Figure 1.
Phylogenetic tree of Mrakia blollopis SK-4 and related species.
(A) Maximum parsimony analysis of the D1/D2 domain of the 26 rRNA gene sequence. Bootstrap percentages from 1000 replications are shown on the branches. Mrakiella cryoconiti CBS 10834T and Mrakiella cryoconiti CBS 10835 were used as an out group. (B) Neighbor-joining tree of the ITS region containing the 5.8 S rRNA gene sequence. Bootstrap percentages from 1000 replications are shown on the branches. Mrakiella aquatica DBVPG4994 and Mrakiella aquatica DBVPG4990 were used as an out group.
Table 1.
Comparison of physiological characteristics of Mrakia blollopis SK-4 and other Mrakia species.
Figure 2.
Performance of activated sludge system treating model milking parlor wastewater.
(A) Results of measurement of initial BOD and final BOD. (B) Effect of BOD removal rate by ASM treatment. (0.35AS) for 0.35 BOD loading rate of model parlor wastewater treated by activated sludge (control), (0.35ASM) for 0.35 BOD loading rate of model parlor wastewater treated by activated sludge containing M. blollopis SK-4, (0.52AS) for 0.52 BOD loading rate of model parlor wastewater treated by activated sludge (control) and (0.52ASM) for 0.52 BOD loading rate of model parlor wastewater treated by activated sludge containing M. blollopis SK-4. Abbrebiations for Figure 3 are biochemical oxygen demand (BOD), activated sludge (AS) and activated sludge containing Mrakia blollopis SK-4 (ASM).
Table 2.
Purification of lipase from Mrakia blollopis SK-4.
Figure 3.
Effects of temperature and pH on SK-4 lipase.
(A) Effects of temperature on lipase activity (○) and thermostability of the lipase (•). For effect of temperature, lipase activity assay was performed at various temperatures in 50 mM sodium phosphate buffer (pH 7.0) for 30 min. For thermostability, lipase was preincubated at various temperatures for 30 min. Remaining lipase activity was examined at 65°C for 30 min in 50 mM Tris-HCl buffer (pH 8.5). The line was fitted by using the Eyring-Arrhenius equation. (B) Effects of pH on lipase activity (○) and pH stability of lipase (•). For effect of pH, lipase activity assay was performed with various buffers at 30°C for 30 min using p-nitrophenyl-palmitate as a substrate. For pH stability, lipase was preincubated in various pH buffers at 30°C for 15 h and then pH of the buffer was adjusted to 8.5. The remaining enzyme activity was examined at 65°C for 30 min using p-nitrophenyl-palmitate as a substrate. The line was fitted by Henderson- Hasselbalch equation.
Figure 4.
Substrate specificity of lipase form Mrakia blollopis SK-4.
Substrates were p-nitrophenyl esters. Relative activity for each substrate (▪) is expressed as the percentage of activity toward p-nitrophenyl-palmitate (□).
Table 3.
Comparison of the effects of various metal ions, EDTA and various organic solvents on M. blollops SK-4 and Cryptococcus sp. S-2 lipase activity.
Table 4.
Comparison of Mrakia blollopis SK-4 lipase characteristics with other yeast lipase characteristics.