ABSTRACT
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.
ABSTRACT
The flux of carbon within the coralline ecosystem has been a subject of great interest in the recent decades. So far several studies had been conducted to understand actual process of carbon transfer within this system and it is an elusive factor on science because of the complex process. An attempt had been made to delineate the source and sink of carbon within the coral ecosystem by establishing small experimental set up in the present study. For these study, four experimental tanks, each consisted of a different community of coral ecosystem was set up in Pondicherry University, Port Blair, Andaman Islands, India. The Tank A was set up with a most prevalent sponge species Stylissa massa, in this part of the study area, Tank B consisted of sponge Lamellodysidea spp., Tank C consisted of macroalgae community i.e. of Padina spp. of an area of 620 cm2 and Tank D had a soft coral Sarcophyton spp. All these species were collected from Burmanallha, a region characterized by rich species diversity. The results indicated that the algal and sponge community provided carbon to support the growth of coral reefs. Coral utilized this carbon for their growth. It was also observed that fluctuation of environmental and physical parameters induced biological stress within the life forms resulted in the release of excess inorganic carbon to the surrounding water. Whenever, the opportunity were available this carbon was utilized by the system itself and managed full extent without any excess carbon.
ABSTRACT
This study was conducted to evaluate the association of job characteristics and stress indicators, from May 1st to 10th, 1996. The study population was 210 workers (clerical workers, 67; engineers, 82; assembly line workers, 61) engaged in a television manufacturing company. A questionnaire method was used to collect the data regarding to job demand, job control, behavioral type, life style and psychiatric symptoms. Clinical examination was conducted to measure blood pressure, serum cholesterol, fasting blood sugar and HbA1c. Percentage of high subjective job strain group was significantly higher in clerical workers(9.0 %) than in engineers(4.9 %) and in assembly line workers(3.3 %) (p < 0.01). Mean values of fasting blood sugar and HbA1c were significantly different between types of occupation and were the highest in clerical workers (p < 0.05). Significant association was found between perceived job characteristics and psychiatric symptom score (p < 0.01). The more job demand and the less job control was, the higher psychiatric symptom score was reported. Diastolic blood pressure was significantly related to job control (p < 0.05). The more job control was, the higher blood pressure was reported. In multiple regression analysis, job demand, job control and age were significant variables explaining the psychiatric symptoms and R2 was 0.23. Perceived job characteristics and type of occupation were not significant in explaining diastolic blood pressure and cholesterol. Type of occupation, job demand, age and BMI were significant variables explaining lasting blood sugar and R2 was 0.25. Type of occupation was the only significant variable explaining HbA1c and R2 was 0.07. According to this result, occupational type and subjective job characteristics must be considered in study of job stress. As a result of multiple analysis, subjective job characterics are significantly related to psychiatric symptoms and type of occupation is significantly related to fasting blood sugar and HbA1c.