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Chinese Journal of Biotechnology ; (12): 1339-1350, 2022.
Article in Chinese | WPRIM | ID: wpr-927784


Human activities increase the concentration of atmospheric carbon dioxide (CO2), which leads to global climate warming. Microbial CO2 fixation is a promising green approach for carbon neutral. In contrast to autotrophic microorganisms, heterotrophic microorganisms are characterized by fast growth and ease of genetic modification, but the efficiency of CO2 fixation is still limited. In the past decade, synthetic biology-based enhancement of heterotrophic CO2 fixation has drawn wide attention, including the optimization of energy supply, modification of carboxylation pathway, and heterotrophic microorganisms-based indirect CO2 fixation. This review focuses on the research progress in CO2 fixation by heterotrophic microorganisms, which is expected to serve as a reference for peaking CO2 emission and achieving carbon neutral by microbial CO2 fixation.

Carbon Cycle , Carbon Dioxide/metabolism , Heterotrophic Processes , Humans , Synthetic Biology
Rev. biol. trop ; 69(4)dic. 2021.
Article in Spanish | LILACS-Express | LILACS, SaludCR | ID: biblio-1387692


Resumen Introducción: Los bosques y sistemas agroforestales (SAF) suministran bienes y servicios ecosistémicos para la sociedad, tal como la mitigación del cambio climático. Objetivo: Se estimó el potencial de reducción de emisiones y captura de carbono en bosques y SAF con cacao de la subcuenca del río Munguidó, Colombia. Métodos: Se seleccionaron tres sistemas de uso del suelo (bosque primario, bosque secundario y SAF con cacao). Se establecieron 18 parcelas temporales de muestreo, seis por sistema, para medir los árboles (diámetro a la altura del pecho -dap ≥ 10 cm) y arbustos de cacao. Se cuantificó la biomasa aérea con ecuaciones alométricas y una fracción de carbono de 0.5. Se estimó la fijación de carbono en el bosque secundario y el SAF con cacao como la razón entre el carbono almacenado y su edad. La pérdida de carbono del bosque primario se estimó con base en la deforestación para Chocó y dicha subcuenca (0.6 y 0.3 %/año, respectivamente). Se realizó un análisis de varianza y comparación de medias LSD Fisher para determinar las diferencias en el almacenamiento y la fijación de carbono entre los usos. Resultados: El bosque primario almacenó más carbono que el bosque secundario y el SAF con cacao (190.1, 22.3 y 5.3 Mg/ha, respectivamente). La fijación de carbono del bosque secundario y el SAF con cacao no difirieron (2.23 vs 1.33 Mg/ha/año). En 20 años, el bosque primario presentaría una reducción de emisiones de 1.4-2.6 Tg CO2; y el bosque secundario y el SAF con cacao presentarían una captura de 100.8 y 30.7 Gg CO2, respectivamente. Conclusiones: En la subcuenca del río Munguidó es posible establecer proyectos para la reducción de emisiones en bosque primario y captura de carbono en bosques secundarios y SAF con cacao, con lo cual se podría emitir 1.4-2.6 millones de toneladas de CO2.

Abstract Introduction: Forests and agroforestry systems (AFS) provide ecosystem goods and services for society, such as climate change mitigation. Objective: The potential for emission reductions and carbon sequestration in forests and cocoa agroforestry systems in the Munguidó river sub-basin in Colombia was estimated. Methods: Three land use systems were selected (primary forest, secondary forest and AFS with cocoa). Eighteen temporary sampling plots were established, six per system, to measure trees (diameter at breast height -dbh ≥ 10 cm) and cocoa shrubs. Aboveground biomass was quantified with allometric equations and a carbon fraction of 0.5. Carbon fixation in secondary forest and AFS with cocoa was estimated as the ratio of carbon stored to its age. Carbon loss from primary forest was estimated based on deforestation for Chocó and that sub-basin (0.6 and 0.3 %/year, respectively). An analysis of variance and LSD Fisher mean comparison was performed to determine differences in carbon storage and carbon sequestration between uses. Results: Primary Forest stored more carbon than secondary forest and AFS with cocoa (190.1, 22.3 and 5.3 Mg/ha, respectively). The carbon fixation of secondary forest and AFS with cocoa did not differ (2.23 vs. 1.33 Mg/ha/year). In 20 years, the primary forest would present an emission reduction of 1.4-2.6 Tg CO2; and the secondary forest and the PFS with cocoa would present a sequestration of 100.8 and 30.7 Gg CO2, respectively. Conclusion: In the Munguidó river sub-basin, it is possible to establish projects for the reduction of emissions in primary forest and carbon sequestration in secondary forests and AFS with cocoa, which could emit 1.4-2.6 million tons of CO2.

Forestry , Carbon Cycle , Cacao , Colombia , Biomass , Conservation of Natural Resources
Chinese Journal of Biotechnology ; (12): 1229-1236, 2021.
Article in Chinese | WPRIM | ID: wpr-878626


Lactate is an important industrial chemical and widely used in various industries. In recent years, with the increasing demand for polylactic acid (PLA), the demand for lactate raw materials is also increasing. The contradiction between the high cost and the market demand caused by the heterotrophic production of lactate attracts researchers to seek other favorable solutions. The production of lactate from photosynthetic carbon fixation by cyanobacteria is a potential new raw material supply strategy. Based on the photosynthetic autotrophic cell factory, it can directly produce high optical purity lactate from carbon dioxide on a single platform driven by solar energy. The raw materials are cheap and easy to obtain, the process is simple and controllable, the products are clear and easy to separate, and the double effects of energy saving and emission reduction and production of high value-added products are achieved at the same time, which has important research and application value. This paper reviews the development history of cyanobacteria carbon sequestration to produce lactate, summarizes its research progress and encounters technical difficulties from the aspects of metabolic basis, metabolic engineering strategy, metabolic kinetics analysis and technical application, and prospects the future of this technology.

Carbon Cycle , Carbon Dioxide , Cyanobacteria/genetics , Lactic Acid , Metabolic Engineering , Photosynthesis
Chinese Journal of Biotechnology ; (12): 195-203, 2019.
Article in Chinese | WPRIM | ID: wpr-771387


Environmental protection and energy supply are our two major concerns. Greenhouse gases released from energy consumption have serious impact on the environment. CO₂ fixation can be used to convert CO₂ into fuels or chemicals. However, natural carbon-fixing organisms usually have some disadvantages such as slow growth and low carbon fixation efficiency. Enhancing or remodeling CO₂ fixation pathways in model microorganisms can realize CO₂ recycling, which can further increase fuel or chemical production and reduce greenhouse gas emission. This review describes in detail metabolic engineering of CO₂ fixation pathways to improve chemical production and sugar synthesis, elaborates the role of relevant metabolic pathways and key enzymes in CO₂ fixation, introduces the application of electro-biochemical synthesis system, shows the great potential of CO₂ fixation, and prospects the future research direction of CO₂ fixation.

Carbon Cycle , Carbon Dioxide , Heterotrophic Processes , Metabolic Engineering , Metabolic Networks and Pathways
Rev. biol. trop ; 62(3): 887-897, jul.-sep. 2014. graf, tab
Article in English | LILACS | ID: lil-753659


Conversion of native rainforest ecosystems in Limón Province of Costa Rica to banana and pineapple monoculture has led to reductions in biodiversity and soil quality. Agroforestry management of cacao (Theobroma cacao) is an alternative system that may maintain the agricultural livelihood of the region while more closely mimicking native ecosystems. This study compared physical, biological and chemical soil quality indicators of a cacao plantation under organic agroforestry management with banana, pineapple, and pasture systems; a native forest nearby served as a control. For bulk density and earthworm analysis, 18 samples were collected between March and April 2012 from each ecosystem paired with 18 samples from the cacao. Cacao had a lower bulk density than banana and pineapple monocultures, but greater than the forest (p<0.05). Cacao also hosted a greater number and mass of earthworms than banana and pineapple (p<0.05), but similar to forest and pasture. For soil chemical characteristics, three composite samples were collected in March 2012 from each agroecosystem paired with three samples from the cacao plantation. Forest and pineapple ecosystems had the lowest pH, cation exchange capacity, and exchangeable nutrient cations, while cacao had the greatest (p<0.05). Total nutrient levels of P and N were slightly greater in banana, pineapple and pasture than in cacao; probably related to addition of chemical fertilizer and manure from cattle grazing. Forest and cacao also had greater %C, than other ecosystems, which is directly related to soil organic matter content (p<0.0001). Overall, cacao had more favorable physical, biological and chemical soil characteristics than banana and pineapple monocultures, while trends were less conclusive compared to the pastureland. While organic cacao was inferior to native forest in some soil characteristics such as bulk density and organic carbon, its soil quality did best mimic that of the native forest. This supports the organic cultivation of cacao as a desirable alternative to banana and pineapple monoculture. Rev. Biol. Trop. 62 (3): 887-897. Epub 2014 September 01.

Muchos de los ecosistemas boscosos naturales de la provincia de Limón, Costa Rica, se han convertido en monocultivos de banano y piña, lo que ha reducido la biodiversidad y la calidad de los suelos. El manejo agroforestal del cacao (Theobroma cacao) es un sistema alternativo, que puede generar ingresos para los agricultores de la región mientras imita mejor los ecosistemas nativos. En esta investigación se compararon los indicadores físicos, biológicos, y químicos de la calidad del suelo en un cacaotal orgánico y agroforestal, una plantación bananera, una piñera, un potrero y un bosque natural. En general, el suelo del cacaotal tuvo características físicas, biológicas y químicas mejores que los monocultivos de banano y piña, mientras las tendencias en comparación con el potrero fueron menos marcadas. Aunque algunas características del suelo en el cacaotal orgánico, como densidad y cantidad de carbono, fueron inferiores al bosque nativo, la calidad del suelo en el cacaotal imitó mejor la del bosque nativo. Los resultados de esta investigación apoyan el cultivo de cacao como una alternativa deseable al monocultivo de banano y piña.

Animals , Cattle , Agriculture/methods , Crops, Agricultural , Carbon/analysis , Nitrogen/analysis , Soil/chemistry , Agriculture/standards , Cacao , Carbon Cycle , Costa Rica , Organic Agriculture , Soil/standards
Chinese Journal of Biotechnology ; (12): 1164-1171, 2014.
Article in Chinese | WPRIM | ID: wpr-279437


Carboxysomes are extremely efficient microcompartments committed to CO2 fixation due to tailored CO2-concentrating mechanism (CCM). In cyanobacteria and some chemoautotrophs, carboxysomes as organelle-like microbodies encapsulate ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) and carbonic anhydrase (CA). Together with active inorganic carbon uptake transporters, carboxysomes accumulate HCO3(-) in the cytoplasm, leading to high efficiency of carbon fixation. Based on the elucidation of structures and functionalities, heterologous production of carboxysomes has been achieved so far. In fact, the genes encoding either vacant carboxysome shell or only interior components have been characterized. This review summarizes the discovery along with types, showcases molecular structures and roles of carboxysomes in CCM, and presents their broad applications in metabolic engineering.

Biological Transport , Carbon , Metabolism , Carbon Cycle , Carbon Dioxide , Metabolism , Cyanobacteria , Metabolism , Metabolic Engineering
Univ. sci ; 16(3): 282-293, sept.-dic. 2011. tab, graf
Article in Spanish | LILACS | ID: lil-619195


Stevia rebaudiana es una planta que acumula un compuesto edulcorante no calórico conocido como esteviosido. Su cultivo tradicionalmente se fertiliza con compuestos químicos que causan daño al ecosistema, obligando a buscar alternativas orgánicas para mitigar este daño. Objetivo. Evaluar el efecto de la materia orgánica y un biofertilizante con base en Azotobacter nigricans en un cultivo de Stevia rebaudiana ubicado en el departamento de Meta, Colombia. Materiales y métodos. Se establecieron cinco tratamientos: T1 y T2 Incorporando al cultivo compost de residuos domiciliarios en concentraciones de 15 y 30 ton ha-1 respectivamente; T3 y T4 con las mismas concentraciones de compost e inoculando el biofertilizante y T5 solamente con el biofertilizante. El control correspondió a las condiciones normales de cultivo con compost Bokashi. El crecimiento vegetal se evaluó por determinación de biomasa en peso seco, producción y área foliar. El análisis fisicoquímico de suelo incluyó: porcentaje carbono orgánico, humedad y pH. Resultados. La inoculación del biofertilizante produjo un incremento en la velocidad de mineralización del compost, con %CO final de 4,85 entre los 90 y 180 días. Se presentaron diferencias estadísticamente significativas (p< 0,05) entre la producción de biomasa de T2 (1538 kg ha-1) y el control (477 kg ha-1). Respecto al contenido de sólidos solubles T1, T3 y T4 presentaron los más altos valores de °Brix (12,4: 12,35 y 12,15). Conclusiones. La concentración 30 ton ha-1 presentó los mejores rendimientos de biomasa y la aplicación del biofertilizante mostró una correlación positiva con la mineralización del compost y síntesis de glucósidos...

Influence of organic matter and Azotobacter nigricans on a Stevia rebaudiana B. plantation Stevia rebaudiana is a plant that accumulates a non-caloric sweetener compound known as stevioside. This crop is traditionally fertilized with chemicals that are harmful for the ecosystem, forcing to find organic alternatives to mitigate this damage. Objective. To study the effect of organic matter and an Azotobacter nigricans-based bio-fertilizer on a Stevia rebaudiana plantation grown in acidic soil in the Department of Meta, Colombia. Materials and methods. Five treatments were established: T1 and T2 with the application of home organic waste compost at concentrations of 15 and 30 ton ha-1. T3 and T4 with the same compost concentrations and inoculating the A. nigricans bio-fertilizer. T5 contained the bio-fertilizer alone. The control consisted of the application of the Bokashi compost under the usual conditions of cultivation. Plant growth was assessed by biomass increase measured as dry weight, production, and leaf area. The physicochemical analysis of soil included: percentage of organic carbon, water content, and pH. Results. The inoculation of the bio-fertilizer produced an increase in the rate of mineralization of compost, reaching a final 4.85% of OC between 90 and 180 days after inoculation. There were significant (p< 0.05) differences between biomass production with T2 (1,538 kg ha-1) and the control (477 kg ha-1). Regarding the soluble solid content, T1, T3 and T4 showed the highest °Brix values (12.4, 12.35 and 12.15, respectively). Conclusions. The concentration of 30 ton ha-1 produced the highest biomass production and the application of the biofertilizer showed a positive correlation with compost mineralization and glucoside synthesis...

Influência da matéria orgânica e Azotobacter nigricans em uma cultura de Stevia rebaudiana B. Stevia rebaudiana é uma planta que acumula um composto edulcorante não-calórico conhecido como esteviosídeo. Sua cultura é tradicionalmente fertilizada com produtos químicos que danificam o ecossistema, forçando a procura de alternativas orgânicas para reduzir esse dano. Objetivo. Avaliar o efeito da matéria orgânica e um biofertilizante com base em Azotobacter nigricans numa cultura de Stevia rebaudiana localizada no departamento de Meta, na Colômbia. Materiais e métodos. Cinco tratamentos foram estabelecidos: T1 e T2 incorporando ao cultivo composto de lixo doméstico em concentrações de 15 e 30 t ha-1, respectivamente; T3 e T4 com as mesmas concentrações do composto e inoculando o biofertilizante e T5 apenas com o biofertilizante. O controle correspondeu a condições normais de cultivo com composto Bokashi. O crescimento das plantas foi avaliado por estimação da biomassa em peso seco, da produção e da área foliar. A análise físico-química do solo inclui o seguinte: porcentagem de carbono orgânico, umidade e pH. Resultados. A inoculação do biofertilizante produz um aumento na taxa de mineralização do composto, com CO final de 4,85% entre 90 e 180 dias. Diferenças estatisticamente significativa (p <0,05) foram observadas entre a produção de biomassa de T2 (1538 kg ha-1) e o controle (477 kg ha-1). Com relação ao conteúdo de sólidos solúveis T1, T3 e T4 tiveram os maiores valores de °Brix (12,4: 12,35 e 12,15). Conclusões. A concentração de 30 ton ha-1 apresentou o melhor rendimento de biomassa e a aplicação do biofertilizante mostrou uma correlação positiva com a mineralização do composto e a síntese de glicosídeos...

Azotobacter , Glucosides , Carbon Cycle
Chinese Journal of Biotechnology ; (12): 1352-1359, 2009.
Article in Chinese | WPRIM | ID: wpr-296917


Metabolic flux analysis is a very powerful tool to understand CO2 fixation and light energy utilization of microalgae during photoautotrophic cultivation. A comprehensive network structure for the autotrophic growth of Synechococcus sp. PCC7942 was proposed, and the carbon and energetic metabolism under different incident light intensity was investigated based on metabolic flux analysis in this paper. These results showed that CO2 fixation was the main energy and reducing potential trap which accounted for 85% and 70% of the total energy and reducing potential consumption respectively. We also found that the cell yield and the maximum cell yield based on ATP synthesis were maintained 2.80 g/mol and 2.97 g/mol respectively under the appointed incident intensity. But the cell yield on absorbed light energy their corresponding energy conversion efficiency were descended with the increasing of incident intensity.

Carbon , Metabolism , Carbon Cycle , Carbon Dioxide , Metabolism , Cell Culture Techniques , Energy Metabolism , Light , Photochemical Processes , Synechococcus , Metabolism
Acta amaz ; 34(4): 605-611, out.-dez. 2004. ilus, graf
Article in Portuguese | LILACS | ID: lil-512638


Mecanismos de vento local, tal como as brisas, influenciam o transporte e dispersão dos gases. Medidas da direção do vento e concentração de ozônio (O3) à 10 metros de altura foram realizadas durante a execução do projeto LBA/CLAIRE-2001 (Large Scale Biosphere-Atmosphere Experiment in Amazônia / Cooperative LBA Airbone Regional Experiment - 2001), no período de 02 a 28.07.2001, nas dependências do Laboratório de Limnologia (01° 55' S, 59°28' W, 174 m) pertencente à Usina Hidrelétrica de Balbina, Amazonas. O lago artificial tem uma área de 2.360 km², sendo suficientemente grande para estabelecer um regime de brisas. As brisas de lago e floresta apresentam-se de forma bem definidas, sendo que a brisa de lago fica melhor caracterizada no período mais quente do dia (10 às 14 horas), enquanto a brisa de floresta evidencia-se no período de 16 às 08 horas com o resfriamento radiativo mais intenso da floresta, o que acarreta um forte contraste térmico. Enquanto isso, a concentração média diária (24 h) de O3 foi de 8,7 ppbv com média de 10,6 ppbv no período diurno e 3,5 ppbv no período noturno. Os resultados também indicaram que quando a brisa é de lago, mesmo a noturna, a concentração de O3 é muito maior do que correspondente a concentração referente a brisa de floresta.

Local wind systems, such as sea or lake breezes, strongly affect the transport and dispersion of atmospheric trace gases. Based on its size and location, the artificial lake of Balbina in the Amazon - can be expected to give rise to a lake/forest breeze regime. During the period 2 to 28 July 2002, within the LBA/CLAIRE-2001 experiment, we have continually measured the ozone concentrations (O3) and the wind directions close to the Balbina dam. We found that there is indeed a well established breeze system, with lake breezes prevailing during mid-day (10 to 14 LT) while forest breezes prevail from the afternoon to early morning (16 to 8 LT). During the latter period radioactive cooling in the forest creates a strong local thermal contrast. The average daily ozone concentration was 8.7 ppbv, with an average of 10.6 ppbv during the day, and 3.5 ppbv at night. When local winds came from the lake, even at night, ozone concentrations were greater compared to breezes coming from the forest.

Climate , Amazonian Ecosystem , Carbon Cycle , Meteorological Concepts