The program LYSIS.BAS presents a simple model of the enzymatic lysis of yeast cells. Microbial cell-wall-lytic enzymes are presently used in the lab for cell breakage on a small scale. There is an interest in using these cells on an industrial scale to rupture microbial cells so that accumulated products can be released.

This simplified model of cell lysis accounts for the release of protein, peptides, and carbohydrates from yeast cells. The yeast cell lyses through both autolysis and enzymatic lysis. Proteins released from the cell are subject to proteolysis, degrading them to simple peptides.

Portions of the SIMBAS code: 

¦35 KA = .0003987                                                              
¦36 KR = 15.51                                                                 _
¦37 KM = 1902                                                                  _
¦38 KP = 4.441: KMP = 4598                                                     _
¦40 KI = 26077                                                                 _
¦41 FPY = .4048                                                                _
¦42 FSY = .0777
¦43 FCY = .3687                                                                _
¦44 Y0 = 780: REM IC of Yeast (mg/l)                                           _
¦45 O(1) = Y0                                                                  _
¦46 O(2) = 20: REM IC of protein                                               _
¦47 O(3) = 100: REM IC of peptides                                             _
¦48 O(4) = 40: REM IC of carbohydrates                                         _
¦49 E = 8: REM IC enzyme % (v/v)                                               _
                                                                              ¦
¦65 YULT = Y0 * (.36342 - E * .0026584 + Y0 * 6.0442E-06 - 99.60299 / Y0)      _
                           _
¦1000 I(1) = -KA * (O(1) - YULT) - KR * E * (O(1) - YULT) / ((O(1) - YULT) + KM_
¦1020 I(2) = -FPY * I(1) - KP * E * O(2) / (O(2) + O(3) + KMP * (1 + O(1) / KI)_
¦1030 I(3) = -FSY * I(1) + KP * E * O(2) / (O(2) + O(3) + KMP * (1 + O(1) / KI)_
¦1040 I(4) = -FCY * I(1)                                                       _
_________________________________________________________________________¦
 "Simple" LYSIS MODEL BY J. B. HUNTER and J. A. ASENJO                
 Separation, Recovery, and Purification in Biotechnology              
¦6080 REM    ka = Rate Constant for Autolysis         (1/min)                  _
¦6090 REM    kr = Rate Constant for Lysis             (mg/L-min-%ez)           _
¦6100 REM    Km = Michaelis constant for Lysis        (mg/L)                   _
¦6110 REM    kp = Rate constant for proteolysis       (mg/L-min-%ez)           _
¦6120 REM  Kmp = Michaelis constant for proteolysis  (mg/L)                    _
¦6130 REM   Ki = Inhibition constant for proteolysis (mg Yeast/L)              _
¦6140 REM  fpy = Fraction of Protein in Yeast                                  _
¦6150 REM  fsy = Fraction of Peptides in Yeast                                 _
¦6160 REM  fcy = Fraction of Carbohydrates in Yeast                            _
¦6170 REM   O(1) = Yeast concentration (mg/L)
¦6180 REM   Y0 = Initial yeast concentration                                   _
¦6190 REM   YULT = Ultimate yeast conc. (A function of residual turbidity)     _
¦6200 REM   O(2) = Protein conc. (TCA-insol.) (mg/L)                           _
¦6210 REM   O(3) = Peptides conc. (TCA-sol.)  (mg/L)                           _
¦6220 REM   O(4) = Carbohydrates (mg/l)                                        
CONTINUE