Vanderlei Perez Canhos

Characterization of Bacillus thuringiensis and related bacteria by ribosomal RNA gene restriction fragment length polymorphisms

Ribosomal RNA gene restriction patterns have been determined for 43 strains of Bacillus thuringiensis representing 10 serovars and eight reference strains of B. anthracis, B. cereus and B. mycoides. Strains within a B. thuringiensis serovar produced highly related or identical ribotype patterns: in particular, 12 strains of serovar israelensis, five strains of serovar kurstaki, two strains of serovar galleriae and three strains of serovar aizawa produced ribotype patterns consistent with serotype designations. Moreover, variety tenebrionis (serotype 8a8b), a coleopteran pathogen, could be distinguished from the more common lepidopteran pathogens of this serotype (serovar morrisoni) by ribotyping. The correlation of ribotype patterns with serotype suggests a clonal population structure for B. thuringiensis.

Screening of lignin-degrading fungi for removal of color from Kraft mill wastewater with no additional extra carbon-source

A screening of 51 ligninolytic strains of fungi to examine their ability to decolorized phenolic industrial effluent was carried out. The selection showed thatLentinus edodes (UEC-2019) strain removed 73% of colour in 5 days, without any additional carbon sources. Under these conditions,L. edodes was more efficient than the knownPhanerochaete chrysosporium (BKM-F-1767) strain (e.g. COD reductions were 60% and 26%, respectively).

Screening filamentous fungi isolated from estuarine sediments for the ability to oxidize polycyclic aromatic hydrocarbons

Nineteen filamentous fungi, isolated from estuarine sediments in Brazil, were screened for degradation of polycyclic aromatic hydrocarbons (PAH). The fungal isolates were incubated with pyrene. The cultures were extracted and metabolites in the extracts were detected by high performance liquid chromatography (HPLC) and u.v. spectral analyses. Six fungi were selected for further studies using [4,5,9,10-14C]pyrene. Cyclothyrium sp., Penicillium simplicissimum, Psilocybe sp., and a sterile mycelium demonstrated the ability to transform pyrene. Cyclothyrium sp. was the most efficient fungus, transforming 48% of pyrene to pyrene trans-4,5-dihydrodiol, pyrene-1,6-quinone, pyrene-1,8-quinone and 1-hydroxypyrene. This fungus was also evaluated with a synthetic mixture of PAH. After 192 h of incubation, Cyclothyrium sp. was able to degrade simultaneously 70, 74, 59 and 38% of phenanthrene, pyrene, anthracene and benzo[a]pyrene, respectively.

Phenoloxidases and hydrolases from Pycnoporus sanguineus (UEC-2050 strain): applications

Abstract The basidiomycete, Pycnoporus sanguineus , possess lignin peroxidase, Mn-peroxidase, phenoloxidases, xylanase and β-glucosidase activities when grown on malt extract. A large induction, mainly in laccase activity with malt extract/E 1 effluent (46 U l −1 ), malt extract (100 U l −1 ) and malt extract/ Eucalyptus grandis wood (61 U l −1 ) as carbon sources was found. The phenoloxidase capacity along with the presence of beta-glucosidase P. sanguineus led us investigate its use in effluent treatment. This fungus was efficient not only in chromophore group transformations but also in the reduction of phenols, biochemical and chemical oxygen demands, and toxicity.

Characterization by Polyacrylamide Gel Electrophoresis of Whole-Cell Proteins of Some Bacillus thuringiensis subsp. israelensis Strains Isolated in Brazil

Summary Of 14 strains of Bacillus thuringiensis selected from 956 isolates from soil samples from Brazil, 12 were toxic to larvae of Aedes fluviatilis and two were nontoxic. Nine of the 14 strains were serotyped as subspecies israelensis (serotype 14), one as subspecies kurstaki (serotype 3a 3b) one as subspecies morrisoni (serotype 8a 8b) and three did not agglutinate any antisera. Electrophoresis of whole cell proteins showed that all subsp. israelensis strains formed a homogeneous group which included two non-typable toxic strains, and could be readily distinguished from reference strains toxic for lepidoptera or coleoptera.

A new alternative process for Kraft E1 effluent treatment

Lentinus edodes (UEC-2019 strain) was selected after screening 51 ligninolytic strains of fungi for their ability to decolorize phenolic industrial effluent with high content of lignin peroxidases, Mn-peroxidases and beta-glucosidases. This strain removed 73 % of color in theEucalyptus Kraft E1 effluent in 5 days without any additional carbon sources. A 13% mycelial adsorption was found. Correlation between mass loss, COD, TOC and decolorization was observed. When an effluent pre-irradiated (10 min) in the presence of ZnO was treated withL. edodes, a marked enhancement of the decolorization at 48 h was obtained.L. edodes is an active fungus in this pre-treatment and biobleaching process. The combined photo-biological decolorization procedure appears to be an efficient decontamination method with great potential in industrial effluent treatment.

Characterization of selected strains of mucorales using fatty acid profiles

The fatty acid profiles of several fungi of the order Mucorales (Zygomycetes), including Backusella lamprospora (Lendner) Benny and R.K. Benj., Benjaminiella youngii P.M. Kirk, Circinella simplex van Tieghem, Cunninghamella blakesleeana Lendner, Mortierella ramanniana (Moller) Linnem., Mucor circinelloides f. janssenii (Lendner) Schipper, Mycotypha microspora Fenner, Rhizomucor miehei (Cooney and R. Emerson) Schipper and Rhizomucor pusillus (Lindt) Schipper, and of Volutella sp. Fr., from the class Ascomycetes, were qualitatively analysed by gas-liquid chromatography in order to determine the taxonomic value of these chemotaxonomic markers. The fatty acids present in all strains were palmitic (16:0), oleic (18:1), linoleic (18:2) and g-linolenic (18:3) acid, with the exception that the latter was not found in Volutella sp. Chemotaxonomic markers for some species and genera were obtained, including a non-identified fatty acid, FAME8 (minimum and maximum retention times of 27.92 and 28.28 minutes) for Rhizomucor miehei CCT 2236 and Rhizomucor pusillus CCT 4133, and FAME3 (minimum and maximum of 16.53 and 16.61 minutes) for Benjaminiella youngii CCT 4121. The chemotaxonomic marker of the order Mucorales was the fatty acid 18:3w6, confirming previous data from literature. The results of the present study suggest that qualitative fatty acid analysis can be an important chemotaxonomic tool for the classification of fungi assigned to the order Mucorales (Zygomycetes).

Software tools and databases for bacterial systematics and their dissemination via global networks.

The dynamic expansion of the taxonomic knowledge base is fundamental to further developments in biotechnology and sustainable conservation strategies. The vast array of software tools for numerical taxonomy and probabilistic identification, in conjunction with automated systems for data generation are allowing the construction of large computerised strain databases. New techniques available for the generation of chemical and molecular data, associated with new software tools for data analysis, are leading to a quantum leap in bacterial systematics. The easy exchange of data through an interactive and highly distributed global computer network, such as the Internet, is facilitating the dissemination of taxonomic data. Relevant information for comparative sequence analysis, ribotyping, protein and DNA electrophoretic pattern analysis is available on-line through computerised networks. Several software packages are available for the analysis of molecular data. Nomenclatural and taxonomic ‘Authority Files’ are available from different sources together with strain specific information. The increasing availability of public domain software, is leading to the establishment and integration of public domain databases all over the world, and promoting co-operative research projects on a scale never seen before.

Microbial Resource Centres and Ex-Situ Conservation

Biodiversity encompasses ‘genetic diversity’, the diversity of genomes within and between populations of organisms,’ species diversity’, the number of species in a site or habitat (commonly used as a synonym of’ species richness) and ‘ecosystem diversity’, the quantitative assessment of diversity at the ecosystem, habitat or community level, taking into account species richness, abundance, size classes, trophic, functional and taxonomic groups (Norse et al., 1986; World Conservation Monitoring Centre, 1992; Harper & Hawksworth, 1994).

Networking the microbial diversity information

The Internet, the electronic global network of computers, has expanded significantly over the last few years, connecting segments from academia, industry and the private sector. The use of the Internet by researchers has diversified substantially from the primordial exchange of electronic messages to the current use of highly developed graphic interfaces capable of accessing images, sounds and retrieving information from databases in different computers around the world. The reduced costs for data storage and ease of connection to the net have nourished a steady exponential growth in the number of sites. Microbiologists now benefit from a wealth of databases and Web sites with microbiological information, ranging from culture collection data, information on microbial diversity, taxonomic and phylogenetic data, biotechnological applications and taxonomic expertise. Efforts are required to stimulate the integration of complex molecular and image databases with more traditional information resources, such as bibliographic, strain data, compendia of species descriptions and metabolic products databases. Coordinating and linking mechanisms are needed in order to promote the development of protocols, guidelines and minimal standards to ensure data quality. Future challenges to the scientific use of Internet resources include the setting up of clearing-house mechanisms and virtual libraries for the organization of the microbiological resources on the network.