Host-plant selectivity of rhizobacteria in a crop/weed model system

Belowground microorganisms are known to influence plants' performance by altering the soil environment. Plant pathogens such as cyanide-producing strains of the rhizobacterium Pseudomonas may show strong host-plant selectivity. We analyzed interactions between different host plants and Pseudomonas strains and tested if these can be linked to the cyanide sensitivity of host plants, the cyanide production of bacterial strains or the plant identity from which strains had been isolated. Eight strains (four cyanide producing) were isolated from roots of four weed species and then re-inoculated on the four weed and two additional crop species. Bacterial strain composition varied strongly among the four weed species. Although all six plant species showed different reductions in root growth when cyanide was artificially applied to seedlings, they were generally not negatively affected by inoculation with cyanide-producing bacterial strains. We found a highly significant plant species x bacterial strain interaction. Partitioning this interaction into contrasts showed that it was entirely due to a strongly negative effect of a bacterial strain (Pseudomonas kilonensis/brassicacearum, isolated from Galium mollugo) on Echinochloa crus-galli. This exotic weed may not have become adapted to the bacterial strain isolated from a native weed. Our findings suggest that host-specific rhizobacteria hold some promise as biological weed-control agents.     

Genetic diversity and biological control activity of novel species of closely related pseudomonads isolated from wheat field soils in South Australia

Rhizobacteria closely related to two recently described species of pseudomonads, Pseudomonas brassicacearum and Pseudomonas thivervalensis, were isolated from two geographically distinct wheat field soils in South Australia. Isolation was undertaken by either selective plating or immunotrapping utilizing a polyclonal antibody raised against P. brassicacearum. A subset of 42 isolates were characterized by amplified 16S ribosomal DNA restriction analysis (ARDRA), BIOLOG analysis, and gas chromatography-fatty acid methyl ester (GC-FAME) analysis and separated into closely related phenetic groups. More than 75% of isolates tested by ARDRA were found to have >95% similarity to either Pseudomonas corrugata or P. brassicacearum-P. thivervalensis type strains, and all isolates had >90% similarity to either type strain. BIOLOG and GC-FAME clustering showed a >70% match to ARDRA profiles. Strains representing different ARDRA groups were tested in two soil types for biological control activity against the soilborne plant pathogen Gaeumannomyces graminis var. tritici, the causative agent of take-all of wheat and barley. Three isolates out of 11 significantly reduced take-all-induced root lesions on wheat plants grown in a red-brown earth soil. Only one strain, K208, was consistent in reducing disease symptoms in both the acidic red-brown earth and a calcareous sandy loam. Results from this study indicate that P. brassicacearum and P. thivervalensis are present in Australian soils and that a level of genetic diversity exists within these two novel species but that this diversity does not appear to be related to geographic distribution. The result of the glasshouse pot trial suggests that some isolates of these species may have potential as biological control agents for plant disease.     

Pseudomonas brassicacearum strain Am3 containing 1-aminocyclopropane-1-carboxylate deaminase can show both pathogenic and growth-promoting properties in its interaction with tomato

The role of bacterial 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity in the interaction between tomato (Lycopersicon esculentum=Solanum lycopersicum) and Pseudomonas brassicacearum was studied in different strains. The phytopathogenic strain 520-1 possesses ACC deaminase activity, an important trait of plant growth-promoting rhizobacteria (PGPR) that stimulates root growth. The ACC-utilizing PGPR strain Am3 increased in vitro root elongation and root biomass of soil-grown tomato cv. Ailsa Craig at low bacterial concentrations (10(6) cells ml-1 in vitro and 10(6) cells g-1 soil) but had negative effects on in vitro root elongation at higher bacterial concentrations. A mutant strain of Am3 (designated T8-1) that was engineered to be ACC deaminase deficient failed to promote tomato root growth in vitro and in soil. Although strains T8-1 and 520-1 inhibited root growth in vitro at higher bacterial concentrations (>10(6) cells ml-1), they did not cause disease symptoms in vitro after seed inoculation, or in soil supplemented with bacteria. All the P. brassicacearum strains studied caused pith necrosis when stems or fruits were inoculated with a bacterial suspension, as did the causal organism of this disease (P. corrugata 176), but the non-pathogenic strain Pseudomonas sp. Dp2 did not. Strains Am3 and T8-1 were marked with antibiotic resistance and fluorescence to show that bacteria introduced to the nutrient solution or on seeds in vitro, or in soil were capable of colonizing the root surface, but were not detected inside root tissues. Both strains showed similar colonization ability either on root surfaces or in wounded stems. The results suggest that bacterial ACC deaminase of P. brassicacearum Am3 can promote growth in tomato by masking the phytopathogenic properties of this bacterium.     

Characterization of plant growth promoting rhizobacteria isolated from polluted soils and containing 1-aminocyclopropane-1-carboxylate deaminase

Fifteen bacterial strains containing 1-aminocyclopropane-1-carboxylate (ACC) deaminase were isolated from the rhizoplane of pea (Pisum sativum L.) and Indian mustard (Brassica juncea L.) grown in different soils and a long-standing sewage sludge contaminated with heavy metals. The isolated strains were characterized and assigned to various genera and species, such as Pseudomonas brassicacearum, Pseudomonas marginalis, Pseudomonas oryzihabitans, Pseudomonas putida, Pseudomonas sp., Alcaligenes xylosoxidans, Alcaligenes sp., Variovorax paradoxus, Bacillus pumilus, and Rhodococcus sp. by determination of 16S rRNA gene sequences. The root elongation of Indian mustard and rape (Brassica napus var. oleifera L.) germinating seedlings was stimulated by inoculation with 8 and 13 isolated strains, respectively. The bacteria were tolerant to cadmium toxicity and stimulated root elongation of rape seedlings in the presence of 300 microM CdCl2 in the nutrient solution. The effect of ACC-utilising bacteria on root elongation correlated with the impact of aminoethoxyvinylglycine and silver ions, chemical inhibitors of ethylene biosynthesis. A significant improvement in the growth of rape caused by inoculation with certain selected strains was also observed in pot experiments, when the plants were cultivated in cadmium-supplemented soil. The biomass of pea cv. Sparkle and its ethylene sensitive mutant E2 (sym5), in particular, was increased through inoculation with certain strains of ACC-utilising bacteria in pot experiments in quartz sand culture. The beneficial effect of the bacteria on plant growth varied significantly depending on individual bacterial strains, plant genotype, and growth conditions. The results suggest that plant growth promoting rhizobacteria containing ACC deaminase are present in various soils and offer promise as a bacterial inoculum for improvement of plant growth, particularly under unfavourable environmental conditions.     

Isolation and characterization of Pseudomonas brassicacearum J12 as an antagonist against Ralstonia solanacearum and identification of its antimicrobial components

A bacterial strain, J12, isolated from the rhizosphere soil of tomato plants strongly inhibited the growth of phytopathogenic bacteria Ralstonia solanacearum. Strain J12 was identified as Pseudomonas brassicacearum based on its 16S rRNA gene sequence. J12 could produce 2,4-diacetylphloroglucinol (2,4-DAPG), hydrogen cyanide (HCN), siderophore(s) and protease. The maximum growth and antagonistic activity were recorded at 30°C and pH 8. Glucose and tryptone were used as the most suitable carbon and nitrogen sources, respectively. Strain J12 significantly suppressed tomato bacteria wilt by 45.5% in the greenhouse experiment. The main antimicrobial compound of J12 was identified as 2,4-diacetylphloroglucinol (2,4-DAPG) by HPLC-ESI-MS analysis. The gene cluster phlACBD, which is responsible for 2,4-DAPG production, was identified and expressed in the bacterial strain Escherichia coli DH5α.     

Complete genome sequence of a beneficial plant root-associated bacterium, Pseudomonas brassicacearum

To shed light on the genetic equipment of the beneficial plant-associated bacterium Pseudomonas brassicacearum, we sequenced the whole genome of the strain NFM421. Its genome consists of one chromosome equipped with a repertoire of factors beneficial for plant growth. In addition, a complete type III secretion system and two complete type VI secretion systems were identified. We report here the first genome sequence of this species.     

Recharacterization of Pseudomonas fulva Iizuka and Komagata 1963, and proposals of Pseudomonas parafulva sp. nov. and Pseudomonas cremoricolorata sp. nov

Seven Pseudomonas fulva strains obtained from culture collections were taxonomically studied. The seven strains were separated into three clusters (Clusters I to III) on the basis of 16S rRNA gene sequences, and located phylogenetically in the genus Pseudomonas sensu stricto. Further, the strains were classified into 4 groups (Groups I to IV) on the basis of DNA-DNA similarity. As a result, Cluster I was split into Groups I and II. Group I included the type strain of P. fulva and two strains, and levels of DNA-DNA similarity ranged from 88 to 100% among the strains. Group II contained two strains, and the level between the two strains ranged from 91 to 100%. Group III consisted of one strain. Group IV included one strain, and this strain showed a high level of DNA-DNA similarity with the type strain of Pseudomonas straminea NRIC 0164(T). Clusters II and III corresponded to Groups III and IV, respectively. The four groups were separated from one another and from related Pseudomonas species at the level from 3 to 45% of DNA-DNA similarity. The strains of Groups I, II, and III had ubiquinone 9 as the major quinone. According to numerical analysis by the use of 133 phenotypic characteristics, the seven P. fulva strains were split into four phenons (Phenons I to IV). The groups by DNA-DNA similarity corresponded well with the phenons produced by numerical taxonomy, and differential characteristics were recognized. Consequently, Group I was regarded as P. fulva because the type strain (NRIC 0180(T)) of this species was included in this group. Strains in Group II were identified as a new species, Pseudomonas parafulva sp. nov., and the type strain is AJ 2129 (=IFO 16636=JCM 11244=NRIC 0501). NRIC 0181 in Group III was identified as a new species, Pseudomonas cremoricolorata sp. nov., and the type strain is NRIC 0181 (=IFO 16634=JCM 11246). NRIC 0182 in Group IV was identified as P. straminea on the basis of the high level of DNA-DNA similarity with the type strain of this species.     

The Naturally Transformable Marine Bacterium WJT-1C Formally Identified as “Vibrio” Is a Pseudomonad

A marine bacterial isolate, previously identified as Vibrio WJT-1C (ATCC 55351) and used as a model for investigating the process of natural transformation in the marine environment, has been further examined to determine its taxonomic identity. API 20E test strips, phenotypic testing, and flagellar staining had previously assigned the strain to the genus Vibrio, most closely related to V. campbelli. 16S rRNA analysis indicated that WJT-1C was in the Pseudomonas subgroup of the gamma proteobacteria. Bacteriophage typing and natural transformation with chromosomal DNA indicated that it was distinct from previously described marine transforming pseudomonads including Pseudomonas stutzeri strain JM300. The importance and abundance of the Pseudomonas subgroup of the gamma proteobacteria in the environment suggest that these marine strains are well suited as model organisms for describing the process and importance of natural transformation in nature. Received: 19 February 1996 / Accepted: 29 April 1996     

Structure and Species Composition of Mercury-Reducing Biofilms

Mercury-reducing biofilms from packed-bed bioreactors treating nonsterile industrial effluents were shown to consist of a monolayer of bacteria by scanning electron microscopy. Droplets of several micrometers in diameter which accumulated outside of the bacterial cells were identified as elemental mercury by electron-dispersive X-ray analysis. The monospecies biofilms of Pseudomonas putida Spi3 initially present were invaded by additional strains, which were identified to the species level by thermogradient gel electrophoresis (TGGE) and 16S rDNA sequencing. TGGE community fingerprints of the biofilms showed that they were composed of the effluent bacteria and did not contain uncultivable microorganisms. Of the 13 effluent bacterial strains, 2 were not mercury resistant, while all the others had resistance levels similar to or higher than the inoculant strain.     

Bacterial cell‐to‐cell signaling promotes the evolution of resistance to parasitic bacteriophages

The evolution of host–parasite interactions could be affected by intraspecies variation between different host and parasite genotypes. Here we studied how bacterial host cell‐to‐cell signaling affects the interaction with parasites using two bacteria‐specific viruses (bacteriophages) and the host bacterium Pseudomonas aeruginosa that communicates by secreting and responding to quorum sensing (QS) signal molecules. We found that a QS‐signaling proficient strain was able to evolve higher levels of resistance to phages during a short‐term selection experiment. This was unlikely driven by demographic effects (mutation supply and encounter rates), as nonsignaling strains reached higher population densities in the absence of phages in our selective environment. Instead, the evolved nonsignaling strains suffered relatively higher growth reduction in the absence of the phage, which could have constrained the phage resistance evolution. Complementation experiments with synthetic signal molecules showed that the Pseudomonas quinolone signal (PQS) improved the growth of nonsignaling bacteria in the presence of a phage, while the activation of las and rhl quorum sensing systems had no effect. Together, these results suggest that QS‐signaling can promote the evolution of phage resistance and that the loss of QS‐signaling could be costly in the presence of phages. Phage–bacteria interactions could therefore indirectly shape the evolution of intraspecies social interactions and PQS‐mediated virulence in P. aeruginosa.     

Bacteriocin activity of Pseudomonas sp. on enteropathogenic bacteria in an artificial aquatic system

The bacteriocin of Pseudomonas sp. strain R10 was active in vitro against several enteropathogenic bacteria: enterotoxigenic Escherichia coli, Salmonella typhimurium, Salmonella typhi, Shigella flexneri and Shigella sonnei. Pseudomonas sp. R10 was studied for 5 d in an aquatic system in the presence of strains of the enteropathogenic species mentioned. All the target strains were inhibited in the presence of bacteriocinogenic Pseudomonas sp. R10 and the highest antibacterial action was observed on the second day. Similar results were obtained with the partially purified bacteriocin, although the greatest bactericidal action, in all the studied target strains, was observed on the first day and the bacterial recounts were slightly higher overall.     

Utility of Microcosm Studies for Predicting Phylloplane Bacterium Population Sizes in the Field

Population sizes of two ice nucleation-active strains of Pseudomonas syringae were compared on leaves in controlled environments and in the field to determine the ability of microcosm studies to predict plant habitat preferences in the field. The P. syringae strains investigated were the parental strains of recombinant deletion mutant strains deficient in ice nucleation activity that had been field tested for their ability to control plant frost injury. The population size of the P. syringae strains was measured after inoculation at three field locations on up to 40 of the same plant species that were studied in the growth chamber. There was seldom a significant relationship between the mean population size of a given P. syringae strain incubated under either wet or dry conditions in microcosms and the mean population size which could be recovered from the same species when inoculated in the field. Specifically, on some plant species, the population size recovered from leaves in the field was substantially greater than from that species in a controlled environment, while for other plant species field populations were significantly smaller than those observed under controlled conditions. Population sizes of inoculated P. syringae strains, however, were frequently highly positively correlated with the indigenous bacterial population size on the same plant species in the field, suggesting that the ability of a particular plant species to support introduced bacterial strains is correlated with its ability to support large bacterial populations or that indigenous bacteria enhance the survival of introduced strains. Microcosm studies therefore seem most effective at assessing possible differences between parental and recombinant strains under a given environmental regime but are limited in their ability to predict the specific population sizes or plant habitat preferences of bacteria on leaves under field conditions.     

Siderophore typing,a powerful tool for the identification of fluorescent and nonfluorescent pseudomonads

A total of 301 strains of fluorescent pseudomonads previously characterized by conventional phenotypic and/or genomic taxonomic methods were analyzed through siderotyping, i.e., by the isoelectrophoretic characterization of their main siderophores and pyoverdines and determination of the pyoverdine-mediated iron uptake specificity of the strains. As a general rule, strains within a well-circumscribed taxonomic group, namely the species Pseudomonas brassicacearum, Pseudomonas fuscovaginae, Pseudomonas jessenii, Pseudomonas mandelii, Pseudomonas monteilii, "Pseudomonas mosselii," "Pseudomonas palleronii," Pseudomonas rhodesiae, "Pseudomonas salomonii," Pseudomonas syringae, Pseudomonas thivervalensis, Pseudomonas tolaasii, and Pseudomonas veronii and the genomospecies FP1, FP2, and FP3 produced an identical pyoverdine which, in addition, was characteristic of the group, since it was structurally different from the pyoverdines produced by the other groups. In contrast, 28 strains belonging to the notoriously heterogeneous Pseudomonas fluorescens species were characterized by great heterogeneity at the pyoverdine level. The study of 23 partially characterized phenotypic clusters demonstrated that siderotyping is very useful in suggesting correlations between clusters and well-defined species and in detecting misclassified individual strains, as verified by DNA-DNA hybridization. The usefulness of siderotyping as a determinative tool was extended to the nonfluorescent species Pseudomonas corrugata, Pseudomonas frederiksbergensis, Pseudomonas graminis, and Pseudomonas plecoglossicida, which were seen to have an identical species-specific siderophore system and thus were easily differentiated from one another. Thus, the fast, accurate, and easy-to-perform siderotyping method compares favorably with the usual phenotypic and genomic methods presently necessary for accurate identification of pseudomonads at the species level.     

Structure and species composition of mercury-reducing biofilms

Mercury-reducing biofilms from packed-bed bioreactors treating nonsterile industrial effluents were shown to consist of a monolayer of bacteria by scanning electron microscopy. Droplets of several micrometers in diameter which accumulated outside of the bacterial cells were identified as elemental mercury by electron-dispersive X-ray analysis. The monospecies biofilms of Pseudomonas putida Spi3 initially present were invaded by additional strains, which were identified to the species level by thermogradient gel electrophoresis (TGGE) and 16S rDNA sequencing. TGGE community fingerprints of the biofilms showed that they were composed of the effluent bacteria and did not contain uncultivable microorganisms. Of the 13 effluent bacterial strains, 2 were not mercury resistant, while all the others had resistance levels similar to or higher than the inoculant strain.     

Molecular evidence supporting the existence of two major groups in uropathogenic Escherichia coli

Abstract Molecular methods allow an extremely fine strain typing that can be used to establish the population structure of bacterial species. This methodology has been used to characterize a collection of 74 uropathogenic Escherichia coli obtained from three hospitals located in geographically distant towns in Spain, some representatives of the ECOR collection and other reference strains. Genomic DNA was analyzed by RAPD (Random Amplified Polymorphic DNA) that can characterize a bacterial strain to the level of defining individual clones. The 16S rDNA-23S rDNA spacers were amplified by PCR and submitted to restriction analysis. Finally, the presence or absence of G adhesins in Escherichia coli as well as the type of adhesin (three types are known) have been shown by PCR amplification followed by digestion with restriction enzymes. As expected a wide diversity was shown by RAPD and identical patterns were only found in the case of strains isolated from the same individual, an obvious case of relapse. Analysis of the spacers' restriction patterns showed the presence of two markedly differentiated clusters that we have named α and ß. Both RAPD and spacer restriction patterns originated similar clusters of strains showing a consistency in the evolution of the global genome with the sequence variation of the ribosomal spacers. Furthermore, most of the strains having G-adhesin, with only a few exceptions, corresponded to the α rRNA spacer group. The two spacer types detected were also consistent with some phenotypic markers such as sucrose and raffinose utilization. The α and β clusters could be intraspecific groups produced by partial sexual isolation or other barriers that are originating a divergent evolution.     

Genotype versus phenotype in the circumscription of bacterial species: the case of Pseudomonas stutzeri and Pseudomonas chloritidismutans

The phenotypic characteristic of strain AW-1(T) of Pseudomonas chloritidismutans that is most relevant from the taxonomic point of view appears to be the capacity of growth under anaerobic conditions using chlorate as electron acceptor. This property is not restricted to this species only within the genus Pseudomonas, since it is also present in strains of genomovars 1 or 5, and 3 of Pseudomonas stutzeri. P. chloritidismutans has been described as a non-denitrifying species, but the isolation of variants that are able to grow anaerobically in the presence of nitrate is possible after subcultivation under selective conditions. The subdivision of P. stutzeri into a number of species on the basis of these characteristics does not help to clarify the phylogenetic relationships among the members of an otherwise coherent group of strains, and the considerations presented in this communication support the reclassification of the new species name P. chloritidismutans, which in our opinion, should be considered as a Junior name of P. stutzeri. A multilocus sequence analysis, together with a phenotypic analysis of the anaerobic oxidative metabolism, gives new insights into the phylogeny and evolution of the species.     

Construction of species-specific primers for Pseudomonas andropogonis based on 16S rDNA sequences

Approximately 94% of the total 16S rDNA of Pseudomonas andropogonis strain ACH 01053A was sequenced and compared with that of strain ATCC 23061 obtained from the GenBank database. The two sequences were highly homologous with 1·3% difference. Alignment of sequences with those from closely related bacteria revealed two possible regions for design of a specific primer suitable for detection of Ps. andropogonis . Using primers designed to these variable regions in a PCR test, an amplification product of approximately 410 bp was specifically produced by 40 strains of Ps. andropogonis . No other bacterial species showed an amplification product under optimized PCR conditions. As few as 1000 cells per reaction were detected.     

明永冰川垂直气候带中可培养低温细菌多样性分析

本研究对位于云南滇西北的明永冰川地区暖温带、中温带和寒温带三个不同垂直气候带中可培养低温细菌的多样性进行了研究。利用四种不同培养基对该地区可培养低温细菌进行了分离纯化,共得到细菌37 513株,根据菌落形态特征分为了391种,其中LB培养基分离到99种,Organic培养基分离到78种,PSG培养基分离到96种,PYGV培养基分离得到118种,可以看出寡营养培养基PYGV分离得到的细菌种类多于LB和Organnic等富营养培养基,表明PYGV针对冰川地区细菌的分离与鉴定更为合适;通过革兰氏染色和扫描电镜观察表明大部分菌株为革兰阴性杆菌;对已分离得到的优势菌进行了16S rRNA基因测序并构建系统发育树,分析得出:假单胞菌属(Pseudomonas)、耶尔森氏菌属(Yersinia)和黄杆菌属(Flavobacterium)在明永冰川不同垂直气候带上均有分布,其中假单胞菌属最多占据35%;而寡养单胞菌属(Stenotrophomonas)是寒温带上特有的菌属。本研究证明明永冰川地区垂直气候带中可培养低温细菌多样性非常丰富,也为下一步了解这一特殊地理生态环境下微生物的群落演替规律、研究冰川环境中微生物群落如何响应气候变化提供了参考。     

Biological control of Sclerotinia sclerotiorum (Lib.) de Bary, the causal agent of white mold, by Pseudomonas species on canola petals

Sclerotinia sclerotiorum is an important pathogen on canola. Due to the public concern over pesticide use, alternative methods of disease control, such as biological control, should be considered. Several bacterial strains were isolated from canola and soja plants. Inhibition of S. sclerotiorum by bacterial strains in vitro was assayed on PDA medium in dual culture test. Eight Pseudomonas sp. strains (PB-3, PB-4, PB-5, PB-6, PB-7, PB-8, PB-10 and PB-11) caused inhibition zone against 5. sclerotiorum hyphal growth. The biocontrol potential of the bacteria was tested in a plant assay. Disease suppression was investigated using a petal inoculation technique. Canola petals were pretreated with bacteria, and then inoculated with 5. sclerotiorum ascospores 24 h later. Greenhouse experiment showed that application of Pseudomonas sp. strains (1 x 10(8) cfu ml(-1)) effectively suppressed S. sclerotiorum (1 x 10(5) ascospores ml(-1)) on petals and all of them achieved significant (P<0.01) disease suppression. Fourteen days after inoculation, strain PB-3 had 88/7% disease control and strain PB-4 had 69/9% disease control. Result from all studies indicates PB-3 to be effective biocontrol against S. sclerotiorum of canola. PB-3, PB-4, PB-7, PB-8, PB-10 and PB-11 were identified as Pseudomonas fluorescens biovar III. PB-5 and PB-6 was identified as Pseudomonas fluorescens biovar II. Strains PB-3, PB-4, PB-6, PB-10 and PB-11 produced protease and HCN. Strain PB-5 produce protease; no HCN.     

Characterization and Phylogenetic Diversity of Carboxymethyl Cellulase Producing <Emphasis Type="Italic">Bacillus</Emphasis> Species from a Landfill Ecosystem

Total population of cellulose degrading bacteria was studied in a landfill ecosystem as a part of microbial diversity study. Samples were obtained from 3 and 5 feet depth of a local landfill being operated for past 10 years. Among many isolates, 22 bacterial strains were selected based on their capability to decompose carboxymethyl cellulose (CMC). These isolates were cultivated on agar medium with CMC as the carbon source. All isolates were Gram positive, endospore forming and alkalophilic bacteria with optimum growth pH 9–10. They were grouped based on the phenotypic and chemotaxonomic characters and representative strains of different groups along with high carboxymethyl cellulase (CMCase) producing strains were included for further characterization. Analysis of 16S rRNA gene indicated that these strains belong to different species of the genus Bacillus. Maximum CMCase activity of 4.8 U/ml at 50°C was obtained by strain LFC15. Results in the present study indicated the potential of waste land ecosystems such as landfill are potential source for isolation of industrially important microorganisms.