Development of a New <Emphasis Type="Italic">Amycolatopsis orientalis</Emphasis> Strain for High-Yield Eremomycin Production

A multistep random UV mutagenesis of an eremomycin-producing strain Amycolatopsis orientalis VKPM Ac-1125 with rather low productivity (0.5 g/L) and the further selection of the most high-yield mutant strains have resulted in a highly productive E 13-26 strain. After optimization of the fermentation medium by multifactor analysis, the most efficient composition for the fermentation medium was established, %: glycerol, 8; soybean meals, 2.0; MgCl₂, 0.02; KH₂PO₄, 0.02; KNO₃, 0.6; CaCl₂, 0.3; skim milk powder, 0.46; and glucose, 0.8. The maximum productivity of this strain on the optimized medium reached 3.42 ± 0.17 g/L. Therefore, the obtained strain is considered to be very promising for further use in the selection and development of technology for the large-scale eremomycin production.     

Complete mitochondrial genome of compactin-producing fungus Penicillium solitum and comparative analysis of Trichocomaceae mitochondrial genomes

We determined the complete mitochondrial genome sequence of the compactin-producing fungus Penicillium solitum strain 20-01. The 28?601-base pair circular-mapping DNA molecule encodes a characteristic set of mitochondrial proteins and RNA genes and is intron-free. All 46 protein- and RNA-encoding genes are located on one strand and apparently transcribed in one direction. Comparative analysis of this mtDNA and previously sequenced but unannotated mitochondrial genomes of several medically and industrially important species of the Aspergillus/Penicillium group revealed their extensive similarity in terms of size, gene content and sequence, which is also reflected in the almost perfect conservation of mitochondrial gene order in Penicillium and Aspergillus. Phylogenetic analysis based on concatenated mitochondrial protein sequences confirmed the monophyletic origin of Eurotiomycetes.     

Matrix approach to the simultaneous detection of multiple potato pathogens by real‐time PCR

Aim

Create a method for highly sensitive, selective, rapid and easy‐to‐use detection and identification of economically significant potato pathogens, including viruses, bacteria and oomycetes, be it single pathogen, or a range of various pathogens occurring simultaneously.

Methods and Results

Test‐systems for real‐time PCR, operating in the unified amplification regime, have been developed for Phytophthora infestans, Pectobacterium atrosepticum, Dickeya dianthicola, Dickeya solani, Ralstonia solanacearum, Pectobacterium carotovorum, Clavibacter michiganensis subsp. sepedonicus, potato viruses Y (ordinary and necrotic forms as well as indiscriminative test system, detecting all forms), A, X, S, M, potato leaf roll virus, potato mop top virus and potato spindle tuber viroid. The test‐systems (including polymerase and revertase) were immobilized and lyophilized in miniature microreactors (1·2 μl) on silicon DNA/RNA microarrays (micromatrices) to be used with a mobile AriaDNA^® amplifier.

Conclusions

Preloaded 30‐reaction micromatrices having shelf life of 3 and 6 months (for RNA‐ and DNA‐based pathogens, respectively) at room temperature with no special conditions were successfully tested on both reference and field samples in comparison with traditional ELISA and microbiological methods, showing perfect performance and sensitivity (1 pg).

Significance and Impact of the Study

The accurate, rapid and user‐friendly diagnostic system in a micromatrix format may significantly contribute to pathogen screening and phytopathological studies.