Journal of Applied Biotechnology

1-10

Authors: Abuelhija Mahmoud

Isolation of rare cells from peripheral blood may be helpful either in the detection of circulating tumor cells and directing aggressiveness of therapy, or it can be helpful for prenatal diagnosis by the enrichment of fetal cells from maternal blood. The major limit of detection rare cells using magnetic beads is primarily influenced by the non-specific binding of non-target cells. The depletion of non-target cells is considered an important prerequisite for rare cells detection. In this study, we examined and compared the depletion efficiency of CD45 cell from peripheral blood samples using two different forms of immunomagnetic separation technology namely: the Cell enrichment process (CEPir) and DynaMAG technology. Our results indicate significantly lower number of CD45 cells in negative fractions using the CEPir technology. Moreover, the CD45 depletion efficiency was found to be higher in CEPir technology when compared with the DynaMAG. Negative selection is a promising approach for isolation of rare cells, we concluded that the negative selection (depletion) of leukocytes using CD45 marker is an effective pre-enrichment step for the detection of rare cells using CEPir technology. Further studies are required to validate its efficacy at capturing specific rare cells for downstream application.

20-40

Authors: Obssi Dessalegn, Kassahun Bantte, Mulugeta Diro

Seed tubers are expensive, bulky and the multiplication rate in the field is very low. Shortage of seed tubers for planting is one of the major constraints for yam production in Ethiopia. No information is available on micropropagation of Dioscorea spp. in Ethiopia. To overcome such problem, the current study was, initiated to optimize type and concentration of plant growth regulators for shoot multiplication and rooting. Shoot multiplication and rooting in vitro were carried out using a completely randomized design with five replications. For shoot multiplication, shoots initiated from nodal cuttings were treated with BAP in combination with NAA. For rooting, the micro-shoots were transferred to ½ MS media containing NAA and IBA. Data on number of shoots per explant, roots per shoot and related growth parameters were recorded and statistically analyzed. The results showed that MS media supplemented with 1.5 mg/l BAP + 0.15 mgl-1 NAA gave an average of 6.40 ± 0.28 shoots per explant with a mean shoot length of 2.0±0.11 cm. MS supplemented with BAP (1.0 mg l-l) and NAA (0.15 mg l-l) gave 5.40 ± 0.28 with a mean shoot length of 1.84 ± 0.20 cm. Plantlets grown on half strength MS media supplemented with 2.0 mg l-l NAA and 0.5 mg l-l IBA produced 5.7 ± 0.27 roots per plantlet and an average root length of 4.63±0.23 cm. Thus MS + 1.5 mgl-1 BAP + 0.15 mg l-l NAA and 1/2 MS +2.0 mg l-l NAA + 0.5 mgl-1 IBA is the best hormone combination for shoot multiplication and in vitro rooting respectively.

61-73

Authors: Renata Aguirre Trindade, Adriel Penha Munhoz, Carlos André Veiga Burkert

The large-scale use of biodiesel has shown significant environmental benefits as regards the reduction of global warming impacts. The increased generation of glycerol, the main byproduct of the reaction, makes necessary to propose alternatives to its use. In this context, the aim of this study was to evaluate raw glycerol (RG), a byproduct from biodiesel synthesis, as a carbon source for the cultivation of bacteria recognized as exopolysaccharides (EPSs) producers, compared with sucrose (S) and with a mixture of both components in a ratio of 1:1 w:w (SRG). The bacteria used were: Xanthomonas campestris pv. mangiferaeindicae IBSBF 1230, Pseudomonas oleovorans NRRL B-14683, Sphingomonas capsulata NRRL B-4261 and Zymomonas mobilis NRRL B-4286. All bacteria were capable of growing and producing EPSs using RG as the sole carbon source. For X. campestris, EPSs concentration of around 4.00 g L-1 was found for the different carbon sources tested. For P. oleovorans, only the medium composed by S (0.85 g L-1) differed from the other media, with better results being found using RG and SRG. S. capsulata showed higher concentration in the medium containing S and SRG, around 3.40 g L-1, and in the medium containing RG this value decreased to 1.70 g L-1. Z. mobilis, on the other hand, showed a better result using SRG (1.41 g L-1), and in the medium containing S and RG, these values were lower, reaching 0.27 and 0.77 g L-1, respectively.