The influence of treatment by different microorganisms on the development of alternariosis (Alternaria solani) and the potato yield

Alternariosis is a dangerous disease of potatoes, which reduces its production in Russia and abroad. Due to the intraspecific variability of the pathogen, wide symptoms and a long period of immunity, it is very difficult to diagnose the disease and take protective measures. As a biological method of protection, eight microorganisms have been tested with an effect on alternaria (Alternariasolani (Ell. Et Mart.). Sor.); these bioagents were screened for their disease inhibitory activity in the field. Studies have shown that the treatment of potatoes with Trichoderma sp. and Bacillus thuringiensis showed a high value for the increase in plant size in both cultivars (44.6, 43.1 cm for Romano), (47.6, 42.7 cm for Labella) compared to control. The number of stems in plants treated with Pseudomonas jessenii was higher (4.0, 4.4 pcs) than in the control of both varieties. Potato processing Trichoderma sp. and Bacillus thuringiensis reduced the spread of the disease in the studied cultivars (23.0, 24.6% for Romano), (17.4, 20.3% for Labella) compared to controls. Treatment of potatoes with Trichoderma sp. and Bacillus thuringiensis increased the weight of the marketable yield on both varieties (18.1, 17.1 t / g for Romano), (19.8, 19.2 t / g for Labella) compared to the control.

Identification of Pseudomonas jessenii and Pseudomonas gessardii as the most proteolytic Pseudomonas isolates in Iranian raw milk and their impact on stability of sterilized milk during storage

Identification of the most proteolytic Pseudomonas strains that can produce heat-resistant proteases and contribute to the Ultra High Temperature (UHT) milk destabilization is of great interest. In the present study, among the 146 Pseudomonas isolates that encoded the aprX gene, five isolates with the highest proteolytic activity were selected and identified based on 16S rRNA, rpoD and gyrB gene sequences data. The identification results were confirmed by phylogenetic analysis based on multilocus sequence analysis and identified the representative isolates as P. jessenii (two isolates) and P. gessardii (three isolates). Casein zymography demonstrated the ability of these species to produce heat-resistant enzymes, AprX, with molecular mass of about 48 kDa during storage at 7° C for 72 h. In sterilized milk samples, the residual activity of AprX caused a considerable enhancement in the degree of protein hydrolysis, non-protein nitrogen and non-casein nitrogen contents of the samples during a two-month storage. This enhancement was slightly higher in samples containing enzyme produced by P. jessenii compared to P. gessardii ones, resulting in earlier onset of sterilized milk destabilization. Hence, this study revealed that P. jessenii and P. gessardii can play a considerable role in deterioration of Iranian commercial long-life milk.

Pseudomonas izuensis sp. nov., a novel species isolated from Izu Oshima, Japan

An aerobic, Gram-stain-negative, rod-shaped bacterial strain, IzPS43_3003T, was isolated from Izu Oshima, an active volcanic island located 22 km east of the Izu Peninsula, Japan. The sequence of its 16S rRNA gene indicated that IzPS43_3003T belongs to the Pseudomonas fluorescens lineage, with its sequence being most similar to that of Pseudomonas vancouverensis DhA-51T (99.79 %). Phylogenetic analysis based on whole genome sequences showed that IzPS43_3003T was a member of the Pseudomonas jessenii subgroup. The average nucleotide identity values and genome-to genome distances between the whole genome sequences of IzPS43_3003T and other type strains showed that the highest correlations were with Pseudomonas moorei DSM 12647T (87.3 and 33.5% respectively). These genotypic and phenotypic analyses indicated that IzPS43_3003T belongs to a novel species, Pseudomonas izuensis sp. nov. Its type strain is IzPS43_3003T (=LMG 31527T,=CECT 9963T).

Draft Genome Sequence of the Type Strain Pseudomonas jessenii DSM 17150

ABSTRACT We present the draft genome sequence of Pseudomonas jessenii type strain DSM 17150. The assembly consists of 13 contigs, contains 6,537,206 bp, and has a GC content of 59.7%.