Table 2.

Phenotypic characteristics of stationary Lactococcus lactis strains measured at pH 6.7. Mean values ± standard deviation of biological triplicates (n = 3) are shown. ZP, zeta potential (mV); CSH, cell surface hydrophobicity (%); NaCN, cell attachment to sodium caseinate (%); NaCN90C, cell attachment to sodium caseinate heated at 90°C for 10 min (%); ParaCN, cell attachment to para‐caseinate (%); E24, emulsion stability after 24 h (%)

L. lactis	ZP, mV	CSH, %	NaCN, %	NaCN90C, %	ParaCN, %	E24,%
Pili‐overexpressing strains are chaining and clumping
IL1403	−7.2 ± 0.5	0 ± 19.9	41.7 ± 13.6	67.2 ± 2.2	63.7 ± 1.6	0 ± 0
IL1403(pIL253pil)	−13.9 ± 1.3*	93.2 ± 4.5*	93 ± 2.8*	94 ± 0.4*	91.8 ± 1.8*	88.9 ± 19.3*
MG1299	−30.3 ± 2.1	75.5 ± 3.3	82.8 ± 2.7	82.7 ± 0.3	79.2 ± 2.2	35.6 ± 24.9
MG1299(pIL253pil)	−18.1 ± 1.3*	99.1 ± 1.2*	97.5 ± 1.1*	99 ± 0.6*	97 ± 1*	99.3 ± 0.6
MG1363pIL253	−26.4 ± 1.8	3.8 ± 6.8	99.2 ± 0.1	99.4 ± 0.3	80.6 ± 6.2	0 ± 0
MG1363(pIL253pil)	−11.9 ± 0.2*	94 ± 2.2*	82.8 ± 7.4	81 ± 6.8*	66 ± 16.4	85.2 ± 15*
MG1363(pNZ521)	−31.7 ± 0.8	18.7 ± 10.1	90.3 ± 2.8	88.8 ± 2.4	79.2 ± 9	0 ± 0
MG1363(pNZ521;pIL253pil)	−17 ± 1.9*	99 ± 1*	95.4 ± 0.2	96.5 ± 2.5	89.4 ± 3	65.6 ± 29.9*
NCDO712	−20 ± 0.5	99.4 ± 0.3	96 ± 0.6	95.7 ± 2	94.7 ± 0.6	99.7 ± 0.6
NCDO712(pIL253pil)	−20.5 ± 1.3	96.3 ± 0.6	85 ± 10.4	84.2 ± 9	92 ± 3.6	100 ± 0
Chaining phenotypeb
IL1403∆acmAacmD	−12 ± 0.4*	9.5 ± 4.6	97.2 ± 0.6*	96.2 ± 2.1*	96.4 ± 1.3*	0 ± 0
MG1363∆acmA	−31.4 ± 1.4	15.5 ± 4.5	89 ± 0.7*	87.6 ± 1	83.5 ± 10	0 ± 0
MG1363∆galE	−28.7 ± 0.8	14.9 ± 4.4	94.2 ± 2.1*	95.6 ± 0.5*	37.5 ± 24.6	0 ± 0
MG1363∆dltD	−29.2 ± 0.2	15.4 ± 3.5	84.9 ± 0.6	83.9 ± 3.1	82.4 ± 3.2	0 ± 0
Non‐chaining, non‐clumping phenotype*
MG1363	−30.2 ± 0.7	5.8 ± 0.2	82.3 ± 0.9	82.8 ± 1.9	79.4 ± 1.7	0 ± 0
MG1261	−30 ± 1.2	21.8 ± 0.2*	93.9 ± 1.4*	92.6 ± 0.8*	88.8 ± 6.3	0 ± 0
MG1063	−29 ± 0.9	16.7 ± 0*	89.5 ± 2.6	89.6 ± 2.1	83 ± 5.1	0 ± 0
MG1362	−31.7 ± 3.3	5.6 ± 9.6	89.6 ± 3.4	84.9 ± 9.7	79.6 ± 14.1	0 ± 0
MG1365	−30.3 ± 1.2	28.6 ± 6.1*	92.9 ± 1.8*	93.1 ± 1.3*	76.6 ± 26.4	0 ± 0
MG1614	−42 ± 2.4	20.4 ± 3.1	97.1 ± 0.8	94.8 ± 4.1	97.7 ± 1.3	0 ± 0
MG1614_clu−	−39.4 ± 0.5	73.9 ± 4.1*	96.3 ± 0.9	94.6 ± 0.6	89.4 ± 4.9	0 ± 0
MG1363∆ahrC	−29.5 ± 1.2	79.9 ± 10.7*	84.5 ± 1.1	81 ± 2.7	80.2 ± 1.7	23.8 ± 2.1*
MG1363(pIL253pil∆1)	−16.9 ± 0.9*	79.7 ± 16.9*	66 ± 11*	64.5 ± 14.4	86.3 ± 5.2	97.8 ± 3.9*
Clumping phenotypea
MG1614_clu+	−36 ± 0.4	90.2 ± 3.7*	81.7 ± 15	58.1 ± 26.3	94.6 ± 0.6	31.3 ± 4*
EPS producinga
MG1363(pNZ4120)	−18.8 ± 2.2*	0 ± 23.8	96.2 ± 1*	98.3 ± 0.5*	97.4 ± 0.2*	0 ± 0

^aComparisons were made to L. lactis MG1363 except for MG1614_clu⁻/clu⁺ and MG1363(pIL253pil∆1) which were compared with MG1614 and MG1363pIL253 respectively.

^bComparisons were made to strains IL1403 and MG1363.

* Significant at P < 0.01 – comparisons were made to non‐surface modified controls.