Genetic diversity of the endangered Brazilian endemic herb Cunila menthoides Benth. (Lamiaceae) and its implications for conservation

Cunila menthoides is classified as a xylopodiferous subshrub found in fragmented environments threatened by local agriculture and pasture activities. The species presents strong and pleasant smell, and is commonly used in south Brazilian folk medicine. Based on the species’ medicinal and aromatic potential, the aim of this work was to examine the genetic variation within and among C. menthoides populations, focusing on the conservation of this species. In this context, six C. menthoides populations collected in Rio Grande do Sul, Brazil, were analyzed by ISSR. The populations were sorted as four clusters according to geographic distribution. The six C. menthoides populations analyzed presented low genetic variability, indicating that each population derives from a limited number of plants in a low gene flow scenario. In situ and ex situ conservation approaches may be useful in this species. Conservation strategies for the species should be based on in situ and ex situ approaches.     

Variation in the essential oils composition in Brazilian populations of Schinus molle L. (Anacardiaceae)

Schinus molle L. is popularly known as “peppertree” and presents high essential oil contents with a pleasant spicy scent. Its fruits are used in beverages or dried and ground as a substitute for pepper. Air-dried samples of 11 Brazilian populations of S. molle were extracted using steam distillation and analyzed using GC and GC–MS. A total of 22 volatile compounds were detected and identified. Four groups were formed by the Average Linkage cluster analysis. The first group was characterized by the compound sabinene; the second, which was the largest group, was characterized by the presence of α- and β-pinene; the third group comprised the samples corresponding to the São Borja population and was characterized by the high contents of α-cadinol; and the fourth group was characterized by the high concentrations of myrcene.     

Long-term impacts of selective logging on two Amazonian tree species with contrasting ecological and reproductive characteristics: inferences from Eco-gene model simulations

The impact of logging and subsequent recovery after logging is predicted to vary depending on specific life history traits of the logged species. The Eco-gene simulation model was used to evaluate the long-term impacts of selective logging over 300 years on two contrasting Brazilian Amazon tree species, Dipteryx odorata and Jacaranda copaia. D. odorata (Leguminosae), a slow growing climax tree, occurs at very low densities, whereas J. copaia (Bignoniaceae) is a fast growing pioneer tree that occurs at high densities. Microsatellite multilocus genotypes of the pre-logging populations were used as data inputs for the Eco-gene model and post-logging genetic data was used to verify the output from the simulations. Overall, under current Brazilian forest management regulations, there were neither short nor long-term impacts on J. copaia. By contrast, D. odorata cannot be sustainably logged under current regulations, a sustainable scenario was achieved by increasing the minimum cutting diameter at breast height from 50 to 100 cm over 30-year logging cycles. Genetic parameters were only slightly affected by selective logging, with reductions in the numbers of alleles and single genotypes. In the short term, the loss of alleles seen in J. copaia simulations was the same as in real data, whereas fewer alleles were lost in D. odorata simulations than in the field. The different impacts and periods of recovery for each species support the idea that ecological and genetic information are essential at species, ecological guild or reproductive group levels to help derive sustainable management scenarios for tropical forests.     

Comparative analysis of volatiles from Drimys brasiliensis Miers and D. angustifolia Miers (Winteraceae) from Southern Brazil

The essential oils obtained from Southern Brazilian native Drimys brasiliensis Miers and Drimys angustifolia Miers were analyzed by GC and GC/MS. The oils from leaves of both species showed predominance of monoterpenoids, while the oils from stem barks were characterized by sesquiterpenoids. Bicyclogermacrene (20.0% in leaves and 25.4% in stem bark) and drimenol (1.4% in leaves and 26.2% in stem bark) were the most abundant in D. angustifolia, and cyclocolorenone (from 16.0% to 32.3% in fresh and dried leaves and almost 50% in stem bark) in D. brasiliensis. The oil from fruits of D. brasiliensis was also analyzed and presented 31.0% of cyclocolorenone. The predominance of this unusual aromadendrane-type sesquiterpene in D. brasiliensis essential oils could be used as a chemosystematic marker.     

Ectomycorrhizal Pisolithus albus inoculation of Acacia spirorbis and Eucalyptus globulus grown in ultramafic topsoil enhances plant growth and mineral nutrition while limits metal uptake

Ectomycorrhizal fungi (ECM) isolates of Pisolithus albus (Cooke and Massee) from nickel-rich ultramafic topsoils in New Caledonia were inoculated onto Acacia spirorbis Labill. (an endemic Fabaceae) and Eucalyptus globulus Labill. (used as a Myrtaceae plant host model). The aim of the study was to analyze the growth of symbiotic ECM plants growing on the ultramafic substrate that is characterized by high and toxic metal concentrations i.e. Co, Cr, Fe, Mn and Ni, deficient concentrations of plant essential nutrients such as N, P, K, and that presents an unbalanced Ca/Mg ratio (1/19). ECM inoculation was successful with a plant level of root mycorrhization up to 6.7%. ECM symbiosis enhanced plant growth as indicated by significant increases in shoot and root biomass. Presence of ECM enhanced uptake of major elements that are deficient in ultramafic substrates; in particular P, K and Ca. On the contrary, the ECM symbioses strongly reduced transfer to plants of element in excess in soils; in particular all metals. ECM-inoculated plants released metal complexing molecules as free thiols and oxalic acid mostly at lower concentrations than in controls. Data showed that ECM symbiosis helped plant growth by supplying uptake of deficient elements while acting as a protective barrier to toxic metals, in particular for plants growing on ultramafic substrate with extreme soil conditions. Isolation of indigenous and stress-adapted beneficial ECM fungi could serve as a potential tool for inoculation of ECM endemic plants for the successful restoration of ultramafic ecosystems degraded by mining activities.     

Cytogenetics of the Brazilian Bolitoglossa paraensis (Unterstein, 1930) salamanders (Caudata,Plethodontidae)

Plethodontid salamanders of genus Bolitoglossa constitute the largest and most diverse group of salamanders, including around 20% of living caudate species. Recent studies have indicated the occurrence of five recognized species in the Brazilian Amazon Rainforest. We present here the first cytogenetic data of a Brazilian salamander, which may prove to be a useful by contribution to the cytotaxonomy of the genus. Specimens were collected near the “type” locality (Utinga, Belém, PA, Brazil). Chromosomal preparations from duodenal epithelial cells and testes were subjected to Giemsa staining, C-banding and DAPI/CMA₃ fluorochrome staining. All specimens showed a karyotype with 13 bi-armed chromosome pairs (2n = 26). Nucleolar Organizer Regions, evidenced by CMA₃, were located distally on the long arm of pair 7 (7q). DAPI+ heterochromatin was predominantly centromeric, with some small pericentromeric bands. Although the C-banding patterns of other Bolitoglossa species are so far unknown, cytogenetic studies conducted in other Plethodontid salamanders have demonstrated that pericentromeric heterochromatin is a useful cytological marker for identifying interspecific homeologies. Species diversification is usually accompanied by chromosomal changes. Therefore, the cytogenetic characterization of Bolitoglossa populations from the middle and western Brazilian Amazon Basin could identify differences which may lead to the identification of new species.     

Essential oil composition of Hypericum L. species from Southeastern Serbia and their chemotaxonomy

The essential oils of the aerial parts of nine species of Hypericum (Hypericum barbatum, Hypericum hirsutum, Hypericum linarioides, Hypericum maculatum, Hypericum olympicum, Hypericum perforatum, Hypericum richeri, Hypericum rumeliacum and Hypericum tetrapterum), collected from different locations in Southeast Serbia, were obtained by steam distillation and analyzed by GC and GC–MS. The essential oils investigated were characterized by a high content of non-terpene compounds and a low content of monoterpenes. The contents of non-terpenes, monoterpenes and sesquiterpenes in oils of the species H. barbatum, H. richeri and H. rumeliacum (section Drosocaprium) were similar and these oils were characterized by high contents of fatty acids. The oils of H. hirsutum and H. linarioides (section Taeniocarpium) contained a high percentage of n-nonane. There were similarities in contents of non-terpenes and sesquiterpenes in oils of species that belong to the section Hypericum (H. maculatum, H. perforatum and H. tetrapterum). The oil of H. olympicum differed from others by higher terpene content. A comparison was also carried out of the chemical composition of the essential oils from flower, leaf and stem of H. perforatum and it revealed that the highest concentration of non-terpene compounds was found in the flower and stem oil, while a high concentration of sesquiterpenes was characteristic for leaf oil. There were significant differences in the concentrations of the same compounds in the essential oils of H. maculatum, H. olympicum and H. perforatum, collected in different years from the same location which could be explained by seasonal differences. All data were statistically processed with principal component analysis and cluster analysis. The main conclusion from the above data is that genetic and environmental factors both play a role in determining the composition of essential oils of the Hypericum species studied.     

Halotolerant and halophilic fungi

Extreme environments have for long been considered to be populated almost exclusively by prokaryotic organisms and therefore monopolized by bacteriologists. Solar salterns are natural hypersaline environments characterized by extreme concentrations of NaCl, often high concentrations of other ions, high uv irradiation and in some cases extremes in pH. In 2000 fungi were first reported to be active inhabitants of solar salterns. Since then many new species and species previously known only as food contaminants have been discovered in hypersaline environments around the globe. The eukaryotic microorganism most studied for its salt tolerance is Saccharomyces cerevisiae. However, S. cerevisiae is rather salt sensitive and not able to adapt to hypersaline conditions. In contrast, some species like Debaryomyces hansenii, Hortaea werneckii, and Wallemia ichthyophaga have been isolated globally from natural hypersaline environments. We believe that all three are more suitable model organisms to study halotolerance in eukaryotes than S. cerevisiae. Furthermore, they belong to different and distant taxonomic groups and have developed different strategies to cope with the same problems of ion toxicity and loss of water.     

Innate immune response in the sea urchin Echinometra lucunter (Echinodermata)

Echinometra lucunter, (Pindá) is a sea urchin encountered in the Brazilian coast and exposed to high and low temperatures related to low and high tides. Despite their great distribution and importance, few studies have been done on the biological function of their coelomocytes. Thus, Echinometra lucunter perivisceral coelomocytes were characterized under optical and transmission electron microscopy. Phagocytic amoebocytes in the perivisceral coelom were labelled by injecting ferritin, and ferritin labelled phagocytic amoebocytes were found in the peristomial connective tissue after injecting India ink into the tissue, indicating the amoebocytes ability to respond to an inflammatory stimulus. Results showed that the phagocytic amoebocytes were the main inflammatory cells found in the innate immune response of E. lucunter. While other works have recorded these phenomena in sea urchins found in moderate and constant temperature, this study reports on these same phenomena in a tropical sea urchin under great variation of temperature, thus providing new data to inflammatory studies in invertebrate pathology.     

An invasive Mimosa in India does not adopt the symbionts of its native relatives

Background and Aims

The large monophyletic genus Mimosa comprises approx. 500 species, most of which are native to the New World, with Central Brazil being the main centre of radiation. All Brazilian Mimosa spp. so far examined are nodulated by rhizobia in the betaproteobacterial genus Burkholderia. Approximately 10 Mya, transoceanic dispersal resulted in the Indian subcontinent hosting up to six endemic Mimosa spp. The nodulation ability and rhizobial symbionts of two of these, M. hamata and M. himalayana, both from north-west India, are here examined, and compared with those of M. pudica, an invasive species.

Methods

Nodules were collected from several locations, and examined by light and electron microscopy. Rhizobia isolated from them were characterized in terms of their abilities to nodulate the three Mimosa hosts. The molecular phylogenetic relationships of the rhizobia were determined by analysis of 16S rRNA, nifH and nodA gene sequences.

Key Results

Both native Indian Mimosa spp. nodulated effectively in their respective rhizosphere soils. Based on 16S rRNA, nifH and nodA sequences, their symbionts were identified as belonging to the alphaproteobacterial genus Ensifer, and were closest to the ‘Old World’ Ensifer saheli, E. kostiensis and E. arboris. In contrast, the invasive M. pudica was predominantly nodulated by Betaproteobacteria in the genera Cupriavidus and Burkholderia. All rhizobial strains tested effectively nodulated their original hosts, but the symbionts of the native species could not nodulate M. pudica.

Conclusions

The native Mimosa spp. in India are not nodulated by the Burkholderia symbionts of their South American relatives, but by a unique group of alpha-rhizobial microsymbionts that are closely related to the ‘local’ Old World Ensifer symbionts of other mimosoid legumes in north-west India. They appear not to share symbionts with the invasive M. pudica, symbionts of which are mostly beta-rhizobial.     

Molecular analysis of AMF diversity in aquatic macrophytes: A comparison of oligotrophic and utra-oligotrophic lakes

This study aimed to assess AMF diversity in various plant species in lakes with low and relatively high P concentrations to elucidate possible correlations with environmental factors in order for better understanding the functioning of mycorrhizal fungi in submerged plants. A considerable diversity of AMF communities was observed in the lakes with low dissolved P concentrations, especially in the roots of Littorella uniflora. Glomus group A, Archaeospora and Acaulospora were the most frequent and diverse AMF lineages with eight, seven and four phylotypes at Littorella uniflora in at least six lakes with low dissolved P concentrations. In theses lakes, AMF were for the first time observed in the roots of J. bulbosus, a member of a family previously thought to be non-mycorrhizal. In the lakes with relatively high dissolved P concentrations, the frequency decreased from Acaulospora, found at three locations, to Archaeospora at two locations and Glomus group A and Paraglomus at one location.All chemical parameters of the surface water layer, except pH, revealed significant (p ≤ 0.01) differences between the lakes with low and relatively high dissolved P concentrations. Mean Mg²⁺, Ca²⁺, K⁺, NH₄⁺, CO₂, o-PO₄³⁻ and HCO₃⁻ were 3, 13.5, 15.7, 19.5, 31 and 42.6 times higher, respectively, in the lakes with relatively high dissolved P concentrations compared to the lakes with low dissolved P concentrations. AMF occurred more abundantly with low phosphate and high redox values in the lakes than with high phosphate and low redox values. The pH-value, the total-calcium and total-phosphorus concentrations were strongly correlated with the occurrence of Glomus phylotypes 4 and Archaeospora phylotypes 5 and 8, and a bit less with Acaulospora phylotype 4 and Archaeospora phylotype 3. In such lakes the presence of a diverse AMF community still enables the uptake of sufficient P for isoetid plant species despite the prevailing ‘ultra-oligotrophic’ conditions. As a consequence, macrophyte plant communities in lakes with relatively high dissolved P concentrations are less dependent on AMF colonization for their development.     

Genetic structure of Phlebotomus (Larroussius) ariasi populations, the vector of Leishmania infantum in the western Mediterranean: Epidemiological implications

In recent years there has been growing interest in analyzing the geographical variations between populations of different Phlebotomus spp. by comparing the sequences of various genes. However, little is known about the genetic structure of Phlebotomus ariasi. In this study, we were able to sequence a fragment of the mitochondrial Cyt b gene in 133 sandflies morphologically identified as P. ariasi and proceeding from a wide geographical range covering 35 locations in 11 different regions from five countries. The intra-specific diversity of P. ariasi is high, with 45 haplotypes differing from each other by one to 26 bases and they are distributed in two mitochondrial lineages, one limited geographically to Algeria and the other widely dispersed across Mediterranean countries. The Algerian lineage is characterized by having 13 fixed polymorphisms and is made up of one sole haplotype. The European/Moroccan P. ariasi lineage is characterized by being made up of a great diversity of haplotypes (44) which display some geographical structuring. This could be one of the multiple factors involved in the epidemiological heterogeneity of the foci of leishmaniasis. Phlebotomus chadlii is the sister group of European/Moroccan P. ariasi. The separation of the Algerian haplotype, H45, from the rest of the specimens, European/Moroccan P. ariasi and P. chadlii, is well supported by the bootstrap analysis.     

Distinct population structure for co-occurring Anopheles goeldii and Anopheles triannulatus in Amazonian Brazil

To evaluate whether environmental heterogeneity contributes to the genetic heterogeneity in Anopheles triannulatus, larval habitat characteristics across the Brazilian states of Roraima and Pará and genetic sequences were examined. A comparison with Anopheles goeldii was utilised to determine whether high genetic diversity was unique to An. triannulatus. Student t test and analysis of variance found no differences in habitat characteristics between the species. Analysis of population structure of An. triannulatus and An. goeldii revealed distinct demographic histories in a largely overlapping geographic range. Cytochrome oxidase I sequence parsimony networks found geographic clustering for both species; however nuclear marker networks depicted An. triannulatus with a more complex history of fragmentation, secondary contact and recent divergence. Evidence of Pleistocene expansions suggests both species are more likely to be genetically structured by geographic and ecological barriers than demography. We hypothesise that niche partitioning is a driving force for diversity, particularly in An. triannulatus.     

The mitogenome of Onchocerca volvulus from the Brazilian Amazonia focus

We report here the first complete mitochondria genome of Onchocerca volvulus from a focus outside of Africa. An O. volvulus mitogenome from the Brazilian Amazonia focus was obtained using a combination of high-throughput and Sanger sequencing technologies. Comparisons made between this mitochondrial genome and publicly available mitochondrial sequences identified 46 variant nucleotide positions and suggested that our Brazilian mitogenome is more closely related to Cameroon-origin mitochondria than West African-origin mitochondria. As well as providing insights into the origins of Latin American onchocerciasis, the Brazilian Amazonia focus mitogenome may also have value as an epidemiological resource.     

Relationship between Meloidogyne arenaria and Aflatoxin Contamination in Peanut

Damaged and developing kernels of peanut (Arachis hypogaea) are susceptible to colonization by fungi in the Aspergillus flavus group which, under certain conditions, produces aflatoxins prior to harvest. Our objective was to determine whether infection of peanut roots and pods by Meloidogyne arenaria increases aflatoxin contamination of the kernels when peanut is subjected to drought stress. The experiment was a completely randomized 2-x-2 factorial with 6 replicates/treatment. The treatment factors were nematodes (plus and minus M. arenaria) and fungus (plus and minus A. flavus inoculum). The experiment was conducted in 2001 and 2002 in microplots under an automatic rain-out shelter. In treatments where A. flavus inoculum was added, aflatoxin concentrations were high (> 1,000 ppb) and not affected by nematode infection; in treatments without added fungal inoculum, aflatoxin concentrations were greater (P ≤ 0.05) in kernels from nematode-infected plants (1,190 ppb) than in kernels from uninfected plants (79 ppb). There was also an increase in aflatoxin contamination of kernels with increasing pod galling (r² = 0.83 in 2001, r² = 0.43 in 2002; P ≤ 0.04). Colonization of kernels by A. flavus increased with increasing pod galling (r² = 0.18; P = 0.04) in 2001 but not in 2002. Root-knot nematodes may have a greater role in enhancing aflatoxin contamination of peanut when conditions are not optimal for growth and aflatoxin production by fungi in the A. flavus group.     

Identification of a novel acetate-utilizing bacterium belonging to Synergistes group 4 in anaerobic digester sludge

Major acetate-utilizing bacterial and archaeal populations in methanogenic anaerobic digester sludge were identified and quantified by radioisotope- and stable-isotope-based functional analyses, microautoradiography-fluorescence in situ hybridization (MAR-FISH) and stable-isotope probing of 16S rRNA (RNA-SIP) that can directly link 16S rRNA phylogeny with in situ metabolic function. First, MAR-FISH with ¹⁴C-acetate indicated the significant utilization of acetate by only two major groups, unidentified bacterial cells and Methanosaeta-like filamentous archaeal cells, in the digester sludge. To identify the acetate-utilizing unidentified bacteria, RNA-SIP was conducted with ¹³C₆-glucose and ¹³C₃-propionate as sole carbon source, which were followed by phylogenetic analysis of 16S rRNA. We found that bacteria belonging to Synergistes group 4 were commonly detected in both 16S rRNA clone libraries derived from the sludge incubated with ¹³C-glucose and ¹³C-propionate. To confirm that this bacterial group can utilize acetate, specific FISH probe targeting for Synergistes group 4 was newly designed and applied to the sludge incubated with ¹⁴C-acetate for MAR-FISH. The MAR-FISH result showed that bacteria belonging to Synergistes group 4 significantly took up acetate and their active population size was comparable to that of Methanosaeta in this sludge. In addition, as bacteria belonging to Synergistes group 4 had high K_m for acetate and maximum utilization rate, they are more competitive for acetate over Methanosaeta at high acetate concentrations (2.5–10 m). To our knowledge, it is the first time to report the acetate-utilizing activity of uncultured bacteria belonging to Synergistes group 4 and its competitive significance to acetoclastic methanogen, Methanosaeta.     

The effect of fucoidan from brown seaweed Sargassum wightii on WSSV resistance and immune activity in shrimp Penaeus monodon (Fab)

The polysaccharide-fucoidan was extracted from brown seaweed Sargassum wightii and characterized through FT-IR and ¹³C & ¹H NMR analysis. The extracted fucoidan was supplemented with pellet diets at three different concentrations (0.1, 0.2 and 0.3%). The fucoidan supplemented diets were fed to Penaeus monodon for 45 days, then challenged with WSSV and the mortality percentage was recorded daily up to 21 days. During the challenge test, the control group showed 100% mortality within 10 days, but in the experimental groups, the mortality percentage (51-72% within 21 days) was decreased considerably (P < 0.05) with respect to the concentrations of fucoidan. The reduction in mortality percentage of experimental groups over control group was ranged from 50.81 to 68.06%. During challenge experiment, the immunological parameters such as THC, prophenoloxidase activity, respiratory burst activity, superoxide dismutase activity and phagocytic activity were measured before injection of WSSV (0 day) and after the injection of WSSV on 10th and 21st days, respectively. All the immunological parameters of experimental groups were significantly (P < 0.05) increased than control group. RT-PCR analysis confirmed the considerable reduction of WSSV DNA copy numbers with respect to the concentration of fucoidan. It was concluded that P. monodon fed with fucoidan of S. wightii supplemented diet had enhanced the innate immunity and increased resistance against WSSV infection.     

A prevalent alpha-proteobacterium Paracoccus sp. in a population of the Cayenne ticks (Amblyomma cajennense) from Rio de Janeiro,Brazil

As Rocky Mountain Spotted Fever is the most common tick-borne disease in South America, the presence of Rickettsia sp. in Amblyomma ticks is a possible indication of its endemicity in certain geographic regions. In the present work, bacterial DNA sequences related to Rickettsia amblyommii genes in A. dubitatum ticks, collected in the Brazilian state of Mato Grosso, were discovered. Simultaneously, Paracoccus sp. was detected in aproximately 77% of A. cajennense specimens collected in Rio de Janeiro, Brazil. This is the first report of Paracoccus sp. infection in a specific tick population, and raises the possibility of these bacteria being maintained and/or transmitted by ticks. Whether Paracoccus sp. represents another group of pathogenic Rhodobacteraceae or simply plays a role in A. cajennense physiology, is unknown. The data also demonstrate that the rickettsial 16S rRNA specific primers used forRickettsia spp. screening can also detect Paracoccus alpha-proteobacteria infection in biological samples. Hence, a PCR-RFLP strategy is presented to distinguish between these two groups of bacteria.     

Study of model systems to test the potential function of Artemia group 1 late embryogenesis abundant (LEA) proteins

Embryos of the brine shrimp, Artemia franciscana, are genetically programmed to develop either ovoviparously or oviparously depending on environmental conditions. Shortly upon their release from the female, oviparous embryos enter diapause during which time they undergo major metabolic rate depression while simultaneously synthesize proteins that permit them to tolerate a wide range of stressful environmental events including prolonged periods of desiccation, freezing, and anoxia. Among the known stress-related proteins that accumulate in embryos entering diapause are the late embryogenesis abundant (LEA) proteins. This large group of intrinsically disordered proteins has been proposed to act as molecular shields or chaperones of macromolecules which are otherwise intolerant to harsh conditions associated with diapause. In this research, we used two model systems to study the potential function of the group 1 LEA proteins from Artemia. Expression of the Artemia group 1 gene (AfrLEA-1) in Escherichia coli inhibited growth in proportion to the number of 20-mer amino acid motifs expressed. As well, clones of E. coli, transformed with the AfrLEA-1 gene, expressed multiple bands of LEA proteins, either intrinsically or upon induction with isopropyl-β-thiogalactoside (IPTG), in a vector-specific manner. Expression of AfrLEA-1 in E. coli did not overcome the inhibitory effects of high concentrations of NaCl and KCl but modulated growth inhibition resulting from high concentrations of sorbitol in the growth medium. In contrast, expression of the AfrLEA-1 gene in Saccharomyces cerevisiae did not alter the growth kinetics or permit yeast to tolerate high concentrations of NaCl, KCl, or sorbitol. However, expression of AfrLEA-1 in yeast improved its tolerance to drying (desiccation) and freezing. Under our experimental conditions, both E. coli and S. cerevisiae appear to be potentially suitable hosts to study the function of Artemia group 1 LEA proteins under environmentally stressful conditions.

Electronic supplementary material

The online version of this article (doi:10.1007/s12192-015-0647-3) contains supplementary material, which is available to authorized users.     

Identification of LI-F type antibiotics and di-n-butyl phthalate produced by Paenibacillus polymyxa

Paenibacillus polymyxa strain JSa-9, a soil isolate that displayed antibacterial and antifungal activities in vitro, had been found to produce two types of antimicrobial substances. The two compounds were extracted from the fermentation broth of JSa-9 using ethyl acetate and subsequently purified by high performance liquid chromatography. By means of liquid chromatography-mass spectrometry and tandem mass spectrometry analysis, one of two antagonistic compounds was determined as di-n-butyl phthalate. And another was characterized as a mixture of related peptides of molecular masses of 883, 897, 911, 947, and 961 Da, with the most likely structure of them determined to be a cyclic depsipeptide with an unusual 15-guanidino-3-hydroxypentadecanoic acid moiety bound to a free amino group. These peptides were therefore members of the LI-F group of cyclic depsipeptides.