Comparison Of Cell Density Research Articles

The growth of Synechococcus sp RDB001 at temperature of 30 ± 5 °C and 50 ± 5 °C: a comparison study of cell density and chlorophyll content

Research on comparison of cell density and chlorophyll content of Synechococcus sp. RDB001 grown at a temperature of 30 ± 5 °C and 50 ± 5 °C has been carried out. Synechococcus sp. RDB001 was isolated from hot spring water samples in the area of Rawa Danau-Banten with a water temperature of 50 °C which grown in MA medium (pH 6). The research aims to determine the comparison of the average cell density and chlorophyll content of Synechococcus sp. RDB001 grown at a temperature of 30 ± 5 °C and 50 ± 5 °C in incubation cabinets. The research results are useful for understanding the physiological tolerance limits and adaptation of Synechococcus sp. RDB001 ex-situ. Culturing of Synechococcus sp. RDB001 was carried out in cabinets with the incubation temperature of 30 ± 5 °C and 50 ± 5 °C for 16 days, from day 0 (t0) until day 16 (t16). Each treatment was done in 16 replicates. Non-parametric statistical analysis using the Mann Whitney test (α = 0.05) and the Spearman test (α = 0,01). The results showed there were significant differences (α = 0.05) in cell density of Synechococcus sp. RDB001 grown at a temperature of 30 ± 5 °C and 50 ± 5 °C. The highest average of cell density of Synechococcus sp. RDB001 at a temperature of 30 ± 5 °C occurred at t12, (24.2075 ± 5.33926 x 106 cells.mL−1), while at a temperature of 50 ± 5 °C occurred at t14 (1.21313 ± 2.92573 x 106 cells.mL−1). There was no correlation (α = 0.01) between cell density and chlorophyll content of Synechococcus sp. RDB001 grown at a temperature of 30 ± 5 °C and 50 ± 5 °C. The research showed that increasing the cell density of Synechococcus sp. RDB001 is not always followed by an increase in chlorophyll content of Synechococcus sp. RDB001.

EFFECT OF HARVESTING MICROALGAE (Chlorella sp.) CONTINUOUSLY TO ITS GROWTH IN THE FOTOBIOREAKTOR

Currently, the photobioreactor (FBR) has been developed and utilized to investigate (knowing in detail) the metabolic processes of cells of microorganisms, such as microalgae. FBR technology MTAP (Multi Tubular Photobioreactor Airlift) is a continuous system that is closed and controled for the growth. Then, this technology conducted continuous harvesting trial. Continuous harvesting system is cultivated by reducing of microalgae solution volume then is added by new solution of FBR MTAP system in operation. The number of reactors in the FBR MTAP are two reactors were used that Reactor 1 and Reactor 2. Microalgae was grown in 21 DAP (Days After Planting) and then harvested by reducing the volume 16.7% in each reactor in DAP 12. Based on the results of cells density, harvesting in the first phase, the optimum growth occurred at DAP 7 for Reactor 1 and Reactor 2, while harvesting their optimum growth phase II DAP 16 for Reactor 1 and DAP 19 for Reactor 2. Comparison of cell density on both reactors FBR MTAP conducted trial period of harvesting microalgae Chlorella sp. freshwater DAP 12 and DAP 21 are optimal to be done continuously without dewatering and sterilization performed the FBR system MTAP.Key words: photobioreactor, continuous harvesting, microalgae growth, cell density, Chlorella sp.

Primary anlage formation in diphyllobothriid tapeworms

The primary or genital anlagen in cestodes arise segmentally. They first appear as clusters of a few cells. At the site of anlage formation in the inner parenchyma the dominating cells are germinative cells and dorsoventral muscle cells. In forming anlagen there is no detectable increase of mitotic activity as compared with the surrounding parenchyma. In the initial stage the anlage is composed of loosely packed germinative cells. Even in larger, growing anlagen the mitotic index is not significantly higher than in the parenchyma. However, the mitotically active cells are located in the periphery, mitosis being inhibited in the cells in the core. A comparison of cell density and number in the inner parenchyma in different regions of the neck indicates that the number of cells does not increase posteriorly, in spite of high cell division activity. It is concluded that anlagen are formed by aggregation of germinative cells.