Search results for "microbiology"

Whey lactose bioconversion to valuable products by non-conventional yeasts Kluyveromyces marxianus

2016

2-Phenylethanol production by Kluyveromyces marxianus on glucose and lactose substrates

2016

Carbohydrates in Jerusalem artichoke powder suspension

2007

Purpose – The aim of this study was to evaluate the influence of temperature and action time on the extraction rate of carbohydrates of Jerusalem artichoke concentrate powder and inactivation of inulin during boiling and sterilization.Design/methodology/approach – Water suspension of Jerusalem artichoke concentrate (5g/100ml) at 25, 50 and 100○C was tested after 5, 15, 30 and 60min to determine the content of inulin, glucose, fructose and sucrose and evaluate the extraction rate. The stability of inulin was studied after boiling and sterilization at 120○C during 1, 2 and 3h. The extraction rate was evaluated by Fourier‐Transform Infrared (FT‐IR) spectroscopy as well.Findings – It was shown …

Zum Abbau von 14C-markierter �pfels�ure durch Bacterium gracile

1962

Der Apfelsaureabbau durch B. gracile wird mit Hilfe 14C-markierter Sauren quantitativ untersucht. Die nach dem Abbau wiedergefundene Aktivitat in Restapfelsaure, Milchsaure und Kohlendioxyd betragt zusammen 96–97% der Aktivitat der eingesetzten dl-Apfelsaure-[1,4-14C2]. Die molaren Verhaltnisse von abgebauter Apfelsaure zu Milchsaure und Kohlendioxyd sind 1:1:0,9. Ein Weiterabbau der Apfelsaure uber Milchsaure hinaus ist zu verneinen, da in diesem Fall mehr Kohlendioxyd entstehen muste als dem Verhaltnis 1:1:1 entsprache. D-Apfelsaure und Fumarsaure werden von den Bakterien ebenfalls dissimiliert, Milchsaure wird nicht angegriffen. Citronensaure-[1,5-14C2] wird sehr langsam abgebaut; als ei…

Malic-Enzym-Synthese und pH-Adaptation bei L-�pfels�ure abbauenden Bakterien

1968

Es wird die Malic-Enzym-Synthese bei sechs verschiedenen Arten L-Apfelsaure abbauender Bakterien untersucht. Die homofermentativen Arten bilden unter den gepruften Bedingungen ausschlieslich ein adaptives Malic-Enzym, wahrend die Synthese bei den heterofermentativen in Abhangigkeit vom Zuchtungsmilieu adaptiv oder konstitutiv erfolgen kann. Beim konstitutiven Malic-Enzym ist der sonst positive Glucose-Effekt auf Aktivitat und Induktion nicht festzustellen, wie Versuche mit Enzymlosungen ergeben haben. Die pH-Maxima der Apfelsaureabbau-Aktivitat der intakten Bakterien verschieben sich bei Gewohnung der Zellen an hohere H+-Ionen-Konzentrationen im kunstlichen und naturlichen Milieu zu tiefer …

Effect of Cd-containing wood ash on the microflora of coniferous forest humus

2000

The use of wood ash in forestry has been questioned because the cadmium (Cd) concentration of ash, which varies between 1 and 20 mg kg(-1) ash, exceeds the level allowed for fertilizers (3 mg kg(-1)) used in agriculture. To investigate the combined and separated effects of Cd and ash on the forest humus microflora, pumice or wood ash, spiked with a water-soluble (CdCl(2)) or -insoluble (CdO) form of Cd at three levels (0, 400 and 1000 mg kg(-1)), were applied at a fertilization level of 5000 kg ha(-1) in a laboratory microcosm study. The trial consisted of 60 microcosms (five replications per treatment), which were incubated in darkness at +20 degrees C and a constant relative air humidity …

Abundance and activity of nitrate reducers in an arable soil are more affected by temporal variation and soil depth than by elevated atmospheric [CO2]

2011

Elevated atmospheric carbon dioxide concentrations ([CO2]) might change the abundance and the function of soil microorganisms in the depth profile of agricultural soils by plant-mediated reactions. The seasonal pattern of abundance and activity of nitrate-reducing bacteria was studied in a Mini-FACE experiment planted with oilseed rape (Brassica napus). Three depths (0–10, 10–20 and 20–30 cm) were sampled. Analyses of the abundances of total (16S rRNA gene) and nitrate-reducing bacteria (narG, napA) revealed strong influences of sampling date and depth, but no [CO2] effects. Abundance and activity of nitrate reducers were higher in the top soil layer and decreased with depth but were not re…

Phenazine antibiotics produced by fluorescent pseudomonads contribute to natural soil suppressiveness to Fusarium wilt

2009

Natural disease-suppressive soils provide an untapped resource for the discovery of novel beneficial microorganisms and traits. For most suppressive soils, however, the consortia of microorganisms and mechanisms involved in pathogen control are unknown. To date, soil suppressiveness to Fusarium wilt disease has been ascribed to carbon and iron competition between pathogenic Fusarium oxysporum and resident non-pathogenic F. oxysporum and fluorescent pseudomonads. In this study, the role of bacterial antibiosis in Fusarium wilt suppressiveness was assessed by comparing the densities, diversity and activity of fluorescent Pseudomonas species producing 2,4-diacetylphloroglucinol (DAPG) (phlD+) …

Taxonomical and Functional Assessment of the Endometrial Microbiota in A Context of Recurrent Reproductive Failure: A Case Report

2019

Investigation of the microbial community in the female reproductive tract has revealed that the replacement of a community dominated by Lactobacillus with pathogenic bacteria may be associated with implantation failure or early spontaneous abortion in patients undergoing assisted reproductive technology (ART) treatment. Herein we describe taxonomically and functionally the endometrial microbiome of an infertile patient with repeated reproductive failures (involving an ectopic pregnancy and two clinical miscarriages). The microbiological follow-up is presented over 18-month in which the microbiota was evaluated in six endometrial fluid samples. The microbial profile of 16S rRNA gene sequenci…

Serological and molecular characteristics of Vibrio vulnificus biotype 3: evidence for high clonality.

2007

Vibrio vulnificus biotype 3 has been implicated as the causative pathogen of an ongoing disease outbreak that erupted in Israel in 1996. Recent work based on multi-locus sequence typing (MLST) showed that V. vulnificus biotype 3 is genetically homogeneous. The aim of this study was to investigate the existence of subpopulations within this homogeneous biotype by characterizing the surface antigens and analysing the sequence diversity of selected outer-membrane protein (OMP)-encoding genes. Rabbit antisera were prepared against biotype 1, 2 and 3 strains. The results of the slide-agglutination test, dot-blot assay (using fresh and boiled cells), and immunoblotting of lipopolysaccharides (LPS…