Articles

Found 2 Documents
Search
Journal : Microbiology Indonesia

The Process of Xylanase Production from Bacillus pumilus RXAIII-5 RICHANA, NUR; IRAWADI, TUN TEDJA; NUR, M. ANWAR; SAILAH, ILLAH; SYAMSU, KHASWAR
Microbiology Indonesia Vol 1, No 2 (2007): August 2007
Publisher : Indonesian Society for microbiology

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

The optimum conditions for the growth of Bacillus pumilus RXAIII-5 (a potential xylanase producer) were sought, these included temperature, pH, aeration, and agitation of the culture batch. Afterwards a mathematical model based on the parameter of cultivation kinetics was formulated. At the same time, the rheology of the fluid used for bacterial cultivation in a bioreactor was studied. The data obtained was used for estimating the ‘scaling up’ of enzyme production. The results of the study indicate that the optimum condition for processing in 50 ml Erlenmeyer flask are used temperature of 35 oC (308oK), pH 7, and an agitation rate of 140 rpm. The highest xylanase activity and its specific activity are 297.132 U.ml-1 and 655.32 U.g-1protein, respectively. Subsequent experiments in a bioreactor using all of the experiment parameters mentioned above, except for the agitation rate, shows that the results are as follows. The highest specific growth was at 0.082 hour-1 at an aeration and agitation rate of 0.5 vvm and 150 rpm, respectively. Based on the data of the cultivation kinetics, the optimum conditions for the fermentation in Biostat 2L-bioreactor is 1 vvm and 200 rpm of aeration and agitation, respectively . The efficiency of substrate (Yp/s) and of cell biomass (Yp/x) to produce xylanase is 50.744 U.g-1 and 43.906 U.g-1, respectively. The efficiency of substrate to cell production (Yx/s) is 1.178g.g-1. The liquid cultivation-medium has non-Newtonian properties. Based on a mathematical model it is found that the consistency index (k constant) and index of liquid behavior (n value) are 0.179 g.cm-1.second-1 and 0.3212, respectively. Becouse the value of 0
Medium Optimization for Penicillin Acylase (PAc) Production by Recombinant B. megaterium MS941 Containing pac Gene from B. thuringiensis BGSC BD1 Using Response Surface Methodology PUTRI, FENTRI PARAMITHA; NURHASANAH, ASTUTIATI; NURHAYATI, NIKNIK; HELIANTI, IS; SYAMSU, KHASWAR
Microbiology Indonesia Vol 9, No 2 (2015): June 2015
Publisher : Indonesian Society for microbiology

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5454/mi.9.2.3

Abstract

Penicillin G acylase (PAc) hydrolyses of the amide bond of benzylpenicillin (Pen-G) releasing PAA and 6-APA, key intermediate in the production of various semisynthetic penicillins. In this study, we optimised the production medium of PAc by RSM using two variables (xylose as inducer and CaCl2 as divalent cations) to obtain the optimum PAc specific activity from Bacillus megaterium btpacBD1. For this purpose, combinations of five different xylose concentrations (0.13 – 0.87 %) and five different CaCl2 concentrations (0.64 – 4.36 mM) were analysed, in a total of 22 experiments. CCD used for the analysis showed that in shake flask cultivations, xylose and CaCl2 showed significant effects on PAc volumetric activity and the quadratic model was in good agreement with the experimental results (R2= 0.86 (p-value < 0.0001)). The maximum specific activity (130.669 ± 50.241 units mg protein-1) was reached when xylose and CaCl2 concentrations were 0.49% and 2.4 mM, respectively, and medium pH was around 7. Under such conditions, the activity of PAc and protein concentration achieved were 1.318 ± 0.406 units mL-1 and  0.0101 ± 0.01 mg mL-1. The shake flask validation experiments demonstrated that with such medium composition the volumetric activity, protein concentration and specific activity achieved were 1.294 ± 0.171 units mL-1, 0.0102 ± 0.0003 mg mL-1 and 125.91 ± 13.309 units mg-1, respectively. When the optimum medium composition was applied in 10 L bioreactor, the optimum volumetric activity (2.0687 ± 0.0820 units mL-1) and protein concentration (0.0078 ± 0.0008 mg mL-1) were achieved 48 h after the start of the cultivation. However, the optimum PAc specific acivity (1260.52  ± 27.5711 units mg protein-1) was achieved 18 h after the start of the cultivation.