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1.
Coaggregation among Nonflocculating Bacteria Isolated from Activated Sludge 总被引:7,自引:3,他引:4
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Anushree Malik Masashi Sakamoto Shohei Hanazaki Masamitsu Osawa Takanori Suzuki Masaki Tochigi Kazuo Kakii 《Applied microbiology》2003,69(10):6056-6063
Thirty-two strains of nonflocculating bacteria isolated from sewage-activated sludge were tested by a spectrophotometric assay for their ability to coaggregate with one other in two-membered systems. Among these strains, eight showed significant (74 to 99%) coaggregation with Acinetobacter johnsonii S35 while only four strains coaggregated, to a lesser extent (43 to 65%), with Acinetobacter junii S33. The extent and pattern of coaggregation as well as the aggregate size showed good correlation with cellular characteristics of the coaggregating partners. These strains were identified by sequencing of full-length 16S rRNA genes. A. johnsonii S35 could coaggregate with strains of several genera, such as Oligotropha carboxidovorans, Microbacterium esteraromaticum, and Xanthomonas spp. The role of Acinetobacter isolates as bridging organisms in multigeneric coaggregates is indicated. This investigation revealed the role of much-neglected nonflocculating bacteria in floc formation in activated sludge. 相似文献
2.
Two strains of non-flocculating sewage sludge bacteria (Xanthomonassp. S53 and Microbacterium esteraromaticum S51) showed 91% and 77% co-aggregation, respectively, with Acinetobacter johnsonii S35 using a spectrophometric assay. The co-aggregates in case of Xanthomonas sp. S53 and A. johnsonii S35 were above 100 m and stable against EDTA (2 mM) and a commercial protease (0.2 mg ml–1). Protease/periodate pretreatment of the partners did not affect this co-aggregation. On the other hand, co-aggregates of M. esteraromaticum S51 and A. johnsonii S35 (50–70 m) were deflocculated by EDTA or protease. Protease pretreatment of M. esteraromaticum S51 and periodate pretreatment of A. johnsonii S35 prevented their co-aggregation with respective untreated partners. The potential co-aggregation mechanisms of A. johnsonii S35 varied depending upon the other partner involved. 相似文献
3.
Acinetobacter johnsonii S35 has an ability to coaggregate with Oligotropha carboxidovorans S23 when grown with favorable carbon substrate and nutrient-rich growth media. However, nutrient-deficient situations or poorly accessible carbon substrates in waste streams could trigger changes in the cell surface properties and thus modify the coaggregation behavior. Thus, in the present study, we test the stability of these novel interactions under various stresses that might transpire in the waste streams. The effect of mineral-component deficiency and shortage of substrate on the growth, cell surface hydrophobicity and coaggregation ability of S35 and O. carboxidovorans S23 has been investigated. As compared to the control, growth of S35 was adversely affected in mineral-deficient medium; the cells had lower hydrophobicity but displayed only slightly lower aggregation index (AI, 75-84%) as compared to control (92%). S35 grown on marginally supplemented Sterile Filtrate of Activated Sludge (SFAS) could also grow well and form larger stable coaggregates with S23. S35 grown with mineral-deficient medium and with the supplemented SFAS still posses the ability to coaggregate with S23. Hence the coaggregation ability of S35 strain is constitutive and is not significantly affected by environmental factors. It would be desirable to work out suitable formulations of such robust and environmentally relevant microbes. 相似文献
4.
Volodymyr Ivanov Xiao-Hui Wang Olena Stabnikova 《World journal of microbiology & biotechnology》2008,24(4):533-539
Aggregation of bacterial cells is used in formation of microbial granules. Aerobically grown microbial granules can be used
as the bio-agents in the treatment of wastewater. However, there are problems with start up of microbial granulation and biosafety
of this process. Aim of this research was selection and testing of safe microbial strain with high cell aggregation ability
to shorten period of microbial granules formation. Five bacterial strains with cell aggregation index higher than 50% have
been isolated from the granules. Strain of Pseudomonas veronii species was considered as most probably safe starter culture for granulation because other strains belonged to the species
known as human pathogens. The microbial granules were formed after 3 days of cultivation in case when P. veronii strain B was applied to start-up aerobic granulation process using model wastewater. The granules were produced from activated
sludge after 9 days of cultivation. Microbial aggregates produced from starter culture of P. veronii strain B were more compact (sludge volume index was 70 ml/g) than those produced from activated sludge (sludge volume index
was 106 ml/g). It is a first proof that application of selected safe starter pure culture with high cell aggregation ability
can accelerate and enhance formation of microbial granules. 相似文献
5.
A. Pijanowska E. Kaczorek Ł. Chrzanowski A. Olszanowski 《World journal of microbiology & biotechnology》2007,23(5):677-682
Biodegradation and hydrophobicity of Pseudomonas spp. and Bacillus spp. strains were tested at different concentrations of the biosurfactant Quillaya saponin. A model mixture of hydrocarbon
(dodecane and hexadecane) was used for estimating the influence of surfactants on biodegradation. The bacterial adhesion to
hydrocarbon method for determination of bacterial cell surface hydrophobicity was exploited. Among the tested bacterial strains
the higher hydrophobicity was noticed for Pseudomonas aeruginosa TK. The hydrophobicity of this strain was 84%. The highest hydrocarbon biodegradation was observed for P. aeruginosa TK (49%) and Bacillus subtilis (35%) strains after 7 days of experiments. Generally the addition of Quillaya saponin increased hydrocarbon biodegradation
remarkably. The optimal concentration proved to be 80 mg l−1. The degree of hydrocarbon biodegradation was 75% for P. aeruginosa TK after the addition of saponin. However the most significant increase in biodegradation after addition of Quillaya saponin
was in the case of P. aeruginosa 25 and Pseudomonas putida (the increase of biodegradation from 21 to 52% and from 31 to 66%, respectively). It is worth mentioning that decrease of
hydrophobicity is correlated with the best biodegradation by P. aeruginosa strain. For the remaining strains, no significant hydrophobicity changes in relation to the system without surfactant were
noticed. 相似文献
6.
Effects of a fungal endophyte, Fusarium mairei, on growth and paclitaxel formation of Taxus cuspidata cells were investigated by adding fungal endophyte culture supernatant (FECS) to suspension cultures of T. cuspidata cells. The main effective chemical responsible for paclitaxel formation in FECS was an exopolysaccharide (EPS) of molecular
weight ~2 kDa. FECS fractions except EPS stimulated growth of Taxus cells but had no effects on paclitaxel accumulation. Additionally, elicitation efficiency of FECS based on different culture
conditions was studied. EPS content in FECS was related to FECS culture conditions. FECS with long cultivation and high-aeration
cultivation contained higher EPS content and resulted in higher paclitaxel yield than that with short cultivation and low-aeration
cultivation. The maximum yield of paclitaxel from Taxus cultures, elicited by FECS with 9-day cultivation, was 4.7-fold that of the control cultures. 相似文献
7.
The effect of anionic (sodium dodecyl sulphate or SDS) and cationic (cetyltrimethylammonium bromide or CTAB) surfactants on the stability of binary bacterial coaggregates comprising Acinetobacter johnsonii S35 and Oligotropha carboxidovorans S23 (both sewage sludge isolates) was studied and compared with that on the complex sewage sludge flocs. Both SDS and CTAB enhanced the bacterial coaggregation at their lower concentrations of 0.2 and 0.07 mg ml(-1), respectively. However, complete deflocculation of coaggregates was observed at 1 mg ml(-1) SDS and 0.3 mg l(-1) CTAB concentrations. Further, sewage sludge flocs did not deflocculate in the presence of CTAB, although a concentration-dependent deflocculation was observed in the presence of SDS. A. johnsonii S35 and O. carboxidovorans S23 cells were separately pretreated (prior to coaggregation) with the surfactants. In spite of the partial (complete) loss of viability during SDS (CTAB) pretreatment, washed cells still retained hydrophobic character and displayed significant coaggregation (aggregation index ranging from 84% to 97% in comparison to 96% in the case of non-treated cells), demonstrating reversibility of the surfactant induced deflocculation. Further, when exposed to lower concentration of surfactants (0.2 mg ml(-1) SDS), coaggregates were more resistant (76% viability) as compared to the individual partner (S35: 52%; S23: 39% viability). Since the coaggregates are stable and provide protection from surfactants at lower concentrations (those normally expected in the sewage treatment plants), their presence as well as a sustained role in the sewage sludge bioflocculation is evident. 相似文献
8.
Pratiksha Bhadauriya Radha Gupta Surendra Singh Prakash Singh Bisen 《World journal of microbiology & biotechnology》2008,24(1):139-141
n-Alkanes pattern in response to NaCl stress has been studied in the cyanobacterium Anabaena cylindrica. Saturated hydrocarbons were separated and identified by gas chromatography-mass spectrometry (GC-MS) using serially coupled
capillary column. Light chain n-alkanes in the range of C9–C17 (43%) and heavy chain n-alkanes in range of C17–C23 (34%) and C23–C31 (23%) were identified as the major components of total hydrocarbons in the NaCl adapted cells of A. cylindrica. In contrast, NaCl-untreated cells of A. cylindrica had dominance of only long chain n-alkanes in the range of C23–C31 comprising about 94% of its total n-alkanes. The persistence of high level (43%) of short chain n-alkanes (C9–C17) in NaCl adapted cells of A. cylindrica as compared to its negligible level (0.2%) in NaCl untreated counterpart clearly indicates that NaCl stress causes the A. cylindrica to shift towards the synthesis of short chain n-alkanes. 相似文献
9.
Flavobacterium spp. isolates have been identified in diverse biofilm structures, but the mechanism of adherence has not been elucidated.
The absence of conventional biofilm-associated structures such as fimbriae, pili, and flagella suggest that surface hydrophobicity,
and/or autoaggregation and coaggregation may play an important role in adherence and biofilm formation. The biofilm-forming
capacity of 29 Flavobacterium johnsoniae-like isolates obtained from South African aquaculture systems was assessed using microtiter plate assays. The role of hydrophobicity
[salting aggregation test (SAT) and bacterial adherence to hydrocarbons (BATH) assays], autoaggregation, and coaggregation
on biofilm formation by Flavobacterium spp. was also investigated, while biofilm structure was examined using flow cells and microscopy. All isolates displayed
a hydrophilic nature, but showed varying levels of adherence in microtiter assays. Significant negative correlations were
observed between adherence and biofilm-forming capacity in nutrient-poor medium at 26°C and BATH hydrophobicity and motility,
respectively. Isolates displayed strain-to-strain variation in their autoaggregation indices and their abilities to coaggregate
with various Gram-negative and Gram-positive organisms. Microcolony and/or biofilm development were observed microscopically,
and flavobacterial isolates displayed stronger biofilm structures and interaction with a Vibrio spp. isolate than with an Aeromonas hydrophila isolate. The role of extracellular polysaccharides and specific outer membrane proteins will have to be examined to reveal
mechanisms of adherence and coaggregation employed by biofilm-forming F. johnsoniae-like strains. 相似文献
10.
The relationship between Sporidiobolus johnsonii and S. salmonicolor was investigated using rDNA sequence data. Two statistically well-supported clades were obtained. One clade included the
type strain of S. johnsonii and the other included the type strain of S. salmonicolor. However, some mating strains of S. salmonicolor were found in the S. johnsonii group. These strains belonged to mating type A2 and were sexually compatible with mating type A1 strains from the S. salmonicolor group. DNA–DNA reassociation values were high within each clade and moderate between the two clades. In the re-investigation
of teliospore germination, we observed that the basidia of S. salmonicolor were two-celled. In S. johnsonii, basidia were not formed and teliospore germination resulted in direct formation of yeast cells. We hypothesize that the
S. johnsonii clade is becoming genetically isolated from the S. salmonicolor group and that a speciation process is presently going on. We suspect that the observed sexual compatibility between strains
of the S. johnsonii and S. salmonicolor groups and the possible genetic flow between the two species has little biological relevance because distinct phenotypes
have been fixed in the two taxa and intermediate (hybrid) sequences for LSU and ITS rDNAs have not been detected.
An erratum to this article can be found at 相似文献
11.
Studying the spatial pattern of insect pests and the temporal stability of their patterns is important in understanding underlying
ecological mechanisms and in developing pest management programs in cultivated crop systems. To elucidate the spatio-temporal
pattern of the black rice bug, Scotinophara lurida, in rice fields, samplings were conducted in two rice fields over 2 years. Using spatial analysis by distance indices, the
spatial pattern of each developmental stage of S. lurida and their temporal stability of the spatial pattern were identified. Most of the I
a (the index of aggregation) values for overwintered adults and eggs of S. lurda were close to 1, indicating random distribution pattern while nymphs and new adults mainly had I
a values >1, indicating an aggregated distribution pattern. According to spatial association analysis between successive samples
using X (the index of spatial association), the spatial pattern of S. lurida showed strong temporal stability throughout the season. Also, there was strong association between the spatial patterns of
developmental stages, indicating the great effect of the spatial pattern of the previous developmental stage on that of later
developmental stage. Factors influencing the spatial pattern and spatial stability of S. lurida are discussed. 相似文献
12.
13.
Purification and properties of pyrophosphatase of Acinetobacter johnsonii 210A and its involvement in the degradation of polyphosphate 总被引:1,自引:0,他引:1
Inorganic pyrophosphatase (E.C. 3.6.1.1) of Acinetobacter johnsonii210A was purified 200-fold to apparent homogeneity. The enzyme catalyzedthe hydrolysis of inorganic pyrophosphate and triphosphate to orthophosphate.No activity was observed with other polyphosphates and a wide variety oforganic phosphate esters. The molecular mass of the enzyme was estimatedto be 141 kDa by gelfiltration. Sodium dodecyl sulfate-polyacrylamide gelelectrophoresis indicated a subunit composition of six identical polypeptideswith a molecular mass of 23 kDa. The cation Mg2 was required foractivity, the activity with Mn2, Co2 and Zn2 was 48, 48 and 182% of the activity observed with Mg2, respectively. The enzyme was heat-stable and inhibited by fluoride and iodoacetamide. The analysis of the kinetic properties of the enzyme revealed an apparent Km for pyrophosphate of 0.26 mM. In A. johnsonii 210A, pyrophosphatase may be involved in the degradation of high-molecular polyphosphates under anaerobic conditions: (i) it catalyses the further hydrolysis of pyrophosphate and triphosphate formed from high-molecular weight polyphosphates by the action of exopolyphosphatase, and (ii) it abolishes the inhibition of polyphosphate: AMP phosphotransferase-mediated degradation by pyrophosphate and triphosphate. 相似文献
14.
Bioassays were performed to investigate the effects of the novel allelochemical, ethyl 2-methylacetoacetate (EMA), isolated
from the reed (Phragmitis australis) on the growth of three common species of algae; Scenedesmus obliquus, Selenastrum capricornutum and Chlamydomonas reinhardtii. The results demonstrated that EMA has three quite different types of effect on these three species of algae. The growth
of S. capricornutum was significantly inhibited by EMA during the whole cultivation period. The EC50 values of EMA on S. capricornutum was 0.6 mg L−1(7 days). However, the inhibitory effect of EMA on S. obliquus was apparent during the first 4 days of batch cultivation and then the inhibitory effect disappeared, and a stimulating effect
was observed instead. The EC50 value of EMA on S. obliquus was 0.43 mg L−1(4 days). In addition, following the addition of EMA, the cells of S. obliquus and S. capricornutum became significantly larger than the normal untreated one and the algal cells changed morphologically. The microstructure
of the algal cells was disrupted by the addition of EMA. There was no significant inhibition of the growth of C. reinhardtii by EMA, but cell motility was affected. 相似文献
15.
The objectives of this research were first to isolate plastid gene sequences from cabbage (Brassica oleracea L. var. capitata L.), and to establish the chloroplast transformation technology of Brassica. A universal transformation vector (pASCC201) for Brassica chloroplast was constructed with trnV–rrn16S (left) and trnI–trnA–rrn23S (right) of the IRA region as a recombination site for the transformed gene. In transforming plasmid pASCC201, a chimeric aadA gene was cloned between the rrn16S and rrn23S plastid gene borders. Expression of aadA confers resistance to spectinomycin and streptomycin antibiotics. The uidA gene was also inserted into the pASCC201 and transferred into the leaf cells of cabbage via particle gun mediated transformation.
Regenerated plantlets were selected by 200 mg/l spectinomycin and streptomycin. After antibiotic selection, the regeneration
percentage of the two cabbage cultivars was about 2.7–3.3%. The results of PCR testing and Southern blot analysis confirmed
that the uidA and aadA genes were present in the chloroplast genome via homologously recombined. Northern blot hybridizations, immunoblotting and
GUS histochemical assays indicated that the uidA gene were stable integrated into the chloroplast genome. Foreign protein was accumulated at 3.2–5.2% of the total soluble
protein in transgenic mature leaves. These results suggest that the expression of a variety of foreign genes in the chloroplast
genome will be a powerful tool for use in future studies. 相似文献
16.
Ottem KF Nylund A Karlsbakk E Friis-Møller A Krossøy B Knappskog D 《Archives of microbiology》2007,188(5):547-550
A Francisella strain, GM2212, previously isolated from moribund farmed Atlantic cod (Gadus morhua) in Norway, is closely related to Francisella philomiragia among Francisella spp. according to its complete 16S rDNA, 16S-23S intergenic spacer, 23S rDNA, 23S–5S intergenic spacer, 5S rDNA, FopA, lipoprotein
TUL4 (LpnA), malate dehydrogenase and hypothetical lipoprotein (LpnB) sequences. A comparison between GM2212 and the type
strain of Francisella philomiragia were performed by DNA–DNA hybridization and fatty acid analysis. The DNA–DNA hybridization showed a 70% similarity. The fatty
acid analysis showed only minor differences between the Francisella isolates. Due to the inconclusive result from the DNA–DNA hybridisation, major emphasis concerning the status of this isolate
is made on previously published molecular, phenotypic and biochemical characters. All characteristics taken together support
the establishment of GM2212 as a novel species, for which the name Francisella piscicida sp. nov. is proposed (=CNCM I-3511T = DSM 18777T = LMG registration number not yet
available). 相似文献
17.
Dr AR Holmes RD Cannon HF Jenkinson 《Journal of industrial microbiology & biotechnology》1995,15(3):208-213
The yeastCandida albicans coaggregates with a variety of streptococcal species, an interaction that may promote oral colonization by yeast cells.C. albicans andCandida tropicalis are the yeasts most frequently isolated from the human oral cavity and our data demonstrate that both these species bind toStreptococcus gordonii NCTC 7869 while two otherCandida species (Candida krusei andCandida kefyr) do not. Adherence ofC. albicans was greatest when the yeast had been grown at 30° C to mid-exponential growth phase. For 21 strains ofC. albicans there was a positive correlation between the ability to adhere toS. gordonii and adherence to experimental salivary pellicle. Whole saliva either stimulated or slightly inhibited adherence ofC. albicans toS. gordonii depending on the streptococcal growth conditions. The results suggest that the major salivary adhesins and coaggregation adhesins ofC. albicans are co-expressed. 相似文献
18.
Localization and antioxidant capacity of flavonoids from intertidal and subtidal Halophila johnsonii and Halophila decipiens 总被引:1,自引:0,他引:1
In this study, flavonoid localization, content and total antioxidant capacity in leaves of subtidal Halophila decipiens were compared to intertidal and subtidal Halophila johnsonii. H. johnsonii leaves had significantly higher flavonoid content (3.5 and 3.8 nmol quercetin equivalent mm−2 leaf for intertidal and subtidal H. johnsonii, respectively) and antioxidant capacity (101.7 and 224.2 nmol Trolox equivalent mm−2 leaf for intertidal and subtidal H. johnsonii, respectively) than H. decipiens leaves (1.4 nmol quercetin equivalent mm−2 leaf and 21.0 nmol Trolox equivalent mm−2 leaf). Flavonoid content did not significantly differ between intertidal and subtidal H. johnsonii, however, antioxidant capacity was significantly higher in subtidal plants. Confocal laser scanning microscopy of fresh leaf cross sections indicated that both species contained flavonoids in the cuticle, but only H. johnsonii contained intracellular flavonoids. Intracellular flavonoids are better situated to perform antioxidant functions in planta. These results suggest that flavonoid compounds in H. johnsonii are capable of sunscreen and antioxidant functions while an antioxidant role for flavonoids within H. decipiens is not supported. 相似文献
19.
Scoaris Dde O Colacite J Nakamura CV Ueda-Nakamura T de Abreu Filho BA Dias Filho BP 《Antonie van Leeuwenhoek》2008,93(1-2):111-122
Aeromonas isolates from tap water, mineral water, and artesian well water were investigated for their ability to produce different
potential virulence factors or markers such as hemolysins, cytotoxins, phospholipase, DNase, hydrophobicity and their ability
to adhere to epithelial cells and to abiotic surfaces. The susceptibility to antibiotics of Aeromonas isolates was also examined. Majority of the isolates displayed hemolytic activity against sheep erythrocytes, while only
7 of the 23 Aeromonas strains displayed DNase activity and 4 of the 23 Aeromonas strains tested were regarded as positive for phospholipase production. Most of the isolates showed cytotoxic activities in
culture filtrate dilutions at titer of 1/8 or lower. No general relation between the strain isolated and the ability to interact
with epithelial cells could be established. Using the bacterial adherence to hydrocarbons method, most of the strains were
classified as highly hydrophilic. All five Aeromonas jandaei strains isolates, 9 of the 12 Aeromonas sp strains and four of the five Aeromonas hydrophila were multidrug resistant. The most active antimicrobial was ciprofloxacin (susceptible in 100% of the isolates), and the
least active antibiotic was ampicillin (resistance in 92% of the isolates). The majority of the isolates tested were not killed
by chlorine at 1.2 mg/l. Whether the high tolerance to chlorine of Aeromonas isolates can be linked to greater virulence is not know. 相似文献
20.
Origin of chloroplast DNA diversity in the Andean potatoes 总被引:1,自引:1,他引:0
K. Hosaka R. E. Hanneman Jr. 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1988,76(3):333-340
Summary Wide chloroplast DNA (ctDNA) diversity has been reported in the Andean cultivated tetraploid potato, Solanum tuberosum ssp. andigena. Andean diploid potatoes were analyzed in this study to elucidate the origin of the diverse ctDNA variation of the cultivated tetraploids. The ctDNA types of 58 cultivated diploid potatoes (S. stenotomum, S. goniocalyx and S. phureja), 35 accessions of S. sparsipilum, a diploid weed species, and 40 accessions of the wild or weed species, S. chacoense, were determined based on ctDNA restriction fragment patterns of BamHI, HindIII and PvuII. Several different ctDNA types were found in the cultivated potatoes as well as in weed and wild potato species; thus, intraspecific ctDNA variation may be common in both wild and cultivated potato species and perhaps in the higher plant kingdom as a whole. The ctDNA variation range of cultivated diploid potatoes was similar to that of the tetraploid potatoes, suggesting that the ctDNA diversity of the tetraploid potato could have been introduced from cultivated diploid potatoes. This provided further evidence that the Andean cultivated tetraploid potato, ssp. andigena, could have arisen many times from the cultivated diploid populations. The diverse but conserved ctDNA variation noted in the Andean potatoes may have occurred in the early stage of species differentiation of South American tuber-bearing Solanums. 相似文献