Polyadenylation plays a role in decay of some bacterial mRNAs, as well as in the quality control of stable RNA. In Escherichia coli, poly(A) polymerase I (PAP I) is the main polyadenylating enzyme, but the addition of 3 tails also occurs in the absence of PAP I via the synthetic activity of polynucleotide phosphorylase (PNPase). The nature of 3-tail addition in Bacillus subtilis, which lacks an identifiable PAP I homologue, was studied. Sizing of poly(A) sequences revealed a similar pattern in wild-type and PNPase-deficient strains. Sequencing of 152 cloned cDNAs, representing 3-end sequences of nontranslated and translated RNAs, revealed modified ends mostly on incomplete transcripts, which are likely to be decay intermediates. The 3-end additions consisted of either short poly(A) sequences or longer heteropolymeric ends with a mean size of about 40 nucleotides. Interestingly, multiple independent clones exhibited complex heteropolymeric ends of very similar but not identical nucleotide sequences. Similar polyadenylated and heteropolymeric ends were observed at 3 ends of RNA isolated from wild-type and pnpA mutant strains. These data demonstrated that, unlike the case of some other bacterial species and chloroplasts, PNPase of Bacillus subtilis is not the major enzyme responsible for the addition of nucleotides to RNA 3 ends.Polyadenylation is an important posttranscriptional modification of prokaryotic, eukaryotic, and organellar RNA. In Escherichia coli, polyadenylation has been shown to play a role in the process of decay, and the enzymes responsible for both polyadenylation and degradation are known (reviewed by ). Poly(A) polymerase I (PAP I), an enzyme belonging to the nucleotidyltransferase family, adds poly(A) extensions to the 3Ј ends of mRNAs, as well as to tRNA and rRNA (22). It has been shown that such extensions aid in the 3Ј-to-5Ј exoribonucleolytic degradation of RNAs, particularly for the degradation by polynucleotide phosphorylase (PNPase) of RNAs containing structured ends, such as transcription terminators (1,9,13,16,20,35). Coordination of endo-and exonucleolytic activities is thought to occur through the physical interaction of RNase E and PNPase, which, together with RNA helicase RhlB and enolase, form the degradosome (reviewed in reference 8). Physical interaction between PAP I and RNase E has also been observed (28), suggesting that polyadenylation may also be a part of the coordinated decay process.PNPase can act as a 3Ј-to-5Ј phosphorolytic exoribonuclease or as an RNA polymerase, depending on the availability of phosphate and ribonucleoside diphosphates. The possibility of in vivo polymerase activity of PNPase has gained more attention recently. In an E. coli strain deficient for PAP

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We report the identification of a fungus, a member of the genus Neoscytalidium which is associated with human keratitis. Phylogenetic analysis and morphological observations on conidiogenous cells, which occur only in arthric chains in aerial mycelium and the coelomycetous synasexual morph is absent, identified a new species, Neoscytalidium oculus sp. nov. The fungus formed biofilm at a concentration of 1 × 10 conidia/mL, during 96 hours of incubation at 37°C, and also manifested haemolysis and melanin production. This is the first report in Latin America of a new species of Neoscytalidium from a clinical isolate has been identified.

We generated a conditional CCase mutant of Bacillus subtilis to explore the participation in vivo of the tRNA nucleotidyltransferase (CCA transferase or CCase) in the maturation of the singlecopy tRNA Cys , which lacks an encoded CCA 39 end. We observed that shorter tRNA Cys species, presumably lacking CCA, only accumulated when the inducible Pspac : cca was introduced into an rnr mutant strain, but not in combination with pnp. We sequenced the tRNA 39 ends produced in the various mutant tRNA Cys species to detect maturation and decay intermediates and observed that decay of the tRNA Cys occurs through the addition of poly(A) or heteropolymeric tails. A few clones corresponding to full-size tRNAs contained either CCA or other C and/or A sequences, suggesting that these are substrates for repair and/or decay. We also observed editing of tRNA Cys at position 21, which seems to occur preferentially in mature tRNAs. Altogether, our results provide in vivo evidence for the participation of the B. subtilis cca gene product in the maturation of tRNAs lacking CCA. We also suggest that RNase R exoRNase in B. subtilis participates in the quality control of tRNA.

Purpose -The purpose of this paper is to report a study of microbiological influenced corrosion (MIC) of copper due to bacteria strains isolated from potable water pipes and oxidation lagoons using electrochemical noise (EN) analysis and scanning electron microscopy (SEM). Design/methodology/approach -Bacteria strains isolated from copper surfaces of potable water pipes and from oxidation lagoons were identified, based on the 16S rDNA gene sequence analysis. Corrosion studies were undertaken over a period of six weeks, placing copper electrodes inside an LB culture media with and without bacteria. The corrosion resistance was obtained using EN analysis. In all the cases, the corrosion type was identified. SEM images of the copper electrodes were taken to evaluate the surface condition. Findings -The bacteria strains identified were: Pantoea agglomerans, Alcaligenes faecalis, Bacillus cereus, Brucellaceae bacterium, Enterobacter cloacae, Delftia tsuruhatensis, and Pseudochrobactrum asaccharolyticum. EN analysis gave noise resistance values in the range 1,036-5,040 Vcm 2 for the control samples and in the range of 2,336-22,573 Vcm 2 for samples that had been inoculated with bacteria. It was found that a decrease in the rate of corrosion took place due to the development of a biofilm by the microorganisms on the copper surface. SEM images corroborated the presence of the biofilm on the copper electrodes. Practical implications -The isolated bacteria strain reduced the rate of corrosion on the copper electrodes, as shown by the SEM images and EN analysis results, due to the formation of a biofilm that can act as an anticorrosive coating. Originality/value -Even though MIC is a known phenomenon, it has not been reported that isolated bacteria strains can reduce corrosion on the surface of copper potable water pipes and in oxidation lagoons.

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The potential presence of spore-forming bacteria related to the Bacillus cereus group in Mexican chili powder elaborated from Capsicum annuum L. is of commercial and clinical interest, because chili powder is an essential spice in the Mexican diet and in diets around the globe. To facilitate detection and isolation of members of this group of spore-forming bacteria from Mexican chili powder samples, we identified colonies that grew on agar medium selective for Bacillus cereus sensu lato, supplemented with polymyxin B (10 µg/mL) and ampicillin (10 to 100 µg/mL). The presumptive B. cereus (s.l.) isolates were tested using a tRNACys-PCR-based approach and the results identified species related phylogenetically to B. cereus, B. thuringiensis, and B. toyonensis. Their toxigenic potential was assessed by serological tests to detect enterotoxins (Nhe and Hbl) and by PCR targeting the hemolysin BL (hbl) component C (hblC) and non-hemolytic enterotoxin component A (nheA). The antibiotic profiles of the isolates showed a high resistance to β-lactams (100% of the isolates), trimethoprim-sulfamethoxazole (100%), tetracycline (90%), erythromycin (77%), clindamycin (74%), and chloramphenicol (42%). Our results indicate the presence of B. cereus s.l. with toxigenic characteristics in Mexican chili powder. Because of the potential for these organisms to cause disease through their production of various toxins, and resistance to antibiotics, we recommend that a microbiological risk assessment must be considered in the Mexican regulatory requirements.

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