Genomic analysis and biochemical profiling of an unaxenic strain of Synechococcus sp. isolated from the Peruvian Amazon Basin region.

Cyanobacteria are diverse photosynthetic microorganisms able to produce a myriad of bioactive chemicals. To make possible the rational exploitation of these microorganisms, it is fundamental to know their metabolic capabilities and to have genomic resources. In this context, the main objective of this research was to determine the genome features and the biochemical profile of Synechococcus sp. UCP002. The cyanobacterium was isolated from the Peruvian Amazon Basin region and cultured in BG-11 medium. Growth parameters, genome features, and the biochemical profile of the cyanobacterium were determined using standardized methods. Synechococcus sp. UCP002 had a specific growth rate of 0.086 ± 0.008 µ and a doubling time of 8.08 ± 0.78 h. The complete genome of Synechococcus sp. UCP002 had a size of ∼3.53 Mb with a high coverage (∼200x), and its quality parameters were acceptable (completeness = 99.29%, complete and single-copy genes = 97.5%, and contamination = 0.35%). Additionally, the cyanobacterium had six plasmids ranging from 24 to 200 kbp. The annotated genome revealed ∼3,422 genes, ∼ 3,374 protein-coding genes (with ∼41.31% hypothetical protein-coding genes), two CRISPR Cas systems, and 61 non-coding RNAs. Both the genome and plasmids had the genes for prokaryotic defense systems. Additionally, the genome had genes coding the transcription factors of the metalloregulator ArsR/SmtB family, involved in sensing heavy metal pollution. The biochemical profile showed primary nutrients, essential amino acids, some essential fatty acids, pigments (e.g., all-trans-ß-carotene, chlorophyll a, and phycocyanin), and phenolic compounds. In conclusion, Synechococcus sp. UCP002 shows biotechnological potential to produce human and animal nutrients and raw materials for biofuels and could be a new source of genes for synthetic biological applications.

Structural Characterization of L-Galactose Dehydrogenase: An Essential Enzyme for Vitamin C Biosynthesis.

In plants, it is well-known that ascorbic acid (vitamin C) can be synthesized via multiple metabolic pathways but there is still much to be learned concerning their integration and control mechanisms. Furthermore, the structural biology of the component enzymes has been poorly exploited. Here we describe the first crystal structure for an L-galactose dehydrogenase [Spinacia oleracea GDH (SoGDH) from spinach], from the D-mannose/L-galactose (Smirnoff-Wheeler) pathway which converts L-galactose into L-galactono-1,4-lactone. The kinetic parameters for the enzyme are similar to those from its homolog from camu camu, a super-accumulator of vitamin C found in the Peruvian Amazon. Both enzymes are monomers in solution and have a pH optimum of 7, and their activity is largely unaffected by high concentrations of ascorbic acid, suggesting the absence of a feedback mechanism acting via GDH. Previous reports may have been influenced by changes of the pH of the reaction medium as a function of ascorbic acid concentration. The structure of SoGDH is dominated by a (ß/α)8 barrel closely related to aldehyde-keto reductases (AKRs). The structure bound to NAD+ shows that the lack of Arg279 justifies its preference for NAD+ over NADP+, as employed by many AKRs. This favors the oxidation reaction that ultimately leads to ascorbic acid accumulation. When compared with other AKRs, residue substitutions at the C-terminal end of the barrel (Tyr185, Tyr61, Ser59 and Asp128) can be identified to be likely determinants of substrate specificity. The present work contributes toward a more comprehensive understanding of structure-function relationships in the enzymes involved in vitamin C synthesis.

Soil microbial diversity and functional profiling of a tropical rainforest of a highly dissected low hill from the upper Itaya river basin revealed by analysis of shotgun metagenomics sequencing data.

The tropical rainforest of a highly dissected low hill from the upper Itaya river basin belongs to the western Amazonia region. Some investigations on the biodiversity of these rainforests were more focused on animals and plants diversity. The soils of this region are composed of moderately fertile sediments deposited recently from the initiation of the Andean orogenesis in the Miocene until now. However, scientific information about the soil microbial and functional diversity is still missing. This report presents shotgun metagenomics sequencing data from soils of this rainforest type. A composite loamy soil sample was collected from a primary forest, and metagenomic DNA was purified with standardized methods. Furthermore, libraries were prepared and paired-end sequenced on the Illumina NextSeq 550 platform. Raw Illumina paired-end reads have been uploaded and analysed in the Metagenomics RAST server (MG-RAST). The raw sequence data in fastq format is available at NCBI's Sequence Read Archive (SRA) with accession number SRX12846710.

Structural characterization of L-Galactose Dehydrogenase: an essential enzyme for vitamin C biosynthesis

In plants, it is well-known that ascorbic acid (vitamin C) can be synthesized via multiple metabolic pathways but there is still much to be learnt concerning their integration and control mechanisms. Furthermore, the structural biology of the component enzymes has been poorly exploited. Here we describe the first crystal structure for an L-galactose dehydrogenase (SoGDH from spinach), from the D-mannose/L-galactose (Smirnoff Wheeler) pathway which converts L-galactose into L-galactono-1,4-lactone. The kinetic parameters for the enzyme are similar to those from its homologue from camu-camu, a super-accumulator of vitamin C found in the Peruvian amazon. Both enzymes are monomers in solution, have a pH optimum of 7 and their activity is largely unaffected by high concentrations of ascorbic acid, suggesting the absence of a feedback mechanism acting via GDH. Previous reports may have been influenced by changes of the pH of the reaction medium as a function of ascorbic acid concentration. The structure of SoGDH is dominated by a (β/α)8 barrel closely related to aldehyde-keto reductases (AKRs). The structure bound to NAD+ shows that the lack of Arg279 justifies its preference for NAD+ over NADP+, as employed by many AKRs. This favours the oxidation reaction which ultimately leads to ascorbic acid accumulation. When compared with other AKRs, residue substitutions at the C-terminal end of the barrel (Tyr185, Tyr61, Ser59 and Asp128) can be identified to be likely determinants of substrate specificity. The present work contributes towards a more comprehensive understanding of structure-function relationships in the enzymes involved in vitamin C synthesis.

The complete mitochondrial genome of the oleaginous microalgae Ankistrodesmus falcatus strain UCP001 from the Peruvian Amazon.

Ankistrodesmus falcatus strain UCP001 is a native oleaginous microalgae isolated from the Peruvian Amazon basin. In this study we sequenced, de novo assembled, and functionally annotated the complete mitochondrial genome of the native oleaginous microalgae Ankistrodesmus falcatus strain UCP001 (Accesion number MT701044). This mitogenome is a typical circular double stranded DNA molecule of 41,048 bp in total length with G + C content of 37.4%. The mitogenome contains 49 genes, including 18 protein coding genes, 5 ribosomal (rRNA) genes and 26 transfer RNA (tRNA) genes. A phylogenetic analysis of 18 microalgae species indicated that Ankistrodesmus falcatus strain UCP001 was closely related to Ourococcus multisporus and Raphidocelis subcapitata. The complete mitochondrial genome sequence of Ankistrodesmus falcatus strain UCP001 enriches genomic resources of oleaginous native microalgae from the Peruvian Amazon for further basic and applied research.

Dataset of de novo assembly and functional annotation of the transcriptomes of three native oleaginous microalgae from the Peruvian Amazon.

Microalgae are photosynthetic organisms with cosmopolitan distribution (i.e., marine, freshwater and terrestrial habitats) and possess a great diversity of species [1] and consequently an immense variation in biochemical compositions [2]. To date genomic information is available mainly from the model green microalga Chlamydomonas reinhardtii[3]. Here we provide the dataset of a de novo assembly and functional annotation of the transcriptomes of three native oleaginous microalgae from the Peruvian Amazon. Native oleaginous microalgae species Ankistrodesmus sp., Chlorella sp., and Scenedesmus sp. were cultured in triplicate using Chu-10 medium with or without a source of nitrate (NaNO3). Total RNA was purified, the cDNA libraries were constructed and sequenced as paired-end reads on an Illumina HiSeq™2500 platform. Transcriptomes were de novo assembled using Trinity v2.9.1. A total of 48,554 transcripts (range from 250 to 7966 bp; N50 = 1047) for Ankistrodesmus sp., 108,126 transcripts (range from 250 to 8160 bp; N50 = 1090) for Chlorella sp., and 77,689 transcripts (range from 250 to 8481 bp; N50 = 1281) for Scenedesmus sp. were de novo assembled. Completeness of the assembled transcriptomes were evaluated with the Benchmarking Universal Single-Copy Orthologs (BUSCO) software v2/v3. Functional annotation of the assembled transcriptomes was conducted with TransDecoder v3.0.1 and the web-based platforms Kyoto Encyclopedia of Genes and Genomes (KEGG) Automatic Annotation Server (KAAS) and FunctionAnnotator. The raw reads were deposited into NCBI and are accessible via BioProject accession number PRJNA628966 (https://www.ncbi.nlm.nih.gov/bioproject/PRJNA628966) and Sequence Read Archive (SRA) with accession numbers: SRX8295665 (https://www.ncbi.nlm.nih.gov/sra/SRX8295665), SRX8295666 (https://www.ncbi.nlm.nih.gov/sra/SRX8295666), SRX8295667 (https://www.ncbi.nlm.nih.gov/sra/SRX8295667), SRX8295668 (https://www.ncbi.nlm.nih.gov/sra/SRX8295668), SRX8295669 (https://www.ncbi.nlm.nih.gov/sra/SRX8295669), and SRX8295670 (https://www.ncbi.nlm.nih.gov/sra/SRX8295670). Additionally, transcriptome shotgun assembly sequences and functional annotations are available via Discover Mendeley Data (https://data.mendeley.com/datasets/47wdjmw9xr/1).

Dataset of de novo assembly and functional annotation of the transcriptome during germination and initial growth of seedlings of Myrciaria Dubia "camu-camu".

Myrciaria dubia "camu-camu" is a native shrub of the Amazon that is commonly found in areas that are flooded for three to four months during the annual hydrological cycle. This plant species is exceptional for its capacity to biosynthesize and accumulate important quantities of a variety of health-promoting phytochemicals, especially vitamin C [1], yet few genomic resources are available [2]. Here we provide the dataset of a de novo assembly and functional annotation of the transcriptome from a pool of samples obtained from seeds during the germination process and seedlings during the initial growth (until one month after germination). Total RNA/mRNA was purified from different types of plant materials (i.e., imbibited seeds, germinated seeds, and seedlings of one, two, three, and four weeks old), pooled in equimolar ratio to generate the cDNA library and RNA paired-end sequencing was conducted on an Illumina HiSeq™2500 platform. The transcriptome was de novo assembled using Trinity v2.9.1 and SuperTranscripts v2.9.1. A total of 21,161 transcripts were assembled ranging in size from 500 to 10,001 bp with a N50 value of 1,485 bp. Completeness of the assembly dataset was assessed using the Benchmarking Universal Single-Copy Orthologs (BUSCO) software v2/v3. Finally, the assembled transcripts were functionally annotated using TransDecoder v3.0.1 and the web-based platforms Kyoto Encyclopedia of Genes and Genomes (KEGG) Automatic Annotation Server (KAAS), and FunctionAnnotator. The raw reads were deposited into NCBI and are accessible via BioProject accession number PRJNA615000 (https://www.ncbi.nlm.nih.gov/bioproject/PRJNA615000) and Sequence Read Archive (SRA) with accession number SRX7990430 (https://www.ncbi.nlm.nih.gov/sra/SRX7990430). Additionally, transcriptome shotgun assembly sequences and functional annotations are available via Discover Mendeley Data (https://data.mendeley.com/datasets/2csj3h29fr/1).

Metagenomic 16S rDNA amplicon data on bacterial diversity profiling and its predicted metabolic functions of varillales in Allpahuayo-Mishana National Reserve.

The white-sands forests or varillales of the Peruvian Amazon are characterized by their distinct physical characteristics, patchy distribution, and endemism [1, 2]. Much research has been conducted on the specialized plant and animal communities that inhabit these ecosystems, yet their soil microbiomes have yet to be studied. Here we provide metagenomic 16S rDNA amplicon data of soil microbiomes from three types of varillales in Allpahuayo-Mishana National Reserve near Iquitos, Peru. Composite soil samples were collected from very low varillal, high-dry varillal, and high-wet varillal. Purified metagenomic DNA was used to prepare and sequence 16S rDNA metagenomic libraries on the Illumina MiqSeq platform. Raw paired-endsequences were analyzed using the Metagenomics RAST server (MG-RAST) and Parallel-Meta3 software and revealed the existence of a high percentage of undiscovered sequences, potentially indicating specialized bacterial communities in these forests. Also, were predicted several metabolic functions in this dataset. The raw sequence data in fastq format is available in the public repository Discover Mendeley Data (https://data.mendeley.com/datasets/syktzxcnp6/2). Also, is available at NCBI's Sequence Read Archive (SRA) with accession numbers SRX7891206 (very low varillal), SRX7891207 (high-dry varillal), and SRX7891208 (high-wet varillal).

In Silico Characterization and Expression Analysis Of The Alpha Subunit Of The Heteromeric Acetyl-Coenzyme A Carboxylase From Two Microalgae / Caracterización in silico y análisis de la expresión de la subunidad alfa de la acetil-coenzima a carboxilasa heteromérica de dos microalgas

RESUMEN Las microalgas son microorganismos fotosintéticos con gran potencial para abastecer las demandas energéticas mundiales. Sin embargo, los limitados conocimientos que se tienen de estos organismos, en particular a nivel molecular de los procesos metabólicos, han limitado su uso con estos propósitos. En esta investigación se ha realizado el análisis in silico de la subunidad alfa de la acetil-Coenzima A carboxilasa heteromérica (αACCasa), una enzima clave en la biosíntesis de lípidos de las microalgas Chlorella sp. y Scenedesmus sp. Asimismo, se ha medido la expresión de este gen en ambas especies cultivadas en medios deficientes de nitrógeno. Los resultados indican que la αACCasa muestra conservación estructural y funcional en ambas especies de microalgas y su mayor similitud genética con otras especies de microalgas. Asimismo, se ha mostrado que el nivel de expresión del gen se incrementa significativamente cuando las microalgas son cultivadas en ausencia de nitrógeno, lo cual se relaciona a su vez con una mayor acumulación de lípidos microalgales. En conclusión, el análisis in silico de la αACCasa de Chlorella sp. y Scenedesmus sp. presentan características estructurales, funcionales y evolutivas muy similares con otras especies de microalgas y plantas. Asimismo, el estudio revela que en ambas especies el gen se sobreexpresa cuando las microalgas son sometidas a estrés por deficiencia de nitrógeno, el cual se relaciona significativamente con la acumulación de lípidos totales en estas células.

ABSTRACT Microalgae are photosynthetic microorganisms with great potential to supply the world's energy demands. However, the limited knowledge of these organisms, particularly at the molecular level of metabolic processes, has limited their use to these purposes. In this investigation, the in silico analysis of the alpha subunit of the heteromeric acetyl-coenzyme A carboxylase (αACCase), a key enzyme in lipid biosynthesis of microalgae Chlorella sp. and Scenedesmus sp. was carried out. Also, the expression of this gene has been measured in both species cultivated in nitrogen-depleted media. Results indicate that αACCase shows structural and functional conservation in both species of microalgae and their greater genetic similarity with other species of microalgae. Also, it has been shown that the expression levels of this gene are significantly increased when the microalgae are cultured in the absence of nitrogen, which in turn is related to a greater accumulation of microalgal lipids. In conclusion, the in silico analysis of the Chlorella sp. and Scenedesmus sp. αACCase reveals structural, functional and evolutionary characteristics very similar to other microalgae and plant species. Also, the study reveals that in both species the gene is overexpressed when microalgae are subjected to nitrogen deficiency stress, which is significantly related to total lipids accumulation in these cells.