. 2016 Jan 7;82(2):585–595. doi: 10.1128/AEM.02868-15

TABLE 3.

Microbial loads of samples collected during experimental cheese production^a

Sample type	Production vat	Microbial load^b
Sample type	Production vat	PCA-SkM 7°C	PCA-SkM 30°C	M17 30°C	M17 44°C	MRS	WBAM	VRBGA	KAA	E. coli	CPS
VS	TA1	3.2 ± 1.0^A	5.7 ± 0.6^B	5.8 ± 0.7^B	4.0 ± 0.9^B	4.5 ± 0.5^B	1.9 ± 0.9^B	2.4 ± 1.0^D	2.5 ± 1.0^D	<1^A	<1^A
	TA2	4.4 ± 0.9^B	5.9 ± 0.9^B	6.1 ± 0.9^B	2.9 ± 0.9^A	5.8 ± 0.7^C	1.8 ± 0.8^B	1.2 ± 0.8^B	2.0 ± 0.8^C	<1^A	<1^A
	TZ1	3.5 ± 0.9^A	3.8 ± 0.9^A	4.6 ± 1.1^A	2.9 ± 0.8^A	3.2 ± 1.0^A	1.9 ± 0.4^B	1.7 ± 0.7^C	1.6 ± 0.9^B	<1^A	<1^A
	TZ2	4.3 ± 0.9^B	6.0 ± 1.0^B	5.7 ± 1.0^B	2.8 ± 0.9^A	4.5 ± 1.0^B	1.3 ± 0.6^A	<1^A	<1^A	<1^A	<1^A
Statistical significance		*	***	***	**	***	*	***	***
BMAR	TA1	5.4 ± 0.6^B	5.8 ± 0.9^B	6.2 ± 0.5^BC	5.0 ± 0.6^C	5.1 ± 0.4^B	2.8 ± 1.0^B	3.9 ± 0.9^C	3.3 ± 0.7^C	2.5 ± 1.3^B	2.4 ± 1.7^C
	TA2	5.2 ± 0.4^B	6.4 ± 0.5^C	6.3 ± 0.6^C	5.2 ± 0.8^C	5.4 ± 0.6^B	2.4 ± 0.9^AB	3.2 ± 1.0^B	3.1 ± 0.4^C	2.4 ± 1.4^B	1.8 ± 1.1^B
	TZ1	4.6 ± 0.9^A	5.1 ± 0.6^A	5.5 ± 0.4^A	4.0 ± 0.7^B	3.8 ± 0.5^A	2.1 ± 0.8^A	2.2 ± 0.5^A	1.3 ± 0.5^B	1.4 ± 0.8^A	1.0 ± 0.6^A
	TZ2	4.5 ± 1.3^A	5.5 ± 0.8^AB	5.9 ± 0.8^AB	2.5 ± 0.9^A	3.5 ± 1.0^A	2.1 ± 0.9^A	1.9 ± 0.8^A	<1^A	1.3 ± 0.6^A	1.1 ± 0.5^A
Statistical significance		*	**	*	***	***	*	***	***	**	**
C	TA1	5.8 ± 0.5^C	7.0 ± 0.6^B	7.3 ± 1.2^B	6.3 ± 0.5^B	7.1 ± 0.9^B	4.1 ± 0.9^B	5.1 ± 0.8^C	4.7 ± 0.5^C	3.9 ± 0.9^C	2.3 ± 0.9^B
	TA2	5.3 ± 1.0^B	7.0 ± 0.5^B	7.2 ± 0.8^B	5.9 ± 0.9^B	7.4 ± 0.7^B	3.8 ± 0.8^B	4.6 ± 0.7^B	4.7 ± 0.8^C	2.5 ± 0.5^B	2.0 ± 1.0^B
	TZ1	4.8 ± 0.9^A	6.4 ± 0.8^A	6.7 ± 0.7^A	4.1 ± 0.7^A	4.5 ± 1.0^A	3.1 ± 0.9^A	2.8 ± 0.9^A	1.7 ± 0.7^B	<1^A	1.4 ± 1.1^A
	TZ2	4.5 ± 0.8^A	7.1 ± 0.8^B	7.5 ± 0.7^B	3.7 ± 0.6^A	4.6 ± 0.6^A	2.9 ± 0.8^A	2.9 ± 0.9^A	1.0 ± 0.9^A	<1^A	1.4 ± 1.2^A
Statistical significance		**	*	*	***	***	**	***	***	***	*
W	TA1	4.6 ± 0.8^B	5.8 ± 0.5^A	6.2 ± 1.2^B	4.4 ± 0.8^BC	5.8 ± 0.8^A	3.8 ± 0.9^A	ND	ND	ND	ND
	TA2	4.3 ± 0.7^AB	6.3 ± 0.6^B	7.0 ± 0.8^C	4.7 ± 0.8^C	5.8 ± 0.5^A	4.6 ± 0.8^B	ND	ND	ND	ND
	TZ1	4.6 ± 0.9^B	5.4 ± 0.9^A	5.6 ± 0.9^A	4.2 ± 0.8^AB	6.1 ± 1.0^A	3.9 ± 0.7^A	ND	ND	ND	ND
	TZ2	3.9 ± 0.8^A	6.7 ± 0.8^B	7.3 ± 0.9^C	3.8 ± 0.9^A	5.7 ± 0.9^A	4.1 ± 0.6^A	ND	ND	ND	ND
Statistical significance		*	**	***	*	NS	*
AC	TA1	6.1 ± 0.6^A	8.1 ± 0.6^A	8.4 ± 0.9^A	6.0 ± 0.5^A	7.8 ± 0.7^A	4.5 ± 1.0^B	4.7 ± 0.7^C	5.9 ± 1.1^B	1.9 ± 0.7^B	1.3 ± 0.5^B
	TA2	6.2 ± 0.9^A	9.1 ± 0.8^B	9.7 ± 0.6^B	6.1 ± 0.9^AB	8.7 ± 1.0^B	4.6 ± 0.7^B	3.2 ± 0.8^B	5.8 ± 0.7^B	<1^A	<2^A
	TZ1	6.5 ± 0.7^A	7.9 ± 0.5^A	8.0 ± 0.5^A	6.3 ± 0.9^AB	7.5 ± 0.7^A	4.1 ± 0.8^AB	4.8 ± 0.9^C	5.5 ± 0.8^B	2.0 ± 0.9^B	1.8 ± 0.9^C
	TZ2	6.1 ± 0.9^A	9.3 ± 0.9^B	9.5 ± 0.7^B	6.5 ± 0.65^B	8.4 ± 0.9^B	3.9 ± 0.8^A	1.8 ± 0.9^A	2.8 ± 0.9^A	<1^A	<2^A
Statistical significance		NS	**	**	*	*	*	***	***	***	***
ChT₀	TA1	6.3 ± 0.8^AB	7.3 ± 1.0^A	7.4 ± 0.7^A	7.2 ± 0.6^A	8.2 ± 0.8^A	4.7 ± 0.9^A	2.4 ± 0.9^C	5.2 ± 0.6^B	1.8 ± 1.1^B	1.4 ± 1.2^B
	TA2	6.1 ± 1.2^A	8.1 ± 0.7^BC	8.4 ± 0.9^B	7.4 ± 0.8^A	8.2 ± 0.5^A	4.8 ± 0.7^A	<1^A	5.3 ± 0.8^B	<1^A	<2^A
	TZ1	6.6 ± 0.7^B	7.7 ± 0.5^AB	7.6 ± 0.8^A	7.6 ± 0.9^A	8.6 ± 0.9^A	4.8 ± 1.1^A	1.5 ± 0.8^B	5.6 ± 0.5^B	2.3 ± 1.1^C	2.6 ± 1.2^C
	TZ2	6.4 ± 0.9^AB	8.2 ± 0.8^C	8.5 ± 1.2^B	7.4 ± 0.7^A	8.5 ± 0.7^A	4.7 ± 0.8^A	<1^A	1.7 ± 0.7^A	<1^A	<2^A
Statistical significance		*	*	**	NS	NS	NS	***	***	***	***
ChT₁₅	TA1	6.8 ± 0.8^AB	8.1 ± 0.7^AB	8.2 ± 0.5^A	7.1 ± 0.9^A	7.4 ± 0.8^A	3.5 ± 0.7^AB	2.4 ± 0.8^C	6.4 ± 0.8^C	<1^A	<2^A
	TA2	7.2 ± 0.7^BC	8.8 ± 1.1^C	9.1 ± 0.8^B	6.8 ± 0.8^A	7.4 ± 0.6^A	3.1 ± 1.2^A	<1^A	4.9 ± 0.6^B	<1^A	<2^A
	TZ1	6.7 ± 0.6^A	7.8 ± 0.8^A	8.3 ± 0.9^A	7.8 ± 0.9^B	7.8 ± 1.0^A	4.7 ± 0.8^C	1.7 ± 0.8^B	6.3 ± 0.4^C	<1^A	<2^A
	TZ2	7.4 ± 0.9^C	8.4 ± 0.5^BC	9.0 ± 0.7^B	6.7 ± 0.6^A	7.7 ± 0.7^A	3.6 ± 0.9^B	<1^A	3.2 ± 0.8^A	<1^A	<2^A
Statistical significance		*	**	*	**	NS	***	***	***

Abbreviations: PCA-SkM 7°C, plate count agar with skimmed milk, incubated at 7°C for detection of total psychrotrophic microorganisms; PCA-SkM 30°C, plate count agar with skimmed milk, incubated at 30°C for detection of total mesophilic microorganisms; M17 30°C, medium 17 agar incubated at 30°C for detection of mesophilic coccus LAB; M17 44°C, medium 17 agar incubated at 44°C for detection of thermophilic coccus LAB; MRS, de Man-Rogosa-Sharpe agar for detection of mesophilic rod LAB; WBAM, whey-based agar medium for detection of thermophilic rod LAB; VRBGA, violet red bile glucose agar for detection of Enterobacteriaceae; KAA, kanamycin esculin azide agar for detection of enterococci; CPS, coagulase-positive staphylococci; TA1, control production at the dairy factory; TZ1, control production at the dairy pilot plant; TA2, experimental production at the dairy factory; TZ2, experimental production at the dairy pilot plant; VS, vat surfaces; BMAR, bulk milk after resting; C, curds; W, whey; AC, acidified curds; ChT₀, cheese at T₀; ChT₁₅, cheese at 15 days; ND, not determined; NS, not significant.

Loads are reported as log CFU/cm² for vat surfaces, log CFU/ml for milk and whey samples, and log CFU/g for curds and cheeses. Results are mean values ± SD for 20 plate counts (carried out in duplicate for 10 days of production). Data within a line followed by the same letter are not significantly different according to Tukey's test. *, P ≤ 0.05; **, P ≤ 0.01; ***, P ≤ 0.001.