Optimization and characterization of an extracellular polysaccharide produced byPaecilomyces lilacinus

Summary A new strain of the fungusPaecilomyces lilacinus has been isolated which produces a viscous extracellular polysaccharide in a simple medium. The polysaccharide consists of glucose and galactose moieties. The viscosity of the polysaccharide was unchanged by a range of temperature and pH.     

Cadmium adsorption by bacterial capsular polysaccharide coatings

Conclusions Excretion of a polysaccharide capsular coating byP.putida provided enhanced cadmium uptake when compared to the noncapsularP.cruciviae. As this advantage is most significant for cadmium concentrations below 2.5 mg/l, levels which are commonly found in waste discharges, it does suggest a potential role for extracellular polysaccharide producers as biosorbents. These encouraging results have led to further work to determine the desorption characteristics, by pH adjustment, ofP.putida along with long term viability after successive cycles of adsorption and desorption.     

Optimization and characterization of an extracellular polysaccharide produced byGlomerella cingulata

Summary A new strain of the fungusGlomerella cingulata has been isolated, which produces an extracellular highly viscous polysaccharide in a simple mineral medium. Optimum conditions for its production and properties are described. The polysaccharide produced was a glucan type. The viscosity remained stable during storage over a period of seven days. Large changes in temperature and pH have no effect on viscosity.     

Influence of impeller speed upon the pullulan fermentation

Summary The effect of impeller speed on pullulan production and the morphology ofAureobasidium pullulans in batch culture was studied. Pullulan production and the percentage of yeast cells in the culture rose with impeller speed, as did molecular weight of the polysaccharide.     

Ocimum basilicum seeds as a pellicular support for immobilizing enzymes

Summary The swollen seeds ofOcimum basilicum consist of a hard core with a pectious porous outer layer to which urease was bound after epoxy activation, through ethylenediamine-glutaraldehyde arm. These seeds can serve as an inexpensive ready to use natural pellicular polysaccharide support for immobilizing enzymes.     

Optimization and characterization of an extracellular polysaccharide produced byMoniliella pollinis

Summary A yeast strainMoniliella pollinis produces an extracellular highly viscous gum-like polysaccharide of glucan type in a simple mineral medium. Optimum conditions for its production and properties are described. The viscosity decreased after lyophilization.     

New polysaccharide produced byE. coli CF3

Summary E. coli CF3 isolated after the infection ofE. coli K12 C600 with the bacteriophage B278 produces quantities of extracellular exopoly-saccharide characterized by gas chromatography as composed of glucose, galactose and fucose in the molar ratio 111.2 and being partly acetylated. Solutions of the polysaccharide were pseudoplastic and its viscosity is constant at extreme pH (3.5–10) and compatible with temperature (90°C).     

Tyrosine-kinases in bacteria: from a matter of controversy to the status of key regulatory enzymes

When considering protein phosphorylation in bacteria, phosphorylation of aspartic acid and histidine residues mediated by the two-component systems is the first to spring to mind. And yet other phosphorylation systems have been described in bacteria in the past 20 years including eukaryotic-like serine/threonine kinases and more recently tyrosine-kinases. Among the latter, a peculiar type is widespread among bacteria, but not in higher organisms. These enzymes possess unique structural features defining thus a new family of enzymes termed Bacterial tyrosine kinases (BY-kinases). BY-kinases have been shown to be mainly involved in polysaccharide production, but their ability to phosphorylate endogenous substrates indicates that they participate in the regulation of other functions of the bacterial cell. Recent advances in mass spectrometry based phosphoproteomics provided lists of many new phosphotyrosine-proteins, indicating that BY-kinases may be involved in regulating a large array of other cellular functions. One may expect that in a near future, tyrosine phosphorylation will turn out to be one of the key regulatory processes in the bacterial cell and will yield new insights into the understanding of its physiology.     

Enhancement of pullulan elaboration by fluoroacetate

Summary The addition of fluoroacetate, the precursor of the aconitase inhibitor, fluorocitrate, to resting cell suspensions of Aureobasidium pullulans was found to increase the quantity of extracellular polysaccharide elaborated and to raise the pullulan content to 93%.     

Extraction and quantitation of astaxanthin from Phaffia rhodozyma

Summary The rapid, quantitative release of astaxanthin and other carotenoids from the yeast Phaffia rhodozyma is described. Hashed cells are ruptured with dimethylsulfoxide (DMSO) and carotenoids extracted into an organic solvent. Extraction and spectrophotometric quantitation of total carotenoids is rapid, reproducible and only small volumes (0.1–2 ml) of culture are required. HPLC analysis in normal phase silica gel column indicates that astaxanthin comprises 65–95% of the total pigmented carotenoids of P. rhodozyma.     

Sucrose syrup from carob pod

Summary The ripe carob pod (pericarp) is rich in water-soluble sugars, mainly sucrose (63% on total sugars). Sucrose crystallization from aqueous carob extract is prevented by its reducing sugar content. The selective consumption of these sugars by mixed culture ofRhizopus oligosporus andSaccharomyces rouxii gives a sucrose syrup suitable for several uses e.g. sucrose extraction.     

Polynucleotide phosphorylase from plant cells

The isolation of polynucleotide phosphorylase (EC 2. 7. 7. 8) from suspension cultured plant cells of parsley (Petroselinum sativum) and from tomato seedlings (Lycopersicon esculentum) is described. The procedure includes an ultracentrifugation step, a glycerol density gradient centrifugation and preparative gel electrophoresis under nondenaturing conditions. Isoelectric focusing gives rise to a major component (pI ≈ 7.5) and to a minor one (pI ≈ 5). The enzyme contains five subunits with apparent M_r values of 160 000, 140 000, 70 000, 34 000 and 12 000, the 70 000-dalton one being a glycoprotein.     

Exocellular polysaccharide production byStreptococcus thermophilus

Summary Streptococcus thermophilus strains grown on skim milk produce exocellular polysaccharide, essentially composed of galactose and glucose. Small amounts of xylose, arabinose, rhamnose and mannose are identified also. A relationship exists between viscosity of the culture medium and the amount of polymer produced. However, the thickness producing trait in the strains studied is highly unstable.     

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     

Factor C-LHIH which inhibits the luteinizing hormone from basal release and from synthetic LHRH and studies on purification of FSHRH

Mutants of the nitrogen-fixing blue-green alga Nostocmuscorum have been isolated which do not fix nitrogen or reduce acetylene, and which are resistant to streptomycin (1000 μg ml^?1). One such mutant (nif^-st-R) was crossed with the wild-type nitrogen-fixing streptomycin-sensitive parent (nif⁺st-S) and under conditions which counterselected the latter, recombinants (nif⁺st-R) were obtained at a frequency of up to 4.6 in 10⁵ colonies. The frequency of spontaneous mutations or revertants of each parent growing alone was 1 in 10⁷ or less. The higher yield of new genotypes from mixed cultures is interpreted as evidence of nif gene transfer in Nostocmuscorum.     

Plant regeneration from protoplasts of Capsicum annuum

Leaf protoplasts were isolated from axenic shoot cultures of four varieties of Capsicum annuum (Americano, Dulce Italiano Florida Gynat and Nigrum) and a wild species C. chinense. Protoplasts of both species, cultured in KM8P medium and using agarose bead culture, entered division with the exception of the variety Nigrum. Cell colonies formed callus in agar-solified MS medium supplemented with zeatin and for C. annuum v. Dulce Italiano shoots were regenerated when protoplast-derived calli were transferred to MS medium with 6-BAP. Excised shoots were rooted on MS medium which lacked phytohormones.Abbreviations 6-BAP 6-benzylamino purine - MS Murashige and Skoog (1962) - KM8P Kao and Michayluk (1975) - SDS sodium dodecyl sulphate     

Protein synthesis elongation factor EFTu from streptomyces collinus producing kirromycin

Elongation factor EFTu of Streptomyces collinus has been purified. The molecular weight of the factor determined by SDS-polyacrylamide gel electrophoresis is 52,500 (±1,500). The factor shares common immunochemical determinants with EFTu of Streptomyces aureofaciens and Escherichia coli. The factor is not involved in the mechanism of resistance to the drug produced, since translation of poly(U) in the presence of EFTu and ribosomes of S. collinus is sensitive to the kirromycin effect.     

Ethanol production by Zymomonas mobilis CP4 from sugar cane chips

Summary The fermentation of large sugar cane chips (1.0–1.5 in) to ethanol by Zymomonas mobilis CP4 (Z. mobilis) was studied in two glass fermentors operating with culture circulation for agitation (the EX-FERM type): a. A laboratory scale(2.5 liter) cylindrical vessel; b. A bench scale (8 liter) wide vessel. Z. mobilis cultures consumed 89–96% of the cane sucrose, converting it to ethanol by 90–97% of the theoretical yield in the laboratory scale fermentor and by 83–90% in the bench scale fermentor culture. Comparative Saccharomyces spp. cultures in laboratory fermentor consumed 96–98% of the cane sucrose, with ethanol conversion of only 75–79% of the theoretical yield.These preliminary results indicated that sucrose in agricultural size sugar cane chips was ethanol fermentable as compared to small size sugar cane chips or to sugar cane juice. Z. mobilis CP4 cultures converted sucrose more efficiently to ethanol than Saccharomyces spp. as shown in the laboratory scale fermentor studies.The ethanol yields in a wide bench scale fermentor cultures were slightly lower than in a laboratory fermentor.     

Extraction of bovine serum albumin with reverse micelles from glucosylammonium and lactosylammonium surfactants

Reverse micelle extraction is still in the stage of laboratory. Major limitation associated with use of synthetic surfactants in reverse micelle extraction process is the unfolding or denaturation of proteins. Sugar surfactants are thought non-toxic and environmentally benign, and can exhibit interesting interfacial properties, but the application of sugar-based surfactants in protein extraction is still limited. In the present study, we extracted bovine serum albumin (BSA) by using reverse micelles from glucosylammonium (GA) and lactosylammonium (LA) surfactants (with dicarboxylate as counter ion). It was found that under optimum condition, (1) the maximum forward extraction efficiency was ca. 86% with GA, while only around 50% with LA, and (2) almost all BSA solubilized in reverse micelles prepared from GA could be recovered into aqueous phase, while the recovery of BSA from the reverse micelles of LA was lower. In addition, the optimum extraction parameters were closely related to surfactant structure. Therefore, the electrostatic interaction, H-bonding and sugar head size should be important for BSA transfer.     

The structure of nicotine blue from Arthrobacter oxidans

Summary Nicotine blue was separated into two major components. Their chromophores are anions of the diazadiphenoquinones (1) (nicotine blue I) and (2) (nicotine blue II). The dihydrate of the potassium salt of (1) is the major component of the extracellular crystals which are excreted on a solid medium. The acid-labile nicotine blue II is water-soluble and the main coloring agent of the agar and culture broth respectively.