Difference between revisions of "Part:BBa K1509002"

Revision as of 10:22, 17 October 2014

Mainly responsible for the flocculation of Bacillus sp. F2

It is responsible for the flocculent ability of Bacillus sp. F2 and has been converted to E.coli DH5α. It has been proved that strain of E.coli positive clone FC2 could express flocculent activity, with the flocculent efficiency of 90%, thus can be a good choice in environmental applications. The 1071bp gene consists of 29%T, 18%C, 25%G and 29%A.

Usage and Biology

The Bacillus sp. F2 [1] that was used in this study was stored at -40°C in 20% glycerol. The bacteria from the stock cultures were pre-cultured in Luria-Bertani culture medium (LB) prior to use.DH5α was taken as the host for recombinant plasmids. The pET-28b (+) was prepared as an overexpression vector to produce the target protein. Rosetta pLysS was used as the host for expression of the flocculation gene under the control of the T7 promoter. E. coli transformants were grown at 37°C in LB medium.

Result

For comparative purposes, two E.coli strains with or without flocculation gene were used. The results were shown in Fig. 1. It was showed that the control strain could not settle efficiently within a short time. After 20 min static placement, only 55% of cells were flocculated. In contrast, the recombinant strain was strongly flocculent, 70% of cells were flocculated within only 10 min. At last, about 80% of the cells were settled after 20 min. The results indicated that the flocculation gene was expressed successfully in the E.coli strain. The flocculation ability of the recombinant strain could give us a new sight to remove cells from liquid environment. However, we only observed the flocculation characters of the strain in phosphate buffer containing 4 mM Ca²⁺, and we did not test the flocculation ability of the strain in the waste water which contains various metal ions and organic pollutant, and that is what we will focus on in our further study.

References

1. Fang Ma, Junliang Liu, Shugeng Li, Jixian Yang, Liqiu Zhang, Bo Wu, Yanbin Zhu.Development of complex microbial flocculant. China water and wastewater, 2003, 19(4):1-5.

Sequence and Features