Trichoderma koningiopsis (Hypocreaceae) has the smallest mitogenome of the genus Trichoderma.

Introduction: Fungal mitogenomes exhibit remarkable variation in conformation, size, gene content, arrangement and expression, including their intergenic spacers and introns. Methods: The complete mitochondrial genome sequence of the mycoparasitic fungus Trichoderma koningiopsis was determined using the Illumina next-generation sequencing technology. We used data from our recent Illumina NGS-based project of T. koningiopsis genome sequencing to study its mitochondrial genome. The mitogenome was assembled, annotated, and compared with other fungal mitogenomes. Results: T. koningiopsis strain POS7 mitogenome is a circular molecule of 27,560 bp long with a GC content of 27.80%. It harbors the whole complement of the 14 conserved mitochondrial protein-coding genes (PCG) such as atp6, atp8, atp9, cox1, cox2, cox3, cob, nad1, nad2, nad3, nad4, nad4L, nad5, and nad6, also found in the same gene order to other Hypocreales. The mitogenome also contains 26 transfer RNA genes (tRNAs), 5 of them with more than one copy. Other genes also present in the assembled mitochondrial genome are a small rRNA subunit and a large rRNA subunit containing ribosomal protein S3 gene. Despite the small genome size, two introns were detected in the T. koningiopsis POS7 mitogenome, one of them in cox3 gene and the other in rnl gene, accounting 7.34% of this mitogenome with a total size of 2,024 bp. A phylogenetic analysis was done using the 14 PCGs genes of T. koningiopsis strain POS7 mitogenome to compare them with those from other fungi of the Subphyla Pezizomycotina and Saccharomycotina. T. koningiopsis strain POS7 was clustered together with other representatives of Trichoderma lineage, within the Hypocreales group, which is also supported by previous phylogenetic studies based on nuclear markers. Discussion: The mitochondrial genome of T. koningiopsis POS7 will allow further investigations into the taxonomy, phylogenetics, conservation genetics, and evolutionary biology of this important genus as well as other closely related species.

EFECTO DEL FILTRADO DE SECUENCIAS EN EL ENSAMBLADO DEL GENOMA DE Bacillus altitudinis 19RS3 AISLADO DE Ilex paraguariensis / Effect of sequence filtering on the assembly of the Bacillus altitudinis 19RS3 genome isolated from Ilex paraguariensis

RESUMEN El filtrado de secuencias es un paso esencial sin importar el tipo de tecnología aplicada para la secuenciación de un genoma, en el cual las lecturas de baja calidad o una parte son eliminadas. En un ensamblado la construcción de un genoma se realiza a partir de la unión de lecturas cortas en cóntigos. Algunos ensambladores miden la relación que existe entre secuencias de una longitud fija (k-mer) que puede verse afectada por la presencia de secuencias de baja calidad. Un enfoque común para evaluar los ensamblados se basa en el análisis del número de cóntigos, la longitud del cóntigo más largo y el valor del N50, definido como la longitud del cóntigo que representa el 50 % de la longitud del conjunto. En este contexto, el presente estudio tuvo como objetivo evaluar el efecto del uso de lecturas crudas y filtradas en los valores de los parámetros de calidad obtenidos en el ensamblado del genoma de Bacillus altitudinis 19RS3 aislada de Ilex paraguariensis. Se realizó el análisis de calidad de ambos archivos de partida con el software FastqC y se filtraron las lecturas con el softwareTrimmomatic. Para el ensamblado se utilizó el software SPAdes y para su evaluación la herramienta QUAST. El mejor ensamblado para B. altitudinis 19RS3 se obtuvo a partir de las lecturas filtradas con el valor de k-mer 79, que generó 16 cóntigos mayores a 500 pb con un N50 de 931 914 pb y el cóntigo más largo de 966 271 pb.

ABSTRACT Sequence filtering is an essential step regardless of the type of technology applied for sequencing a genome, in which low-quality readings or a portion are eliminated. In an assembly, the construction of a genome is carried out from the union of short reads in contigs. Some assemblers measure the relationship between sequences of a fixed length (k-mer) that can be affected by the presence of low-quality sequences. A common approach to evaluating assemblies is based on the analysis of the number of contigs, the length of the longest contig, and the value of N50 defined as the length of the contig representing 50 % of the length of the assembly. In this context, the objective of this study was to evaluate the effect of the use of crude and filtered reads on the values of the quality parameters obtained from the genome assembly of Bacillus altituidinis 19RS3 isolated from Ilex paraguariensis. The quality analysis of both starting files was performed with the FastqC software and the readings were filtered with the Trimmomatic software. The SPAdes software was used for the assembly and the QUAST tool for its evaluation. The best assembly for B. altitudinis 19RS3 was obtained from the filtered readings with the value of k-mer 79, which generated 16 contigs greater than 500 bp with a N50 of 931 914 bp and the longest contig of 966 271 bp.

De novo genome assembly of Bacillus altitudinis 19RS3 and Bacillus altitudinis T5S-T4, two plant growth-promoting bacteria isolated from Ilex paraguariensis St. Hil. (yerba mate).

Plant growth-promoting bacteria (PGPB) are a heterogeneous group of bacteria that can exert beneficial effects on plant growth directly or indirectly by different mechanisms. PGPB-based inoculant formulation has been used to replace chemical fertilizers and pesticides. In our previous studies, two endophytic endospore-forming bacteria identified as Bacillus altitudinis were isolated from roots of Ilex paraguariensis St. Hil. seedlings and selected for their plant growth-promoting (PGP) properties shown in vitro and in vivo. The purposes of this work were to assemble the genomes of B. altitudinis 19RS3 and T5S-T4, using different assemblers available for Windows and Linux and to select the best assembly for each strain. Both genomes were also automatically annotated to detect PGP genes and compare sequences with other genomes reported. Library construction and draft genome sequencing were performed by Macrogen services. Raw reads were filtered using the Trimmomatic tool. Genomes were assembled using SPAdes, ABySS, Velvet, and SOAPdenovo2 assemblers for Linux, and Geneious and CLC Genomics Workbench assemblers for Windows. Assembly evaluation was done by the QUAST tool. The parameters evaluated were the number of contigs ≥ 500 bp and ≥ 1000 bp, the length of the longest contig, and the N50 value. For genome annotation PROKKA, RAST, and KAAS tools were used. The best assembly for both genomes was obtained using Velvet. The B. altitudinis 19RS3 genome was assembled into 15 contigs with an N50 value of 1,943,801 bp. The B. altitudinis T5S-T4 genome was assembled into 24 contigs with an N50 of 344,151 bp. Both genomes comprise several genes related to PGP mechanisms, such as those for nitrogen fixation, iron metabolism, phosphate metabolism, and auxin biosynthesis. The results obtained offer the basis for a better understanding of B. altitudinis 19RS3 and T5S-T4 and make them promissory for bioinoculant development.

Isolation and selection of endophytic spore-forming bacteria with plant growth promoting properties isolated from Ilex paraguariensis St. Hil. (yerba mate).

Yerba mate (Ilex paraguariensis St. Hil.) is a species native to the subtropical regions of South America. Despite being an important crop for the region, there are few studies on the use of microorganisms to improve the growth of seedlings in the nursery stage. The objective of this study was to isolate spore-forming endophytic bacteria with plant growth promoting properties associated with yerba mate seedlings and determine their phytobeneficial effect under controlled laboratory conditions. Isolates were selected based on their sporulation capacity and evaluated for in vitro plant growth promoting properties (nitrogen fixation, phosphate solubilization, production of siderophores and synthesis of indolic compounds). Yerba mate seedlings were inoculated with the most promising isolates, which were identified via analyses of the sequence of their 16S rDNA gene as Bacillus circulans (12RS3) and Bacillus altitudinis (19RS3, T5S-T4). After 120 days plants showed higher root dry weight when inoculated with isolate 19RS3 and higher shoot dry weight with 19RS3 and T5S-T4. In conclusion, further studies to determine the ability of these isolates to adapt to the climatic conditions and to survive amidst the native soil microflora in yerba mate cultivated native soils, will be crucial for developing such strains as biofertilizer.

First Whole-Genome Shotgun Sequence of a Promising Cellulase Secretor, Trichoderma koningiopsis Strain POS7.

Trichoderma koningiopsis strain POS7 produces significantly large amounts of cellulase enzymes in solid-state fermentation. The Illumina-based sequence analysis reveals an approximate genome size of 36.6 Mbp, with a G+C content of 48.82% for T. koningiopsis POS7. Based on ab initio prediction, 12,661 coding genes were annotated.