The culturable bacterial community of frass produced by larvae of Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae) in the Canary island date palm

Aims:  Larvae of the red palm weevil (RPW) Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae) feed inside palm stem tissues, making galleries and producing a wet fermenting frass. We characterized the culturable bacteria associated with frass produced by tunnelling larvae inside the Canary island date palms and investigated the role of frass and gut bacteria in plant polymers breakdown. Methods and Results:  A culture-dependent method was used to isolate bacteria from frass and noninfested palm tissues. Bacterial isolates were grouped into operational taxonomic units based on polymorphisms in the ITS-PCR profiles, and representative isolates were identified by partial sequencing …

CBS and MTRR mutations, observed in Sicily, in thromboembolic and hyperhomocystemic patients, unresponsive to administration of folate and vitamin B12

biotecnologiche di batteri del suolo

Expression in Streptomyces lividans of Nonomuraea genes cloned in an artificial chromosome

A bacterial artificial chromosomal library of Nonomuraea sp. ATCC39727 was constructed using Escherichia coli-Streptomyces artificial chromosome (ESAC) and screened for the presence of dbv genes known to be involved in the biosynthesis of the glycopeptide A40926. dbv genes were cloned as two large, partially overlapping, fragments and transferred into the host Streptomyces lividans, thus generating strains S. lividansColon, two colonsNmESAC50 and S. lividansColon, two colonsNmESAC57. The heterologous expression of Nonomuraea genes in S. lividans was successfully demonstrated by using combined RT-PCR and proteomic approaches. MALDI-TOF analysis revealed that a Nonomuraea ABC transporter is e…

Applicazioni biotecnologiche di batteri del suolo

Analisi della comunità microbica intestinale di Reticulitermes lucifugus (Rossi) (Isoptera: Rhinotermitidae).

L’intestino delle termiti ospita una comunità microbica di batteri e flagellati anaerobi, responsabile della degradazione del materiale lignocellulosico. La digestione della lignocellulosa da parte delle termiti dipende dalla simbiosi con microrganismi procarioti ed eucarioti che vivono nel loro intestino. I microrganismi trasformano la cellulosa in zuccheri e acetato, producendo idrogeno, metano e anidride carbonica. Abbiamo analizzato la comunità microbica intestinale di Reticulitermes lucifugus lucifugus, una delle due specie di termiti italiane, che vive in ambienti sotterranei, è distruttiva per le strutture legnose degli ambienti urbani causando seri danni ai monumenti storici e può c…

A Two-Component regulatory system with opposite effects on glycopeptide antibiotic biosynthesis and resistance

AbstractThe glycopeptide A40926, produced by the actinomycete Nonomuraea gerenzanensis, is the precursor of dalbavancin, a second-generation glycopeptide antibiotic approved for clinical use in the USA and Europe in 2014 and 2015, respectively. The final product of the biosynthetic pathway is an O-acetylated form of A40926 (acA40926). Glycopeptide biosynthesis in N. gerenzanensis is dependent upon the dbv gene cluster that encodes, in addition to the two essential positive regulators Dbv3 and Dbv4, the putative members of a two-component signal transduction system, specifically the response regulator Dbv6 and the sensor kinase Dbv22. The aim of this work was to assign a role to these two ge…

Analisi della comunità batterica intestinale di larve del Punteruolo Rosso.

Le larve del Punteruolo rosso, Rhynchophorus ferrugineus (Oliv.) (Coleoptera: Curculionidae), hanno uno sviluppo endofita durante il quale innescano nella pianta fenomeni di marcescenza e di fermentazione. Quando questa attività coinvolge la gemma apicale, la pianta è destinata a soccombere. Studi condotti negli ultimi dieci anni hanno dimostrato che i microorganismi simbionti presenti nell’intestino degli insetti xilofagi giocano un ruolo chiave in diverse funzioni fisiologiche quali la digestione della cellulosa e dell’emicellulosa, l’acetogenesi, l’idrogenogenesi, la riduzione dei solfati e la fissazione dell’azoto (König et al, 2006; Khiyami e Alyamani 2008). Di conseguenza, lo studio d…

Phosphate-controlled regulator for the biosynthesis of the dalbavancin precursor A40926

ABSTRACT The actinomycete Nonomuraea sp. strain ATCC 39727 produces the glycopeptide A40926, the precursor of the novel antibiotic dalbavancin. Previous studies have shown that phosphate limitation results in enhanced A40926 production. The A40926 biosynthetic gene ( dbv ) cluster, which consists of 37 genes, encodes two putative regulators, Dbv3 and Dbv4, as well as the response regulator (Dbv6) and the sensor-kinase (Dbv22) of a putative two-component system. Reverse transcription-PCR (RT-PCR) and real-time RT-PCR analysis revealed that the dbv14 - dbv8 and the dbv30 - dbv35 operons, as well as dbv4 , were negatively influenced by phosphate. Dbv4 shows a putative helix-turn-helix DNA-bind…

AN ABC-TRANSPORTER AND A MEMBRANE PROTEIN OF PLANOBISPORA ROSEA INDUCE ANTIBACTERIAL ACTIVITY IN STREPTOMYCES LIVIDANS

Transcriptional analysis of the biosynthetic gene cluster encoding the glycopeptide antibiotic A40926

The gut microbiota of the wood-feeding termite Reticulitermes lucifugus (Isoptera; Rhinotermitidae)

Termite gut is host to a complex microbial community consisting of prokaryotes, and in some cases flagellates, responsible for the degradation of lignocellulosic material. Here we report data concerning the analysis of the gut microbiota of Reticulitermes lucifugus (Rossi), a lower termite species that lives in underground environments and is widespread in Italy, where it causes damage to wood structures of historical and artistic monuments. A 16S rRNA gene clone library revealed that the R. lucifugus gut is colonized by members of five phyla in the domain Bacteria: Firmicutes (49 % of clones), Proteobacteria (24 %), Spirochaetes (14 %), the candidatus TG1 phylum (12 %), and Bacteroidetes (…