Biomass Valorization: Sustainable Methods for the Production of Hemicellulolytic Catalysts from Thermoanaerobacterium thermostercoris strain BUFF

Processing and selection of fruits and vegetables generate high quantities of wastes that represent an economic and environmental issue for the agroindustry sector. According to the so-called “biorefinery” approach, this biomass can be exploited for the recovery of value-added molecules. In this study, the residues of industrial processing of tomato (Lycopersicon esculentum variety “Hybrid Rome”), fennel (Foeniculum vulgare), potato (Solanum tuberosum) and carrot (Daucus carota) were used as sole carbon sources to support cheap and sustainable microbial growth as well as the production of secondary metabolites (hydrogen and ethanol) by Thermoanaerobacterium thermostercoris strain BUFF, a thermophilic anaerobic microorganism isolated from buffalo-dung compost. Moreover, the use of hemicellulolytic enzymes of T. thermostercoris was assayed in the bioconversion reaction of the polymer fraction extracted from the rhizome of giant reed (Arundo donax) and of the leaves and stems of cardoon (Cynara cardunculus), dedicated non-food crops employed in energy supply.

What we actually know about the pathogenicity of Bacteroides pyogenes

The aim of the study was to evaluate the pathogenic potential of Bacteroides pyogenes, rarely identified in clinical laboratories anaerobic bacteria. To increase the knowledge about this poorly understood anaerobic microorganism, the study also includes cases of infections described so far in the literature. Only the use of 16S rRNA sequencing and mass spectrometry technique allowed the identification of B. pyogenes from clinical specimens. We reported 13 severe human infections caused by B. pyogenes. Bacteria were cultured from the wound after biting by animals, chronic infections within the oral cavity, from patients with histologically or radiological proven osteomyelitis, surgical site infection, and from urine sample collected after a urological procedure. Most (9/13) of the patients required hospitalization. Almost 70% of them needed urgent admission via the emergency room. Two inpatients due to a life-threatening condition were admitted to the intensive care unit. Almost 50% of isolates were resistant to penicillin. All resistant to penicillin strains were isolated from skin and mucous membrane infections.

Mediastinal Actinomycosis: A Rare Mediastinal Pseudotumour

Actinomycosis, once fairly common and often catastrophic, has now become an occasional infection in the era of antibiotics. The infection is caused by a branching Gram-positive, facultative anaerobic microorganism Actinomycetes. Various forms of the diseases in decreasing order of their frequency include cervico-facial form, abdomino-pelvic form and thoracic form. The thoracic involvement occurs in approximately 15% of all cases of actinomycosis. The disease presents with nonspecific signs and symptoms and therefore establishment of a definitive diagnosis with clinical and radiological investigations is difficult. The clinical and radiological picture mimics a number of other pulmonary conditions like cancer, tuberculosis, lung abscess and pneumonia. To reach at a definitive diagnosis one needs to have a high degree of suspicion and carry out histopathological studies in order to look for colonies of Actinomycetes as well as sulphur granules which are pathognomic for the infection. Here is a case of a 48-year-old diabetic male presenting with complaints of pain and swelling of neck, fever, dysphagia, dyspnea and cough with a mediastinal tumour like appearance on chest radiography. The patient underwent various noninvasive and invasive diagnostic modalities that included Contrast Enhanced Computed Tomography (CECT), Ultrasonography (USG) of thorax and histopathological examination of the cervical lymph nodes (level 2 and 3). The disease process was initially thought to be tubercular or malignant in origin which later turned out to be an actinomycotic lesion which was confirmed on the histopathological study of the lymph node specimen, that responded to antibiotics over a period of few months.

Utility of microcalorimetry in describing the growth curve of C. albicans at different temperatures – indentifying the optimal growth temperature

In comparison with other medical specialties, Orthopedics and Traumatology are continuously impressively developing, intrinsically connected to technological evolution. More than in other fields, in Orthopedics and Traumatology, the technological progress becomes obvious also by the frequent use of implants or osteosynthesis materials. By performing a simple search in the specialty literature, an exponential growth of arthroplasty surgeries in correlation with the life span of the population and implying a need that presupposes the increase of the quality of life, also by maintaining or improving mobility at a satisfying level, can be observed. At the same time, due to the increase in the number of traffic and sports accidents, the use of artificial joints and implants for osteosynthesis will constantly rise. The prostheses and the osteosynthesis materials used for the treatment of degenerative, traumatic or even esthetic pathologies are made of materials with a good biocompatibility.Candida albicans is an optional anaerobic microorganism so the experiments performed with different volumes of environment were most likely influenced by the amount of oxygen, nutrient.In the described research, we demonstrated that, using microcalorimetry, it is possible to identify this fungus in half the time required for classical microbiological identification. In addition, as our team has shown, there is the possibility of real-time antifungigram by using microcalorimetry.

Cathodic reduction characteristics of 2-chloro-4-nitrophenol in microbial electrolysis cell

Microbial electrolysis cell (MEC) has been constructed to study the degradation characters of 2-chloro-4-nitrophenol (2C4NP) in waste water. The effects of applied voltage, initial concentration of substrate and co-matrix species on the reduction and degradation of 2C4NP were studied. Qualitative and quantitative analysis of 2C4NP residues and degradation intermediate by using UV-Vis, HPLC, HPLC/MS/MS, IC and other analytical testing techniques. The degradation mechanism of 2C4NP in MEC cathode was proposed. The results showed that electron and electroactive microorganisms would produce coupling effect and accelerate the degradation of 2C4NP under adding 0.5 V DC; Under the condition of satisfying the C/N ratio of electroactive anaerobic microorganism, the addition of organic substances such as glucose and sodium acetate which were easily degraded by microorganisms would hinder the degradation of 2C4NP in the cathode compartment. 2C4NP can be effectively degraded by adding appropriate amount of glucose as carbon source with the low C/N. 2C4NP undergoes reduction, dechlorination, denitrification and assimilation in the cathode compartment to form 2-chloro-4-aminophenol, 4-aminophenol, 2-chlorophenol, 2-chloro-4-hydroxyphenol, nitrophenol, hydroquinone, 4-hydroxyhexadienoic acid semialdehyde, valeric acid, oxalic acid and many other intermediate products. According to the degradation intermediates, the degradation mechanism of 2C4NP in the cathode compartment was presumed.

Anaerobic Bioreduction of Jarosites and Biofilm Formation by a Natural Microbial Consortium

Jarosite occurs naturally in acid sulphate soils and is a common feature of streams impacted by acid mine drainage (AMD). Biological reduction of iron-sulphate minerals, such as jarosite, has the potential to contribute to the natural attenuation of acid mine drainage sites. The reduction of different jarosites (including minerals containing precious and toxic metals) by a natural bacterial/microbial consortium was examined in this study. Jarosites was used as a sole terminal electron acceptor via the reductive dissolution of Fe(III) minerals. The production of Fe(II) and the presence of sulphate-reducing bacteria in the consortium lead to the precipitation of metal sulphides immobilizing toxic heavy metals. Microbial attachment and biofilm formation of minerals have a great impact on the production and transformation of minerals and can influence the mobility of metals. After the adaptation to different jarosites, a unique specie was found: Desulfosporosinus orientis. Desulfosporosinus species are sulphate-reducing bacteria and can be found in sulphate-rich heavy metal-polluted environments, such as acid mine/rock drainage sites, being responsible for the sulphides formation. D. orientis is an obligate anaerobic microorganism and is able to reduce Fe(III) D. orientis is an obligate anaerobic microorganism and is able to reduce Fe(III). Confocal laser scanning microscopy and fluorescent lectin-binding analyses (FLBA) were used to study the arrangement and composition of the exopolysaccharides/glycoconjugates in biofilms indicating the presence of mannose, glucose, and N-acetylglucosamine residues. This study provides insights to understand the processes leading to the mobility or retention of metals in mine waste and industrial landfill environments.

Genome-scale metabolic reconstruction and analysis for Clostridium kluyveri

Clostridium kluyveri is an anaerobic microorganism that is well-known for producing butyrate and hexanoate using ethanol and acetate. It is also an important bacterium in the production of Chinese strong flavour baijiu (SFB). To obtain a comprehensive understanding of its metabolism, a curated genome-scale metabolic model (GSMM) of C. kluyveri, including 708 genes, 994 reactions, and 804 metabolites, was constructed and named iCKL708. This model was used to simulate the growth of C. kluyveri on different carbon substrates and the results agreed well with the experimental data. The butyrate, pentanoate, and hexanoate biosynthesis pathways were also elucidated. Flux balance analysis indicated that the ratio of ethanol to acetate, as well as the uptake rate of carbon dioxide, affected hexanoate production. The GSMM iCKL708 described here provides a platform to further our understanding and exploration of the metabolic potential of C. kluyveri.

Bioleaching for Removal of Chromium and Associated Metals from LD Slag

The ability of Acidithiobacillus ferrooxidans to remove chromium and other metals from LD slag was examined. Additionally the option to retrieve P from LD slag was evaluated. Due to the facts that A. ferrooxidans is a facultative anaerobic microorganism and LD slag is an alkaline and oxidic material, both oxidative and reductive bioleaching experiments were carried out. In the reductive mode, four different gas atmospheres (nitrogen, carbon dioxide, air and a mixture of N2 and CO2) were considered. Promising results were obtained by reductive bioleaching with A. ferrooxidans and a pure carbon dioxide atmosphere, 83 % chromium could be removed. In comparison, only 27 % Cr were removed by oxidative bioleaching. The degree of P removal could not be easily determined due to imbalanced data obtained.