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Pasteuria thornei sp. nov. and Pasteuria penetrans sensu stricto emend., mycelial and endospore-forming bacteria parasitic, respectively, on plant-parasitic nematodes of the genera Pratylenchus and Meloidogyne.

Descriptions are presented of two members of the Pasteuria penetrans group of mycelial and endospore-forming bacteria, parasitic on plant-parasitic nematodes. In one case, the epithet P. penetrans sensu stricto emend. has now been limited to members of this group with cup-shaped sporangia and ellipsoidal endospores, parasitic primarily on the root-knot nematode Meloidogyne incognita. The second organism, with rhomboidal sporangia and nearly spherical endospores, which is parasitic primarily on the root-lesion nematode Pratylenchus brachyurus, is assigned to P. thornei sp. nov. An updated and emended description is offered of the genus Pasteuria Metchnikoff 1888 emend. The relationships are analysed among these two nematode parasites and the type species of this genus, P. ramosa Metchnikoff 1888, a parasite of cladoceran invertebrates. Because none of these microbes has been publicly reported to have been cultivated axenically, these relationships are based mainly on morphological, developmental, and pathological criteria.

Animals↗

Bacillus methanolicus sp. nov., a new species of thermotolerant, methanol-utilizing, endospore-forming bacteria.

The generic position of 14 strains of gram-positive bacteria able to use methanol as a growth substrate was determined. All are obligately aerobic, thermotolerant organisms that are able to grow at temperatures of 35 to 60 degrees C. Nine of the strains produce oval spores at a subterminal-to-central position in slightly swollen rod-shaped cells. DNA-DNA hybridization studies, 5S rRNA sequence analysis, and physiological characteristics revealed that all 14 strains cluster as a well-defined group and form a distinct new genospecies. Analysis of the 16S and 5S rRNA sequences indicated that this new species is distinct from Bacillus brevis but closely related to B. firmus and B. azotoformans. The name proposed for this new species is B. methanolicus. The type strain, PB1, has been deposited in the National Collection of Industrial and Marine Bacteria as NCIMB 13113.

Bacillus↗

[Comparative studies of the kinetics of hygienically relevant microorganisms in activated sludge].

Several samples were taken regularly from 14 different activated sludge ponds in 11 municipal wastewater treatment plants (Table 1). During 7 days, the samples were supplied with oxygen continuously by stirring and the following parameters were determined daily in the filtrate and also in the insoluble sludge: total bacterial plate count grown at 36 degrees C; additionally the oxidase-positive bacteria; the gram-negative bacteria grown on MacConkey agar; also the lactose-positive bacteria of these; C. coli; aerobic endospore-forming bacteria; and protozoa. Furthermore, salmonellae were determined in some aerated and non-aerated samples. The sludge index (SI) as the quotient of volume and dry weight of sludge, in addition the optical density of the sludge-free filtrate was measured. The total bacterial plate count, the count of gram-negative rods, and the lactose-positive enterobacteria were found to be reduced in 12 of the 14 investigated series. The amount of E. coli diminished in as many as 13 of the 14 series and the oxidase-positive bacteria dropped in 11 of 13 cases. The concentration of aerobic spore-forming bacteria remained constant or increased. A propagation of salmonellae was observed only under anaerobic conditions in sludge (Fig. 4). An analysis of the bacterial dynamics shows that the propagation of all bacteria occurs mainly in the free water. Also the reduction of bacteria is more in the free water than in the insoluble flocs of sludge (Table 2). Hence it follows that the flocs are not the centres of microbial activity although most bacteria (medium 76%) are attached to them. Moreover, we found characteristic relations between SI and optical density of the filtrate for the different wastewater treatment plants. There is also a positive correlation between the frequency of protozoa in sludge and the SI (Fig. 2). The SI is correlated positively also with the reduction rate of the most groups of bacteria, excluding the aerobic spore-forming bacteria (Fig. 3). This fact shows a conflict of two possibilities. On the one hand, the reduction of bacteria in wastewater is being improved by increasing SI but the deposition of such sludge is poor. On the other hand, sludge with a lower SI is settling better but the removal of bacteria by protozoa is diminished. Altogether, the sedimentation of flocs is the most important step of elimination of fecal bacteria from wastewater. The process reduces the concentration by the factor 10. Therefore, the successive sedimentation of raw sewage and activated sludge is about 10 time more effective than the simultaneous sedimentation.

Animals↗

The aerobic psychotrophic populations on meat and meat contact surfaces in a meat production system and on meat stored at chill temperatures.

At a city abattoir, a wholesaler and 10 different supermarkets, surface microbiological samples were taken of carcasses, hands and apron fronts of members of staff and equipment (mincers and saws). In addition, minced meat, packaged and displayed in chilled cabinets, was also sampled. Carcasses, personnel surfaces and equipment were monitored by a modified agar sausage technique. From each of the highest dilution psychotrophic plate counts, five colonies were selected randomly, isolated and identified (1265 in total). Microbes developing on chilled meat were also isolated from other surfaces in the production chain. On chilled meat (51%) and at the abattoir (36%) pseudomonads were the predominant organisms followed by the Gram-positive cocci on chilled meat and by Acinetobacter, Moraxella and Alcaligenes spp. at the abattoir. At the wholesaler Gram-positive cocci (32%) predominated, followed by Alcaligenes, Moraxella and Alcaligenes spp. Pseudomonas, Alcaligenes, Neisseriaceae and related genera, Gram-positive cocci, species from the coryneform groups of bacteria and yeasts were identified from all the surfaces monitored. Identification with the API NE20 was unsatisfactory. Enterbacteriaceae, lactobacilli and endospore-forming bacteria were identified occasionally, but their significance as contaminating organisms seems low. No Salmonella spp. were identified.

Abattoirs↗

[Study on the discrimination of bacteria by gas chromatographic profiles of cellular monosaccharides].

A procedure for obtaining gas chromatographic (GC) profiles of bacterial cellular monosaccharides was described. Some of the unknown component peaks in these profiles were identified. And, based on the complete linkage cluster analysis with the Euclidean distance coefficient, the interpretation of the resulting cellular monosaccharides of bacteria were performed by mini-computer. By means of this method, the discrimination of 5 species (24 strains) of aerobic endospore-forming bacteria. The results showed that there were defined differences between the profiles of cellular monosaccharides of B. anthracis and B. cereus. This procedure has provided a useful method for the classification and identification of microorganisms, for their physiological and biochemical studies, and for studies on their subcellular components.

Bacillus↗

Polar lipid and isoprenoid quinone composition in the classification of Staphylococcus.

Representatives of 13 species of Staphylococcus were examined using a small-scale procedure for the sequential extraction of isoprenoid quinones and polar lipids. Menaquinones were the only isoprenoid quinones found in the 77 test strains which were divided into three groups based upon the predominant isoprenologue detected: (i) S. hyicus subsp. hyicus, S. sciuri subsp. lentus and S. sciuri subsp. sciuri contained unsaturated menaquinones with six isoprene units; (ii) S. capitis, S. cohnii, S. epidermidis, S. haemolyticus, S. hominis, S. hyicus subsp. chromogenes, S. intermedius, S. saprophyticus, S. simulans, S. warneri and S. xylosus contained unsaturated menaquinones with seven isoprene units and (iii) S. aureus contained unsaturated menaquinones with eight isoprene units and varying amounts of the corresponding lower isoprenologue. All of the organisms contained very similar polar lipid patterns consisting of diphosphatidylglycerol, phosphatidylglycerol, beta-gentiobiosyl diacylglycerol and a number of glycolipids and phospholipids. One of the glycolipids was chromatographically indistinguishable from beta-gentiotriosyl diacylglycerol. Lysylphosphatidylglycerol was a major component in S. aureus and S. intermedius but was usually present in minor amounts in the coagulase-negative strains. The polar lipid data underline the homogeneity of the genus Staphylococcus and distinguish staphylococci from aerobic, Gram-positive cocci and from the phylogenetically related aerobic, endospore-forming bacteria. Menaquinone composition can also be used to separate staphylococci from other aerobic, Gram-positive cocci.

Chromatography, Thin Layer↗

A numerical classification of the genus Bacillus.

Three hundred and sixty-eight strains of aerobic, endospore-forming bacteria which included type and reference cultures of Bacillus and environmental isolates were studied. Overall similarities of these strains for 118 unit characters were determined by the SSM, SJ and DP coefficients and clustering achieved using the UPGMA algorithm. Test error was within acceptable limits. Six cluster-groups were defined at 70% SSM, which corresponded to 69% SP and 48-57% SJ. Groupings obtained with the three coefficients were generally similar but there were some changes in the definition and membership of cluster-groups and clusters, particularly with the SJ coefficient. The Bacillus strains were distributed among 31 major (4 or more strains), 18 minor (2 or 3 strains) and 30 single-member clusters at the 83% SSM level. Most of these clusters can be regarded as taxospecies. The heterogeneity of several species, including Bacillus brevis, B. circulans, B. coagulans, B. megateriun, B. sphaericus and B. stearothermophilus, has been indicated and the species status of several taxa of hitherto uncertain validity confirmed. Thus on the basis of the numerical phenetic and appropriate (published) molecular genetic data, it is proposed that the following names be recognized; Bacillus flexus (Batchelor) nom. rev., Bacillus fusiformis (Smith et al.) comb. nov., Bacillus kaustophilus (Prickett) nom. rev., Bacillus psychrosaccharolyticus (Larkin & Stokes) nom. rev. and Bacillus simplex (Gottheil) nom. rev. Other phenetically well-defined taxospecies included 'B. aneurinolyticus', 'B. apiarius', 'B. cascainensis', 'B. thiaminolyticus' and three clusters of environmental isolates related to B. firmus and previously described as 'B. firmus-B. lentus intermediates'. Future developments in the light of the numerical phenetic data are discussed.

Bacillus↗

Mechanism of chloramphenicol resistance in Bacillus badius 211.

Six strains of chloramphenicol (CM)-resistant endospore-forming bacteria, which can grow in the presence of 100 microgram/ml of CM, were isolated and identified as Bacillus badius. Mechanism of CM-resistance in one of the isolated strains, Bacillus badius 211, was investigated. No inactivation of CM was demonstrated when the strain was grown in nutrient broth containing 100 microgram/ml of CM, as evidenced by paper-disc bioassay of CM in the growth medium. In accordance with this result, no CM acetylation activity was demonstrated either with the intact cells or with the crude extracts of the CM-resistant strain. Poly U- and Poly A-directed polyphenylalanine and polylysine syntheses by S--30 preparations of both CM-resistant and CM-sensitive strains of Bacillus badius were almost equally inhibited by CM. From these results, the mechanism of CM resistance in Bacillus badius 211 seems to be due to other unknown mechanism.

Acetylation↗

Characterisation of potential adhesins of the bacterium Pasteuria penetrans, and of putative receptors on the cuticle of Meloidogyne incognita, a nematode host.

Pasteuria penetrans spores were fragmented by glass bead vortexing, producing exosporial membranes and spore fragments, which consisted of fibre bundles. Both exosporia and spore fragments are capable of host-specific attachment to the cuticle of Meloidogyne incognita, a root-knot nematode host. Putative M. incognita receptors appear to be soluble in beta-mercaptoethanol (BME) but not SDS, and are also sensitive to tryptic digestion and deglycosylation by endoglycosidase F. Polyclonal antibodies against intact spores and spore fragments of antispore antibodies produced 100% inhibition. The antibodies, however, did not show preferential staining of particular spore structures in thin section immunolabelling studies. Exposure of Pasteuria penetrans spores to HCl or urea-SDS-dithiothreitol renders them incapable of attachment to their host juveniles and extensively disrupts fibres that surround the spore core. Protein extracts from spore fragments or from exosporial membranes are identical, and urea-BME extracts from either structure, but not SDS extracts, can inhibit the attachment of spores to juveniles by 60-80%. An inhibitory BME extract from spore fragments was analysed by anion-exchange chromatography and adsorption onto host cuticle followed by immunoblotting. It appeared to contain six potential spore adhesins of approximate Mr 24-29, 38-47, 59, 89, 126, and 190 (x10(3)). Lectin affinity blotting with wheat germ agglutinin and concanavalin A showed that all of these proteins bear terminal N-acetylglucosamine residues and the 38-47 kDa band also bears terminal Glc/Man residues.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Effective surface sterilization of gutta-percha points.

A bacteriologic investigation was conducted to determine the sterilizing effectiveness of various germicidal endodontic irrigants on gutta-percha points. It was found that most effective in surface sterilization was a 5-minute treatment using sodium hypochlorite, Zephiran, and hydrogen peroxide in concentrations of 4.50 percent, 0.53 percent, and 3.00 percent, respectively. These agents were potent against gram-positive and gram-negative bacteria as well as endospore-forming microorganisms. Fungal spores were killed only by the first two but not by the latter germicidal agents. On the other hand, ethanol, chloroform, eugenol, betadine, and Gram's iodine solution were found not to be effective for surface sterilization.

Bacteria↗

L-lysine production at 50 degrees C by mutants of a newly isolated and characterized methylotrophic Bacillus sp.

The amino acid L-lysine was produced from homoserine auxotrophic and S-(2-aminoethyl)-L-cysteine-resistant mutants of a newly isolated gram-positive methylotrophic bacterium, capable of growth on methanol at 60 degrees C. The temperature optimum for growth was between 50 and 53 degrees C. These aerobic, gram-positive, endospore-forming, rod-shaped bacteria required biotin and vitamin B12 for growth. Extracts of the bacteria grown on methanol lacked hydroxypyruvate reductase and contained hexulose 6-phosphate synthase activity. Therefore, these bacteria were considered to be type I methylotrophic bacteria of the genus Bacillus. Fed-batch fermentations resulted in cell densities of 50 g of cell dry weight per liter. Biomass yields on carbon, nitrogen, phosphate, and sulfate were determined. Generation of homoserine auxotrophic and amino acid analog-resistant mutants resulted in L-lysine concentrations of nearly 20 g/liter in fed-batch fermentations.

Bacillus↗

Isolation and characterization of an anaerobic chlorophenol-transforming bacterium.

An obligately anaerobic bacterium which transforms several chlorinated phenols was isolated. Dechlorination of the substituents ortho to the phenolic OH group was preferred, while removal of a meta-substituted chlorine was observed only with 3,5-dichlorophenol. The bacterium was a gram-positive, endospore-forming, motile, slightly curved rod. Sulfate was not reduced. Nitrate was reduced via nitrite to ammonium. The bacterium is related to the genus Clostridium. The highest growth rate was obtained in a medium containing pyruvate and yeast extract. Pyruvate supported growth as the sole source of carbon, and the fermentation of pyruvate produced almost equimolar amounts of acetate.

Bacteria, Anaerobic↗

[Isolation of a large aerobic sporulated sheathed bacteria from soil by elective culture].

Eleven endospore-forming strains of a probably unknown species of Bacillus were isolated from samples of pasteurized soil by aerobic enrichment culture at 32 degrees C in a minimal medium containing benzoate, p-hydroxybenzoate or cyclohexane carboxylate, as source of carbon and energy. They grew in the form of unbranched, flexible filaments 1.8 micrograms in diameter and sometimes more than 1,000 micrograms in length. The organism was not coenocytic because transverse partitions were visible. The endospores were oval (1.8 x 2.2 micrograms) and did not deform the filaments. A thin, translucid sheath was present. The 11 strains were prototrophic, used benzoate and acetate as sources of carbon and energy but did not grow in common peptone media. Only the isolation technique has been described here.

Bacillus↗

Further studies on thymidine kinase: distribution pattern of the enzyme in bacteria.

Various micro-organisms (131 strains of 73 species) were studied for their ability to produce thymidine kinase (TK; EC 2.7.1.21). Taking the specific TK activity of Escherichia coli K12 [specific activity of sonicated cell extracts 95-194 pmol min-1 (mg protein)-1] as 100%, the test organisms had the following relative specific TK activities. In the Gram-positive cocci, Staphylococcus aureus (21-84%) showed higher activity than Staph. epidermidis (1-20%) and Streptococcus (1-7%) except for one strain of Strep. pyogenes (29%). Neisseria sicca, a Gram-negative coccus, lacked TK. Gram-positive endospore-forming rods showed significant activity (Bacillus, 13-51%; Clostridium perfringens, 9-18%) except for one strain of B. megaterium (2%) and C. difficile (1-3%). Among the Gram-positive asporogenous rods, Listeria monocytogenes and six species of Lactobacillus (especially L. brevis, L. buchneri and L. casei) had moderate to high activity (23-348%) but L. acidophilus, L. bulgaricus, L. lactis and L. cellobiosus had low activity (0-8%). Of the species of Pseudomonas studied, most lacked TK but Ps. fluorescens and Ps. maltophilia had significant TK activity (15-53%). Of the Gram-negative facultative anaerobes, Vibrio lacked TK, while Enterobacteriaceae, including Salmonella (148-1120%), Escherichia (59-141%), Klebsiella (78-299%) and Serratia (61-110%), had a high activity. Proteus had a somewhat lower activity (0-34%) except for 'Pr. rettgerella' (307%). Propionibacterium and Bifidobacterium and related organisms other than Streptomyces, Nocardia, Rhodococcus, Corynebacterium and Mycobacterium lacked TK. The seven species of Candida tested, and Cryptococcus neoformans, essentially lacked TK.(ABSTRACT TRUNCATED AT 250 WORDS)

Actinomycetales↗

Acetonema longum gen. nov. sp. nov., an H2/CO2 acetogenic bacterium from the termite, Pterotermes occidentis.

A previously undescribed, H2-oxidizing CO2-reducing acetogenic bacterium was isolated from gut contents of the wood-feeding termite, Pterotermes occidentis. Cells of representative strain APO-1 were strictly anaerobic. Gram-negative, endospore-forming motile rods which measured 0.30-0.40 x 6-60 microm. Cells were catalase positive, oxidase negative, and had 51.5 mol percent G + C in their DNA. Optimum conditions for growth on H2 + CO2 were at 30-33 degrees C and pH (initial) 7.8, and under these conditions cells formed acetate according to the equation: 4 H2 + 2 CO2----CH3COOH + 2 H2O. Other energy sources supporting good growth of strain APO-1 included glucose, ribose, and various organic acids. Acetate and butyrate were major fermentation products from most organic compounds tested, however propionate, succinate, and 1,2-propanediol were also formed from some substrates. Based on comparative analysis of 16S rRNA nucleotide sequences, strain APO-1 was related, to but distinct from, members of the genus Sporomusa. Moreover, physiological and morphological differences between strain APO-1 and the six known species of Sporomusa were significant. Consequently, it is proposed herewith that a new genus, Acetonema, be established with strain APO-1 as the type strain of the new species, Acetonema longum. A. longum may contribute to the nutrition of P. occidentis by forming acetate, propionate and butyrate, compounds which are important carbon and energy sources for termites.

Acetates↗

Pasteuria nishizawae sp. nov., a mycelial and endospore-forming bacterium parasitic on cyst nematodes of genera Heterodera and Globodera.

This study describes Pasteuria nishizawae sp. nov., a fourth species of the genus Pasteuria. This mycelial and endospore-forming bacterium parasitizes the adult females of cyst-forming nematodes in the genera Heterodera and Globodera. The distinct ultrastructural features and unique host range found for this bacterium separate it from two closely related species, Pasteuria penetrans, which parasitizes several species of root-knot nematodes of the genus Meloidogyne, and Pasteuria thornei, which appears to parasitize only one species of the root-lesion nematode, Pratylenchus brachyurus. Because these obligate bacterial parasites of nematodes have not been cultured axenically, the taxonomic relationships described here for each species are based mainly on developmental morphology, fine structure of the respective sporangia and endospores, and their pathogenicity on nematode species.

Animals↗