TABLE 1.

Influence of Trypticase on incorporation of ¹⁵NH₃ by P. bryantii B₁4^a

Parameter	Value for growth medium						SEDc
	Basal	Basal + Trypticase (1 g/liter)	Basal + Trypticase (5 g/liter)	Basal + Trypticase (10 g/liter)	Basal + Trypticase (30 g/liter)	Complete M2
NH3 concn (g of N/liter)
Initial	0.156	0.154	0.190	0.238	0.376	0.353	0.005
Final	0.031	0.042	0.184	0.206	0.491	0.393	0.010
Enrichment in NH3 (atom%)
Initial	34.3	34.4	33.6	31.1	26.0	26.8	0.55
Final	31.8	32.6	29.8	25.1	15.5	17.8	0.56
Microbial N formed (g/liter)	0.102	0.137	0.192	0.197	0.192	0.165	0.013
Enrichment in microbial N (atom%)	38.1	27.9	12.1	8.5	3.0	2.0	0.42
Proportion of microbial N derived from ammonia	1.15	0.83	0.38	0.30	0.14	0.09	0.014
Proportion of microbial amino acids derived from ammoniab
Ala	1.11	0.75	0.29	0.12	0.02	0.01
Gly	1.08	0.71	0.30	0.11	0.01	0.01
Val	1.10	0.68	0.22	0.09	0.01	0.01
Leu	1.11	0.72	0.33	0.18	0.04	0.02
Ile	1.12	0.75	0.33	0.18	0.03	0.02
Pro	1.11	0.21	0.03	0	0	0
Ser	1.12	0.84	0.46	0.26	0.09	0.04
Thr	1.12	0.67	0.28	0.08	0	0.01
Phe	1.08	0.33	0.09	0.02	0.03	0
Asp	1.12	0.86	0.52	0.34	0.17	0.09
Glu	1.10	0.92	0.58	0.42	0.21	0.13
Tyr	1.12	0.75	0.36	0.12	0.01	0
Mean proportion of amino acid N derived from ammonia	1.11	0.68	0.31	0.16	0.05	0.03	0.007

^aResults are mean values from three separate cultures. 

^bStandard errors of difference for proportion of individual microbial amino acids derived from ammonia are as follows: treatment, 0.004; amino acid, 0.005; treatment × amino acid, 0.013 (degrees of freedom, 142). 

^cSED, standard errors of differences of means.