Chromobacterium violaceum is one of millions of species of free-living microorganisms that populate the soil and water in the extant areas of tropical biodiversity around the world. Its complete genome sequence reveals (i) extensive alternative pathways for energy generation, (ii) Ϸ500 ORFs for transport-related proteins, (iii) complex and extensive systems for stress adaptation and motility, and (iv) widespread utilization of quorum sensing for control of inducible systems, all of which underpin the versatility and adaptability of the organism. The genome also contains extensive but incomplete arrays of ORFs coding for proteins associated with mammalian pathogenicity, possibly involved in the occasional but often fatal cases of human C. violaceum infection. There is, in addition, a series of previously unknown but important enzymes and secondary metabolites including paraquat-inducible proteins, drug and heavy-metal-resistance proteins, multiple chitinases, and proteins for the detoxification of xenobiotics that may have biotechnological applications.T he genomes of soil-and water-borne free-living bacteria have received relatively little attention thus far in comparison to pathogenic and extremophilic organisms, yet they provide fundamental insights into environmental adaptation strategies and represent a rich source of genes with biotechnological potential and medical utility. A particularly interesting organism of this kind is Chromobacterium violaceum, a Gram-negative ␤-proteobacterium first described at the end of the 19th century (1), which dominates a variety of ecosystems in tropical and subtropical regions. This bacterium has been found to be highly abundant in the water and borders of the Negro river, a major component of the Brazilian Amazon (2) and as a result has been studied in Brazil over the last three decades. These, in general, have focused on the most notable product of the bacterium, the violacein pigment, which has already been introduced as a therapeutic compound for dermatological purposes (3). Violacein also exhibits antimicrobial activity against the important tropical pathogens Mycobacterium tuberculosis (4), Trypanosoma cruzi (5), and Leishmania sp. (6) and is reported to have other bactericidal (2, 7-10), antiviral (11), and anticancer (12, 13) activities.Some other aspects of the biotechnological potential of C. violaceum have also begun to be explored, including the synthesis of poly(3-hydroxyvaleric acid) homopolyester and other shortchain polyhydroxyalkanoates, which might represent alternatives to plastics derived from petrochemicals (14, 15), the hydrolysis of plastic films (16), and the solubilization of gold through a mercury-free process, thereby avoiding environmental contamination (17, 18). These studies, however, have been based on knowledge of only a tiny fraction of the genetic constitution of the organism. In addition, the more basic issues of the mechanisms and strategies underlying the adaptability of C. violaceum, including its observed but infrequent infection of h...

Phylogenetic analyses, from polymerase chain reaction (PCR)-amplified 12S rRNA and 18S rRNA gene sequences from cochineal insects of the genus Dactylopius present in Mexico, showed that D. ceylonicus, D. confusus, and D. opuntiae are closely related. D. coccus constitutes a separate clade, and D. tomentosus is the most distantly related. Bacterial 16S rRNA sequences from all the Dactylopius species sampled showed a common β-proteobacteria, related to Azoarcus, also found in eggs and in bacteriocytes in D. coccus. We propose the name "Candidatus Dactylopiibacterium carminicum" for this endosymbiont. Other bacterial sequences recovered from the samples were close to those from soil or plant associated bacteria, like Massilia, Herbaspirillum, Acinetobacter, Mesorhizobium, and Sphingomonas, suggesting a possible horizontal transmission from Cactaceae plant sap to Dactylopius spp. during feeding. This is the first molecular analysis of Dactylopius species and of their associated bacteria.

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RESUMO -Visando otimizar a produção de mudas de sabiá (Mimosa caesalpiniifolia Benth), foi conduzido um experimento para avaliar a efetividade da dupla inoculação com fungos micorrízicos arbusculares (FMA) e rizóbio. Os tratamentos, arrumados em esquema fatorial consistiram de presença e ausência de Rhizobium sp. e de FMA (Glomus etunicatum, Acaulospora morrowae e A. longula), e de três níveis de P (0, 20 e 40 kg/ha de P 2 O 5 , na forma de superfosfato triplo). A aplicação de P na ausência e na presença dos fungos não favoreceu o desenvolvimento das plantas. As mudas com a dupla inoculação apresentaram valores significativos no crescimento, área foliar, altura das plantas, atividade da enzima nitrogenase, porcentagem de colonização radicular e outros parâmetros analisados, independentemente do nível de P usado. A nodulação do sabiá foi favorecida pela micorrização, uma vez que as mudas inoculadas apenas com Rhizobium apresentaram nodulação significativamente menor. Houve aumento da colonização micorrízica e diminuição da esporulação na presença de Rhizobium.Termos para indexação: nodulação, colonização micorrízica, fungo vesículo-arbuscular, Rhizobium, Glomus etunicatum, Acaulospora morrowae, Acaulospora longula. EFFECTIVENESS OF INOCULATION WITH ARBUSCULAR MYCORRHIZAL FUNGI AND RHIZOBIUM SP. ON MIMOSA CAESALPINIIFOLIA SEEDLINGS, UNDER DIFFERENT PHOSPHORUS LEVELSABSTRACT -In order to optimize Mimosa caesalpiniifolia Benth seedlings production, an experiment was carried out to evaluate the inoculation with both arbuscular mycorrhizal fungi (AMF) and Rhizobium. Treatments, arranged in a factorial scheme, consisted of presence or absence of Rhizobium, and of AMF (a mixture of Glomus etunicatum, Acaulospora morrowae and A. longula), with three P levels (equivalent to 0, 20 and 40 kg/ha of P 2 O 5 ), applied as triple superphosphate. The P application, in the absence or in the presence of AMF inoculation, did not enhance plant development, while the seedlings which received the double inoculation presented significant values on growth, height, leaf area, nitrogenase activity and others analyzed parameters, regardless of the P level. Mimosa caesalpiniifolia nodulation was enhanced by the inoculation with AMF, since plants which received Rhizobium alone showed significantly lower nodulation values than the ones which received both inoculations. There was an increase of the mycorrhizal and a decrease of the esporulation in the presence of Rhizobium.

CHARACTERIZATION OF ISOLATED RHIZOBIA OF PACHYRHYZUS EROSUS CULTIVATED IN SALINE SOIL Of THE STATE OF PERNAMBUCO, BRAZILInvestigation on microbiological biodiversity in the saline soils involves searching for tolerant genotypes to this type of emvironmental stress. Genotypic data associated to morphologic, physiological and biochemical characteristics of bacteria provide important information regarding its identification and clusters. The objective of this work was to characterize indigenous rhizobial strains of saline soils in the Wasteland and Hinterland of Pernambuco State, using yam bean (Pachyrhizus erosus L. Urban) as plant-tramp. Assays had been performed in YMA media and the observed cultivation characteristics of twenty-four isolates had been: change of pH, time of growth, transparency, form, edge, production of exopolysaccharides of the colonies and resistance to salinity. DNA amplification by the PCR technique of the repetitive sequence BOX indicated a high level of genetic and fenotipic diversity between the thirteen indigenous isolates. Comparing cultivation and genetic characteristics of these isolates with