Anoxia- and hypoxia-induced expression of LDH-A* in the Amazon Oscar, Astronotus crassipinis

Adaptation or acclimation to hypoxia occurs via the modulation of physiologically relevant genes, such as erythropoietin, transferrin, vascular endothelial growth factor, phosphofructokinase and lactate dehydrogenase A. In the present study, we have cloned, sequenced and examined the modulation of the LDH-A gene after an Amazonian fish species, Astronotus crassipinis (the Oscar), was exposed to hypoxia and anoxia. In earlier studies, we have discovered that adults of this species are extremely tolerant to hypoxia and anoxia, while the juveniles are less tolerant. Exposure of juveniles to acute hypoxia and anoxia resulted in increased LDH-A gene expression in skeletal and cardiac muscles. When exposed to graded hypoxia juveniles show decreased LDH-A expression. In adults, the levels of LDH-A mRNA did not increase in hypoxic or anoxic conditions. Our results demonstrate that, when given time for acclimation, fish at different life-stages are able to respond differently to survive hypoxic episodes

Microbial diversity of soils on the banks of the Solimões and Negro rivers, state of Amazonas, Brazil

Analysis of bacterial diversity in soils along the banks of the Solimões and Negro rivers, state of Amazonas, Brazil, was by partial sequencing of the genes codifying the rDNA16S region. Diversity of operational taxonomic units (OTU) and of the divergent sequences obtained were applied in comparative analysis of microbiological diversity in the two environments, based on richness estimators and OTU diversity indices. The higher OTU diversity in the Solimões was based on the higher number of parameters that evoke this. The interaction between the nucleotide sequences of bacteria inhabiting the two riverine environments indicated that the two microrganism communities are similar in composition

Enzymes involved in the biodegradation of sugarcane biomass: Challenges and perspectives

This chapter introduces the role of enzymes in the biomass degradation, namely sugarcane bagasse and straw, leading to the formation of fermentable sugars and second-generation ethanol. The chapter begins with a retrospective of the structuring of the ethanol production chain and then presents current aspects where the deficit of production and its consequences in business can be seen. Subsequently, we list the role of enzymes involved in the biomass hydrolysis, the commercial cocktails, and the proposal of our laboratory in this context. On the other hand, the efficiency of enzymes on the biomass is increased when the bagasse and straw are pretreated. Thus, some technologies that may facilitate the enzymatic hydrolysis and the formation of fermentable sugars are described. Lastly, recent analytical methods that enable a better analysis of the composition and viewing of fiber in the sugarcane biomass are presented.We thank Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, process 2010/52322-3) and Conselho de Desenvolvimento Científico e Tecnológico (CNPq, process 563260-6). This project is also part of National Institute of Science and Technology of the Bioethanol (FAPESP, process 2008/57908-6). Dr. M. L. T. M. Polizeli has a Fellowship of Research Productivity of CNPq. We thank Abilio Borghi for the technical assistance with the English language.info:eu-repo/semantics/publishedVersio

Saccharification of different sugarcane bagasse varieties by enzymatic cocktails produced by Mycothermus thermophilus and Trichoderma reesei RP698 cultures in agro-industrial residues

Lignocellulosic biomasses are promising sources for the obtaining of clean energy through their bioconversion into ethanol. Their saccharification involves a multi-enzymatic system. Here, we evaluated the hydrolysis of a mixture of sugarcane bagasse varieties (SCB), Energy cane fiber (EC), and sugarcane bagasse from the SP80-3280 variety, all in natura, using fungal enzymatic extracts obtained from Mycothermus thermophilus and Trichoderma reesei RP698 cultures supplemented with various agro-industrial residues. The enzymatic extracts from both fungi, when grown in a corn cob and corn straw, led to the highest sugarcane hydrolysis. For M. thermophilus, the reducing sugars released (mg/mL) were 1.21 ± 0.12, 1.25 ± 0.14, and 0.98 ± 0.05 for SCB, EC and SP80-3280, respectively; for T. reesei, the reducing sugars were 0.84 ± 0.08, 0.89 ± 0.06 and 0.68 ± 0.03 for SCB, SP80-3280, and EC, respectively. The cocktail obtained from the co-cultivation of these fungi in corn straw at 35 °C showed the best hydrolysis results, the release of sugars (mg/mL) was 1.31 ± 0.06 (SCB), 2.18 ± 0.08 (EC) and 1.67 ± 0.09 (SP80-3280). Scanning electron microscopy and thermogravimetric analysis confirmed changes in the fiber structures after enzymatic hydrolysis. Thus, these fungi were shown to be promising for an enzymatic cocktail design and sugarcane biomass saccharification.This study was financed by the Coordenaçao de Aperfeiçoamento de Pessoal de Nível Superior - Brazil (CAPES) - Finance Code 001; Fundaçao de Amparo ~ a Pesquisa do Estado de Sao Paulo ~ (FAPESP, Grant 2014/50884-5, 2017/09000e4, 10/52322e3; 2018/07522e6), Portuguese Foundation for Science and Technology (FCT) e POCI-01-0145-FEDER-032206) and Conselho de Desenvolvimento Científico e Tecnologico (CNPq, Grant 465319/2014 e9). MLTMP is a Research Productivity fellow of CNPq (process 301963/2017e7).info:eu-repo/semantics/publishedVersio