Effects of Proteus vulgaris growth on the establishment of a cheese microbial community and on the production of volatile aroma compounds in a model cheese.
OBJECTIVE
To investigate the impact of Proteus vulgaris growth on a multispecies ecosystem and on volatile aroma compound production during cheese ripening.


RESULTS
The microbial community dynamics and the production of volatile aroma compounds of a nine-species cheese ecosystem were compared with or without the presence of P. vulgaris in the initial inoculum. Proteus vulgaris was able to colonize the cheese surface and it was one of the dominant species, representing 37% of total isolates at the end of ripening with counts of 9.2 log(10) CFU g(-1). In the presence of P. vulgaris, counts of Arthrobacter arilaitensis, Brevibacterium aurantiacum and Hafnia alvei significantly decreased. Proteus vulgaris influenced the production of total volatile aroma compounds with branched-chain aldehydes and their corresponding alcohols being most abundant.


CONCLUSIONS
Proteus vulgaris was able to successfully implant itself in a complex cheese ecosystem and significantly contributed to the organoleptic properties of cheese during ripening. This bacterium also interacted negatively with other bacteria in the ecosystem studied.


CONCLUSIONS
This is the first time that the impact of a Gram-negative bacterium on cheese microbial ecology and functionality has been described.
UMR 782 Génie et Microbiologie des Procédés Alimentaires, AgroParisTech/INRA, 78850 Thiverval-Grignon, France.
P
P
Deetae
J
J
Mounier
P
P
Bonnarme
H E
HE
Spinnler
F
F
Irlinger
S
S
Helinck
D000818:Animals; D001419:Bacteria / Q000254:growth & development* / Q000302:isolation & purification; D002611:Cheese / Q000032:analysis* / Q000382:microbiology*; D015169:Colony Count, Microbial; D003116:Color; D017753:Ecosystem; D005516:Food Microbiology; D008401:Gas Chromatography-Mass Spectrometry; D006863:Hydrogen-Ion Concentration; D009930:Organic Chemicals / Q000032:analysis*; D011514:Proteus vulgaris / Q000254:growth & development*; D012903:Smell; D013457:Sulfur Compounds / Q000032:analysis*; D014835:Volatilization; D015003:Yeasts / Q000254:growth & development* / Q000302:isolation & purification
D009930:Organic Chemicals; D013457:Sulfur Compounds