Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XXII
Written by Daniel NIŢOI, Florentina MATEI, Călina Petruţa CORNEA

In recent years, microbial infections have become increasingly difficult to treat. Classical treatments, which involve the use of antibiotics in various pharmaceutical compounds with antimicrobial activity, shows the problems difficult to be solved. For this purpose, researchers are looking for a solution and therefore possible alternative treatments to treat microbial infections. Favorable results are obtained from the use of probiotics, a lot of in vitro and in vivo studies demonstrating the ability of certain probiotics, in particular lactic acid bacteria, to inhibit the growth of pathogenic microorganisms. Probiotics are a class of bacteria similar to those existing in specific human microflora, with beneficial role on human health. Real problems came from endemic fungal infections of humans who, in their favorable conditions, proliferate and lead to the appearance of serious diseases. An example and also a cause of many diseases is the genus Candida. The review presents the main findings related to the response of different Candida species to in vitro and in vivo treatments with different probiotics.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XXI
Written by Caterina TOMULESCU, Mişu MOSCOVICI, Bujor ALBU, Roxana STOICA, Claudia SEVCENCO, Delia JITEA, Radu TAMAIAN, Adrian VAMANU

Microbial enzymes are known to be superior to enzymes obtained from other organisms, particularly for applications in industries on commercial scales. The species of the genus Bacillus are known to be producers of enzymes of industrial interest. Among them, amylolytic enzymes have got great biotechnological applications and economic exploitations. Amylases are known to be produced by a variety of bacteria and fungi and their applications at industrial level have stimulated interest to explore their amylolytic activity in several microbes to be used as bioresources. A newly soil-isolate, identified as a Bacillus mycoides strain, was tested for its ability to produce extracellular amylase in liquid media, using multiple carbon sources and starchy substrates. Chip electrophoresis was used to obtain the electrophoretic profile of proteins derived from the bacterial isolate and a molecular weight of 60 kDa, characteristic for amylase produced by Bacillus genus, was obtained in two experimental media. Bioprocess optimization was designed using L9 and L16 Taguchi orthogonal arrays and analyzed by ANOVA statistical methods. A maximum enzymatic activity (10.44 U/ml) was determined when malt extract and ammonium sulphate, as starchy substrate and nitrogen source, were used. Optimum growth conditions were identified to be 32°C, 220 rpm and 48 hrs fermentation time, while the inoculation volume was 2%. A positive effect for amylase production was observed for citric acid and CaCl₂ interaction in the culture media.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XXII
Written by Ricuţa-Vasilica DOBRINOIu, Silvana Mihaela DĂNĂILĂ-GUIDEA, Rodica IVAN Giovanni BEZZE, Davide VITALI

Giant bamboo culture begins to gain increasingly more land in Romania, becoming an attractive crop for farmers, not only because of its multiple utilities, but also because of the ease with which it maintains culture immediately after setting up. Choosing the most effective schemes of fertilization and the practice of alternative methods of weeds control, represent two of the essential technological links which any farmer must take into account when proposing the establishment a culture of giant bamboo, according to some minimal inputs. It was found so that, taking 2 foliar treatments during the growing season of the crop, with total soluble and total assailable fertilizers for the crop, associated with mulching or setting up land cultivation of dwarf clover under ,,culture hidden" to combat weeds, have induced a bamboo plants accelerated growth and development, in the context of the use of technological practice gentle with the environment.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XXI
Written by Mihaela DUMITRU, Ștefana JURCOANE

The objective of the present research was to convert the grape pomace as energy source, by controlling to increase hydrolysis of the complex sugars (celluloses, hemicelluloses) to fermentable sugars. Hydrolysis can be performed chemically or enzymatically following the appropriate pretreatment steps. The chemical pretreatment of the grape pomace substrat present many disadvantages such as the high costs, the special conditions and the formation of toxic by-products. For this reason, we used hydrolysis enzymatic process, as the most efficient method. The efficiency a commercial enzymatic product - MethaPlus L 100 (containing β-glucanase, cellulase, xylanase) was investigated to hydrolyse dry grape pomace, after physical pretreatment (ground 1mm sieve diameter) to fermentable sugar. The enzyme MethaPlus L 100 was added in different concentrations 0.1 – 1 % (w/w) referred to the substrate dry matter content. The reducing sugars concentration increased of 4.0 fold (when 0.01% MethaPlus L 100 was added) reported relatively to the untreated sample. However, an increase of enzymes concentrations not economically relevant. In the future, the efforts should be focused on the improving the enzymatic treatment of the grape pomace, to be used as nutritional component in animal feed.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XXII
Written by Mihaela DUMITRU, Cristina TABUC, Ionuț SORESCU, Andreea VASILACHI, Mihaela HĂBEANU, Stelian PETRE, Ștefana JURCOANE

The objective of this experimental study was to evaluate the enzymatic hydrolysis process in order to obtain fermentable sugars from feed materials (maize, field peas, field beans), usually used in animal nutrition. For breaking down the carbohydrates from cell materials raw, it was used a carbohydrase enzyme preparation (IUB No. 3.2.1.6) with activity of 50 FBG/g. The enzyme was tested at concentration of 0.05-0.5% (w/v). For measuring accumulation of reducing sugars, it was used 3,5 dinitrosalicylic acid (DNS) assay. Results from experimental samples supplemented with carbohydrase enzyme were compared with control sample without enzyme addition. The activity of carbohydrase enzyme was evaluated using a carboxymethyl cellulose medium (4.19 UDNS/ml). For the experimental data, the total amount of available sugars was significantly higher (P<0.0001) for peas (19.60±0.105), followed by maize (17.17±0.105) and beans field (10.50±0.055) at a concentration of 0.5% enzyme. The results suggest that hydrolytic potential of enzyme preparation to produce fermentable sugars was superior on field peas, knowed as source of protein in animal nutrition and can be used as feed additive to improve nutrient availability.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XXII
Written by Diana GROPOŞILĂ-CONSTANTINESCU, Luminiţa VIŞAN, Radu-Cristian TOMA, Gabriela MĂRGĂRIT, Dana BARBA

The theme of the paper was chosen because we considered it important that people know not only the negative part about whey - it is a waste, but also the positive side - that it can be successfully used in the production of value-added products. The purpose of the paper was to obtain a probiotic product by superior capitalizing of whey. The objectives of the paper were: (1) Processing of whey in a slightly fermentable form for the cultivation of Saccharomyces cerevisiae and Lactobacillus bulgaricus strains; (2) Optimizing the composition of the whey culture medium in order to obtain the highest biomass productivity; (3) Obtaining probiotics based on Saccharomyces cerevisiae and Lactobacillus bulgaricus strains. Several media variants with different glucose concentrations (0%, 0.5%, 1%, 2%) were used for the biosynthesis of probiotics. In the case of yeasts, glucose supplementation of culture media increases the amount of wet biomass by 21% compared to glucose-free media, and 16% for lactobacilli. However, good results were also obtained on whey as such, without additional glucose, yielding 52 g/l yeast and 42 g/l lactobacilli.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XXII
Written by Monica POPA, Andreea TICAN, Mihaela CIOLOCA, Carmen Liliana BĂDĂRĂU

Plantlets of three cultivars Sarmis, Christian and Roclas were induced to microtuberized under dark conditions and at temperature of 17°C. In medium of tuberisation were applied two different sugar alcohols (sorbitol ans mannitol) for evaluate the influence of this under the number of microtubers obtained/plantlet and the average weight of a microtuber. It was used three concentrations of sugar alcohols (0.05; 0.11; 0.17 mol/l) which were compared with controlled medium in which was not added any type sugar alcohol.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XXII
Written by Getuța DOPCEA, Florentina MATEI

This article will review some current antiseptics used for skin disinfection: povidone iodine (PVP-I), chlorhexidine digluconate (CHG) and octenidine dihydrochloride (OCTD). These antiseptics are used in both healthcare and household products, for different types of applications preoperative skin preparation, surgical hand scrub, skin wound cleanser, skin wound protectant, hand hygiene, oral care and body wash. In the past years more and more concerns have been raised due to increased resistance to antiseptics and antibiotics of pathogens over the years. Some studies support the cross-resistance to antibiotics triggered by antiseptics. Increased resistance and cross-resistance may result from inadequate skin disinfection, over dilution of the antiseptics and environmental residues of antiseptics. More studies are required to assess the mechanisms of resistance and cross-resistance to antiseptics and antibiotics and also the impact of sub-lethal antiseptic concentration on clinical isolates. Usage guidelines of chlorhexidine were proposed recently, but usage guidelines should address all valuable skin antiseptics in order to be used only in cases where there is a clear benefit.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XXI
Written by Irinel Gabriel PROCA, Florentina MATEI, Camelia Filofteia DIGUȚĂ, Ștefana JURCOANE

Saline waters are environments largely unexplored in which organisms are able to survive/withstand in the extreme conditions. The aim of this research was to explore saline water located in Lopătari, Buzău County, România. Several physico-chemical properties were assessed such as pH, density, concentration of cations and anions. The pH of water sample was slightly acidic (5.2).The ions of sodium, chloride and total dissolved solids were detected dominant 129.9 g.L^-1, 209.83 g.L^-1 and 113 gL^-1, respectively. A total of fourty four (44) aerobic bacteria were isolated on culture media supplemented with 5%, 10 %, and 15% NaCl, respectively. The isolates were screened by morphological criteria, Gram stain. All bacterial isolates were tested for their tolerance to different concentrations of salt in solid media. Two bacterial isolates (4.5%) has grown over a wide range of salt concentrations ranging from 0% to 12.5%, 17 bacterial isolates (38.6%) under salt concentration between 0% and 7.5%. Other 19 bacterial isolates (41%) demonstrated a large salt tolerance ranging from 5 to 25%. Halophiles can offer important opportunities in biotechnological applications such as food, pharmaceutical, detergents, environmental bioremediation and biosynthetic processes, being one of the main reasons for the future research of them.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XX
Written by Gabriela MARGARIT, Radu Cristian TOMA, Diana GROPOSILA, Dana BARBA

A lot of studies about online education are meant to answer about how efficient is this new way of a learning system, or how interested are students to learn using online platform, choosing themselves when or where to study without a program which requires their simultaneous presence in the same place and at the same time. In 1999, American Teachers Federation and National Association for Education initiate a research about distance learning efficiency. From that year till now, many researchers or teachers have been interested in how good is the e-learning system, the feedback from students being anytime important.

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