Affiliation:
1. Department of Food Science, Cornell University, Ithaca, New York 14853
Abstract
ABSTRACT
Putative
Pseudomonas
spp. isolated predominantly from raw and processed milk were characterized by automated ribotyping and by biochemical reactions. Isolates were biochemically profiled using the Biolog system and API 20 NE and by determining the production of proteases, lipases, and lecithinases for each isolate. Isolates grouped into five coherent clusters, predominated by the species
P. putida
(cluster A),
P. fluorescens
(cluster B),
P. fragi
(as identified by Biolog) or
P. fluorescens
(as identified by API 20 NE) (cluster C),
P. fragi
(as identified by Biolog) or
P. putida
(as identified by API 20 NE) (cluster D), and
P. fluorescens
(cluster E). Isolates within each cluster also displayed similar enzyme activities. Isolates in clusters A, C, and D were generally negative for all three enzyme activities; isolates in cluster B were predominantly positive for all three enzyme activities; and isolates in cluster E were negative for lecithinase but predominantly positive for protease and lipase activities. Thus, only isolates from clusters B and E produced enzyme activities associated with dairy product flavor defects. Thirty-eight ribogroups were differentiated among the 70 isolates. Ribotyping was highly discriminatory for dairy
Pseudomonas
isolates, with a Simpson's index of discrimination of 0.955. Isolates of the same ribotype were never classified into different clusters, and ribotypes within a given cluster generally showed similar ribotype patterns; thus, specific ribotype fragments may be useful markers for tracking the sources of pseudomonads in dairy production systems. Our results suggest that ribogroups are generally homogeneous with respect to nomenspecies and biovars, confirming the identification potential of ribotyping for
Pseudomonas
spp.
Publisher
American Society for Microbiology
Subject
Ecology,Applied Microbiology and Biotechnology,Food Science,Biotechnology
Reference36 articles.
1. Basic local alignment search tool.;Altschul S. F.;J. Mol. Biol.,1990
2. The phylogeny of the genera Chryseomonas,Flavimonas, and Pseudomonas supports synonymy of these three genera.;Anzai Y.;Int. J. Syst. Bacteriol.,1997
3. “Breathprints” at the microbial level.;Bochner B. R.;ASM News,1989
4. Taxonomic diversity of pseudomonads revealed by computer-interpretation of ribotyping data.;Brosch R.;Syst. Appl. Microbiol.,1996
5. Automated system rapidly identifies and characterizes microorganisms in food.;Bruce J.;Food Technol.,1996
Cited by
110 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献