Morphology, molecular phylogeny and biomass evaluation of Desmodesmus abundans (Scenedesmaceae-Chlorophyceae) from Brazil.

The biotechnological potential of microalgae has been the target of a range of research aimed at using its potential to produce macromolecules with high added value. Particular focus has been given to biofuels' production, such as biohydrogen, biodiesel, and bioethanol from lipids and carbohydrates extracted from microalgal biomass. Bioprospecting and accurate identification of microalgae from the environment are important in the search for strains with better performance. Methodologies that combine morphology and molecular techniques allow more precise knowledge of species. Thereby, this work aimed to identify the new strain LGMM0013 collected at Iraí Reservoir, located in Paraná state, Brazil, and to evaluate the production of biomass, carbohydrates, and lipids from this new microalgal strain. Based on morphology and phylogenetic tree from internal transcribed spacer (ITS), strain LGMM0013 was identified as Desmodesmus abundans. D. abundans accumulated 1500 mg L-1 of dried biomass after 22 days of cultivation in autotrophic conditions, 50% higher than Tetradesmus obliquus (LGMM0001) (Scenedesmaceae-Chlorophyceae), usually grown in photobioreactors located at NPDEAS at the Federal University of Paraná (UFPR) to produce biomass. Analysis of the D. abundans biomass from showed an accumulation of 673.39 mg L-1 of carbohydrates, 130% higher than T. obliquus (LGMM0001). Lipid production was 259.7 mg L-1, equivalent to that of T. obliquus. Nitrogen deprivation increased the production of biomass and carbohydrates in D. abundans LGMM0013, indicating this new strain greater biomass production capacity.

Morphology, molecular phylogeny and biomass evaluation of Desmodesmus abundans (Scenedesmaceae-Chlorophyceae) from Brazil / Morfologia, filogenia molecular e avaliação da biomassa de Desmodesmus abundans (Scenedesmaceae-Chlorophyceae) do Brasil

The biotechnological potential of microalgae has been the target of a range of research aimed at using its potential to produce macromolecules with high added value. Particular focus has been given to biofuels' production, such as biohydrogen, biodiesel, and bioethanol from lipids and carbohydrates extracted from microalgal biomass. Bioprospecting and accurate identification of microalgae from the environment are important in the search for strains with better performance. Methodologies that combine morphology and molecular techniques allow more precise knowledge of species. Thereby, this work aimed to identify the new strain LGMM0013 collected at Iraí Reservoir, located in Paraná state, Brazil, and to evaluate the production of biomass, carbohydrates, and lipids from this new microalgal strain. Based on morphology and phylogenetic tree from internal transcribed spacer (ITS), strain LGMM0013 was identified as Desmodesmus abundans. D. abundans accumulated 1500 mg L-1 of dried biomass after 22 days of cultivation in autotrophic conditions, 50% higher than Tetradesmus obliquus (LGMM0001) (Scenedesmaceae-Chlorophyceae), usually grown in photobioreactors located at NPDEAS at the Federal University of Paraná (UFPR) to produce biomass. Analysis of the D. abundans biomass from showed an accumulation of 673.39 mg L-1 of carbohydrates, 130% higher than T. obliquus (LGMM0001). Lipid production was 259.7 mg L-1, equivalent to that of T. obliquus. Nitrogen deprivation increased the production of biomass and carbohydrates in D. abundans LGMM0013, indicating this new strain greater biomass production capacity.

O potencial biotecnológico das microalgas tem sido alvo de uma série de pesquisas que visam utilizar seu potencial para produzir macromoléculas de alto valor agregado. Uma especial atenção tem sido dada à produção de biocombustíveis, como biohidrogênio, biodiesel e bioetanol, a partir de lipídios e carboidratos de microalgas. A bioprospecção e a identificação precisa de microalgas são importantes na busca de linhagens com melhor desempenho em termos de produção de biomassa e lipídios. Metodologias que combinam morfologia e técnicas moleculares permitem uma identificação mais precisa das espécies. Assim, este trabalho teve como objetivo identificar a nova cepa LGMM0013 coletada na Represa do Iraí, localizado no estado do Paraná, Brasil e avaliar a produção de biomassa, carboidratos e lipídios. Com base na morfologia e na árvore filogenética obtida com sequências ITS ("Internal Transcribed Spacer"), a cepa LGMM0013 foi identificada como Desmodesmus abundans. D. abundans acumulou 1500 mg L-1 de biomassa seca após 22 dias de crescimento em condições autotróficas, 50% superior a Tetradesmus obliquus (LGMM0001) (Scenedesmaceae-Chlorophyceae), uma cepa cultivada frequentemente em fotobiorreatores para produção de biomassa no NPDEAS, na Universidade Federal do Paraná (UFPR) para a produção de biomassa. Na análise da biomassa de D. abundans LGMM0013 constatou-se acúmulo de 673,39 mg L-1 de carboidratos, 130% maior que T. obliquus (LGMM0001). A produção de lipídios foi de 259,7 mg L-1, equivalente à de T. obliquus. A privação de nitrogênio aumentou a produção de biomassa e carboidratos em D. abundans LGMM0013, indicando uma maior capacidade de produção de biomassa desta cepa.

16S-gyrB-rpoB multilocus sequence analysis for species identification in the genus Microbispora.

The genus Microbispora has been considered difficult to define taxonomically. While 16S rRNA gene analysis is required to determine phylogenetic relationships among species in this genus, most 16S rRNA gene-based phylogenetic tree topologies are not reliable. The genus Microbispora currently contains eight species along with six reclassified species (Microbispora chromogenes, Microbispora diastatica, Microbispora parva, Microbispora indica, Microbispora karnatakensis, Microbispora rosea) and Microbispora rosea subsp. aerata, a taxon composed of three further reclassified species (Microbispora aerata, Microbispora thermodiastatica, and Microbispora thermorosea). 16S rRNA, 23S rRNA, gyrB, and rpoB gene sequences were obtained for the type strains of Microbispora species, and eleven endophytic isolates from a Brazilian medicinal plant, Vochysia divergens. Using the concatenated sequence, most Microbispora type strains could be distinguished with high probability support. Based on these analyses, we propose that five of the species reclassified within the subspecies of M. rosea (M. chromogenes, M. karnatakensis, M. parva, M. aerata and M. thermorosea) are distinct from M. rosea and so should be retained as distinct species. The concatenated 16S-gyrB-rpoB gene phylogenic tree had significant probability support and topology. We propose the use of concatenated 16S-gyrB-rpoB gene sequences to determine phylogenetic relationships within the genus Microbispora. We also suggest that strains sharing >98.1 % 16S-gyrB-rpoB gene sequences similarity be defined as a single species, based on results from this analysis. Seven of the strains isolated from V. divergens were not related to any previously described Microbispora species.