Mechanism controlling the extended lag period associated with vinyl chloride starvation in Nocardioides sp. strain JS614.

The extended lag period associated with vinyl chloride (VC) starvation in VC- and ethene-assimilating Nocardioides sp. strain JS614 was examined. The extended lag periods were variable (3-7 days), only associated with growth on VC or ethene, and were observed in VC- or ethene-grown cultures following 24 h carbon starvation and mid-exponential phase cultures grown on non-alkene carbon sources (e.g. acetate). Alkene monooxygenase (AkMO) and epoxyalkane:coenzyme M transferase (EaCoMT) are the initial enzymes of VC and ethene biodegradation in strain JS614. Reverse-transcription PCR confirmed that the AkMO gene etnC was expressed in response to epoxyethane, a metabolic intermediate of ethene biodegradation. Epoxyethane (0.5 mM) eliminated the extended lag period in both starved and mid-exponential phase cultures, suggesting that epoxyethane accumulation activates AkMO expression in strain JS614. AkMO activity in ethene-grown cultures was not detected after 6.7 h of carbon starvation, while 40% of the initial EaCoMT activity remained after 24 h. Acetate eliminated the extended lag period in starved cultures but not in mid-exponential phase cultures suggesting that acetate reactivates extant AkMO in starved VC- or ethene-grown cultures. The imbalance between AkMO and EaCoMT activities during starvation likely contributes to the extended lag period by delaying epoxide accumulation and subsequent AkMO induction.

Nocardiopsis aegyptia sp. nov., isolated from marine sediment.

An actinomycete, strain SNG49(T), was isolated from marine sediment of Abu Qir Bay, on the western seashore of Alexandria, Egypt. The bacterium was aerobic and Gram-positive. It produced beige to light-yellow aerial mycelium, brown substrate mycelium and straight to flexuous hyphae, but no specific spore chains. 16S rDNA sequence analysis and chemotaxonomic markers were consistent with classification of strain SNG49(T) in the genus Nocardiopsis, i.e. meso-diaminopimelic acid; no diagnostic sugars; phosphatidylcholine, phosphatidylmethylethanolamine, phosphatidylinositol, phosphatidylglycerol and diphosphatidylglycerol as polar lipids; menaquinones of the MK-10 series from MK-10(H(0)) to MK-10(H(8)); and iso/anteiso-branched and 10-methyl-branched fatty acids, the principal fatty acids being anteiso-17 : 0 and tuberculostearic acid. Nocardiopsis lucentensis and Nocardiopsis alba are the phylogenetic neighbours of strain SNG49(T), respectively showing 98.8 and 98.7 % 16S rRNA gene sequence similarity; however, moderate DNA-DNA reassociation values between these two species and strain SNG49(T) (44 and 60 %, respectively) showed that strain SNG49(T) could be clearly separated from them. These data, together with distinct physiological traits, led to the conclusion that this isolate represents a novel species within the genus Nocardiopsis, for which the name Nocardiopsis aegyptia is proposed. The type strain is SNG49(T) (=DSM 44442(T)=NRRL B-24244(T)).

Aeromicrobium marinum sp. nov., an abundant pelagic bacterium isolated from the German Wadden Sea.

An obligately salt-dependent Gram-positive bacterium, designated strain T2(T), was isolated from surface waters of the German Wadden Sea. The organism exhibited optimum growth at salt concentrations similar to that of sea water. On the basis of phenotypic, chemotaxonomic and phylogenetic differences, it is concluded that strain T2(T) (=DSM 15272(T)=LMG 21768(T)) is the first marine species of the genus Aeromicrobium to be identified, for which the name Aeromicrobium marinum is proposed. It is also the first described marine bacterium within the family Nocardioidaceae. Strain T2(T) is a rod-shaped, aerobic, heterotrophic bacterium containing LL-diaminopimelic acid in the peptidoglycan and MK-9(H(4)) as the major menaquinone. The bacterium is characterized by high proportions of the fatty acids palmitic acid, oleic acid, tuberculostearic acid and hydroxypalmitic acid. DNA-DNA hybridization analysis showed the marine bacterium to display 29.1 % relatedness with Aeromicrobium fastidiosum DSM 10552(T) and 44.4 % relatedness with Aeromicrobium erythreum DSM 8599(T). A. marinum was demonstrated to be an abundant member of the pelagic bacterial community in the German Wadden Sea since it represented about 1 % of the total bacterial population as revealed by dot-blot hybridization and most-probable-number counts.

[Preparation of fed-batch culture of Nocardioides sp]. / Poluchenie uplotnennoi kul'tury Nocardioides sp.

A screening for carbon sources revealed ethanol to be the best substrate for condensed Nocardioides sp. culture. A strategy achieving the maximum (21 g/l) yield of biomass was developed for the control over the condensed fed-batch culture production. This control based on the algorithm ExpoDense should be predetermined in the first phase and adaptive in the second phase of two-phase process of condensed culture production.

Characterization of JP-7 jet fuel degradation by the bacterium Nocardioides luteus strain BAFB.

In the fall of 1996, numerous bacteria capable of degrading JP-7 jet fuel were isolated from soil collected at Beale Air Force Base in northern California. The most prevalent organism, identified as Nocardioides luteus by16s rRNA sequencing (MIDI Labs, Inc.), was selected for further analysis. Analysis of JP-7 following inoculation with N. luteus demonstrated degradation of the C(11) alkane component of the fuel. Growth rates of N. luteus were determined with alkanes of various lengths as the sole carbon and energy source. The organism grew best on shorter length alkanes (C(8) and C(10)). Growth was measurably slower on C(11), and minimal on C(12), C(13), and C(14).

[Actinomadura species as antibiotic producers]. / Vidy roda Actinomadura kak produtsenty antibiotikov.

Screening of antibiotic-producing cultures among Actinomadura showed that definite species mainly produced antibiotics of the same groups. Thus, carminomycins were produced by all the 4 studied strains of A. carminata, maduramycins were produced by 3 strains of A. rubra, prodigiozines were produced by 3 strains of A. madurae and luzopeptines were produced by 6 strains of A. recticatena. Supposedly, new antibiotics with original spectral characteristics were isolated from 2 strains of A. fulvescens. There was a clear-cut relation of the number of the active strains and their antibiotic productivity in definite media to their species. The liquid nutrient media, such as yeast-sucrose, soya-glucose and soya-glucose with cobalt chloride proved to be the most efficient in the primary screening of antibiotic-producing cultures.

Cultivation of a nocardioform acid-fast chemoautotrophic bacterium from armadillo tissues infected with Mycobacterium leprae.

A nocardioform bacterium was isolated from the spleen tissue of an armadillo infected with M. leprae and easily propagated in pure culture in mineral salt medium supplemented with only simple C and N sources (e.g., liquid paraffin, tetradecane, ammonium salts, urea, asparagine, gelatin, xanthin, hypoxanthin etc.). Complex organic substances, e.g., tyrosin, casein, peptone, meat extract, egg proteins, serum, blood, yeast extract as well as medium 199, did not support the growth of this organism. Microscopically, the organism consisted of acid-fast, long, slender rods which originated from long, fragmented hyphae, or sporulating mycelial tufts; it was acid-fast (at less than 4.0% H2SO4) which was pyridine-susceptible. It produced DOPA-oxidase and Catalase and was lysozyme resistant; this grew best under reduced O2 tension, at pH 7.0 to 8.0 and 28 degrees C. Serologically, it appeared to be only weakly related to the prototype human multibacillary leprosy-derived (reference) nocardioform strain, Nocardia brasiliensis and N. caviae, but was variably related to several mycobacteria strains.

[Isolation of Actinomycetales from the soil of Kazakhstan on selective media with antibiotics]. / Vydelenie aktinomitsetov iz pochv Kazakhstana na selektivnykh sredakh s antibiotikami.

About 3000 actinomycetes were isolated from various soil samples collected in 11 regions of Kazakhstan. 62.7 per cent of them proved to be antagonists. For isolation of the strains, selective media supplemented with antibiotics were used. Kanamycin promoted growth of Actinomadura and Nocardia. Rubomycin promoted growth of Actinomadura. Tavromycetin and roseofungin were used as selective agents for the first time. Tavromycetin favoured isolation of Actinomadura and Nocardia. Roseofungin favoured isolation of Actinomadura. Light chestnut and serozemic soils were the most rich in antagonists (67.1 and 61.3 per cent, respectively) while saline and chestnut soils were the poorest in antagonists (32.2 and 30.6 per cent, respectively). Actinomadura were more frequent in light-chestnut light-loamy and serozemic soils. Half of the antibiotics isolated in the form of concentrates were identified with the known antibiotics or classified as belonging to various groups. A culture producing a novel antibiotic was isolated.

A new species of Actinomadura producing a polyether antibiotic, cationomycin.

Taxonomic studies on the new species, Actinomadura azurea are presented. A significant property of this species is the production of a new polyether antibiotic, cationomycin.

[Key Rhodococcus enzymes in the catabolism of aromatic compounds]. / Kliuchevye fermenty katabolizma aromaticheskikh soedinenii Rhodococcus.

The enzyme apparatus involved in the catabolism of aromatic compounds in rhodococci is characterized by the presence of pyrocatechase and protocatechoate-3,4-dioxygenase as principal enzymes cleaving the aromatic cycle. Metapyrocatechase was found in about 30% of the rhodococci. All the enzymes are inducible. The inductor of pyrocatechase seems to be cyc-cys-muconate, and that of protocatechase appears to be 3-oxoadipate. The metapyrocatechase of rhodococci, in contrast to that of Pseudomonas, is not induced by benzoate, p-toluylate, p-xylene and phenol. The activity of metapyrocatechase rises 20-50 times comparing to the basal level only in the presence of p-cresol. The enzyme has a relatively low activity in rhodococci (50-200 nmole per 1 min per 1 mg of protein), though a very high affinity for methylcatechols. The activity of metapyrocatechase with methylcatechols is 2-5 times as high as that with catechol as a substrate, whereas the activity of pyrocatechase with methylcatechols is two times as low as that with catechol as a substrate. Such additional substrates as acetate, glycerol or fumarate have no effect on the qualitative composition of the key enzymes involved in the degradation of aromatic compounds in Rhodococcus carollinus 172. Glucose represses the synthesis of enzymes cleaving the aromatic ring by 100%. Fumarate taken in a 5-fold excess inhibits the activity of catechol oxygenases by 40%; if it is taken in a 1000-fold excess, it inhibits the enzyme activity by 100%.

Analysis of morphogenesis of the nocardioform organism Oerskovia xanthineolytica.

Depending on the nutritional and physicochemical conditions of growth the shape of Oerskovia xanthineolytica varied within a broad range. In different exponentially growing cultures five morphological types could be distinguished. In liquid cultures with increasing growth rate Oerskovia grew either as rods, filaments or branched filaments, whereas for the agar-microcultures pseudomycelia, but under reduced aeration mycelia were typical. The morphogenetic parameters of each type were determined, such as frequencies of septation and cell separation and - since wall extension was found to occur by the synthesizing activity of elongation sites (e-sites), their frequency, position and elongation rate as well. The cell length varied between 1 and about 20 micron, roughly correlated to the specific growth rate, but was also influenced by the composition and the consistence of the medium. The longest cells were found within the faster growing cultures, forming branched filaments, mycelia or pseudomycelia. During transition to the stationary growth phase these forms fragmented into rods by increase of the frequency of septation and cell separation. Increased cell length was accompanied by a reduced frequency of e-site formation which was compensated by an enhancement of their synthesizing activity. The rate of envelope synthesis varied with the morphological type from 0.12 to 9.60 micron/h. In agar-microcultures these values were much higher than in liquid media. In liquid cultures the e-sites preferentially were situated at one (rod) or the 2 cell poles (filaments), but during faster growth additional e-sites were formed within the cylindrical part of the envelope, thus leading to branching. In pseudomycelia the e-sites were formed laterally at the poles. In mycelia the poles did not receive e-site-activity, which instead occurred remote from the cell poles, also causing branching. This means that branching is either the result of the formation of more than two (up to 7) e-sites per cell (fast growing liquid cultures) or of a specific lack of transforming the poles into e-sites, (weakly aerated agar-cultures). The separation of sister cells was correlated to the transformation of poles into e-sites.

Interaction of bacteriophage O2 with strains of the genus Oerskovia.

Bacteriophage O2 multiplies normally on Oerskovia turbata IMET 47 153. It has a burst size of about 100 p.f.u. per infected cell and a latent period of 100 min at 30 degrees C. On Oerskovia xanthineolytica IMET 47 383 clear spots were formed after addition of high phage concentrations onto agar top layers. By phase contrast observation, and measurement of the optical density of infected cultures, it was found that the clearing effect on strain IMET 47 383 was due to lysis-from-without. Phage O2 adsorbs and injects its DNA into cells of strain IMET 47 383 but phage multiplication does not occur, and the phage DNA becomes degraded. Inhibition of phage DNA injection by the combined action of xanthotoxin -- u.v. irradiation abolished the clearing activity of phage lysates. Therefore, both adsorption and DNA injection seem to be prerequisites for the release of a lytic activity out of the phage particle, which is responsible for the clearing effect on strain IMET 47 383.

[Development cycles of coryneform and Nocardia-like bacteria]. / Tsikly razvitiia nekotorykh korinepodobnykh i nokardiopodobnykh bakterii.

The growth cycles and the types of cell separation were studied in a microchamber with the collection strains of Brevibacterium ammoniagenes ATTC 6871, B. helvolum ATCC 19239, B. linens CCM 47 and ATCC 9174, B. maris VKM B-464 and B. stationis ATCC 14403, as well as with the strains of the genus Rhodococcus isolated from soils, viz. R. maris sp. nov. IMB 283 and R. luteus sp. nov. IMB 385. According to the increasing complexity of cellular morphological transformation in the life cycle, the organisms may be arranged in a series: R. maris -- B. ammoniagenes -- B. stationis -- B. linens -- B. helvolum -- R. luteus. The first three organisms are characterized by the snapping type of separation of short rod-like daughter cells. The cells of B. linens separate by both the snapping and bending types. The coccoid cells of B. helvolum ATCC 19239 produce many buds which are transformed into rod-like cells in the course of growth. In the log phase of growth, both true and false branching of the cells is observed; the latter is the result of a peculiar growth of the ends in the separated cells of B. helvolum. The cells of R. luteus form a rudimentary, rapidly fragmenting mycelium whose rod-like elements divide then by binary fission; the daughter cells separate the bending and snapping types.

Isolation and characterization of Actinopolyspora halophila, gen. et sp. nov., an extremely halophilic actinomycete.

An actinomycete, isolated as a contaminant of a culture medium containing 25% NaCl, has been classified as Actinopolyspora halophila gen. et sp. nov. in the family Nocardiaceae. The morphology and biochemical characteristics of this organism distinguish it from other members of the family Nocardiaceae and other genera possessing a type IV cell wall. It requires high NaCl concentrations for growth and can grow in saturated NaCl. The lowest concentration permitting growth in liquid medium is 12%, and on solid medium, 10%. Colonies developing at lower salt concentrations contain holes resembling viral plaques. No growth occurred in a medium containing 30% KCl instead of NaCl. This organism can grow in simple media with NH4+ salts as nitrogen source and different sugars and other compounds as carbon source. Though it has a salt requirement almost as great as the extremely halophilic rods and cocci, it differs from these in containing diaminopimelic acid and in sensitivity to lysozyme; both properties suggest that it has a mucopeptide cell wall. It also contains some phospholipids common to other actinomycetes, but does not contain any phytanyl ether linked lipids characteristic of other extremely halophilic bacteria.