Aislamientos de bacterias en medios deficientes en fósforo

Se aislan una serie de microorganismos capaces de desarrollarse en un medio defidente de fósforo (medio P) observándose conjuntamente con la característica de crecer perfectamente una morfología un tanto particular (formas alargadas, a veces con varías granulaciones en el interior) y originando formas quísticas. Bacterias de la colección del laboratorio (38 cepas se sembraron en el medio mencionado) apreciándose que el Azotobacter crecía muy bien y observándose en Az chrococcum una pigmentación negra, mucho más oscura que la clásica pigmentación marrón que se produce en medios desprovistos de nitrógeno

Aislamientos de bacterias en medios deficientes en fósforo

Se aíslan una serie de microorganismos capaces de desarrollarse en un medio deficiente de fosforo (medio P) observándose conjuntamente con la Característica de crecer imperfectamente una morfología Un tanto particular (formas alargadas, a- veces ,con. varias granulaciones en el interior) y originando formas quísticas. Bacterias de la colección del laboratorio (38 cepas} se sembraron en el medio mencionado apreciándose que el Azotobacter -crecía muy bien y observándose en: Az. chrococcum una pigmentación negra, mucho más oscura que la clásica pigmentación marrón que se produce en medios desprovistos de nitrógeno.Bacteria able to -growth by subcultures in phophorus deficient media (P. medium) have been isolated and conserved. lt was observed a peculiar morphology (like empty cells with intemal particles) and the ability to form cystes like structures. Other ba,cteria (38 identified strains, from culture collection) were also proved in P. medium and it was determined that Azotobacter shows positive growth. All the Az. chrococcum strains used give a black pigment darker than the normal brow black pigment when were cultured in nitrogen free medium

Bioremediation and biovalorisation of olive-mill wastes

Olive-mill wastes are produced by the industry of olive oil production, which is a very important economic activity, particularly for Spain, Italy and Greece, leading to a large environmental problem of current concern in the Mediterranean basin. There is as yet no accepted treatment method for all the wastes generated during olive oil production, mainly due to technical and economical limitations but also the scattered nature of olive mills across the Mediterranean basin. The production of virgin olive oil is expanding worldwide, which will lead to even larger amounts of olive-mill waste, unless new treatment and valorisation technologies are devised. These are encouraged by the trend of current environmental policies, which favour protocols that include valorisation of the waste. This makes biological treatments of particular interest. Thus, research into different biodegradation options for olive-mill wastes and the development of new bioremediation technologies and/or strategies, as well as the valorisation of microbial biotechnology, are all currently needed. This review, whilst presenting a general overview, focus critically on the most significant recent advances in the various types of biological treatments, the bioremediation technology most commonly applied and the valorisation options, which together will form the pillar for future developments within this fiel

Aislamiento de microorganismos halófilos procedentes de ríos, pantanos y aguas residuales de la provincia de Granada

The purpose of this study was the isolation of halophilic micro-organisms from atipically satine environments located in different areas of Granada, Spain; we tried al so to know the number of viable cells per mL in these tested water samples. A total of 130 halophilic microorganisms was examined: 37.7% strains selected were halotolerant rods and they were isolated from rivers; 60.8% of isolated strains was classified as halophilic microorganisms and, in contrast of the majority ecologic stl.ldies conceming moderately halophilic bacteria, strains studied are grouped as Gram-positive.El presente trabajo se planteó con el objetivo de aislar microorganismos halófilos a partir de hábitats atípicamente salinos, tales como ríos, pantanos y aguas residuales de la provincia de Granada, realizando además una detenninación del número de aerobios totales mediante recuento de heterótrofos. Tras seleccionar 130 cepas al azar, el espectro salino nos confinnó que el número de bacterias halotolerantes era notable, el 37.7% y se aislaron principalmente de ríos. Los microorganismos halófilos hallados se clasificaron generalmente como moderados constituyendo el 60.8% de las cepas estudiadas, por lo que se confinna su presencia en dichos ecosistemas. Es importante señalar que el 69.2% del total son bacilos y cocos Gram positivos, el 11.5% presentaron un Gram variable y el 19.3% resultaron ser bacilos Gram negativos, distribución totalmente distinta a la descrita por numerosos autores al realizar estudios ecológicos de la microbiota halófila en medios hipersalinos

Investigación de la secreción de aminoácidos por especies del genero Bacillus

The secretior of the arginine, lisine, leucine, aspartic acid, glutamic acid and alanine aminoalcids, for species of the Bacillus was studied using a detected technic in salid medium with auxotrofic strains. From the 38 essayed Bacillus strains, 31 produce argmme, 30 lisine, 26 leucine, 26 aspartic, 30 alanine and no glutamic acid was produced. It is very important this result because it can mean an interest character in the taxonomy of the genus Bacillus. It is pointed out that the aspartic acid production by B. subtilis and the no production by B. licheniformis can also be used as differential purpose between both species. The strains that have shown the best production ability are also indicated.Se investiga la secreción de los aminoácidos argmma, lisina, leucina, ácido aspártico, ácido glutámico y alanina por especies del género Bacillus empleando una técnica de revelado en medio sólido con cepas auxotróficas. De las 38 estirpes ensayadas, 31 producen arginina, 30 lisina, 26 leucina, 26 aspártico, 30 alanina y ninguna ácido glutámico. Es muy significativo este último resultado por lo que se sugiere puede ser un carácter de interés en la taxonomia del género Bacillus. Se señala que la producción de ácido aspártico por B. subtilis y la no producción por B. licheniformis puede emplearse como prueba diferencial entre ambas especies. También se indican las estirpes que se han mostrado con mayor capacidad productoras de los aminoácidos investigados

Influencia del NO3K en la formación de cristales de CO3Ca por bacterias

In the present work, it was studied the influence of KNO3 in crystals formation of CaCO3 by 96 bacterial strains isolated from soil. This influence is null or very weak, so the KNO3 could be excluded of the culture media to investigate crystals formation, without greats consequences for it.En el presente trabajo se ,estudia ia influencia del KNO3 en la forma,ción de cristales de CaCO3 por 96 cepas de microorganismos aislados del suelo. Esta influencia es nula o muy débil, por lo que el KNO3 puede excluirse de los medios para la investigación de formación de cristales sin grandes consecuencias para la misma

Cultivo de Azotobacter vinelandii en medios limitados en hierro y molibdeno

Se cultivó Azotobacter vinelandii ATCC 12837 en medios limitados en hierro y molibdeno. Bajo estas condiciones de cultivo, se observó una inhibición del crecimiento como consecuencia de la limitación mineral. Los análisis químicos realizados mostraron que en medios limitados en'hierro las células contenían mayores cantidades de ácido poli-β-hidroxibutírico que en medios control. Asimismo, en condiciones de limitación mineral, Azotobacter mostró un incremento en la formación de quistes, con respecto a medios control. Estas observaciones fueron confirmadas por estudios de fotorreactivación.Azotobacter vinelandii ATCC 12837 was cultured in iron-limited and molybdenum-limited media. Under these culture conditions a growth inhibition was observed as a consequence of mineral-limitation. Chemical analyses showed that cells grown in iron-limited medium contained more large amounts of PHB than control cells. Also, when Azotobacter grown under mineral-limited conditions showed an increase on cyst formation compared with mineral-suffIcient cultures. These observations were confirmed through photorreactivation studies

Numerical taxonomy of moderately halophilic Gram-negative bacteria from hypersaline soils

A total of 132 moderately halophilic bacteria were isolated from hypersaline soils with a C1- content between 2-36 and 12.72% (w/v) located near Alicante (S.E. Spain) and examined for 98 phenotypic characteristics including their response to cytological, physiological, biochemical and nutritional tests. They were submitted to a numerical analysis together with six reference strains using both simple matching (SsM)a nd Jaccard (S,) coefficients, and cluster analysis was carried out by the unweighted pair group method of association (UPGMA), single linkage and complete linkage. With the S, coefficient and UPGMA clustering, eight phenons were obtained at the 65% similarity level. From each phenon representative strains were chosen for the determination of DNA base composition and for electron microscopy. Bacteria belonging to phenons D, E, and F were assigned to the genus Alcaligenes. Phenon G included 27 strains assigned to Acinetobacter, but the high G + C composition (58.9 mol%) of a representative strain of this phenon suggests that it may represent a new taxon. Phenons A, B, and C were designated Flavobacterium and phenon H was Pseudomonas. The bacteria found in these environments are not related to those from hypersaline waters or normal soils

Cultivo de Azotobacter vinelandii en medios limitados en hierro y molibdeno

Azotobacter vinelandii ATCC 12837 was cultured in iron-limited and molybdenum-limited media. Under these culture conditions a growth inhibition was observed as a consequence of mineral-limitation. Chemical analyses showed that cells grown in iron-limited medium contained more large amounts of PHB than control cells. Also, when Azotobacter grown under mineral-limited conditions showed an increase on cyst formation compared with mineral-suffIcient cultures. These observations were confirmed through photorreactivation studies.Se cultivó Azotobacter vinelandii ATCC 12837 en medios limitados en hierro y molibdeno. Bajo estas condiciones de cultivo, se observó una inhibición del crecimiento como consecuencia de la limitación mineral. Los análisis químicos realizados mostraron que en medios limitados en'hierro las células contenían mayores cantidades de ácido poli-β-hidroxibutírico que en medios control. Asimismo, en condiciones de limitación mineral, Azotobacter mostró un incremento en la formación de quistes, con respecto a medios control. Estas observaciones fueron confirmadas por estudios de fotorreactivación

Numerical taxonomy of moderately halophilic Gram-negative rods

A study was made of 516 randomly selected isolates of moderately halophilic bacteria from solar salterns showing salinities between 8.8 and 40.0% (w/v) total salts, located in S.E. Spain. After purification, many cytological, physiological, biochemical, nutritional and an ti biot ic sensitivity characters were determined for 106 selected saltern isolates and two reference strains. Data were coded and analysed by numerical techniques using the Jaccard coefficient ( S J ) ,a nd clusters of strains were obtained by average linkage (UPGMA) analysis. Nine major phenons were found at the 72.5 % similarity level. The properties of each phenon are given, their taxonomic affinities are discussed, and typical reference strains are suggested. Almost all the strains were related to genera known to contain marine species. A large number of the strains could be tentatively assigned to the genus Vibrio, suggesting that this may be an abundant taxon of moderately halophilic Gram-negative rods in solar salterns