Macroalgal eukaryotic microbiome composition indicates novel phylogenetic diversity and broad host spectrum of oomycete pathogens.

Seaweeds are important components of marine ecosystems with emerging potential in aquaculture and as sources of biofuel, food products and pharmacological compounds. However, an increasingly recognised threat to natural and industrial seaweed populations is infection with parasitic single-celled eukaryotes from the relatively understudied oomycete lineage. Here we examine the eukaryomes of diverse brown, red and green marine macroalgae collected from polar (Baffin Island), cold-temperate (Falkland Islands) and tropical (Ascension Island) locations, with a focus on oomycete and closely related diatom taxa. Using 18S rRNA gene amplicon sequencing, we show unexpected genetic and taxonomic diversity of the eukaryomes, a strong broad-brush association between eukaryome composition and geographic location, and some evidence of association between eukaryome structure and macroalgal phylogenetic relationships (phylosymbiosis). However, the oomycete fraction of the eukaryome showed disparate patterns of diversity and structure, highlighting much weaker association with geography and no evidence of phylosymbiosis. We present several novel haplotypes of the most common oomycete Eurychasma dicksonii and report for the first time a cosmopolitan distribution and absence of host specificity of this important pathogen. This indicates rich diversity in macroalgal oomycete pathogens and highlights that these pathogens may be generalist and highly adaptable to diverse environmental conditions.

Detecting Pathogenic Phytophthora Species Using Volatile Organic Compounds.

There are several highly damaging Phytophthora species pathogenic to forest trees, many of which have been spread beyond their native range by the international trade of live plants and infested materials. Such introductions can be reduced through the development of better tools capable of the early, rapid, and high-throughput detection of contaminated plants. This study utilized a volatilomics approach (solid-phase microextraction coupled to gas chromatography-mass spectrometry) to differentiate between several Phytophthora species in culture and discriminate between healthy and Phytophthora-inoculated European beech and pedunculate oak trees. We tentatively identified 14 compounds that could differentiate eight Phytophthora species from each other in vitro. All of the Phytophthora species examined, except Phytophthora cambivora, uniquely produced at least one compound not observed in the other species; however, most detected compounds were shared between multiple species. Phytophthora polonica had the most unique compounds and was the least similar of all the species examined. The inoculated seedlings had qualitatively different volatile profiles and could be distinguished from the healthy controls by the presence of isokaurene, anisole, and a mix of three unknown compounds. This study supports the notion that volatiles are suitable for screening plant material, detecting tree pathogens, and differentiating between healthy and diseased material.

Sleep and Dreaming in Posttraumatic Stress Disorder.

PURPOSE OF REVIEW: Sleep disturbances are core features of posttraumatic stress disorder (PTSD). This review aims to characterize sleep disturbances, summarize the knowledge regarding the relationships between trauma exposure and sleep difficulties, and highlight empirically supported and/or utilized treatments for trauma-related nightmares and insomnia. RECENT FINDINGS: Trauma-related nightmares and insomnia, and other sleep disorders, are frequently reported among trauma survivors. The roles of fear of sleep, REM density, and decreased parasympathetic activity are beginning to inform the relationship between trauma exposure and sleep difficulties. Additionally, the potential adaptive role of sleep loss immediately following a traumatic experience is being recognized. Interventions targeting these sleep disturbances show promise in reducing symptoms. Research in understanding the role of sleep on the development, course, and treatment of PTSD is expanding. Longitudinal investigations are needed to further elucidate these relationships and identify treatments most effective in ameliorating symptoms.

Adaptive biochemical and physiological responses of Eriobotrya japonica to fluoride air pollution.

The biochemical and physiological effects of fluoride were investigated in loquat trees (Eriobotrya japonica) grown in the vicinity of a phosphate fertilizer plant in Tunisia. Photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (E), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities were assessed; along with photosynthetic pigments, lipid peroxidation, electrolytic leakage (EL) and total phenolic contents in foliage and roots of trees at different distances from the phosphate fertilizer plant. All assessed parameters showed significant discrepancies in comparison with unpolluted sites. Obtained results showed high oxidative stress indices including H2O2, lipid peroxidation, and EL, SOD, CAT and GPx activities and proline contents in leaves and roots at the polluted sites as compared to control. In contrast, leaf Pn, Gs, E and photosynthetic pigment contents were low as compared to the control. These results indicate that even though antioxidant responses increased near the factory, adverse effects on physiology were pronounced.

Strong altitudinal partitioning in the distributions of ectomycorrhizal fungi along a short (300 m) elevation gradient.

Changes in species richness and distributions of ectomycorrhizal (ECM) fungal communities along altitudinal gradients have been attributed to changes in both host distributions and abiotic variables. However, few studies have considered altitudinal relationships of ECM fungi associated with a single host to identify the role of abiotic drivers. To address this, ECM fungal communities associated with one host were assessed along five altitudinal transects in Scotland. Roots of Scots pine (Pinus sylvestris) were collected from sites between 300 and 550-600 m altitude, and ECM fungal communities were identified by 454 pyrosequencing of the fungal internal transcribed spacer (ITS) region. Soil moisture, temperature, pH, carbon : nitrogen (C : N) ratio and organic matter content were measured as potential predictors of fungal species richness and community composition. Altitude did not affect species richness of ECM fungal communities, but strongly influenced fungal community composition. Shifts in community composition along the altitudinal gradient were most clearly related to changes in soil moisture and temperature. Our results show that a 300 m altitudinal gradient produced distinct shifts in ECM fungal communities associated with a single host, and that this pattern was strongly related to climatic variables. This finding suggests significant climatic niche partitioning among ECM fungal species.

Evidence of a Natural Hybrid Oomycete Isolated from Ornamental Nursery Stock.

The oomycete genus Phytophthora includes many plant pathogens important in agricultural and environmental systems. Natural interspecific hybridization has been reported several times in Phytophthora, and although the fundamental processes of interspecific hybridization and the consequences of subsequent ecological distribution are poorly understood, reports suggest some hybrids can infect a broader host range and display enhanced virulence compared to the putative parental species. During a survey carried out at the University of Aberdeen in 2014-2015, of oomycetes present in ornamental plants purchased via the internet, a batch of oomycete isolates remained unidentified, showing, in some isolates, features generally related to hybridization. The aim of this study was to determine whether hybridization events had occurred between endemic and introduced oomycetes, probably/possibly facilitated through the international plant trade. The list of isolates examined included a putative hybrid closely related to Phytophthora cryptogea. The putative hybrid isolate was further characterized, and pathogenicity were tests carried out on Eucalyptus globulus, using an isolate of P. cryptogea as a positive control. Cloning of ITS, COXI and ß-tubulin genes resulted in different sequence versions of the putative hybrid isolate; after mapping and a polymorphism position comparison, it was concluded that the studied isolate contained genetic information from P. cryptogea, P. erythroseptica, P. kelmanii, P. sansomeana and Phytopythium chamaehyphon. A PCR-RFLP assay, a NEBcutter analysis and flow cytometry analysis (genomes ranged between 0.168 to 0.269 pg/2C) added further evidence of the hybrid nature of this isolate. The putative hybrid presented complex growing patterns ranging from rosaceous to chrysanthemum-like and had an optimum growth temperature of 25 °C. Although the putative hybrid produced visible symptoms of disease on E. globulus seedlings, assessment of the relative susceptibility of E. globulus to P. cryptogea and the putative hybrid indicated that P. cryptogea was significantly more virulent than the putative hybrid, based on mortality, disease severity and foliar symptoms.

Insight into trade-off between wood decay and parasitism from the genome of a fungal forest pathogen.

Parasitism and saprotrophic wood decay are two fungal strategies fundamental for succession and nutrient cycling in forest ecosystems. An opportunity to assess the trade-off between these strategies is provided by the forest pathogen and wood decayer Heterobasidion annosum sensu lato. We report the annotated genome sequence and transcript profiling, as well as the quantitative trait loci mapping, of one member of the species complex: H. irregulare. Quantitative trait loci critical for pathogenicity, and rich in transposable elements, orphan and secreted genes, were identified. A wide range of cellulose-degrading enzymes are expressed during wood decay. By contrast, pathogenic interaction between H. irregulare and pine engages fewer carbohydrate-active enzymes, but involves an increase in pectinolytic enzymes, transcription modules for oxidative stress and secondary metabolite production. Our results show a trade-off in terms of constrained carbohydrate decomposition and membrane transport capacity during interaction with living hosts. Our findings establish that saprotrophic wood decay and necrotrophic parasitism involve two distinct, yet overlapping, processes.

Application of elemental bioimaging using laser ablation ICP-MS in forest pathology: distribution of elements in the bark of Picea sitchensis following wounding.

Element distribution in the bark of two 20-year-old clones of Picea sitchensis following wounding was studied using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Bark was sampled at 0, 3, and 43 days after wounding and analysed using a focused Nd:YAG laser (266 nm). Intensities of (13)C, (25)Mg, (27)Al, (31)P, (32)S, (39)K, (48)Ca, (55)Mn, (57)Fe, (63)Cu and (64)Zn were measured by ICP-MS to study elemental distribution across the bark samples during the wound repair process. A clear accumulation of Mg, P and K at the boundary zone between the lesion and healthy tissue was detected in the wounded samples and was more distinctive at 43 than at 3 days after treatment. This zone of accumulation mapped onto the position of formation of the ligno-suberised boundary zone and differentiation of the wound periderm. These accumulations suggest major roles for Mg, P and K in the non-specific response of Sitka spruce both to wounding, possibly as co-factors to enzymes and energy utilisation. The LA-ICP-MS method developed in this work proved useful to study spatial element distribution across bark samples and has great potential for applications in other areas of plant pathology research.

Application of response surface methodology to optimize decolourization of dyes by the laccase-mediator system.

Response surface methodology (RSM) was applied to optimize the decolourization of 3 dyes belonging to 3 dye families such as reactive black 5 (diazoic), indigo carmine (indigoid) and aniline blue (anthraquinonic). Crude laccase from Trametes trogii and the laccase-mediator 1-hydroxybenzotriazole (HBT) were used in this study. Box-Behnken design using RSM with six variables namely pH, temperature, enzyme concentration, HBT concentration, dye concentration and incubation time was used in this study to optimize significant correlation between the effects of these variables on the decolourization of reactive black 5 (RB5), indigo carmine (IC) and aniline blue (AB). The optimum of pH, temperature, laccase, HBT, RB5 and reaction time were 4.5, 0.5 U ml(-1), 0.5 mM, 100 mg ml(-1) and 150 min respectively, for a maximum decolourization of RB5 (about 92.92% ± 7.21). Whereas, the optimum decolourization conditions of both IC (99.76% ± 7.75) and AB (98.44% ± 10) were: pH 4.5, temperature of 45 °C, enzyme concentration of 0.1 U ml(-1) and 0.5 U ml(-1), HBT concentration of 0.9 mM and 0.5 mM, dye concentration of 60 mg l(-1) and reaction time of 150 and 90 min, respectively. The experimental values were in good agreement with the predicted ones and the models were highly significant, the correlation coefficient (R(2)) being 0.864, 0.663 and 0.776 for RB5, IC and AB, respectively. In addition, when the kinetic parameters for the three dyes decolourization were calculated according to Hannes-Wolf plot, the following values were obtained: Km of 268.4, 47.94 and 44.64 mg l(-1) then V(max) of 35.58, 10.43 and 9.23 mg l(-1) min for the RB5, IC and AB decolourizations by laccase, respectively.

Susceptibility of germinating seedlings of European and Eurasian populations of Pinus sylvestris to damping-off caused by Fusarium circinatum.

The effect of inoculation with Fusarium circinatum on survival of seed and seedlings of 19 populations of Pinus sylvestris was examined under environmentally controlled conditions, with four treatments (0, 50, 103, 106 spores ml-1). A single seed source of P. radiata was included as a positive control. Germination (emergence of the plumule above the compost) and health of seedlings was assessed daily, for 85 days. Spore density had a significant effect on germination: at 50 spores ml-1, only germination of a Northeast Scotland population was reduced. Treatment with 1000 spores ml-1, however, reduced germination of six populations of P. sylvestris and of P. radiata. Survival of emerged seedlings also varied with inoculum dose. Approximately 75% of seedlings survived 85 days after germination after inoculation with 50 spores ml-1. Seedlings of all populations were killed within 12-16 days of germination by the 103 and 106 spores ml-1 treatments. Emerged seedlings of the Austrian populations showed the highest susceptibility to F. circinatum following treatment with 50 spores ml-1, although 15% of seedlings of one Austrian population (AU3) survived to the end of the experiment (85 days after germination). There was no clear pattern in survival rates of the P. sylvestris seedlings from other populations treated with 1000 or 1 million spores ml-1 due to death of all emerged seedlings within a short period. Variations in susceptibility of different populations of P. sylvestris to F. circinatum may be used in future selection and breeding programmes to reduce the impact of the pathogen as it spreads over wider areas in Europe and Eurasia.

Impact of biological control agents on fusaric acid secreted from Fusarium oxysporum f. sp. gladioli (Massey) Snyder and Hansen in Gladiolus grandiflorus corms.

Fusaric acid (FA) (5-n-butylpuridine 2-carboxyl acid), a highly toxic secondary metabolite produced by Fusarium oxysporum strains, plays a significant role in disease development. The abilities of three F. oxysporum f. sp. gladioli (Massey) Snyder and Hansen isolates (G010; 649-91; and 160-57) to produce FA in infected Gladiolus corm tissues was evaluated in vitro in relation to the presence of two biological control agents, Trichoderma harzianum T22, and Aneurinobacillus migulanus. Pathogenicity tests were used to differentiate between the abilities of the F. oxysporum strains to secrete FA. FA was identified using LC/MS and quantified using HPLC. Isolate G010 was significantly more virulent (P < 0.01) on Gladiolus grandiflorus corms; it secretes 1.8 µM FA/g fresh weight corm into inoculated Gladiolus. Moreover, G010 was the only isolate that produced FA among the three examined isolates. There was a correlation between the corm lesion area and the FA secretion ability of F. oxysporum f. sp. gladioli (P < 0.001; r (2) = 0.96). No FA was detected in PDA cultures of F.oxysporum f. sp. gladioli isolates. The presence of T. harzianum T22 appeared to prevent FA secretion into the corms. In the presence of A. migulanus, however, the amount of FA secreted into the corm tissues increased. These results support the use of T. harzianum as an effective biological control agent against F. oxysporum f. sp. gladioli.

Application of Real-Time PCR for the Detection and Quantification of Oomycetes in Ornamental Nursery Stock.

Numerous Phytophthora and Pythium disease outbreaks have occurred in Europe following inadvertent introduction of contaminated ornamental plants. Detection and identification of pathogens are crucial to reduce risks and improve plant biosecurity in Europe and globally. Oomycete diversity present in roots and compost was determined in 99 hardy woody plants bought from nurseries, retailers and internet sellers, using both isolations and molecular analyses. Oomycete DNA was quantified using real-time PCR of environmental DNA from the plants using three loci: ITS, trnM-trnP-trnM and atp9-nad9. At least one oomycete species was isolated from 89.9% of plants using classical techniques. In total, 10 Phytophthora spp., 17 Pythium spp. and 5 Phytopythium spp. were isolated. Oomycetes were isolated from 86% of asymptomatic plants, but real-time PCR demonstrated that oomycetes were associated with all plants tested. More oomycete DNA occurred in composts in comparison with roots and filters from baiting water (a mean of 7.91 ng g-1, 6.55 × 10-1 ng g-1 and 5.62 × 10-1 ng g-1 of oomycete DNA detected in compost with ITS, trnM and atp9 probes, respectively); the ITS probe detected the highest quantities of oomycete DNA. No significant differences were found in quantities of oomycete DNA detected using real-time PCR in plants purchased online or from traditional retailers.

Pathogenicity and Host Range of Pythium kashmirense-A Soil-Borne Oomycete Recently Discovered in the UK.

During a survey of oomycetes in ornamental plants carried out at the University of Aberdeen in 2014-2015, Pythium kashmirense was isolated from a specimen of Viburnum plicatum 'Lanarth', the first report of this oomycete in the UK (and in Europe). Pathogenicity of a Py. kashmirense isolate was examined using a range of plant species. Inoculations were carried out under controlled conditions in the absence of other Pythium and Phytophthora species, on Glycine max (soya bean), Phaseolus vulgaris (common bean), Lupinus angustifolius (blue lupin), Cucumis sativa (cucumber) and Viburnum opulus. The majority of inoculations caused pre-emergence damping-off, as well as seed rot and root rot. In the in vitro assays, germination rates (%) of soya bean and blue lupin seeds were less than 50%; in the in vivo inoculations on plants, over 50% of soya bean, blue lupin and common bean plants died; in contrast, cucumber plants showed lower susceptibility in pathogenicity tests, with an approximately 80% germination rate in in vitro tests, and 25% dead plants in the in planta inoculations. Inoculations carried out on root systems of Viburnum opulus caused severe necrosis and root rot. Little research was previously conducted on pathogenicity of Py. kashmirense and its relationship with losses in crop yield and quality. The present study showed varying virulence on the different plant species tested after inoculation with Py. kashmirense. Despite the lack of clear host specialization, infection by Py. kashmirense decreased seedling survival and health of plants in a range of important agricultural and ornamental plant species.

Investigation of endogenous biomass efficiency in the treatment of unhairing effluents from the tanning industry.

The tanning industry is of great economic importance worldwide; however, the potential environmental impact of tanning is significant. An important component in tanning is the removal of hair from the hide (unhairing), a process which generates considerable amounts of toxic effluent characterized by a high concentration of sulphur, rich mineral compounds, a high alkalinity and a high organic load. The purpose of the work described here was to evaluate the biodegradability of the unhairing wastewater by endogenous biomass in batch culture and continuous systems. The detoxification of the effluent was assessed by seed germination tests. The batch culture experiments showed that variations in COD, temperature and pH significantly affected the endogenous biomass growth and activity. The optimal treatment condition corresponded to an initial COD of 6 g/L, pH of 7 and 30 degrees C. Under continuous culture conditions, the reactor was fed for 48 days with the unhairing effluent. The optimal COD removal efficiency was 85.5%. During treatment, a transformation of sulphides into thiosulphates and then sulphates was also observed. The effect of untreated and treated unhairing wastewater on seed germination of different plant species was studied. The data suggested that treatment decreased the wastewater toxicity. Indeed, germination was inhibited when the effluent dilution was lower than 20% and 10% for treated and untreated wastewater, respectively.

Phytophthora cinnamomi and other fine root pathogens in north temperate pine forests.

A number of fine root pathogens, including Phytophthora cinnamomi, Pythium ultimum var. ultimum, Pythium undulatum, Pythium violae, Fusarium sp., and two incompletely identified Verticillium species, were isolated from soils taken from under Scots pine trees at five sites in north Scotland, including semi-natural forests and plantations. At least two root pathogens were recovered from each forest. Morphological and molecular data supported the identification of Phytophthora cinnamomi from three of the sites investigated. Isolates of Phytophthora cinnamomi, Pythium ultimum var. ultimum and an incompletely identified Fusarium sp. caused growth reductions of Scots pine seedlings, as determined by dry weight; the most virulent species were Phytophthora cinnamomi and Fusarium sp. The most severe disease symptoms were caused by a mixed inoculum containing Phytophthora cinnamomi, Pythium ultimum var. ultimum and Fusarium sp., or by the Fusarium isolate alone. These nonspecific pathogens may persist on the roots of understorey and herbaceous plants in the pine forests.

Physical and chemical responses of Sitka spruce (Picea sitchensis) clones to colonization by Heterobasidion annosum as potential markers for relative host susceptibility.

Forty-one 2-year-old clones of Picea sitchensis (Bong.) Carr. from three full-sib families (14 clones from each of two families and 13 clones from a third family) were either wounded and inoculated with an isolate of Heterobasidion annosum (Fr.) Bref. or wounded without inoculation. Lesion lengths on the inner bark from the point of inoculation varied among clones 35 days after treatment. There was no relationship between lesion length and relatedness within families. Two clones (21342 and 25202) with the shortest lesions, tentatively designated as less susceptible to H. annosum, and two clones (21176 and 27166) with the longest lesions, designated more susceptible, were selected for comparison of host anatomical and chemical responses to infection. The position and structure of the ligno-suberized boundary zone (LSZ) in the bark of the clones suggested that the less susceptible clones formed thicker layers of suberized cells in the LSZ following wounding plus inoculation. No LSZ was observed in two ramets of the more susceptible Clone 27166 following wounding and inoculation with H. annosum. Compared with more susceptible genotypes, clones of P. sitchensis with low susceptibility to H. annosum had high relative proportions of (+)-alpha-pinene, (-)-beta-pinene and one unidentified terpene constituent (Unknown-15) in cortical resin sampled 25 cm from the lesions. In contrast, more susceptible clones had higher relative proportions of (-)-limonene, Unknown-16, Unknown-18 and Unknown-19. In the secondary resin produced in bark tissues surrounding the lesions, proportions of several monoterpene constituents varied; these changes included a decrease in the relative amount of beta-phellandrene and corresponding small increases in some minor constituents. The concentrations of the monoterpenes, except a few minor constituents, increased in the infected tissues. Wounding plus inoculation with H. annosum resulted in varied monoterpene responses, with distinct differences between less susceptible and more susceptible clones. In less susceptible clones, Unknown-19 increased following wounding plus inoculation, whereas in more susceptible clones, concentrations of delta-3-carene and Unknown-13 and Unknown-16 increased. Differences in both constitutive and induced resin monoterpene profiles may provide useful markers for resistance to H. annosum in selection and breeding programs.

The Incidence of Alternaria Species Associated with Infected Sesamum indicum L. Seeds from Fields of the Punjab, Pakistan.

Sesame (Sesamum indicum) is an important oil seed crop of Asia. Yields can be negatively impacted by various factors, including disease, particularly those caused by fungi which create problems in both production and storage. Foliar diseases of sesame such as Alternaria leaf blight may cause significant yield losses, with reductions in plant health and seed quality. The work reported here determined the incidence of Alternaria species infecting sesame seeds grown in the Punjab, Pakistan. A total of 428 Alternaria isolates were obtained from 105 seed samples and grouped into 36 distinct taxonomic groups based on growth pattern and morphological characters. Isolation frequency and relative density of surface sterilized and non-surface sterilized seeds showed that three isolates (A13, A47 and A215) were the most common morphological groups present. These isolates were further identified using sequencing of the Internal Transcribed Spacer (ITS) region of ribosomal DNA (rDNA) and the Alternaria major allergen gene (Alt a 1). Whilst ITS of rDNA did not resolve the isolates into Alternaria species, the Alt a 1 sequences exhibited > 99% homology with Alternaria alternata (KP123850.1) in GenBank accessions. The pathogenicity and virulence of these isolates of Alternaria alternata was confirmed in inoculations of sesame plants resulting in typical symptoms of leaf blight disease. This work confirms the identity of a major source of sesame leaf blight in Pakistan which will aid in formulating effective disease management strategies.

Multiplex real-time PCR detection of pathogen colonization in the bark and wood of Picea sitchensis clones differing in resistance to Heterobasidion annosum.

A quantitative multiplex real-time polymerase chain reaction (PCR) procedure was developed to assess the extent of Heterobasidion annosum (Fr.) Bref. growth in Sitka spruce (Picea sitchensis (Bong.) Carr.) bark and wood and to determine correlations between lesion length and fungal colonization. Based on lesion length and real-time PCR, the responses of four 3-year-old Sitka spruce clones to inoculation with H. annosum were characterized as showing either resistance or susceptibility to the pathogen. In susceptible clones, the extent of bark colonization did not differ from the visible length of the bark lesion, whereas lesions were longer than the extent of fungal colonization in resistant clones. The resistant clones contained considerably less fungal DNA than the susceptible clones, relative to the amount of host DNA in both the bark and the wood, indicating less resistance and more host cell death in the susceptible clones following inoculation. In both resistant and susceptible clones, fungal colonization in the wood extended beyond the visible necrotic lesion in the bark, indicating that host defense responses are weaker in wood than in bark. The spread of the pathogen in both bark and wood was less in the resistant clones than in the susceptible clones, indicating that defenses in both bark and wood of the resistant clones were superior to those in the susceptible clones.

Strain-level diversity of secondary metabolism in the biocontrol species Aneurinibacillus migulanus.

Aneurinibacillus migulanus strains Nagano and NCTC 7096 show potential in biocontrol against fungal and fungus-like plant pathogens, including a wide range of Ascomycota, Basidiomycota, and Oomycetes. Differences in terms of the range of pathogens that each strain inhibits, however, suggested that production of a single antibiotic cyclic peptide, gramicidin S (GS), by the two strains, is not the sole mechanism of inhibition. The availability of four sequenced genomes of Aneurinibacillus prompted us to apply genome mining techniques to identify the bioactive potential of A. migulanus and to provide insights into the secondary metabolite arsenal of the genus Aneurinibacillus. Up to eleven secondary metabolite biosynthetic gene clusters were present in the three Aneurinibacillus species. Biosynthetic gene clusters specifying bacteriocins, microcins, non-ribosomal peptides, polyketides, terpenes, phosphonates, lasso peptides and linaridins were identified. Chitinolytic potential and iron metabolism regulation were also investigated. With increasing numbers of biocontrol bacterial genomes being sequenced and mined, the use of approaches similar to those described in this paper will lead to an increase in the numbers of environmentally friendly natural products available to use against plant diseases.

Complete Genome Sequence of Aneurinibacillus migulanus E1, a Gramicidin S- and d-Phenylalanyl-l-Propyl Diketopiperazine-Deficient Mutant.

We report here the complete genome sequence of the Aneurinibacillus migulanus E1 mutant deficient in gramicidin S (GS) and d-phenylalanyl-l-propyl diketopiperazine (DKP) formation. The genome consists of a circular chromosome (6,301,904 bp, 43.20% G+C content) without any plasmid. The complete genome sequence enables further investigation of the biosynthetic mechanism and the biological function of gramicidin S.