Fig. 6

Screening for thermostable variants of endo-β-1,4-xylanase C. a Thermostability of endo-β-1,4-xylanase B and C. Xylanase activity of the crude supernatant for the strains JMY4510 (xlnc; black line) and JMY4346 (xlnb; red line) before (continuous line) and after (dotted line) a heat shock (90 °C, 30 s). The negative control (i.e., growth medium) is shown in gray. Error bars correspond to ±1 standard deviation (N = 3). b Microfluidics library analysis. The two libraries A and B and the parental strain (JMY4510 (xlnc)) were analyzed using the integrated microfluidic screening device. The histograms show the general percentage of variants displaying activity (left) and the proportion of variants with activity levels greater than of the parental strain (right) for the wild-type and each library before (black) and after (white) heat shock (90 °C, 30 s). c 1D histograms showing the number of droplets observed as a function of the xylanase activity before and after heat shock for the wild-type, library A and library B. The mean signal for the wild-type is indicated with a green line, and values σ and >3 σ are to the right of the red lines. Strains were considered to be positives when displaying a xylanase activity higher than (mean wild-type activity + 3 σ)