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BACKGROUND: Bio-hydrogen production from organic residues is an attractive process that combines energy generation with waste treatment. This work describes hydrogen production from molasses and cheese whey by biofilm and suspended-cells of four hyperthermophilicThermotoga spp. For the best performing strain, a preliminary process optimization was performed. RESULTS: In experiments with glucose-fed T.neapolitana, HEPES was the best-performing buffer, whereas the highest H2 rate was obtained with the biofilm support exposing the highest specific surface. All the Thermotoga strains tested (T.neapolitana, T.maritima, T.naphtophila, T.petrophila) were able to produce H2 from glucose, molasses and cheese whey under both suspended- and attached-cell conditions. T.neapolitana was the best H2 producer with all three substrates. The best H2 production rate was higher on molasses (1.7 mmolH2 L −1 medium h −1 ) than on cheese whey (0.94 mmolH2 L −1 medium h −1 ), whereas the highestH2/substrateyieldsweresimilarforthetwosubstrates(2.95 molH2 mol −1 monosaccharide consumed onmolassesand2.50 molH2 mol −1 monosaccharide consumed on cheese whey). With both wastes, the progressive growth medium simplification allowed a drastic reduction of medium cost, without significant losses of process performance. CONCLUSION: Both molasses and cheese whey are suitable substrates for H2 production by suspended- and attached-cells of Thermotoga species. c � 2012 Society of Chemical Industry Supportinginformationmaybefoundintheonlineversionofthisarticle.

Chloroform (CF) is largely produced by both anthropogenic and natural sources. It is detected in ground- and surface-water sources and it represents the most abundant halocarbon in the atmosphere. Microbial CF degradation occurs under both aerobic and anaerobic conditions. Apart from a few reports describing the utilization of CF as a terminal electron acceptor during growth, CF degradation was mainly reported as a cometabolic process. CF aerobic cometabolism is supported by growth on short-chain alkanes (i.e. methane, propane, butane and hexane), aromatic hydrocarbons (i.e. toluene and phenol) and ammonia via the activity of monooxygenases operatively divided into different families. The main factors affecting CF cometabolism are i) the inhibition of CF degradation exerted by the growth substrate, ii) the need for reductant supply to maintain monooxygenase activity, and iii) the toxicity of CF degradation products. Under anaerobic conditions, CF degradation was mainly associated to the activity of methanogens, although some examples of CF-degrading sulfate-reducing, fermenting, and acetogenic bacteria are reported in the literature. Higher CF toxicity levels and lower degradation rates were shown by anaerobic systems in comparison to the aerobic ones. Applied, physiological and genetic aspects of microbial cometabolism of CF will be presented along with bioremediation perspectives.

Spinal synovial cysts are cystic dilatations of the synovial membrane that may arise at all levels of the spine. We describe our experience, paying attention to diagnosis, surgical treatment, and long-term follow-up. Between 1995 and 2007, 18 patients were surgically treated. Of these, three patients were excluded from the study because they presented spinal instability at pre-operative assessment. All patients were evaluated pre-operatively with CT, MRI, and dynamic X-rays, and underwent surgery for removal of the cyst by hemilaminectomy and partial arthrectomy. All patients were evaluated with early MRI and had a minimum 2-year follow-up by dynamic X-rays. None of the patients required instrumented fusion due to the absence of radiological signs of instability on the pre-operative dynamic tests. In all patients, there was an immediate resolution of the symptoms, with evidence of complete removal of the cysts on post-operative MRI. At 2-year follow-up, all patients underwent dynamic X-rays and responded to a questionnaire for evaluation of outcome. None of them showed signs of relapse. The gold standard for treatment is surgery, even though other conservative treatment regimens have been proposed. Correct surgical strategy relies on pre-operative assessment of biomechanical stability for deciding whether patients need instrumented fusion during cyst removal. Patients with no instability signs are suitable for hemilaminectomy with partial arthrectomy, preserving 2/3 of the medial portion of the articular facet, because this represents a valid option of treatment with a low risk of complications and a low rate of relapse.

This work focuses on chloroform (CF) cometabolism by a butane-grown aerobic pure culture (Rhodococcus aetherovorans BCP1) in continuous-flow biofilm reactors. The goals were to obtain preliminary information on the feasibility of CF biodegradation by BCP1 in biofilm reactors and to evaluate the applicability of the pulsed injection of growth substrate and oxygen to biofilm reactors. The attached-cell tests were initially conducted in a 0.165-L bioreactor and, then, scaled-up to a 1.772-L bioreactor. Glass cylinders were utilized as biofilm carriers. The continuous supply of growth substrate (butane), which led to the attainment of the highest CF degradation rate (8.4 mg(CF) day(-1) m (biofilm surface)(-2)), was compared with four schedules of butane and oxygen pulsed feeding. The pulsed injection technique allowed the attainment of a ratio of CF mass degraded per unit mass of butane supplied equal to 0.16 mg(CF) mg (butane)(-1), a value 4.4 times higher than that obtained with the continuous substrate supply. A procedure based on the utilization of integral mass balances and of average concentrations along the bioreactors resulted in a satisfactory match between the predicted and the experimental CF degradation performances, and can therefore be utilized to provide a guideline for optimizing the substrate pulsed injection schedule.

Rhodococcus sp. strain BCP1, known for its capacity to grow on short-chain n -alkanes (C 2 to C 7 ) and to cometabolize chlorinated solvents, was found to also utilize medium- and long-chain n -alkanes (C 12 to C 24 ) as energy and carbon sources. To examine this feature in detail, a chromosomal region which includes the alkB gene cluster encoding a non-heme di-iron monooxygenase ( alkB ), two rubredoxins, and one rubredoxin reductase was cloned from the BCP1 genome. Furthermore, the activity of the alkB gene promoter (P alkB ) was examined in the presence of gaseous, liquid, and solid n -alkanes along with intermediates of the putative n -alkane degradation pathway. A recombinant plasmid, pTP alkB LacZ, was constructed by inserting the lacZ gene downstream of P alkB , and it was used to transform Rhodococcus sp. strain BCP1. Measurements of β-galactosidase activity showed that P alkB is induced by C 6 to C 22 n -alkanes. Conversely, C 2 to C 5 and >C 22 n -alkanes and alkenes, such as hexene, were not inducers of alkB expression. The effects on P alkB expression induced by alternative carbon sources along with putative products of n -hexane metabolism were also evaluated. This report highlights the great versatility of Rhodococcus sp. strain BCP1 and defines for the first time the alkB gene transcriptional start site and the alkB promoter-inducing capacities for substrates different from n -alkanes in a Rhodococcus strain.

Background: There are several non-neoplastic lesions which mimick intramedullary spinal cord neoplasm in their radiographic and clinical presentation. These can be classified as either infectious (TB, fungal, bacterial, parasytic, syphilis, CMV, HSV) and non-infectious (sarcoid, MS, myelitis, ADEM, SLE) inflammatory lesions, idiopathic necrotizing myelopathy, unusual vascular lesions and radiation myelopathy. Although biopsy may be indicated in many cases, an erroneous diagnosis of intramedullary neoplasm can often be eliminated pre-operatively. Case description: the authors report a very rare case of intramedullary non-specific inflammatory lesion of unknown origin, without signs of infection or demyelinization, in a woman who showed no other evidence of systemic disease. Conclusions: Intramedullary lesions that mimick a tumor can be various and difficult to interpret. Preoperative MRI does not allow a certain diagnosis because these lesions have a very similar signal intensity pattern. Specific tests for infective pathologies are useful for diagnosis, but histological examination is essential for establishing a certain diagnosis. In our case the final histological examination and the specific tests that we performed have not cleared our doubts regarding the nature of the lesion that remains controversial. Background There are several non-neoplastic lesions which mimick intramedullary spinal cord neoplasm. These can be classified as either infectious (TB, fungal, bacterial, parasytic, syphilis, CMV, HSV) and non-infectious (sarcoid, MS, myelitis, ADEM, SLE) inflammatory lesions, idiopathic necrotizing myelopathy, unusual vascular lesions and radiation myelopathy. Although biopsy may be indicated in many cases, an erroneous diagnosis of intramedullary

An aerobic bacterial strain, named PB1, was microbiologically characterized and subjected to assays of cometabolic biodegradation of chlorinated aliphatic hydrocarbons (CAHs) aimed at (i) investigating its capacity to biodegrade vinyl chloride (VC), cis-1,2-dichloroethylene (cis-DCE), 1,1,2-trichloroethane (1,1,2-TCA), chloroform (CF) and 1,1,2,2-tetrachloroethane (1,1,2,2-TeCA); and (ii) evaluating the suitability of a kinetic model with inhibition and transformation product toxicity to describe CAH biodegradation by PB1. The strain proved to be closely related to the genus Rhodococcus. It biodegraded VC, cis-DCE, 1,1,2-TCA and CF via aerobic cometabolism on propane, but not 1,1,2,2-TeCA. CAH biodegradation by PB1 was satisfactorily described by the tested kinetic model. The maximum specific biodegradation rates were in the 1-11 micromol/mg protein/day range. The transformation capacities varied from 0.6 to 3 micromol/mg protein. Propane exerted a significant inhibition on both CF and cis-DCE biodegradation. CF, at 52 microM, did not inhibit propane utilization. An analysis of different inhibition models showed that cis-DCE inhibition on propane utilization was satisfactorily simulated with the competitive model, with an inhibition constant equal to 70% of the cis-DCE half-saturation constant. A final assay specifically aimed at validating the kinetic model and the verifying the estimates of the kinetic parameters yielded a satisfactory result. The results provide positive indications on the feasibility of utilizing strain PB1 for CAH biodegradation in aquifers and wastewaters.

Bioremediation efforts worldwide are faced with the problem of metals interfering with the degradation of organic pollutants. There has been little systematic investigation into how the important environmental factors of media composition, buffering agent, and carbon source affect the exertion of metal toxicity on bacteria. This study aimed to systematically separate and investigate the influence of these factors by examining planktonic and biofilm establishment and growth. Two Pseudomonads were chosen, the PCB degrader P. pseudoalcaligenes KF707 and P. fluorescens. The two strains were grown in the presence of Al(3+) and Cu(2+) under different media conditions of carbon source (Lysogeny broth, biphenyl, succinate, aspartic acid, butyric acid, oxaloacetic acid, putrescine and benzoic acid) and under different buffering conditions (high and low phosphate or MOPS). These experiments allowed for the elucidation of an effect of different metabolic conditions and metal speciation on planktonic bacteria growth and biofilm establishment and development under metal stress. Here we show that the nature of bacterial growth (planktonic and biofilm development) is dramatically affected by the interplay between toxic metals, carbon source and media composition. The capacity of a media to bind toxic metals as well as quality of carbon source greatly influences the amount of metal that bacteria can tolerate, depending on both the bacterium and metal. Future studies evaluating metal ion toxicity should consider these effects, as well as their interactions with specific environments into account in order to improve clean-up success.

Lactobacillus crispatus BC5 and Lactobacillus gasseri BC12 possess antipathogenic activities that makes them good candidates as probiotics. Indeed, it has been demonstrated that these Lactobacilli can carry out a fungistatic and fungicidal activities against Candida albicans, inhibit the Chlamydia trachomatis infectivity, reduce the Neisseria gonorrhoeae viability and inhibit HIV-1 replication. The aim of this study is to characterize L. crispatus and L. gasseri from genotypic and phenotypic point of views. Whole genome sequencing was performed followed by gene annotation, genome comparison and single gene analysis, with a specific focus on genes involved in antibiotic resistance and production of antimicrobial compounds. Phenotypic characterization was performed using Phenotype Microarray, revealing carbon and nitrogen sources used by these two strains as well as their specific sensitivity to several drugs and chemical compounds. Functional assays demonstrated the capacity of Lactobacillus biosurfactants to eradicate and inhibit the biofilm formation of methicillin resistant S. aureus (MRSA). Taken together, these results demonstrate that L. crispatus and L. gasseri having possible biotechnological applications, in particular, for the treatment and/or prevention of pathogen infections.

Bacterial strains belonging to the genus Rhodococcus are able to degrade various toxic organic compounds and tolerate high concentrations of metal(loid)s. We have previously shown that Rhodococcus aetherivorans BCP1 is resistant to various levels of the two arsenic inorganic species, arsenite [As(III)] and arsenate [As(V)]. However, while arsenite showed toxic effects at concentrations as low as 5 mM, arsenate at 30 mM boosted the growth rate of BCP1 cells and was toxic only at concentrations of >100 mM. Since such behavior could be linked to peculiar aspects of its metabolism, the transcriptomic analysis of BCP1 cells exposed to 5 mM As(III) and 30 mM As(V) was performed in this work. The aim was to clarify the mechanisms underlying the arsenic stress response of the two growth phenotypes in the presence of the two different oxyanions. The results revealed that As(III) induced higher activity of reactive oxygen species (ROS)-scavenging enzymes than As(V) in relation to the expression of enzymes involved in cellular damage recovery and redox buffers/cofactors (ergothioneine, mycofactocin, and mycothiol). Further, As(III) downregulated pathways related to cell division, while both oxyanions downregulated genes involved in glycolysis. Notably, As(V) induced the expression of enzymes participating in the synthesis of metallophores and rearranged the central and energetic metabolism, also inducing alternative pathways for ATP synthesis and glucose consumption. This study, in providing transcriptomic data on R. aetherivorans exposed to arsenic oxyanions, sheds some light on the plasticity of the rhodococcal response to arsenic stress, which may be important for the improvement of biotechnological applications. IMPORTANCE Members of the genus Rhodococcus show high metabolic versatility and the ability to tolerate/resist numerous stress conditions, including toxic metals. R. aetherivorans BCP1 is able to tolerate high concentrations of the two inorganic arsenic oxyanions, arsenite [As(III)] and arsenate [As(V)]. Despite the fact that BCP1 intracellularly converts As(V) into As(III), this strain responds very differently to the presence of these two oxyanions in terms of cell growth and toxic effects. Indeed, while As(III) is highly toxic, exposure to specific concentrations of As(V) seems to boost cell growth. In this work, we investigated the transcriptomic response, ATP synthesis, glucose consumption, and H(2)O(2) degradation in BCP1 cells exposed to As(III) and As(V), inducing two different growth phenotypes. Our results give an overview of the transcriptional rearrangements associated with the dual response of BCP1 to the two oxyanions and provide novel insights into the energetic metabolism of Rhodococcus under arsenic stress.

Sulfuric acid cave systems host abundant microbial communities that can colonize several environments displaying a variety of morphologies, i.e. white filamentous mats floating on the water surface, white creamy moonmilk deposits on the walls, and biovermiculations. Up to date, only few reports have described the microbiological aspects behind biovermiculation geomicrobiology of Italian sulfuric acid caves despite their overall abundance. Here, we present the first characterization of biovermiculation microbial populations from the Santa Cesarea Terme (Apulia, Italy) using next-generation sequencing and field emission scanning electron microscopy (FESEM) approaches. We focused our analysis on biovermiculations from Fetida Cave located along the Adriatic Sea coastline. This cave is at sea level, and moving from the entrance to its inner part, it is possible to observe a decrease of marine influence accompanied by a corresponding increase in the acidic effect of the upwelling waters. Biovermiculations are copiously observed covering the ceiling and walls mainly in the inner and middle environments of the cave, while they are absent near the entrance. Biovermiculations have a widespread range of colors going from grey to dark brown with an overall slimy appearance; dendritic morphologies alternate to very dense wall-covering sheets. Total DNA was extracted from each sample and 16S rDNA sequences were analyzed through Ilumina MiSeq platform. The main lineages found in all the samples included Gammaproteobacteria, Betaproteobacteria, Alphaproteobacteria, Bacteroidetes, Planctomycetes, Actinobacteria and Acidobacteria. In particular, the samples from the inner part of the cave had the highest abundance of Acidobacteria and showed the presence of Epsilonproteobacteria that can be related to bacterial sulfur-oxidizing activity. FESEM images revealed microbial mats composed of filamentous cells including Actinobacteria and reticulated filaments of unknown origin, as well as prosthecate bacteria. This study shows that the biovermiculation microbial communities from Fetida cave is in accordance with previous data reported in acidic caves from Italy and support the role of Epsilonproteobacteria typically occurring in sulfidic environments.

In the last three years, one of the longest quartz-sandstone caves, Imawarì Yeuta, has been explored in the Precambrian rocks of the Auyan Tepui massif in Venezuela. The uniqueness of this quartz-sandstone cave resides in its great age (estimated over 30 Ma) and its complete isolation from anthropogenic activities. Therefore, subsurface ecosystems might have been preserved from contamination and possible subsequent alteration. The cave contains a high level of microbial activity as demonstrated by the presence of silica stromatolite-like speleothems, biologically mediated sulphate-phosphate deposits and lakes covered by patinas of violaceous or other colourful biofilms. The high diversity of the environments, in terms of mineralogical substrate and geochemistry of the waters, suggests that niche-differentiation of the microbial communities could be mainly controlled by the specific chemical characteristics of each site rather than by light attenuation, i.e., the distance from the entrances of the cave toward the dark zones. To investigate this possibility, we characterised the microbial community composition in 17 samples collected during the expeditions of 2014 and 2016 to the cave system. In particular, the next-generation sequencing (NGS) approach was performed by using Illumina MiSeq technology targeting the 16S rRNA gene. The acquired data have then been correlated with geochemical (water pH, EC, major and minor elements) and mineralogical (predominant and secondary minerals) information from each sampling site. The results showed that the cave hosts three main types of microbial communities, each of these characteristic of a specific environment dominated by silica (crystalline or amorphous), iron hydroxides or hydrated sulphate-phosphates. This work presents a first set of results on the microbial characterisation of each sampling site and proposes a preliminary hypothesis on the functional biological factors supporting the biodiversity distribution in relation with the different geochemical environments described in this exceptional cave.

Naphthenic acids (NAs) are an important group of organic pollutants comprised predominantly of saturated aliphatic and alicyclic carboxylic acids. Although these compounds are toxic, recalcitrant, and persistent in oil sands deposits, we are just learning the diversity of microorganisms involved in NAs-degradation and the mechanisms by which NAs are biodegraded. Here, we described the ability of Rhodococcus sp. BCP1 and Rhodococcus opacus R7 to utilize two model naphthenic acids (NAs) i.e. cyclohexancarboxylic acid (CHCA) and cyclopentanecarboxylic acid (CPCA) as sole carbon and energy source. BCP1 strain degraded both the NAs with higher rates compared to R7; moreover, CHCA was shown to be metabolized faster than CPCA by both the Rhodococcus spp. Furthermore, genes coding for enzymes putatively involved in β-oxidation metabolism were identified in BCP1 genome. RT-PCR experiments showed that all these genes are induced by the growth of BCP1 on either CPCA or CHCA. These results suggest their involvement in β-oxidation metabolism of NAs by R. sp. BCP1.