Use of Lignocellulosic Materials for PHA Production

Polyhydroxyalkanoates (PHAs) are very promising materials that might serve as an environmentally friendly alternative to petrochemical plastics. The main obstacle preventing PHAs from entering the market massively is the final cost of the polymer material, a significant portion of which is attributed to carbon substrate. Hence, the researchers have been intensively seeking cheap substrates for sustainable production of PHAs. Lignocellulose represents a very promising substrate for PHAs production – it is abundant, cheap, and it does not compete with human food chain. On the other hand, utilization of lignocellulose materials as substrates for biotechnological processes represents a challenge due to many factors, such as necessary hydrolysis of the biomass to yield fermentable sugars and presence of numerous antimicrobial agents. Therefore, this work summarizes recent advances in biotechnological conversion of lignocellulose materials into PHAs. The review not only deals with the process of fermentation, but it also considers different approaches of lignocellulose hydrolysis and detoxification

Antimutagenic properties of several kinds of rice as tested upon yeast strain Saccharomyces cerevisiae D7

The aim of this work was to study antimutagenic and antioxidant properties of water extracts of various types of rice. Antioxidant activity, total phenolic andflavonoid contents were measured spectrophotometrically. Individual phenolics — catechins, catechin gallates, ferulic acid — were analysed by HPLC/PDA. Antimutagenic activity of rice extracts was tested using unicellular eukaryotic yeast strain Saccharomyces cerevisiae D7 the first time.Non-processed rice types contained substantially higher amount of soluble total and individual phenolics and had higher antioxidant activity than peeled rice. Parboiled rice, in which technological processing helps to maintain active substances inside the grains, exhibited also relatively high phenolic levels. The highest antimutagenic effect was proved in Indian Rice, Arborio, Jasmine Rice and Three Colours Rice independently of rice extract concentration. Because of relatively high values of phenolics and high antioxidant activity, the antimutagenic activity of these samples could be attributed to biologically active phenolics present mainly in the bran layer of whole rice grain

Probiotic biofilm on carrier surface: A novel promising application for food industry

In this essay work, the ability of probiotic biofilm formation on carrier surface was demonstrated. Probiotic biofilms exhibit the same properties as pathogen microbial biofilms but with higher resistance to low pH values and bile salts. The ability of different probiotic strains (Lactobacillus acidophilus, Bifidobacterium breve, Bifidobacterium longum) to interact with pre-selected carriers divided into 3 categories (polymers, complex food matrices, and inorganic compounds) was tested. Lactobacillus acidophilus and Bifidobacterium longum combined with inorganic silica carrier exhibited the interaction leading to biofilm formation only. Prepared biofilm (Lactobacillus acidophilus) was then subjected to comparative study with planktonic bacterial culture. The ability to survive in the presence of low pH value (pH 1–3) and bile salts (0.3% solution) was evaluated. Low pH value (pH 1) had a harsh effect on free cell culture causing decreased cell viability (71.9±3.2% of viable cells). Biofilm culture exhibited higher resistance to low pH value, the viability exceeded 90%. The exposure of free cell probiotic culture to porcine bile resulted in an almost constant decrease in viability during the study period (68.2±1.1% of viable cells, after 240 min incubation). Viability of biofilm after the exposition to bile was almost constant with a slight decrease of no more than 5% during the study

Comparative Analysis of Clinical, Hormonal and Morphological Studies in Patients with Neuroendocrine ACTH-Producing Tumours

This paper highlights the problem of neuroendocrine tumours (NETs) with clinical symptoms of hypercorticism caused by hypersecretion of adrenocorticotropic hormone (ACTH) by tumour cells. In most cases (85%), the tumours were localized in the pituitary gland (Cushing's disease); 15% of the patients had an extrapituitary tumour that manifest as an ectopic ACTH secretion (EAS). Comparative analysis of clinical, hormonal, histological, and immunohistochemical characteristics of pituitary and extrapituitary ACTH-secreting NET was performed. It included 46 patients with CD and 38 ones exhibiting ectopic ACTH secretion (EAS). Results of the study suggest differences between CD and EAS in terms of the severity of clinical manifestations and duration of the disease. Hormonal studies showed that EAS unlike CD was associated with high plasma ACTH and cortisol levels, late-evening salivary cortisol and daily urinary free cortisol, the absence of a 60% or greater reduction of cortisol in the HDDST test, and the presence of a low (less than 2) ACTH gradient in response to desmopressin administration with catheterization of cavernous sinuses. The study of morphofunctional characteristics of the removed NET demonstrated the ability of both pituitary and extrapituitary NETs to express ACTH as well as GH, PRL, LH, and FSH. The angiogenic markers (CD31 and VEGF) were detected with equal frequency regardless of the NET localization. The histological structure of all corticotropinomas suggested their benign origin, but extrapituitary NETs were represented by different morphological types with varying malignancy, invasiveness, and metastatic properties. A higher cell proliferation potential (Ki-67) was documented for NET in patients presenting with an ectopic ACTH secretion compared to those having corticotropinomas

Clinical guidelines ‘Hyperprolactinemia’ (draft)

Hyperprolactinemia is a persistent excess of the blood serum prolactin. The syndrome contains various symptoms, the most characteristic is a violation of the reproductive system. There are multiple endogenous and exogenous causes of hyperprolactinemia. The main treatment method is dopamine agonist therapy, in case of prolactinoma existence, surgical and radiation methods can be applied. About 15% of patients are resistant to dopamine agonist therapy, which determines creation of individual management tactics. The article presents a draft of clinical guidelines for the diagnosis and treatment of hyperprolactinemia, which provides a modern examination algorithm, discusses the basic principles of diagnostics and treatment approaches

Monitoring of growth and production characteristics of red yeasts cultivated on hydrothermally pretreated lignocellulosic pine material

The aim of this work was to compare the production of carotenes and ergosterol by red yeasts grown on pine lignocellulose substrates. The yeast strains Rhodotorula aurantiaca and Sporobolomyces shibatanus were grown on the liquid fraction of steam pretreated pine (210 °C, catalyst SO2). Biomass production on a pine hydrolysate was lower than on glucose. The highest content of carotenoids and ergosterol in the cells of R. aurantiaca grown on pine hydrolysate was about 1.7 mg g-1 and 0.8 mg g-1 (dwt), respectively, and in S. shibatanus about 0.9 mg g-1 and 0.1 mg g-1, respectively. Hemicellulose hydrolysates may contain many compounds that have inhibitory effects on microorganisms. In this work, the influences of some inhibitors were assessed by cultivating yeasts on media with a representative addition of the selected compounds. From these tests, furfural appears to be the most critical inhibitor, whereas acetic acid and 5-hydroxymethyl furfural (HMF) do not affect the growth so much

PROSPECTS AND PROBLEMS OF USING THE EFFECT OF SURFACE-ENHANCED RAMAN SCATTERING IN THE DIAGNOSIS OF VIRAL INFECTIONS

This review presents the latest advances in the use of surface-enhanced Raman scattering (SERS) immunoassay, which can be used to detect viral markers. As in the case of conventional immunoassays, these methods are often based on «sandwich-type» solid phase immunoassay. In recent years the necessary components of the immunochemical methods with SERS detection is SERS-active substrates to create a variety of approaches have been developed. Despite the difficulty of achieving high sensitivity and specificity in the analysis of clinical samples, a number of successful examples with promising results have been demonstrated

ACTH-producing neuroendocrine tumor of thymus with recurrences. Clinical case

One of the most difficult in diagnostic and treatment options for endogenous Cushing is the ectopic ACTH syndrome, which causes the development of tumors of different histogenesis localization producing adrenocorticotropic hormone (ACTH), and much less - corticotropin hormone (CRH). ACTH-secreting tumors varied in location, morphological structure and the degree of malignancy. Most of these tumors are characterized by an aggressive course with a propensity to metastasize and relapse. The article presents data of the prevalence, pathogenesis of ectopic ACTH tumors localized in the thymus, analyzis of clinical, morphological features, the methods of diagnosis and treatment. Based on the current literature, the world and our own experience on the diagnosis and treatment of patients with ectopic ACTH syndrome with localization of hormone production in the thymus, we want to highlight the current state of the problem in order to create the most efficient algorithm for diagnostic search and treatment of this difficult group of patients