Incidence and biochemical characteristics of Bacillus flora in Sardinian dairy products

Cosentino, Sofia; Mulargia, A; Pisano, Maria Barbara; Tuveri, Pierluigi; Palmas, F.

doi:10.1016/s0168-1605(97)00107-4

Cited by 66 publications

(59 citation statements)

References 16 publications

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“…In addition to confirming FAME identifications, ARDRA enabled nine additional identifications at the species level. ARDRA clusters 4,6,7,8,24,28,29, and 30 and strain R-6443 were identified as Bacillus smithii, B. circulans, Bacillus oleronius, B. sporothermodurans, Brevibacillus brevis, Aneurinibacillus aneurinilyticus, Aneurinibacillus thermoaerophilus, Virgibacillus proomii and Paenibacillus thiaminolyticus, respectively ( Table 4). The strains in ARDRA clusters 6, 7, 8, 12, 13, and 24 grouped together with the type strain of the respective species analyzed simultaneously in this study.…”

Section: Resultsmentioning

confidence: 99%

Incidence and Diversity of Potentially Highly Heat-Resistant Spores Isolated at Dairy Farms

Scheldeman

Pil

Herman

et al. 2005

Appl Environ Microbiol

122

105

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The presence of highly heat-resistant spores of Bacillus sporothermodurans in ultrahigh-temperature or sterilized consumer milk has emerged as an important item in the dairy industry. Their presence is considered undesirable since they hamper the achievement of commercial sterility requirements. By using a selective 30-min heat treatment at 100°C, 17 Belgian dairy farms were screened to evaluate the presence, sources, and nature of potentially highly heat-resistant spores in raw milk. High numbers of these spores were detected in the filter cloth of the milking equipment and in green crop and fodder samples. About 700 strains were isolated after the selective heating, of which 635 could be screened by fatty acid methyl ester analysis. Representative strains were subjected to amplified ribosomal DNA restriction analysis, 16S rRNA gene sequencing, percent G؉C content, and DNA-DNA reassociations for further identification. The strain collection showed a remarkable diversity, with representatives of seven aerobic spore-forming genera. Bacillus licheniformis and Bacillus pallidus were the most predominant species overall. Twenty-three percent of the 603 spore-forming isolates proved to belong to 18 separate novel species. These findings suggest that the selective heating revealed a pool of unknown organisms with a higher heat-resistant character. This study showed that high spore counts can occur at the dairy farm and that feed and milking equipment can act as reservoirs or entry points for potentially highly heat-resistant spores into raw milk. Lowering this spore load by good hygienic measures could probably further reduce the contamination level of raw milk, in this way minimizing the aerobic spore-forming bacteria that could lead to spoilage of milk and dairy products. Assessment and characterization of this particular flora are of great importance to allow the dairy or food industry to adequately deal with newly arising microbiological problems.

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Section: Resultsmentioning

confidence: 99%

Incidence and Diversity of Potentially Highly Heat-Resistant Spores Isolated at Dairy Farms

Scheldeman

Pil

Herman

et al. 2005

Appl Environ Microbiol

122

105

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“…Therefore, we assumed that isolates displaying the same banding pattern in terms of the presence or absence of bands, and thus showing the same fingerprint type, are highly related. The (GTG) 5 primer was applied as in a previous study (6); the use of this primer generated sufficiently complex banding patterns attributable to Bacillus or related genera for all analyzed strains. Hence, as could be expected, a banding pattern was also obtained for all 1,129 isolates studied here.…”

Section: Resultsmentioning

confidence: 99%

“…Template DNA was prepared by using a slight modification of the method of Pitcher et al (20) as previously described (11). The (GTG) 5 primer (5Ј-GTGGTGGTGGTGGTG-3Ј) was used as previously described (32). PCR amplifications were performed as previously described (32) by using a DNA thermocycler (Perkin-Elmer 9600) and Goldstar DNA polymerase (Eurogentec, Seraing, Belgium).…”

Section: Methodsmentioning

confidence: 99%

Isolation, Characterization, and Identification of Bacterial Contaminants in Semifinal Gelatin Extracts

Clerck

Vanhoutte

Hebb

et al. 2004

Appl Environ Microbiol

101

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Bacterial contamination of gelatin is of great concern. Indeed, this animal colloid has many industrial applications, mainly in food and pharmaceutical products. In a previous study (E. De Clerck and P. De Vos, Syst. Appl. Microbiol. 25:611-618), contamination of a gelatin production process with a variety of grampositive and gram-negative bacteria was demonstrated. In this study, bacterial contamination of semifinal gelatin extracts from several production plants was examined. Since these extracts are subjected to harsh conditions during production and a final ultrahigh-temperature treatment, the bacterial load at this stage is expected to be greatly reduced. In total, 1,129 isolates were obtained from a total of 73 gelatin batches originating from six different production plants. Each of these batches was suspected of having bacterial contamination based on quality control testing at the production plant from which it originated. For characterization and identification of the 1,129 bacterial isolates, repetitive-element PCR was used to obtain manageable groups. Representative strains were identified by means of 16S rRNA gene sequencing, species-specific gyrB PCR, and gyrA and rpoB sequencing and were tested for gelatinase activity. The majority of isolates belonged to members of Bacillus or related endospore-forming genera. Representative strains were identified as Bacillus cereus, Bacillus coagulans, Bacillus fumarioli, Bacillus amyloliquefaciens, Bacillus licheniformis, Bacillus pumilus, Bacillus sonorensis, Bacillus subtilis, Bacillus gelatini, Bacillus thermoamylovorans, Anoxybacillus contaminans, Anoxybacillus flavithermus, Brevibacillus agri, Brevibacillus borstelensis, and Geobacillus stearothermophilus. The majority of these species include strains exhibiting gelatinase activity. Moreover, some of these species have known pathogenic properties. These findings are of great concern with regard to the safety and quality of gelatin and its applications.

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“…Klijn et al (1997), Montanari et al (2004) demonstrated that B. sporothermodurans was the predominant sporigenous micro-organisms in UHT milk. Cosentino et al (1997) reported the presence of aerobic spore formers, including B. sphaericus, B. licheniformis and B. brevis, in Sardinian UHT milk samples. Burton (1988) reported that Bacillus stearothermophilus and Bacillus licheniformis may be of the most thermophilic spore formers commonly found in UHT milk and dairy products.…”

Section: Lactose Fermentation Testmentioning

confidence: 99%

Characterization of Aerobic Spore-Forming Bacteria Isolated From Raw Milk, Skim Milk Powder and UHT Milk

2017

Alexandria Science Exchange Journal: An International Quarterly

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Thermoduric and thermophilic aerobic spore-forming bacteria are the common causes of spoilage of pasteurized and Ultra-high-temperature (UHT) milk. The presence of high level of aerobic spore-forming bacteria in raw and recombined milk used in making UHT milk increased the spoilage and/or the reduced shelf life in the final product. In this study, 140 samples of (32) raw milk (RM), (8) skim milk powder (SMP) and (100) UHT milk were collected to isolate aerobic spore-forming bacteria. A total of 210 isolates of heat resistant bacteria were classified according to morphological, physiological and biochemical tests. Out of theses isolates, 144 strains from RM (102), SMP (25) and UHT milk (17) were expected to be Bacillus spp. The isolates were evaluated for proteolytic activity and lactose fermentation, 96.55% of the isolates were able to hydrolyze casein, while 42.76 % of the isolates were able to ferment lactose. Thermophilic Bacillus species were the predominant isolates from raw milk and skimmed milk powder. While, mesophilic Bacillus species were the predominant in UHT milk.

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Incidence and biochemical characteristics of Bacillus flora in Sardinian dairy products

Cited by 66 publications

References 16 publications

Incidence and Diversity of Potentially Highly Heat-Resistant Spores Isolated at Dairy Farms

Incidence and Diversity of Potentially Highly Heat-Resistant Spores Isolated at Dairy Farms

Isolation, Characterization, and Identification of Bacterial Contaminants in Semifinal Gelatin Extracts

Characterization of Aerobic Spore-Forming Bacteria Isolated From Raw Milk, Skim Milk Powder and UHT Milk

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