background and objectives: isolation of xanthomonas campestris from soil has a wide range of applications from monitoring of phytopathogenic populations in soil to screening of improved xanthan-producing strains. identification of xanthomonas campestris and its pathovars requires pathogenicity tests in addition to phenotypic and molecular characterization. materials and methods: thirty phenotyp...

We have found that broadband light (380 to 520 nm) rapidly and selectively kills oral black-pigmented bacteria (BPB) in pure cultures and in dental plaque samples obtained from human subjects with chronic periodontitis. We hypothesize that this killing effect is a result of light excitation of their endogenous porphyrins. Cultures of Prevotella intermedia and P. nigrescens were killed by 4.2 J/...

Antibiotic resistance of heterotrophic bacteria isolated from the surface microlayer and subsurface water of downtown pond was determined. The levels of resistance of bacteria to various antibiotics differed considerably. It follows from the results that bacteria were most resistant to penicillin and sensitive to gentamycin, neomycin and oxytetracycline. Majority of bacterial strains were chara...

Six isolates of pigmented spore-forming bacteria were recovered from human faeces from subjects in Vietnam. 16S rRNA analysis demonstrated close association with known pigmented Bacillus species. All isolates were able to tolerate growth on 8% NaCl and were resistant to arsenate, characteristics that make them most related to Bacillus indicus. Two visible pigments were apparent, a yellow pigmen...

A method for characterizing pigmented bacteria based on the numerical analysis of their carotenoid absorption spectra was examined. To achieve this, some non-phototrophic pigmented bacteria that were isolated from various environments and closely related types of species were used. Bacterial carotenoid pigments were extracted with an acetone:methanol (7:2) mixture and the absorption spectra wer...

isolation of pigmented t.violaceum from a patient with endothrix infection associated with the inflammatory and kerion symptoms and also isolation of the non- pigmented strain from another patient with non-inflammatory symptoms, led us to investigate the enzymic activities in both strains. most of the studies on dermatophyte compoxition have shown the relationship between proteolytic enzymes an...