Fourteen homofermentative lactic acid bacteria that were isolated from kefir grains and kefir fermented milks were assigned to either Lactobacillus kefiranofaciens or Lactobacillus kefirgranum, based on their characteristic morphotypes, phenotypic features and SDS-PAGE profiles of whole-cell proteins. Further genotypic analyses on representative strains from both taxa demonstrated that L. kefiranofaciens and L. kefirgranum share 100 % 16S rDNA sequence similarity and belong phylogenetically to the Lactobacillus acidophilus species group. DNA–DNA binding values of >79 % and analogous DNA G+C contents of 37–38 mol% showed that the strains studied belonged to one species: L. kefirgranum is a later synonym of L. kefiranofaciens. An emended description is proposed for L. kefiranofaciens. Due to the specific morphological and biochemical characteristics of these taxa in kefir grain formation, it is proposed that L. kefirgranum should be reclassified as L. kefiranofaciens subsp. kefirgranum subsp. nov.

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Ten detection media and six cultivation techniques were evaluated for the detection of a harmful brewery contaminant, for which the name Lactobacillus lindneri was recently revived. These bacteria showed slow and weak growth on solid media. However, enrichment of beer with NBB‐C or the use of a mixture of MRS and beer (4:1 v/v) reduced the detection time by 2 days or more, depending on the strain, compared to cultivation on solid brewery media. Eight brewery isolates from different origins, the type strain and a test strain were characterized by carbohydrate fermentation tests (API 50 CHL), by a chemotaxonomical (SDS‐PAGE) and by a genomic fingerprinting (ribotyping) method. The results obtained by all these methods indicated that the isolates studied form a single group and can be assigned to the species L. lindneri. However, using the current standard reagents, ribotyping cannot discriminate the strains isolated from different sources.

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