Evaluation of Econem™, a Formulated Pasteuria sp. Bionematicide, for Management of Belonolaimus longicaudatus on Golf Course Turf

In 2010, a turfgrass bionematicide containing in vitro produced Pasteuria sp. for management of Belonolaimus longicaudatus was launched under the tradename Econem^™. Greenhouse pot studies and field trials on golf course fairways and tee boxes evaluated Econem at varied rates and application frequencies. Trials on putting greens compared efficacy of three applications of Econem at 98 kg/ha to untreated controls and 1,3-dichloropropene at 53 kg a.i/ha. Further putting green trials evaluated the ability of three applications of Econem at 98 kg/ha to prevent resurgence of population densities of B. longicaudatus following treatment with 1,3-dichloropropene at 53 kg a.i./ha. None of the Econem treatments in pot studies were effective at reducing B. longicaudatus numbers (P ≤ 0.05). Econem was associated with reduction in population densities of B. longicaudatus (P ≤ 0.1) on only a single sampling date in one of the eight field trials and did not improve turf health in any of the trials (P > 0.1). These results did not indicate that Econem is an effective treatment for management of B. longicaudatus on golf course turf.     

SYSTEMATIC REVISION OF THE GENERA LIAGORA AND IZZIELLA (LIAGORACEAE,RHODOPHYTA) FROM TAIWAN BASED ON MOLECULAR ANALYSES AND CARPOSPOROPHYTE DEVELOPMENT,WITH THE DESCRIPTION OF TWO NEW SPECIES1

Some Liagora and Izziella distributed in Taiwan display a wide range of morphological variation and can be difficult to distinguish. To clarify species concepts, we applied DNA sequence analyses and examined carposporophyte development in detail. These studies revealed two new species, which are described herein as Izziella hommersandii sp. nov. and Izziella kuroshioensis sp. nov. I. kuroshioensis superficially resembles Izziella formosana and Izziella orientalis in that its involucral filaments subtend rather than surround the lower portion of the gonimoblast mass (= Izziella type) and a fusion cell is formed from cells of the carpogonial branch, but it can be separated by differences in the cell numbers and branching pattern of the involucral filaments, as well as thallus morphology. In contrast to other species that also bear short lateral branchlets, I. hommersandii is unique in possessing a mixture of short and long involucral filaments, a phenomenon not reported before. The length of the involucral filaments is species specific among species of Izziella and contrasts to the behavior of the involucral filaments after fertilization in species such as “Liagora”setchellii [= Titanophycus setchellii comb. nov.], in which the filaments completely envelop the gonimoblast. In addition, the cells of the carpogonial branch in Titanophycus do not fuse after fertilization to form a fusion cell. Thus, a combination of characters with respect to the behavior of the carpogonial branch and the involucral filaments after fertilization is very useful for delineating species boundaries in Izziella and for separating Titanophycus from Izziella and Liagora.     

Geobacillus galactosidasius sp. nov., a new thermophilic galactosidase-producing bacterium isolated from compost

Two thermophilic spore-forming strains, with optimum growth temperature at 70 °C, were isolated from compost of the “Experimental System of Composting” (Teora, Avellino, Italy). A phylogenetic analysis based on 16S rRNA gene sequences showed that these organisms represented a new species of the genus Geobacillus. Based on polyphasic taxonomic data the strains represented a novel species for which the name Geobacillus galactosidasius sp. nov. is proposed. The type strain is CF1B^T (= ATCC BAA-1450^T = DSM 18751^T).     

Extracellular proteases from eight psychrotolerant Antarctic strains

Extracellular proteases from 8 Antarctic psychrotolerant Pseudomonas sp. strains were purified and characterised. All of them are neutral metalloproteases, have an apparent molecular mass of 45kDa, optimal activity at 40 degrees C and pH 7-9, retaining significant activity at pH 5-11. With the exception of P96-18, which is less stable, all retain more than 50% activity after 3 h of incubation at pH 5-9 and show low thermal stability (their half-life times range from 20 to 60 min at 40 degrees C and less than 5 min at 50 degrees C). These proteases can be used in commercial processes carried out at neutral pH and moderate temperatures, and are of special interest for their application in mixtures of enzymes where final thermal selective inactivation is needed. Results also highlight the relevance of Antarctic biotopes for the isolation of protease-producing enzymes active at low temperatures.     

Rhodococcus aetherivorans sp. nov., a new species that contains methyl t-butyl ether-degrading actinomycetes

The taxonomic positions of two actinomycetes, strains Bc663 and 10bc312T, provisionally assigned to the genus Rhodococcus were determined using a combination of genotypic and phenotypic properties. The organisms have phenotypic properties typical of members of the genus Rhodococcus and were assigned to the 16S rRNA subgroup which contains Rhodococcus rhodochrous and closely related species. The two strains, which have many phenotypic features in common, belong to the same genomic species albeit one readily separated from Rhodococcus ruber with which they form a distinct phyletic line. The organisms were also distinguished from all of the species classified in the R. rhodochrous subgroup, including R. ruber, using a combination of phenotypic properties. The genotypic and phenotypic data show that strains Bc663 and 10bc312T merit recognition as a new species of Rhodococcus. The name proposed for the new species is Rhodococcus aetherivorans (10bc312T = DSM 44752T = NCIMB 13964T).     

Sphingomonas sp. strain KA1, carrying a carbazole dioxygenase gene homologue,degrades chlorinated dibenzo-p-dioxins in soil

Hybridization analysis showed that a newly isolated carbazole (CAR)-degrading bacterium Sphingomonas sp. strain KA1 did not possess the gene encoding the terminal oxygenase component (carAa) of CAR 1,9a-dioxygenase at high homology (more than 90% identity) to that of another CAR-degrader, Pseudomonas resinovorans strain CA10. However, PCR experiments using the primers for amplifying the internal fragment of the carAa gene (810 bp for strain CA10) showed that a PCR product of unexpected size (1100 bp) was amplified. Sequence analysis revealed that this DNA region contained the portion of two possible ORFs, which showed moderate homology to CarAa and CarBa from strain CA10 (61% and 40% identities at the amino acid level, respectively). Inoculation of strain KA1 into dioxin-contaminated model soil resulted in 96% and 70% degradation of 2-mono- and 2,3-dichlorinated dibenzo-p-dioxin, respectively, after 7-day incubation.     

Absolute Configurations of Four Resorcylic Acid Lactones,Paecilomycins J − M,by CD/TDDFT Calculations

The absolute configurations of four resorcylic acid lactones (RALs), paecilomycins J ? M ( 1 ? 3 and 5 ), were assigned by Time‐Dependent Density‐Functional Theory (TDDFT) calculations of their electronic circular dichroism (CD) spectra. The previously reported structure 4 for paecilomycin M was found to be incorrect and should be changed to structure 5 . Analysis of structure‐spectrum relationship for this group of RALs suggested that V′‐shape conformations give type I CD spectra (two negative Cotton effects around 300 and 260 nm, a positive Cotton effect around 220 nm) while V‐shape conformations yield type II spectra (signs of three Cotton effects were opposite to those in type I). Chirality 26:44–50, 2013. © 2013 Wiley Periodicals, Inc.     

Boron bridging of rhamnogalacturonan‐II,monitored by gel electrophoresis,occurs during polysaccharide synthesis and secretion but not post‐secretion

The cell‐wall pectic domain rhamnogalacturonan‐II (RG‐II) is cross‐linked via borate diester bridges, which influence the expansion, thickness and porosity of the wall. Previously, little was known about the mechanism or subcellular site of this cross‐linking. Using polyacrylamide gel electrophoresis (PAGE) to separate monomeric from dimeric (boron‐bridged) RG‐II, we confirmed that Pb²⁺ promotes H₃BO₃‐dependent dimerisation in vitro. H₃BO₃ concentrations as high as 50 mm did not prevent cross‐linking. For in‐vivo experiments, we successfully cultured ‘Paul's Scarlet’ rose (Rosa sp.) cells in boron‐free medium: their wall‐bound pectin contained monomeric RG‐II domains but no detectable dimers. Thus pectins containing RG‐II domains can be held in the wall other than via boron bridges. Re‐addition of H₃BO₃ to 3.3 μm triggered a gradual appearance of RG‐II dimer over 24 h but without detectable loss of existing monomers, suggesting that only newly synthesised RG‐II was amenable to boron bridging. In agreement with this, Rosa cultures whose polysaccharide biosynthetic machinery had been compromised (by carbon starvation, respiratory inhibitors, anaerobiosis, freezing or boiling) lost the ability to generate RG‐II dimers. We conclude that RG‐II normally becomes boron‐bridged during synthesis or secretion but not post‐secretion. Supporting this conclusion, exogenous [³H]RG‐II was neither dimerised in the medium nor cross‐linked to existing wall‐associated RG‐II domains when added to Rosa cultures. In conclusion, in cultured Rosa cells RG‐II domains have a brief window of opportunity for boron‐bridging intraprotoplasmically or during secretion, but secretion into the apoplast is a point of no return beyond which additional boron‐bridging does not readily occur.     

Glycosylinositol phosphorylceramides from Rosa cell cultures are boron‐bridged in the plasma membrane and form complexes with rhamnogalacturonan II

Boron (B) is essential for plant cell‐wall structure and membrane functions. Compared with its role in cross‐linking the pectic domain rhamnogalacturonan II (RG‐II), little information is known about the biological role of B in membranes. Here, we investigated the involvement of glycosylinositol phosphorylceramides (GIPCs), major components of lipid rafts, in the membrane requirement for B. Using thin‐layer chromatography and mass spectrometry, we first characterized GIPCs from Rosa cell culture. The major GIPC has one hexose residue, one hexuronic acid residue, inositol phosphate, and a ceramide moiety with a C₁₈ trihydroxylated mono‐unsaturated long‐chain base and a C₂₄ monohydroxylated saturated fatty acid. Disrupting B bridging (by B starvation in vivo or by treatment with cold dilute HCl or with excess borate in vitro) enhanced the GIPCs' extractability. As RG‐II is the main B‐binding site in plants, we investigated whether it could form a B‐centred complex with GIPCs. Using high‐voltage paper electrophoresis, we showed that addition of GIPCs decreased the electrophoretic mobility of radiolabelled RG‐II, suggesting formation of a GIPC–B–RG‐II complex. Last, using polyacrylamide gel electrophoresis, we showed that added GIPCs facilitate RG‐II dimerization in vitro. We conclude that B plays a structural role in the plasma membrane. The disruption of membrane components by high borate may account for the phytotoxicity of excess B. Moreover, the in‐vitro formation of a GIPC–B–RG‐II complex gives the first molecular explanation of the wall–membrane attachment sites observed in vivo. Finally, our results suggest a role for GIPCs in the RG‐II dimerization process.