No abstract

1 Resistance development in pest insects has guided the advance of cleaner and more effective strategies for pest control. An interesting and promising strategy is the manipulation of insects via their gut microbiota. 2 To evaluate the feasibility of this strategy, Diabrotica speciosa, a highly polyphagous pest insect from South America that causes substantial damage to several important crops, was reared under controlled conditions. Aerobic culturable bacteria were isolated from the gut of D. speciosa and identified using proteomic fingerprints obtained by matrix-assisted laser desorption ionization coupled to time-of-flight mass spectrometry (MALDI-TOF MS), as well as by genomic methods via partial sequencing of the 16S rRNA gene. 3 Seventy-three strains belonging to 17 genera and up to 29 different species were isolated. -Proteobacteria of the orders Pseudomonadales and Enterobacteriales were the predominant. A core gut microbiome for the genus Diabrotica could be inferred when microbiotas from different species from the genus were compared. Molecular and spectrometric techniques indicated complete agreement of genera classification, although cluster analysis revealed distinct taxonomic grouping patterns. 4 MALDI-TOF MS provided reliable identification of culturable gut bacteria, demonstrating similar efficacy, with cheaper and faster results relative to partial 16S rRNA gene sequencing, and also showed an interesting and unexpected phyloproteomic correlation.

Modularity applied to new product development together with the externalisation of production has been a strategy adopted by automotive companies. New product development in the context of modular strategy implies a redistribution of inherent activities of production. This is based on a work division among assemblers and their suppliers. In this context, this study investigates the implications of modular strategies in the process of transferring value-added activities in new product development between first and second tier suppliers. The study is developed based on a multiple case study approach. The investigated companies were positioned in distinct levels of modular competencies ('embrionary', 'in development', and 'mature'), according to empirical evidence. A relationship between the stage of maturity and major new product development practices was identified.

The causative agent of Asiatic citrus canker, the Gram-negative bacterium Xanthomonas citri subsp. citri (XAC), produces more severe symptoms and attacks a larger number of citric hosts than Xanthomonas fuscans subsp. aurantifolii XauB and XauC, the causative agents of cancrosis, a milder form of the disease. Here we report a comparative proteomic analysis of periplasmic-enriched fractions of XAC and XauB in XAM-M, a pathogenicity- inducing culture medium, for identification of differential proteins. Proteins were resolved by two-dimensional electrophoresis combined with liquid chromatography-mass spectrometry. Among the 12 proteins identified from the 4 unique spots from XAC in XAM-M (p<0.05) were phosphoglucomutase (PGM), enolase, xylose isomerase (XI), transglycosylase, NAD(P)H-dependent glycerol 3-phosphate dehydrogenase, succinyl-CoA synthetase β subunit, 6-phosphogluconate dehydrogenase, and conserved hypothetical proteins XAC0901 and XAC0223; most of them were not detected as differential for XAC when both bacteria were grown in NB medium, a pathogenicity non-inducing medium. XauB showed a very different profile from XAC in XAM-M, presenting 29 unique spots containing proteins related to a great diversity of metabolic pathways. Preponderant expression of PGM and XI in XAC was validated by Western Blot analysis in the periplasmic-enriched fractions of both bacteria. This work shows remarkable differences between the periplasmic-enriched proteomes of XAC and XauB, bacteria that cause symptoms with distinct degrees of severity during citrus infection. The results suggest that some proteins identified in XAC can have an important role in XAC pathogenicity.