resistance to a higher mercuric chloride concentration as compared toZ. mobilis. The introduction of this plamsid madeE. coli sensitive to concentrations of cadmium acetate which were originally non-inhibitory to it.     

Source of pyrrole-2-carboxylate in mammalian urine

Pyrrole-2-car?ylate, earlier reported in human urine and labeled in rat urine after administration of radioactive proline, arises more directly from labeled hydroxyproline. Antibiotic treatment appeared to exclude epimerization of administered hydroxy-L-proline to a D-epimer by intestinal bacteria. A likely reaction for the in vivo conversion is hydroxy-L-proline oxidation by the L-amino acid oxidase of rat kidney, demonstrable with purified enzyme. Crystalline D-amino acid oxidase also catalyzes a slow oxidation of hydroxy-L-proline. These two reactions are adequate to account for the normal excretion of pyrrole-2-car?ylate by a number of species.     

Construction of aClostridium acetobutylicum-Escherichia coli shuttle vector

Summary A 4.1-kb cryptic plasmid, designated pCA134, has been isolated fromClostridium species. In order to develop a vector suitable for transforming saccharolytic clostridia three hybrid plasmids were constructed by inserting pCA134 into pHV32 withEcoRI, orBglII andBamHI. The newly constructed plasmids were propagated inEscherichia coli and were used to transformBacillus subtilis andClostridium acetobutylicum. One of them, pCAB32 (10.1 kb), which contains chloramphenicol acetyltransferase gene and an origin of replication derived from pCA134 was introduced intoB.subtilis andC.acetobutylicum as well asE.coli.     

Ligninolytic properties of different white-rot fungi

Summary Seven white-rot fungi were examined for the production of ligninase, manganese peroxidase and laccase. All these enzymes were found inTrametes gibbosa andTrametes hirsuta. Only manganese peroxidase and laccase were produced byPycnoporus cinnabarinus,Coriolopsis polyzona,Stereum hirsutum,Dichomitus squalens andGanoderma valesiacum. All fungi decolorized Poly B-411 and Indulin AT plates with low-N medium. The differences in enzyme pattern indicate that different species of fungi may employ different modes of lignin metabolism.     

Partial characterization of anEscherichia coll strain harboring a xylanase encoding plasmid

Summary The plasmid pRH271, harboring a xylanase gene cioned fromBacilius subtilis, has been transferred into a mutant ofE. coli SK2284 which allowed the release of part of the xylanase in the culture supernatant. Kinetic parameters of this recombinantE. coll strain were determined in microscale batch culture with and without the selective pressure of antibiotics. No significant difference in µ_max was observed for the nontransformedE. coli strain when compared to the recombinant strain. However, K₅ values for glucose were two times higher in the case of the recombinant strain. Preliminary study of xylanase production in a large batch farmenter was also described.     

Lactic acid bacteria active during the fermentation of wheat silage in small scale silos

Summary Wheat was ensiled and periodically analyzed for lactic acid bacteria present. Initially Lactobacillus plantarum, Leuconostoc mesenteroides, Lactobacillus cellobiosus and Streptococcus lactis predominated. After two to four days enterococci including S. faecium and S. bovis were present in high populations as well as Lactobacillus plantarum. It was concluded that mixed populations of enterococci and L. plantarum are active in the successful fermentation of wheat silage.     

Transformation of Kluyveromyces lactis cells by plasmid DNA does not require alkaline cations

Summary A procedure for the transformation ofKluyveromyces lactis based on the Li salt method for introducing plasmid DNA into intact yeast cells is described. Contrary toSaccharomyces cerevisiae, lithium salts are dispensable for inducing competence inK. lactis. 2-Mercaptoethanol, a compound that stimulates transformation inS. cerevisiae, showed an opposite effect. inK. lactis. On the other hand, the presence of PEG 4000 and a heat shock were absolutely required to obtain high transformation efficiency.     

Plant regeneration from protoplasts of Dimorphotheca and Rudbeckia

Protoplasts were isolated from leaves, shoots, cotyledons, ray florets and callus cultures of Dimorphotheca aurantiaca (syn. D. sinuata) (Cape Marigold, Star of the Veldt) and Rudbeckia hirta, R. laciniata and R. purpurea; species of ornamental value. For Dimorphotheca, plants were regenerated from protoplasts of all sources apart from the ray floret, whilst for the Rudbeckia species, although protoplast division was induced in most cases, only leaf mesophyll protoplasts of R. hirta c.v. Marmalade gave plants. The establishment of plant regeneration for these ornamental species, from protoplasts, now provides a basis for their somatic hybridisation.Abbreviations BAP 6-benzylaminopurine - IAA indole-3-acetic acid - NAA naphthaleneacetic acid - K kinetin - GA₃ gibberellic acid - MS Murashige and Skoog (1962) - f.wt. fresh weight     

A parenchymatic medium solidifier for plant in vitro culture

A new material for the solidification of liquid culture media was prepared from plant parenchyma tissues by mechanical subdivision, solute extration and dessication from ethanol. It is suitable for in vitro culture and propagation of callus as well as shoot tip cultures. The following plant materials have been grown by means of the new medium solidifier: shoot cultures of Betula pendula Roth, Gerbera jamesonii H. Bolus ex Hook and Floribunda rose "Triumph", callus tissues of Daucus carota L. and Chenopodium album L. The new solidifying material has special advantages over agar for application in the rooting phase of in vitro propagation.Abbrevations PMS parenchymatic medium solidifier - MS Murashige and Scoog's medium - IAA Indole-3-acetic acid - B biotin - K kinetin - 2,4-D 2,4-dichlorophenoxyacetic acid - ch caseine hydrolysate     

Clonal propagation of Trifolium Pratense,T. Resupinatum and T. Subterraneum by direct somatic embryogenesis on cultured immature embryos

Direct somatic embryogenesis on immature zygotic embryos in vitro has been confirmed for Trifolium pratense and extended to T. resupinatum and T. subterraneum. For all species direct embryo cloning can be achieved on an appropriate basal medium supplemented with 1gl^–1 yeast extract and 0.05 mgl^–1 BAP. Basal medium/sucrose formulation, level of yeast extract and level of BAP affected the nature of in vitro responses. In particular, for T. pratense and T. subterraneum lowering of the yeast extract level suppressed embryoid initiation, and raising of the BAP level stimulated formation of nodular morphogenic callus. For T. resupinatum alteration of the basal medium/sucrose formulation changed the tissue site of embryoid initiation from hypocotyl to cotyledons or both. Control of embryoid initiation is briefly discussed.Abbreviation BAP 6-benzylaminopurine     

Stereoselective microbial reduction of planar chiral and prochiral organometallic aldehydes

Summary Candida boidinii IAM 12269 andNocardia erythropolis IAM 12122 were useful for the asymmetric reduction of 1,2-diformylferrocene (1) to the planar chiral semialdehyde3 and for the optical resolution of (±)-tricarbonyl(2-methylbenzaldehyde)chromium (4) and (±)-tricarbonyl(1-formyl-2-methylcyclopentadienyl)manganese (6) having planar chirality.     

Ethanolic fermentation of cane molasses by a highly flocculent yeast

Summary A study of the comparative kinetics of standardS.uvarum ATCC 26602 withS.cerevisiae Y-10 (an isolate) and a highly flocculent strain ofS.uvarum in batch mode has shown that both the isolate and the highly flocculentS. uvarum strain have more desirable characteristics than the standard strains for ethanol production from cane molasses.     

Utilization ofEscherichia coli tac promoter inBacillus subtilis

Summary The tac promoter originally constructed for the use inEscherichia coli was fused to an endoglucanase structural gene isolated fromBacillus subtilis and the expression of the chimeric gene inB. subtilis was observed. The tac promoter-controlled gene expressed well inB. subtilis and produced endoglucanase during the exponential growth phase.     

Isolation and physical characterization of three essential conidiation genes from Aspergillus nidulans

We cloned and characterized three genes from Aspergillus nidulans, designated brlA, abaA and wetA, whose activities are required to complete different stages of conidiophore development. Inactivation of these genes causes major abnormalities in conidiophore morphology and prevents expression of many unrelated, developmentally regulated genes, without affecting expression of nonregulated genes. The three genes code for poly(A)⁺RNAs that begin to accumulate at different times during conidiation. The brlA-and abaA-encoded RNAs accumulate specifically in cells of the conidiophore. The wetA-encoded RNA accumulates in mature conidia. Inactivation of the brlA gene prevents expression of the abaA and wetA genes, whereas inactivation of the abaA gene prevents expression of the wetA gene. Our results confirm genetic predictions as to the temporal and spatial patterns of expression of these genes and demonstrate that these patterns are specified at the level of RNA accumulation.     

Plant regeneration from cultured cell-derived protoplasts of Pelargonium aridum,P. x hortorum and P. peltatum

Cultured protoplasts from cell suspensions of Pelargonium aridum, P.x hortorum and P. peltatum divided and formed callus. On agar-solidified regenerative medium, such protoplast-derived calli (p-calli) underwent plant regeneration at frequencies approaching 100% for P. aridum and 10% for P.x hortorum. Under similar conditions shoot primordia arose in 5% of P. peltatum p-calli, but these never developed into normal shoots. However, following a liquid-shake culture regime, whole plants were induced in 20% of P. peltatum p-calli. This approach also improved regeneration of P.x hortorum to 60%.Abbreviations NAA napthaleneacetic acid - 6-BAP 6-benzylaminopurine     

Resistance of bacterial film to contamination during use as inoculum in repeated batch fermentation

Summary AnEscherichia coli strain constitutive for -galactosidase was immobilized onto cotton cloth. The resultingE.coli film was used as a resident inoculum in repeated batch fermentations for 30 days in the presence ofBrevibacterium ammoniagenes added as a contaminant. Analysis of -galactosidase production shows that contamination did not decrease the capacity of the film to generateE.coli cells, or decrease theE.coli population on the film.     

Somatic hybridization in the genus Solanum: S. tuberosum and S. brevidens

Somatic hybrid plants were regenerated from fused mesophyll protoplasts of an albino potato (Solanum tuberosum spp. tuberosum) variant and Solanum brevidens, a non-tuber bearing species which is sexually incompatible with S. tuberosum. These somatic hybrid plants represent the first example of direct hybridization between potato and members of the taxonomic group Etuberosa, and offer the potential for introgressing valuable germplasm from Solanum species outside the sexually compatible range into a worldwide crop species.