Download Table S1. Model parameter descriptions and values. Parameter Unit

Table S1. Model parameter descriptions and values.
Parameter
Generations
IterPerHour
BoxL
InitCheater
Unit
hours
length of model run
number of model iterations per hour
m
linear dimension of grid box
probability that box is initially occupied by a cheater
probability that box is initially occupied by a producer
InitProducer
InitMass
MassMin
MassCrit
BMR
MetaFact
PDeath
MicCtoN
MicCtoP
EnzCtoN
EnzCtoP
BirthLocal
fg C
fg C
fg C
fg fg–1 min–1
fg fg–1
min-1
ratio
ratio
ratio
ratio
BirthReach
RespEnz
grid box
fg fg–1 min–1
AreaToMass
Description
initial cell mass
microbe mass below which cell dies
microbe mass above which cell may divide
fraction of microbial C respired
mass of nutrients metabolized per unit C
probability that a cell dies at random
optimal microbe biomass C:N
optimal microbe biomass C:P
enzyme C:N
enzyme C:P
dictates if dispersal is global (0) or local (1)
local dispersal distance
respiration during enzyme production as a proportion
of enzyme mass
scaling constant for deriving microbe surface area in
m2 from mass in fg assuming density = 1.2 g cm–3
*vary CNP = model runs with gradients of C, N, and P supply
Values
1500-8000
2.52  107
1
0.01
0: vary CNP*
0.01
0.001: low abundance
150
30
300
1.5  10–4
0.1
3  10–5
6
60
3.5
200
1
0: mixed
1
0.1
0.0428
Table S1 continued.
Parameter
PLocal
Unit
Description
dictates if product diffusion is global (0) or local (1)
dictates if enzyme diffusion is global (0) or local (1)
ELocal
PReach
EReach
InitS
InitP
InitE
SInput
PInput
SDecay
PDecay
EDecay
PDiff
EDiff
EChoose
grid box
grid box
fg m–3
fg m–3
fg m–3
fg min–1 m–2
fg min–1 m–2
min–1
min–1
min–1
m2 min–1
m2 min–1
EConstit
fg fg–1 min–1
AlloFact
fg fg–1
distance between two boxes for local product diffusion
distance between two boxes for local enzyme diffusion
initial substrate concentration
initial product concentration
initial enzyme concentration
substrate input rate
product input rate
substrate loss constant
product loss constant
enzyme loss constant
product diffusion coefficient
enzyme diffusion coefficient
dictates if enzyme production is set to zero (0) or
regulated (1)
fraction of producer biomass allocated to constitutive
enzyme production
fraction of uptake allocated to enzyme production
10–7-10–3
Values
Nitrogen
0
1: vary CNP
0
1: vary CNP
1
1
0
0
0
0.0-0.032
0.0-0.1
0.01
0.01
0.01
0.5
0.01
0
1: vary CNP
10–7
Phosphorus
0
1: vary CNP
0
1: vary CNP
1
1
0
0
0
0.0-0.0032
0.0-0.01
0.01
0.01
0.01
0.5
0.01
0
1: vary CNP
10–7
0.01
0.01
0.01
Carbon
1
0: mixed
1
0: mixed
1
1
0
0
0
0.032-0.32
0.0-0.032
0.01
0.01
0.01
0.5
10–4-0.5
1
Table S1 continued.
Parameter
Vmax
Km
VmaxCheat
VmaxProducer
Unit
fg fg–1 min–1
fg m–3
fg fg–1 min–1
fg fg–1 min–1
KmCheater
KmProducer
EAreaCheater
fg m–3
fg m–3
fg m–2
EAreaProducer fg m–2
Description
maximum catalytic rate per unit enzyme
Michaelis constant for enzyme
maximum catalytic rate per unit cheater uptake protein
maximum catalytic rate per unit producer uptake
protein
Michaelis constant for cheater uptake
Michaelis constant for producer uptake
mass of uptake protein per unit cheater cell surface
area
mass of uptake protein per unit producer cell surface
area
Carbon
10
0.001
10
10
Values
Nitrogen
10
0.001
10
10
Phosphorus
10
0.001
10
10
0.001
0.001
0.1
0.001
0.001
0.1
0.001
0.001
0.1
0.1
0.1
0.1