Heterologous expression of LamA gene encoded endo-β-1,3-glucanase and CO2 fixation by bioengineered Synechococcus sp. PCC 7002
Di Li , Swati Yewalkar , Xiaotao Bi , Sheldon Duff , Dusko Posarac , Heli Wang , Layne A. Woodfin , Jan-Hendrik Hehemann , Sheila C. Potter , Francis E. Nano
Front. Environ. Sci. Eng. ›› 2017, Vol. 11 ›› Issue (2) : 9
Heterologous expression of LamA gene encoded endo-β-1,3-glucanase and CO2 fixation by bioengineered Synechococcus sp. PCC 7002
Maximum growth rate of Synechococcus mutant was 0.083 h−1 with 5% CO2.
Maximum biomass concentration of Synechococcus mutant was 3.697 g·L−1.
Synechococcus mutant can tolerate gas aeration with 15% CO2.
Maximum specific activity of laminarinase was 4.325 U·mg−1 dry mass.
Optimal pH and temperature of laminarinase activity were 8.0 and 70°C.
The gene for the catalytic domain of thermostable endo-β-1,3-glucanase (laminarinase) LamA was cloned from Thermotoga maritima MSB8 and heterologously expressed in a bioengineered Synechococcus sp. PCC 7002. The mutant strain was cultured in a photobioreactor to assess biomass yield, recombinant laminarinase activity, and CO2 uptake. The maximum enzyme activity was observed at a pH of 8.0 and a temperature of 70°C. At a CO2 concentration of 5%, we obtained a maximum specific growth rate of 0.083 h−1, a biomass productivity of 0.42 g·L−1·d−1, a biomass concentration of 3.697 g·L−1, and a specific enzyme activity of the mutant strain of 4.325 U·mg−1 dry mass. All parameters decreased as CO2 concentration increased from 5% to 10% and further to 15% CO2, except enzyme activity, which increased from 5% to 10% CO2. However, the mutant culture still grew at 15% CO2 concentration, as reflected by the biomass productivity (0.26 g·L−1·d−1), biomass concentration (2.416 g·L−1), and specific enzyme activity (3.247 U·mg−1 dry mass).
Synechococcus sp. PCC 7002 / Thermotoga maritima / LamA gene / Endo-β-1 / 3-glucanase / CO2 fixation
| [1] |
|
| [2] |
|
| [3] |
|
| [4] |
|
| [5] |
|
| [6] |
|
| [7] |
|
| [8] |
|
| [9] |
|
| [10] |
|
| [11] |
|
| [12] |
|
| [13] |
|
| [14] |
|
| [15] |
|
| [16] |
|
| [17] |
|
| [18] |
|
| [19] |
|
| [20] |
|
| [21] |
|
| [22] |
|
| [23] |
|
| [24] |
|
| [25] |
|
| [26] |
|
| [27] |
|
| [28] |
|
| [29] |
|
| [30] |
|
| [31] |
|
| [32] |
|
| [33] |
|
| [34] |
|
| [35] |
|
Higher Education Press and Springer-Verlag Berlin Heidelberg
/
| 〈 |
|
〉 |