کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8501529 1553843 2018 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Short communication: Growth of dairy isolates of Geobacillus thermoglucosidans in skim milk depends on lactose degradation products supplied by Anoxybacillus flavithermus as secondary species
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم دامی و جانورشناسی
پیش نمایش صفحه اول مقاله
Short communication: Growth of dairy isolates of Geobacillus thermoglucosidans in skim milk depends on lactose degradation products supplied by Anoxybacillus flavithermus as secondary species
چکیده انگلیسی
Thermophilic bacilli such as Anoxybacillus and Geobacillus are important contaminants in dairy powder products. Remarkably, one of the common contaminants, Geobacillus thermoglucosidans, showed poor growth in skim milk, whereas significant growth of G. thermoglucosidans was observed in the presence of an Anoxybacillus flavithermus dairy isolate. In the present study, we investigated the underlying reason for this growth dependence of G. thermoglucosidans. Whole-genome sequences of 4 A. flavithermus strains and 4 G. thermoglucosidans strains were acquired, with special attention given to carbohydrate utilization clusters and proteolytic enzymes. Focusing on traits relevant for dairy environments, comparative genomic analysis revealed that all G. thermoglucosidans strains lacked the genes necessary for lactose transport and metabolism, showed poor growth in skim milk, and produced white colonies on X-gal plates, indicating the lack of β-galactosidase activity. The A. flavithermus isolates scored positive in these tests, consistent with the presence of a putative lactose utilization gene cluster. All tested isolates from both species showed proteolytic activity on milk plate count agar plates. Adding glucose or galactose to liquid skim milk supported growth of G. thermoglucosidans isolates, in line with the presence of the respective monosaccharide utilization gene clusters in the genomes. Analysis by HPLC of A. flavithermus TNO-09.006 culture filtrate indicated that the previously described growth dependence of G. thermoglucosidans in skim milk was based on the supply of glucose and galactose by A. flavithermus TNO-09.006.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Dairy Science - Volume 101, Issue 2, February 2018, Pages 1013-1019
نویسندگان
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