The fine structure of a tri-lamellar body in various species ofAnabaena

Summary A tri-lamellar body has been observed either near or adjacent to the crosswalls in 16 out of 20 different isolates ofAnabaena examined in thin sections. These bodies appear to consist of three discoid lamellae approximately 0.3 m in diameter. The outer lamella (closest to the plasma membrane) is separated from the middle lamella by a 12 nm space and is about 8 nm in thickness. The middle and inner lamellae, spaced about 8 nm apart, are approximately 8 nm in thickness. Electron dense granules, interpreted to be -granules, are associated with the inner lamella. In different species, osmiophilic lines 3 nm wide were observed. The osmiophilic lines run at right angles to the lamellae, either between the outer and middle lamellae, between the middle and inner lamellae or between all three lamellae. In some species, osmiophilic lines are absent. Up to six tri-lamellar bodies have been observed in median longitudinal sections. Pores 20 nm in diameter and 60 nm apart were observed in layer 2 of the cell wall of all the species ofAnabaena examined. All species which had tri-lamellar bodies also had wall pores closely associated with the bodies. Wall pores were also observed in four species lacking tri-lamellar bodies. The possible role of these structures is discussed.     

A new Cryptococcus species

Summary A newCryptococcus species,Cryptococcus gastricus, is described. Its relationship to the genusLipomyces is discussed.     

An extracellular galactoxylomannan of acapsular Cryptococcus laurentii mutant

An extracellular galactoxylomannan (GalXM) composed of D-Gal (34.0%), D-Xyl (26.6%) and D-Man (31.0%), and a small amount of L-Ara (4.0%) and D-Glc (4.4%) has been isolated from culture medium of acapsulated mutant of Cryptococcus laurentii by ethanol precipitation and gel filtration. Phosphorylated polymer of Mw approximately 75,000 contained 90% carbohydrates, 3.9% phosphorus and 5.3% proteins. Results of chemical and spectroscopic studies showed a highly branched structure of GalXM with a 1,6-linked mannopyranosyl-galactopyranosyl backbone (approximately 44%) branched predominantly at C-2 and C-3 of mannosyl, and C-3 of galactosyl residues by side chains terminated mainly by xylosyl and mannosyl residues, and to a less extent by arabinosyl and glucosyl ones.     

Cryptococcus phylloplanus and Cryptococcus hinnuleus,two new yeast species

Two new species of the genus Cryptococcus, C. phylloplanus and C. hinnuleus are isolated from leaves of Banksia collina R. Br.     

Extracellular enzymatic activity in 11 Cryptococcus species

The extracellular enzymatic activity of 36 strains of yeast belonging to 11 species of the genus Cryptococcus, has been investigated, using the API-ZYM (BioMérieux, France) commercial system, with the objective of determining the differences in the enzymatic profiles of the various species. The strains studied were : 9 of C. neoformans, 7 of C. albidus, 6 of C. laurentii, 5 of C. uniguttulatus, 3 of C. humicolus, and 1 each of C. ater, C. curvatus, C. dimennae, C. hungaricus, C. infirmo-miniatus and C. magnus. All the strains showed enzymatic activity with positivity to Phosphatase alkaline, Esterase lipase C8, Leucine arylamidase, Phosphatase acid and Naphthol-AS-BI-phosphohydrolase, and negativity to Lipase C14, Trypsin, Chemotrypsin, β-galactosidase, β-glucuronidase and α-manosidase. Variable enzymatic activity was shown to Esterase C4, Valine arylamidase, Cystine arylamidase, α-galactosidase,α-glucosidase, β-glucosidase, N-acetyl-β-glucosaminidase and α-fucosidase. This allowed 11 separate enzymatic patterns to be established. The species C. neoformans and C. laurentii each presented two distinct patterns; C. uniguttulatus, C. hungaricus andC. magnus shared the same pattern; C. albidus, C. ater, C. curvatus,C. dimennae, C. humicolus and C. infirmo-miniatus presented an individual enzymatic pattern. The results obtained suggest that the API-ZYM system could be useful for the identification of species of the genus Cryptococcus and for the differentiation of the enzymotypes for epidemiological purposes. This revised version was published online in June 2006 with corrections to the Cover Date.     

The fate of benzoic acid in various species

1. The urinary excretion of orally administered [¹⁴C]benzoic acid in man and 20 other species of animal was examined. 2. At a dose of 50mg/kg, benzoic acid was excreted by the rodents (rat, mouse, guinea pig, golden hamster, steppe lemming and gerbil), the rabbit, the cat and the capuchin monkey almost entirely as hippuric acid (95–100% of 24h excretion). 3. In man at a dose of 1mg/kg and the rhesus monkey at 20mg/kg benzoic acid was excreted entirely as hippuric acid. 4. At 50mg/kg benzoic acid was excreted as hippuric acid to the extent of about 80% of the 24h excretion in the squirrel monkey, pig, dog, ferret, hedgehog and pigeon, the other 20% being found as benzoyl glucuronide and benzoic acid, the latter possibly arising by decomposition of the former. 5. On increasing the dose of benzoic acid to 200mg/kg in the ferret, the proportion of benzoyl glucuronide excreted increased and that of hippuric acid decreased. This did not occur in the rabbit, which excreted 200mg/kg almost entirely as hippuric acid. It appears that the hedgehog and ferret are like the dog in respect to their metabolism of benzoic acid. 6. The Indian fruit bat produced only traces of hippuric acid and possibly has a defect in the glycine conjugation of benzoic acid. The main metabolite in this animal (dose 50mg/kg) was benzoyl glucuronide. 7. The chicken, side-necked turtle and gecko converted benzoic acid mainly into ornithuric acid, but all three species also excreted smaller amounts of hippuric acid.     

Comparison of extracellular proteases produced by Aeromonas salmonicida strains, isolated from various fish species

Extracellular products (ECPs) of five typical and 25 atypical Aeromonas salmonicida isolates from various fish species and geographical locations were analysed by substrate specificity, inhibition of proteolytic activity and substrate SDS-PAGE. The type strains of Aer. salmonicida subsp. salmonicida and Aer. salmonicida subsp. achromogenes were included for comparison. The results indicated that the strains formed six protease groups. The proteases produced by the two type strains were of a different nature. All the typical strains belonged to one group and showed proteolytic activities comparable to P1 and P2 proteases. Three atypical (oxidase-negative) strains secreted a protease comparable to P1. With the exception of these three, all strains produced metallo-gelatinases. A metallo-caseinase (AsaP1) was detected in the ECP of subsp. achromogenes type strain and 10 of the atypical strains. A number of proteolytic components with different apparent molecular weights (AMWs) were identified. These include caseinases with AMWs of > 100, 80, 60 and 30 kDa and gelatinolytic components with different AMWs, including some with AMW higher than P1 and lower than P2. The protease production of the isolates was not found to be host specific.     

The presence of carotenoids in various species of Lepidoptera

The presence of 41 carotenoids in 114 species of Lepidoptera was determined. The carotenoids characteristic of butterflies were zeaxanthin, β-cryptoxanthin, lutein epoxide, astaxanthin, lycopene, torulene and canthaxanthin.     

Production of extracellular ribonuclease by yeasts and yeastlike fungi, and its repression by orthophosphate in species of Cryptococcus and Tremella.

A strain of Cryptococcus laurentii and a haploid isolate of Tremella foliacea were shown to produce orthophosphate-repressible ribonuclease in liquid culture. Addition of as little as 1 mM K2HPO4, pH 7.0, completely repressed enzyme production by both fungi. The orthophosphate-repressible enzyme was not produced by other species of the two genera tested. These results, together with other findings, suggest a close phylogenetic relationship between Cryptococcus laurentii and Tremella foliacea. The ability of other yeasts and yeastlike fungi to hydrolyze ribonucleic acid in a solid test medium was assessed. Based on the limited number of organisms available for study, extracellular ribonuclease activity was found in species having close affinity to the Basidiomycetes and in yeasts classified in the ascomycetous genera, Endomycopsis, Hansenula, and Kluyveromyces. Other ascomycetous yeasts did not exhibit extracellular ribonuclease.     

Carbohydrate patterns ofCandida,Cryptococcus andRhodotorula species

Within the genusCandida three distinct groups are recognized on the basis of carbohydrate patterns of intact whole cell hydrolyzates. In the first, ascomycetous, group mannose is dominant, while rhamnose, fucose and xylose are absent; this is indicative of an affinity with endomycetous families. Among the basidiomycetous representatives, two groups can be recognized. One group is usually characterized by the presence of xylose and has a low mannose content. The pattern is typical for Cryptococcales and Tremellales (e.g.,Cryptococcus, Trichosporon, Bullera andTremella). The other basidiomycetous group is characterized by the presence of fucose and/or rhamnose with significant amounts of mannose. This pattern is characteristic for Sporobolomycetaceae.     

The characterization of hemiacetal bonds formed after periodate oxidation of heteroglycans

The location of inter-residue, cyclic hemiacetals formed following the periodate oxidation of four representative heteroglycans has been determined by methylation analysis of the periodate-oxidized glycans. The cyclic hemiacetals led to the protection of hydroxyl groups during methylation in methyl sulfoxide, and their positions were located by analysis of the resulting di- and mono-methyl ethers. Such derivatives were not observed upon methylation analysis of the native and the periodate-oxidized-borohydride-reduced glycans. Inter-residue hemiacetals were thus identified in all oxidized glycans, between aldehydic groups at C-2 or C-3 of oxidized residues and hydroxyl groups at C-3 or C-2 of adjacent, unoxidized residues. Selective removal of 6-O-substituents from oxidized residues resulted in a decreased ability of the latter to form the inter-residue hemiacetals. Analysis of the types and proportions of the methyl ethers resulting from inter-residue hemiacetal formation may also yield structural information on the glycan.     

The activity of hepatic gamma-glutamyltranspeptidase in various animal species

The activity of gamma-glutamyltranspeptidase was determined in liver homogenates derived from various animals belonging to different phylogenetic groups. Although gamma-glutamyltranspeptidase was present in all livers studied, the activity varied greatly, with the order of activity being: guinea pig much greater than frog much greater than rabbit greater than toad greater than dog congruent to cat = duck greater than hamster = budgerigar = goldfish congruent to rat = mouse. There was no trend with respect to enzyme activity, phylogeny, diet, or habitat.     

Diversity of the Cryptococcus neoformans-Cryptococcus gattii species complex

More than 110 years of study of the Cryptococcus neoformans and Cryptococcus gattii species complex has resulted in an enormous accumulation of fundamental and applied biological and clinical knowledge. Recent developments in our understanding of the diversity within the species complex are presented, emphasizing the intraspecific complexity, which includes species, microspecies, hybrids, serotypes and genotypes. Each of these may have different roles in disease. An overview of obsolete and current names is presented.     

Serum albumin disrupts Cryptococcus neoformans and Bacillus anthracis extracellular vesicles

For both pathogenic fungi and bacteria, extracellular vesicles have been shown to contain many microbial components associated with virulence, suggesting a role in pathogenesis. However, there are many unresolved issues regarding vesicle synthesis and stability, including the fact that vesicular packaging for extracellular factors involved in virulence must also have a mechanism for vesicle unloading. Consequently, we studied the kinetics of vesicle production and stability using [1-(14) C] palmitic acid metabolic labelling and dynamic light scattering techniques. Cryptococcus neoformans vesicles were produced throughout all stages of fungal culture growth and they were stable once isolated. Density gradient analysis revealed that only a portion of the vesicle population carried cryptococcal polysaccharide, implying heterogeneity in vesicular cargo. Vesicle incubation with macrophages resulted in rapid vesicle instability, a phenomenon that was ultimately associated with serum albumin. Additionally, albumin, along with mouse serum and murine immunoglobulin destabilized Bacillus anthracis vesicles, but the effect was not observed with ovalbumin or keyhole limpet haemocyanin, demonstrating that this phenomenon is neither host-, microbe- nor protein-specific. Our findings strongly suggest that cryptococcal vesicles are short-lived in vivo and vesicle destabilization is mediated by albumin. The ability of albumin to promote vesicular offload through destabilization indicates a new activity for this abundant serum protein.