No abstract

The taxonomic position of a marine, gliding, pink-pigmented, aerobic, heterotrophic and Gram-negative bacterium was established using a polyphasic approach. 16S rRNA gene sequence analysis indicated that the strain was a member of the phylum ‘Bacteroidetes’ in which it occupied a separate lineage. The predominant cellular fatty acids were C15 : 0 iso, C17 : 0 iso 3-OH, summed feature 3 and summed feature 4. The DNA G+C content was 48·7 mol%. Phylogenetic evidence and the results of phenotypic, genotypic and chemotaxonomic analyses strongly support the assignment of the newly isolated bacterium as a member of a novel genus and species, for which the name Pontibacter actiniarum gen. nov., sp. nov. is proposed. The type strain is KMM 6156T (=KCTC 12367T=LMG 23027T). It is also proposed that the illegitimate names Reichenbachia and Reichenbachia agariperforans are replaced with Reichenbachiella and Reichenbachiella agariperforans, respectively.

This paper describes and illustrates two new species, Trichoderma pleurotum and T. pleuroticola, associated with green mold disease of oyster mushroom in Korea.

Tricholoma matsutake, the pine mushroom, is a valuable forest product with high economic value in Asia, and plays an important ecological role as an ectomycorrhizal fungus. Around the host tree, T. matsutake hyphae generate a distinctive soil aggregating environment called a fairy ring, where fruiting bodies form. Because T. matsutake hyphae dominate the soil near the fairy ring, this species has the potential to influence the microbial community. To explore the influence of T. matsutake on the microbial communities, we compared the microbial community and predicted bacterial function between two different soil types—T. matsutake dominant and T. matsutake minor. DNA sequence analyses showed that fungal and bacterial diversity were lower in the T. matsutake dominant soil compared to T. matsutake minor soil. Some microbial taxa were significantly more common in the T. matsutake dominant soil across geographic locations, many of which were previously identified as mycophillic or mycorrhiza helper bacteria. Between the two soil types, the predicted bacterial functional profiles (using PICRUSt) had significantly distinct KEGG modules. Modules for amino acid uptake, carbohydrate metabolism, and the type III secretion system were higher in the T. matsutake dominant soil than in the T. matsutake minor soil. Overall, similar microbial diversity, community structure, and bacterial functional profiles of the T. matsutake dominant soil across geographic locations suggest that T. matsutake may generate a dominance effect.

The use of biosurfactants for agricultural crop protection has been gaining interest because they are generally biodegradable and environmentally friendly. In the present study, we identified an insecticidal biosurfactant produced by Pseudomonas protegens F6 (F6) and examined its use for aphid control. The growth of F6 was accompanied by increased aphid mortality and decreased water surface tension. Bioassay-guided chromatography coupled with instrumental analyses, nuclear magnetic resonance (NMR), and time-of-flight mass spectrometer (TOF MS) identified orfamide A as a major metabolite that showed insecticidal activity against green peach aphid ( Myzus persicae ). Orfamide A revealed a dose-dependent mortality against aphids, producing a LC50 value at 34.5 μg/mL, and caused a considerable decrease in the surface tension value of water, giving about 35.7 mN/m at 10 μg/mL. Laboratory and greenhouse mortality bioassays suggested that orfamide A may be applicable to control aphids in organic agriculture. This is the first report of orfamide A as an insecticidal metabolite against Myzus persicae .