RESUMO
One outcome of interspecific hybridization and subsequent effects of evolutionary forces is introgression, which is the integration of genetic material from one species into the genome of an individual in another species. The evolution of several groups of eukaryotic species has involved hybridization, and cases of adaptation through introgression have been already established. In this work, we report on PhyloNet-HMM-a new comparative genomic framework for detecting introgression in genomes. PhyloNet-HMM combines phylogenetic networks with hidden Markov models (HMMs) to simultaneously capture the (potentially reticulate) evolutionary history of the genomes and dependencies within genomes. A novel aspect of our work is that it also accounts for incomplete lineage sorting and dependence across loci. Application of our model to variation data from chromosome 7 in the mouse (Mus musculus domesticus) genome detected a recently reported adaptive introgression event involving the rodent poison resistance gene Vkorc1, in addition to other newly detected introgressed genomic regions. Based on our analysis, it is estimated that about 9% of all sites within chromosome 7 are of introgressive origin (these cover about 13 Mbp of chromosome 7, and over 300 genes). Further, our model detected no introgression in a negative control data set. We also found that our model accurately detected introgression and other evolutionary processes from synthetic data sets simulated under the coalescent model with recombination, isolation, and migration. Our work provides a powerful framework for systematic analysis of introgression while simultaneously accounting for dependence across sites, point mutations, recombination, and ancestral polymorphism.
Assuntos
Hibridização Genômica Comparativa , Evolução Molecular , Modelos Genéticos , Algoritmos , Animais , Mapeamento Cromossômico , Biologia Computacional , Simulação por Computador , Bases de Dados Genéticas , Genética Populacional , Genômica , Cadeias de Markov , Camundongos , FilogeniaRESUMO
This work was the first time to systematically clarify the potential tolerance mechanism of an indigenous Chlorella vulgaris MBFJNU-1 towards the free ammonia (FA) during the original swine wastewater (OSW) treatment by transcriptome analysis using C. vulgaris UETX395 as the control group. The obtained results showed that C. vulgaris MBFJNU-1 was found to be more resistant to the high levels of FA (115 mg/L) and OSW in comparison to C. vulgaris UETX395 (38 mg/L). Moreover, the transcriptomic results stated that some key pathways from arginine biosynthesis, electron generation and transmission, ATP synthesis in chloroplasts, and glutathione synthesis of C. vulgaris MBFJNU-1 were greatly related with the OSW and FA. Additionally, C. vulgaris MBFJNU-1 in OSW and FA performed similar results in the common differentially expressed genes from these mentioned pathways. Overall, these obtained results deliver essential details in microalgal biotechnology to treat swine wastewater and high free ammonia wastewater.
Assuntos
Chlorella vulgaris , Microalgas , Purificação da Água , Animais , Suínos , Águas Residuárias , Chlorella vulgaris/metabolismo , Amônia/metabolismo , Microalgas/metabolismo , BiomassaRESUMO
This work evaluated the performance of real rare earth elements (REEs) wastewater purification and carbon dioxide (CO2) fixation by Chlamydomonas sp. YC with pilot-scale airlift-photobioreactors (AL-PBRs), tubular photobioreactors (TB-PBRs) and raceway ponds (ORWPs) under high-temperature outdoor conditions in summer. The obtained results showed that Chlamydomonas sp. YC at 1 g/L oyster shell piece (OSP) and 3 % CO2 had the highest biomass (1.9 g/L) and NH4+-N removal efficiency (34.0 %) during the REEs wastewater treatment. Among the selected photobioreactors, Chlamydomonas sp. YC to treat real REEs wastewater at 3 % CO2 under high-temperature outdoor conditions attained the highest biomass (2.3 g/L) in the TB-PBRs with the best NH4+-N removal efficiency (43.0 %). Furthermore, the input cost and CO2 net sequestration evaluation revealed that TB-PBRs was more economical photobioreactors to treat REEs wastewater and fix CO2 by Chlamydomonas sp. YC, providing some vital scientific details for REEs wastewater and CO2 fixation by microalgal biotechnology.
Assuntos
Chlamydomonas , Microalgas , Purificação da Água , Águas Residuárias , Dióxido de Carbono , Fotobiorreatores , BiomassaRESUMO
This work was the first time to establish the desired approach with two heterotrophic Chlorella species for ammonium sulfate (AS)-rich rare earth elements (REEs) wastewater treatment by heterotrophic cultivation. The results showed that these two Chlorella species treated by 6 g/L CaCO3 performed the best ability to remove NH4+-N and SO42- of REEs wastewater. Moreover, the established process performed similar features in REEs wastewater treatment by replacing CaCO3 with eggshell powder (ESP) and oyster shell powder (OSP) enriched in CaCO3. Furthermore, microalgae treated by ESP/OSP in a 10-L fermenter showed 837.39 mg/(L·d) NH4+-N and 1,820 mg/(L·d) SO42- removal rates. The developed kinetic models could be well fitted to the experimental data obtained by the 10-L fermenter. Taken together, the established process mediated with two Chlorella species and ESP/OSP by heterotrophic cultivation was the great potential for AS-rich REEs wastewater treatment in a cost-effective manner.
Assuntos
Chlorella , Microalgas , Sulfato de Amônio , Biomassa , Carbonato de Cálcio , Nitrogênio , Águas ResiduáriasRESUMO
This study firstly addressed real swine wastewater (RSW) treatment by an indigenous Chlorella vulgaris MBFJNU-1 in 5-m3 outdoor open raceway ponds and then direct enzymatic transesterification of the resulting lipids from the wet biomass for sustainable biodiesel production. Compared to the control group, C. vulgaris MBFJNU-1 at 3% CO2 achieved higher microalgal biomass (478.5 mg/L) and total fatty acids content (21.3%), higher CO2 bio-fixation (63.2 mg/L/d) and lipid (9.1 mg/L/d) productivities, and greater nutrients removals (total nitrogen, 82.1%; total phosphorus, 28.4%; chemical oxygen demand, 37.1%). The highest biodiesel conversion (93.3%) was attained by enzymatic transesterification of wet disrupted Chlorella biomass with 5% lipase TL and 5% phospholipase PLA. Moreover, the enzymatic transesterification gave around 83% biodiesel conversion in a 15-L stirred tank bioreactor. Furthermore, the integrated process was a cost-effective approach to treat RSW and mitigate CO2 for microalgal biodiesel production, based on the mass and energy balances analysis.
Assuntos
Chlorella vulgaris , Microalgas , Animais , Biocombustíveis , Biomassa , Dióxido de Carbono , Chlorella vulgaris/química , Suínos , Águas ResiduáriasRESUMO
This work was the first time to evaluate the ability of an isolated Chlorella vulgaris MBFJNU-1 to remove nutrients of original swine wastewater (OSW) and fix carbon dioxide (CO2) under outdoor conditions in a simultaneous manner using column photobioreactors. The results showed that microalga cultivated at 3% CO2 in a batch mode achieved the highest biomass and CO2 fixation rate. Then, a semi-continuous process for OSW treatment and CO2 fixation simultaneously by microalga was established and the renewal rate of this process was deeply investigated. Microalga cultivated at 3% CO2 and 80% renewal rate gave the highest productivities of total biomass, CO2 fixation and the greatest average removal rates of total nitrogen, N-NH4+, total phosphorus and chemical oxygen demand. Taken together, C. vulgaris MBFJNU-1 was the promising microalga under outdoor conditions for swine wastewater treatment and CO2 fixation simultaneously for biofuels and biofertilizer production.
Assuntos
Chlorella vulgaris , Microalgas , Animais , Biomassa , Dióxido de Carbono , Nitrogênio , Fotobiorreatores , Suínos , Águas ResiduáriasRESUMO
Peripheral arterial disease (PAD) is a progressive atherosclerotic disorder characterized by narrowing and occlusion of arteries supplying the lower extremities. Approximately 200 million people worldwide are affected by PAD. The current standard of operative care is open or endovascular revascularization in which blood flow restoration is the goal. However, many patients are not appropriate candidates for these treatments and are subject to continuous ischemia of their lower limbs. Current research in the therapy of PAD involves developing modalities that induce angiogenesis, but the results of simple cell transplantation or growth factor delivery have been found to be relatively poor mainly due to difficulties in stem cell retention and survival and rapid diffusion and enzymolysis of growth factors following injection of these agents in the affected tissues. Biomaterials, including hydrogels, have the capability to protect stem cells during injection and to support cell survival. Hydrogels can also provide a sustained release of growth factors at the injection site. This review will focus on biomaterial systems currently being investigated as carriers for cell and growth factor delivery, and will also discuss biomaterials as a potential stand-alone method for the treatment of PAD. Finally, the challenges of development and use of biomaterials systems for PAD treatment will be reviewed.