Production of ethanol from starch by respiration-deficient recombinant Saccharomyces cerevisiae

A 100%-respiration-deficient nuclear petite amylolytic Saccharomyces cerevisiae NPB-G strain was generated, and its employment for direct fermentation of starch into ethanol was investigated. In a comparison of ethanol fermentation performances with the parental respiration-sufficient WTPB-G strain, the NPB-G strain showed an increase of ca. 48% in both ethanol yield and ethanol productivity.     

Invasive lobular carcinoma with extracellular mucin as a distinct variant of lobular carcinoma: a case report

ABSTRACT: The differences between invasive lobular and ductal carcinomas affect the diagnostic and therapeutic management for patients with breast cancer. In most cases, this can be accomplished because of distinct histomorphologic features. However, occasionally, this task may become quite difficult, in particular when dealing with the variants of infiltrating lobular carcinoma. Lobular carcinoma has been considered a variant of mucin-secreting carcinoma with only intracytoplasmic mucin. The presence of extracellular mucin is a feature of ductal carcinoma. Herein is presented a case of lobular carcinoma with extracellular and intracellular mucin in a 43-year-old female patient, and confirmed by immunohistochemistry. Up to the present, infiltrating lobular carcinoma displaying extracellular mucin has not been described in the literature except two case. Virtual slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1839906067716744.     

The stimulatory effect of mannitol on levan biosynthesis: Lessons from metabolic systems analysis of Halomonas smyrnensis AAD6T

Halomonas smyrnensis AAD^T is a halophilic, gram‐negative bacterium that can efficiently produce levan from sucrose as carbon source via levansucrase activity. However, systems‐based approaches are required to further enhance its metabolic performance for industrial application. As an important step toward this goal, the genome‐scale metabolic network of Chromohalobacter salexigens DSM3043, which is considered a model organism for halophilic bacteria, has been reconstructed based on its genome annotation, physiological information, and biochemical information. In the present work, the genome‐scale metabolic network of C. salexigens was recruited, and refined via integration of the available biochemical, physiological, and phenotypic features of H. smyrnensis AAD6^T. The generic metabolic model, which comprises 1,393 metabolites and 1,108 reactions, was then systematically analyzed in silico using constraints‐based simulations. To elucidate the relationship between levan biosynthesis and other metabolic processes, an enzyme‐graph representation of the metabolic network and a graph decomposition technique were employed. Using the concept of control effective fluxes, significant links between several metabolic processes and levan biosynthesis were estimated. The major finding was the elucidation of the stimulatory effect of mannitol on levan biosynthesis, which was further verified experimentally via supplementation of mannitol to the fermentation medium. The optimal concentration of 30 g/L mannitol supplemented to the 50 g/L sucrose‐based medium resulted in a twofold increase in levan production in parallel with increased sucrose hydrolysis rate, accumulated extracellular glucose, and decreased fructose uptake rate. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:1386–1397, 2013     

Bacterial Spectrum and Antimicrobial Susceptibility Pattern of Bloodstream Infections in Children with Febrile Neutropenia: Experience of Single Center in Southeast of Turkey

Empirical antimicrobial therapy is usually started in febrile neutropenic patients without having culture results. The aim of this study was to help determine the policies of empirical antibiotic usage in febrile neutropenic children by detecting the antimicrobial susceptibility profile in this group of patients. In this study 811 blood cultures taken from neutropenic children hospitalized at the Department of Oncology of Gaziantep Children Hospital November 2007 and February 2010 were retrospectively evaluated. Blood cultures were routinely collected in aerobic and anaerobic media and incubated using the BACTEC system. Identification and antimicrobial susceptibility testing of the isolates to antimicrobial agents was performed using the Vitek2^® system according to the recommendations of the Clinical and Laboratory Standards Institute. Of 811 isolates analyzed, 128 (56.4%) were gram positive cocci, 43 (18.9%) were gram negative bacilli and fungi accounted for 56 (24.7%). The main isolated Gram-positive bacteria from blood were coagulase-negative staphylococcus (56.7%), followed by methicillin-resistant Staphylococcus aureus (14.1%). S. aureus and Streptococcus spp. were all susceptible to linezolid, vancomycin and teicoplanin. S aureus was still susceptible to few other antimicrobial agents such as tetracycline (82.4%), chloramphenicol (55.6%). Seven E. faecium, 7 E. fecalis and 1 E. hirae was isolated from blood cultures. Vancomycin resistance was detected in 6 out of 15 (40%) Enterococcus spp. isolates. Among gram-negative bacteria E. coli (30.2%) was followed by Klebsiella pneumoniae (20.9%) and Proteus spp. (18.6%). Imipenem (89.2%), meropenem (86.6%), chloramphenicol (88.9%), amicasin (82.4%) and fosfomycin (81.3%) showed highest susceptibility in vitro activity against all Gram-negative isolates. To know the antimicrobial susceptibility profile of the pathogens frequently isolated from febrile neutropenic children and to consider this profile before starting an empirical antibiotic therapy would help the clinics which have any role in the treatment of these patients to determine the empirical antibiotic usage policies.     

Perturbations in nucleosome structure from heavy metal association

Heavy metals have the potential to engage in strong bonding interactions and can thus function in essential as well as toxic or therapeutic capacities. We conducted crystallographic analyses of heavy cation binding to the nucleosome core particle and found that Co²⁺ and Ni²⁺ preferentially associate with the DNA major groove, in a sequence- and conformation-dependent manner. Conversely, Rb⁺ and Cs⁺ are found to bind only opportunistically to minor groove elements of the DNA, in particular at narrow AT dinucleotide sites. Furthermore, relative to Mn²⁺ the aggressive coordination of Co²⁺ and Ni²⁺ to guanine bases is observed to induce a shift in histone–DNA register around the nucleosome center by stabilizing DNA stretching over one region accompanied by expulsion of two bases at an opposing location. These ‘softer’ transition metals also associate with multiple histone protein sites, including inter-nucleosomal cross-linking, and display a proclivity for coordination to histidine. Sustained binding and the ability to induce structural perturbations at specific locations in the nucleosome may contribute to genetic and epigenetic mechanisms of carcinogenesis mediated by Co²⁺ and Ni²⁺.     

Genetic Polymorphism of β-Lactoglobulin Gene in Native Turkish Sheep Breeds

The genetic polymorphism of the β-lactoglobulin gene was investigated in three native Turkish sheep breeds. The study was carried out on 108 sheep (29 Kıvırcık, 38 G?k?eada, and 41 Sakız) by means of PCR-RFLP methods. Two genetic variants (A and B) and three genotypes (AA, AB, and BB) of β-lactoglobulin have been identified. The gene frequencies of β-LG A and B were 0.7759 and 0.2241 in Kıvırcık, 0.7632 and 0.2368 in G?k?eada, and 0.9756 and 0.0244 in Sakız breeds, respectively. The populations were in Hardy–Weinberg equilibrium in all samples from the three breeds.     

Liver gamma-glutamyl transpeptidase activity following chronic treatment with acetylsalicylic acid in rats

In the present study, rats were administered acetylsalicylic acid (ASA), at low and high doses, by means of a gastric tube for 30 days. Chronic administration of a high dose of ASA (200 mg/kg body weight) resulted in a significant increase in liver plasma membrane gamma-glutamyl transpeptidase activity, cholesterol, and phospholipid levels. The enzymatic activity and lipid levels appeared not to be affected by ASA when given at a lower dose (50 mg/kg body weight). The changes in the enzymatic activity of plasma membrane were positively correlated to membrane cholesterol content. These findings suggest that the hepatotoxicity of high doses of ASA should not be overlooked during clinical use of the drug.