RESUMO
Seven strains belonging to genus Pseudomonas were isolated from an enrichment with hydrocarbon mixtures. Tests for enzyme activities showed that five strains used predominantly the catabolic meta-pathway for aromatic hydrocarbon degradation. Furthermore, the xylE gene which encodes a catechol 2,3-dioxygenase was amplified by PCR, and in two strains the nahAc gene, a key enzyme for naphthalene catabolism, was also found. The xylE gene might be a good marker to identify aromatic hydrocarbon degrading bacteria in soils from Patagonia.
Assuntos
Dioxigenases , Genes Bacterianos , Hidrocarbonetos Aromáticos/metabolismo , Pseudomonas/genética , Microbiologia do Solo , Argentina , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biodegradação Ambiental , Catecol 1,2-Dioxigenase , Catecol 2,3-Dioxigenase , DNA Bacteriano/genética , Indução Enzimática , Naftalenos/metabolismo , Oxigenases/genética , Oxigenases/metabolismo , Reação em Cadeia da Polimerase , Protocatecoate-3,4-Dioxigenase/genética , Protocatecoate-3,4-Dioxigenase/metabolismo , Pseudomonas/classificação , Pseudomonas/enzimologia , Pseudomonas/isolamento & purificação , Poluentes do Solo/metabolismoRESUMO
Seven strains belonging to genus Pseudomonas were isolated from an enrichment with hydrocarbon mixtures. Tests for enzyme activities showed that five strains used predominantly the catabolic meta-pathway for aromatic hydrocarbon degradation. Furthermore, the xylE gene which encodes a catechol 2,3-dioxygenase was amplified by PCR, and in two strains the nahAc gene, a key enzyme for naphthalene catabolism, was also found. The xylE gene might be a good marker to identify aromatic hydrocarbon degrading bacteria in soils from Patagonia.
Assuntos
Genes Bacterianos , Hidrocarbonetos Aromáticos/metabolismo , Pseudomonas , Microbiologia do Solo , Argentina , Biodegradação Ambiental , DNA Bacteriano , Indução Enzimática , Naftalenos , Oxigenases , Reação em Cadeia da Polimerase , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Protocatecoate-3,4-Dioxigenase , Pseudomonas , Poluentes do SoloRESUMO
Seven strains belonging to genus Pseudomonas were isolated from an enrichment with hydrocarbon mixtures. Tests for enzyme activities showed that five strains used predominantly the catabolic meta-pathway for aromatic hydrocarbon degradation. Furthermore, the xylE gene which encodes a catechol 2,3-dioxygenase was amplified by PCR, and in two strains the nahAc gene, a key enzyme for naphthalene catabolism, was also found. The xylE gene might be a good marker to identify aromatic hydrocarbon degrading bacteria in soils from Patagonia.(AU)
Assuntos
Estudo Comparativo , Genes Bacterianos , Hidrocarbonetos Aromáticos/metabolismo , Pseudomonas/genética , Microbiologia do Solo , Argentina , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , DNA Bacteriano/genética , Indução Enzimática , Naftalenos/metabolismo , Oxigenases/genética , Oxigenases/metabolismo , Reação em Cadeia da Polimerase , Protocatecoate-3,4-Dioxigenase/genética , Protocatecoate-3,4-Dioxigenase/metabolismo , Pseudomonas/classificação , Pseudomonas/enzimologia , Pseudomonas/isolamento & purificação , Poluentes do Solo/metabolismoRESUMO
Phage Acm1, generally virulent for the acidophilic facultatively methanol-utilizing strain of Acetobacter methanolicus MB 58/4, is also capable of lysogenizing its host strain at a low rate. Using amino acid-auxotrophic mutants of A. methanolicus MB 58/4 as recipient strains, transduction of His, Leu and Tyr markers could be demonstrated in this system. The ability to prepare transducing lysates by propagation of phage Acm1 on the prototrophic donor strain A. methanolicus MB 58/4, the transduction of three different markers as well as the efficiency of transduction, and the occurrence of permutations in the phage genome indicate that phage Acm1 mediates generalized transduction. Phage Acm1 might be a useful tool in genetic studies of methylotrophic A. methanolicus.
Assuntos
Acetobacter/genética , Bacteriófagos/genética , Transdução Genética , Acetobacter/metabolismo , Bacteriófagos/metabolismo , Bacteriófagos/ultraestrutura , Metanol/metabolismo , Microscopia Eletrônica , MutagêneseRESUMO
1. De novo sterol biosynthesis in the sponges Tethya aurantia and Aplysina fistularis was investigated, using sodium [5,5-3H]-mevalonate, [1-3H]-farnesol and [3-3H]-squalene. [3-3H]-Squalene was found to be the best precursor for demonstrating de novo sterol biosynthesis in a wider range of sponges. 2. By feeding [3-3H]-squalene and using cell-free techniques, the de novo sterol biosynthesis was established in 18 sponges belonging to nine orders. Among these sponges were Axinella polypoides and Axinella verrucosa which had previously been thought to be incapable of de novo sterol biosynthesis based on work with radiolabeled lanosterol, cycloartenol, mevalonate, and acetate. 3. In contrast to earlier assumptions, it is likely that all sponges are capable of de novo sterol biosynthesis.
Assuntos
Esteróis/biossíntese , Animais , Farneseno Álcool/metabolismo , Ácido Mevalônico/metabolismo , Poríferos , Esqualeno/metabolismo , TrítioRESUMO
A new bacterial strain is described belonging to Acetobacter methanolicus species. It is of industrial value as a producer of protein and methanol products. The strain is acidophile and this feature comprises a conspicuous technological advantage. The results of bacteriophage and cell interactions are reported. They might be potentially useful for elaboration of the transduction technique for the strain. The collection of mutants was obtained including those utilizing methanol, having auxotrophic markers as well as streptomycin and rifampicin resistances. The transfer of plasmids RSF1010 and R68 to Acetobacter methanolicus from other bacteria has been demonstrated.
Assuntos
Acetobacter/genética , Acetobacter/isolamento & purificação , Lisogenia , Mutação , PlasmídeosRESUMO
The lysogenic state of the methylotrophic strain Acetobacter MB 58/1 is completely demonstrated by curing and lysogenization experiments. During these investigations we found that some phenotypic characteristics are modified by the presence or loss of the prophage MO 1. It could be shown that changes of the serological behaviour, the adsorption of the phages and the sensitivity against oxytetracycline are caused by lysogenic conversion. The phenotypic alterations of the bacterial cells induced by the phage genome are the result of modifications of the lipopolysaccharide structures on the cell surface. In the case of oxytetracycline resistance, interactions between the modified lipopolysaccharide structures and specific transport proteins of the cell membranes must be assumed.
Assuntos
Acetobacter/genética , Lisogenia , Metanol/metabolismo , Acetobacter/efeitos dos fármacos , Acetobacter/metabolismo , Adsorção , Bacteriófagos/crescimento & desenvolvimento , Resistência Microbiana a Medicamentos , Mutação , Oxitetraciclina/farmacologia , Fenótipo , Ativação ViralRESUMO
An accompanying flora of the production strains always develops in each unprotected continuous fermentation process. In the process of production of fodder biomass from gas oil the high specific growth rate provides sufficient selection advantages to the production strain Lodderomyces elongisporus "D" EH 15 against substrate competitors. The accompanying flora uses products of metabolism and lysis as carbon and energy sources. The concentration of these compounds in the medium and consequently the development of the accompanying flora depends on the process conditions. During a period of more than ten years the taxonomic-diagnostic and technological properties of the production strain Lodderomyces elongisporus "D" EH 15 did not change, caused by the permanent selection stress in the continuous fermentation process.
