Table 2.

Linear models predicting the volatilome contribution of Pseudomonas helmanticensis and Mortierellaceae strains in co-cultures.

Species	Strain	Growth rate pure|co [mm d-1]	Model 1			Model 2			Model 3
			Fungal coefficient	Bacterial coefficient	adj.R2	Bacterial coefficient	adj.R2	#VOCs	Fungal coefficient	adj.R2	#VOCs
L. exigua	HFSF103	8.1 > 7.3*	1.8 ± 0.16**	0.20 ± 0.023**	0.739	0.29 ± 0.029**	0.797	27	1.4 ± 0.30**	0.205	34
L. exigua	HFSF26	ns	0.7 ± 0.20**	0.29 ± 0.019**	0.723	0.23 ± 0.039**	0.539	30	1.01 ± 0.052**	0.292	33
L. exigua	Ks2_4	8.9 < 9.8*	0.3 ± 0.17	0.29 ± 0.023**	0.699	0.14 ± 0.028**	0.472	28	0.8 ± 0.28*	0.287	39
L. exigua	Pats4_2	ns	1.1 ± 0.18**	0.27 ± 0.024**	0.757	0.33 ± 0.011**	0.981	18	0.9 ± 0.11**	0.271	55
L. exigua	Pr2s22	ns	0.66 ± 0.077**	0.059 ± 0.0086**	0.633	0.08 ± 0.019**	0.365	31	0.55 ± 0.06**	0.06	37
L. gamsii	Ks2_13	7.7 < 8.0*	0.25 ± 0.094*	0.20 ± 0.014**	0.75	0.11 ± 0.023**	0.447	25	0.50 ± 0.030**	0.204	30
L. gamsii	M10	ns	0.19 ± 0.108	0.20 ± 0.014**	0.71	0.16 ± 0.023**	0.647	29	0.51 ± 0.039**	0.202	27
L. gamsii	M42	ns	0.02 ± 0.133	0.27 ± 0.015**	0.769	0.27 ± 0.024**	0.833	26	− 0.03 ± 0.087	0.273	29
L. gamsii	Pats3_1	7.9 < 9.0*	0.3 ± 0.16*	0.22 ± 0.018**	0.664	0.28 ± 0.047**	0.524	31	− 0.17 ± 0.134	0.219	26
L. gamsii	Pr2s1	ns	0.34 ± 0.066**	0.18 ± 0.016**	0.688	0.14 ± 0.031**	0.45	26	0.21 ± 0.017**	0.179	35
L. hyalina	Ks1_7	8.6 > 8.4*	0.45 ± 0.098**	0.18 ± 0.015**	0.679	0.37 ± 0.043**	0.692	33	0.09 ± 0.086	0.182	31
L. hyalina	Ks2_11	ns	0.59 ± 0.086**	0.17 ± 0.014**	0.699	0.21 ± 0.033**	0.561	32	0.63 ± 0.068**	0.173	29
L. hyalina	Ks2_12	ns	0.6 ± 0.11**	0.24 ± 0.015**	0.762	0.29 ± 0.047**	0.52	35	0.36 ± 0.041**	0.237	28
L. hyalina	Patw2_7	6.3 < 8.5*	0.14 ± 0.035**	0.22 ± 0.012**	0.781	0.13 ± 0.019**	0.63	30	0.3 ± 0.11*	0.224	29
L. sclerotiella	HFSF81	7.7 > 7.2*	0.89 ± 0.036**	0.01 ± 0.036	0.877	− 0.01 ± 0.011	− 0.054	10	0.91 ± 0.020**	0.012	80
L. sclerotiella	HFSF83	7.4 < 8.5*	0.2 ± 0.14	0.31 ± 0.019**	0.771	0.4 ± 0.059**	0.639	26	− 0.13 ± 0.097	0.312	40
L. sclerotiella	HFSF85	8.3 > 7.5*	0.5 ± 0.13**	0.27 ± 0.019**	0.751	0.2 ± 0.058**	0.457	25	0.46 ± 0.048**	0.272	41
L. solitaria	OAS3	ns	0.96 ± 0.037**	0.022 ± 0.0042**	0.911	0.03 ± 0.021	0.045	29	0.86 ± 0.030**	0.022	38
L. solitaria	OAS4	ns	0.93 ± 0.076**	0.040 ± 0.0089**	0.727	0.08 ± 0.028*	0.217	30	0.11 ± 0.060	0.038	37
L. solitaria	OAS5	ns	0.4 ± 0.22**	0.22 ± 0.022**	0.583	0.23 ± 0.055**	0.33	35	0.2 ± 0.11	0.218	28
E. galaxiae	M1	7.4 > 6.9*	− 0.2 ± 0.29	0.55 ± 0.035**	0.718	0.59 ± 0.082**	0.668	26	− 0.17 ± 0.138	0.552	29
E. galaxiae	M22	ns	− 0.1 ± 0.22	0.60 ± 0.025**	0.855	0.56 ± 0.042**	0.885	24	− 0.9 ± 0.11**	0.598	30
E. galaxiae	Pfs28	6.6 < 6.8*	1.00 ± 0.024**	0.01 ± 0.003	0.95	− 0.01 ± 0.002**	0.388	33	1.18 ± 0.035***	0.007	29
E. galaxiae	Pr1s18	6.9 < 7.3*	0.6 ± 0.30	0.57 ± 0.035**	0.787	0.53 ± 0.092**	0.539	29	0.6 ± 0.16***	0.572	40
E. galaxiae	Prw1_1	8.9 > 8.4*	− 0.01 ± 0.186	0.61 ± 0.029**	0.833	0.63 ± 0.073**	0.718	30	− 0.01 ± 0.188	0.609	28

Three models were calculated: (1) Co-culture volatilome predicted from both, fungal and bacterial pure cultures. All volatile organic compounds (VOCs) detected were used for prediction. (2) Co-culture predicted from pure P. helmanticensis cultures. The model considers only VOCs never produced/consumed in the respective fungal pure culture, but produced in P. helmanticensis pure cultures. (3) Bacterial contribution to the volatilome was predicted from model (1) and subtracted from the measured concentrations in the co-cultures. From this predicted volatilome, the fungal contribution to the co-culture volatilome was modelled. In none of the three models calculated, the intercept differed from zero. The coefficient of the equation can be considered as a proxy for the bacterial and fungal contribution to the co-culture volatilome, respectively, and indirectly for growth. Coefficient ± standard error. #VOCs = number of VOCs considered in the model. Significances: ns = not significant; * = p < 0.05; ** = p < 0.001.