Journal of BioScience and Biotechnology (JBB)

Permanent URI for this collection

p-ISSN: 1314-6238 / e-ISSN: 1314-6246

Browse

Recent Submissions

Now showing 1 - 20 of 259
  • Item
    In vitro inhibitory effect of plant extracts on growth of seed-borne Alternaria alternata fungs
    (Plovdiv University Press “Paisii Hilendarski”, 2018-12-05) Farehani, Saeideh Maleki; Paravar, Arezoo; Eisanejad, Nasrin S.
    Antifungal substances of plant origin could be used as an inhibitor to control fungal seed diseases growth and development. The purpose of this study was to evaluate the influence of alcoholic and aqueous extracts of few medicinal plants (Fennel, Cichorium, Asafoetida, Echinacea, Balangu (Lady’s mantle and Olender) on growth and development of Alternaria alternata fungi. The experimental treatments were arranged as factorial and the data was analyzed based on a completely randomized design with three replications. The effect of seed and plant extracts, plant type (plant), and their interactions were significant on the fungal growth and development. The strong antifungal properties of aqueous and alcoholic extracts of balangu and oleander showed a broad-spectrum natural antifungal resistance in those plants. However, the results indicated a high resistance for A. alternata against the aqueous extract of fennel. This study concluded a high potential for alcoholic extract of balangu and oleander (100% inhibition) in the biological control of the A. alternata fungus.
  • Item
    Effect of irrigation scheduling on some characteristics of Barley under water deficit conditions
    (Plovdiv University Press “Paisii Hilendarski”, 2018-11-06) Safdari, Seyyedeh Fahimeh; Farahani, Saeideh Maleki; Eskandari, Ali; Nezhad, Asghar Abbas
    A field experiment was conducted during 2016-2017 to investigate the effect of irrigation scheduling on three barley cultivars viz. Nosrat, Roudasht and Behrokh under water deficit stress conditions. Irrigation treatment was applied based on the maximum allowable depletion of available soil water. Treatment levels comprised of irrigation scheduled at: (I1) 30%; (I2) 60%; and (I3) 90% depletion of available soil water which was applied after flowering stage. Results showed that all traits were significantly reduced with increase in the severity of stress due to reduction in the availability of water. However, no significant reduction was observed for cultivar Nosrat regarding grain yield, biological yield and the number of spikes per plant between I2 and I3 treatment levels. Estimation of production functions with respect to yield contributing traits revealed that, at a severe drought stress, the order of the importance of yield-contributing traits was as: harvest index>biomass>spikes per plant>grains per spike. Based on the results, to achieve the highest grain yield and grain total protein content, irrigation should be scheduled at a maximum allowable depletion equal to 30% of available soil water. Nevertheless, an economic production can be achieved with a delayed irrigation.
  • Item
    Growth and development of saffron (Crocus sativus L.) in response to temperature pre-treatment and environmental conditions
    (Plovdiv University Press “Paisii Hilendarski”, 2018-11-06) Zahmati, Roghaieh; Shekari, Hosein Amir; Fotokian, Mohammd Hosein
    Climatic indices, such as temperature, have an important role in saffron yield. This study was undertaken to investigate the effect of temperature-controlled conditions on the growth and development of saffron. For this purpose, saffron mother corms were initially pre-treated with two temperature levels of 17 and 30 ° C for four days. The treated corms were then planted in a greenhouse. Subsequently, the young plants were transferred to the main field at 4 different times including: i) no transfer, ii) transfer immediately after flowering, iii) transfer 10 days after flowering and iv) transfer 20 days after flowering. Results showed that temperature pre-treatment of corms had no significant effect on studied traits while, time of transferring significantly affected on some traits. The plants kept in the greenhouse had more length and more number of leaves while, those that transferred immediately after flowering had more fresh weight, dry weight and diameter of corm. It seems that the temperature of the greenhouse (23-25 ° C) was suitable for vegetative growth whereas, farm temperature (10-18 ° C) led to further corm attributes.
  • Item
    Biochemical and molecular study of glycinebetaine synthesis in Salsola aucheri under salt stress
    (Plovdiv University Press “Paisii Hilendarski”, 2018-11-06) Doktorzadeh, Mohammad Ali; Movafeghi, Ali; Nosrati, Houshang; Salehi-Lisar, Seyed Yahya; Feizi, Mohammad Ali Hosseinpour
    Salinity promotes the generation of reactive oxygen species (ROS) and oxidative damages of different cellular components. Thus, salt stress tolerance requires activation of antioxidative pathways to protect plant cells from damages. In this study, seedlings of Salsola aucheri were treated with 100, 200, 300, 400 and 500 mM of NaCl and consequently the activities of some antioxidant enzymes were evaluated. Enhanced activities of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) were determined by the increasing salinity to 300 mM. Furthermore, accumulation of glycinebetaine (GB) as a common response to salt stress was assessed. Accordingly, concentration of GB enhanced by the increasing concentration of NaCl and decreased at higher salinity. Assessing the activity of betaine aldehyde dehydrogenase (BADH) as a key enzyme in biosynthesis of GB showed that BADH activity enhanced by increasing salinity to 300 mM and decreased at higher concentrations. Cloning and characterization of BADH cDNA from Salsola aucheri and the expression pattern of BADH transcript were also examined. An open reading frame of 797 bp encoded a protein which showed high homology to BADH enzymes in other plants. These results suggest that salinity tolerance of Salsola aucheri might be closely associated with the increasing function of antioxidative system to scavenge reactive oxygen species and with the accumulation of osmoprotectant glycinebetaine contents under salinity conditions.
  • Item
    Production of ACE-inhibitory peptides in milk fermented with selected lactic acid bacteria
    (Plovdiv University Press “Paisii Hilendarski”, 2018-11-06) Panayotova, Teodora; Pashova-Baltova, Kalinka; Dimitrov, Zhechko
    The ability of lactic acid bacteria to release bioactive peptides is strain specific and is dependent of the dairy processing conditions. In the present study we developed a starter for fermented milk with increased proteolytic and peptidolytic activity. The structure and concentration of bioactive peptides are strongly dependent on the strain-specific proteolytic complex. It could be expected that such peptides would be released during the process of manufacture of fermented milk. Among the possible bioactivities of released peptides is the inhibitory effect against angiotensin converting enzyme (ACE), whose increased activity could lead to elevation of the blood pressure. Evaluation of several peptides with proven ACE-inhibitory activity was performed by LC-MS-MS. The structure of these peptides was determined by comparison with peptide library. The quantification of IPP, VPP, and ALPM was performed by SRM MS3 method using certified standards. The ACE inhibitory effect was expressed as the peptide concentration needed to inhibit 50% of ACE activity (IC50). In this study we developed a starter containing L. helveticus, L. bulgaricus, and S. thermophilus strains. The strains L. helveticus A1 and L. bulgaricus J24 possess strong proteolytic complex which lead to increased content of ACE inhibitory peptides. After a pilot production of fermented yoghurt with the developed starter the ACE inhibitory effect was confirmed using enzyme assay. The inclusion of the highly proteolytic strain L. helveticus A1 in the starter culture leads to increased production of bioactive peptides in the fermented milk.
  • Item
    Isolation and screening of biopolyester (poly-β-hydroxybutyrate) producing bacteria from compost samples in Bangladesh
    (Plovdiv University Press “Paisii Hilendarski”, 2018-11-06) Karim, Fahmida; Mumtaz, Tabassum; Fakhruddin, A.N.M.; Khan, Mahbubar Rahman
    Poly-β-hydroxybutyrate (PHB) is the simplest member of polyhydroxyalkanoates (PHAs) that are biological polyesters or biopolymers produced by a wide variety of bacteria as an intracellular storage material of carbon and energy. Compost is one of the richest sources of microorganisms; therefore, an attempt was made to isolate Poly-β-hydroxybutyrate producing bacteria from compost samples. Out of six compost samples, bioslurry showed the highest mesophilic bacterial count of 3.75×109 cfu/g. A total of 48 mesophilic bacteria were isolated by growing samples on nutrient agar medium at pH 7.0 and a temperature of 37°C. All isolates were purified and screened for PHB production using lipophilic stains such as Nile red, Sudan black B, Acridine orange. 16 out of 48 isolates exhibited PHB production ability after screening by plate assay. PHB granule formation was also confirmed by observation under fluorescent microscope. Number of PHB producer and accumulators in different compost samples were in the order of Bioslurry > Cow dung > Cotton seed > Tobacco dust. Based on morphological, cultural and biochemical characteristics, all isolates were assigned to four genera viz. Bacillus, Micrococcus, Veillonella and Pseudomonas. Batch fermentation in shake flask was carried out using glucose as carbon source. By analyzing photomicrographs of 24 hour old cultures, 7 out of 16 bacterial isolates were found with a good PHB accumulation capacity. These bacteria are being currently studied for biopolymer production using different carbon sources and renewable biomass.
  • Item
    New data on zooplankton communities of two Bulgarian reservoirs: Konush and Sinyata Reka, Plovdiv Region
    (Plovdiv University Press “Paisii Hilendarski”, 2018-11-06) Subeva, Monika; Evtimova, Vesela; Kenderov, Lyubomir
    Zooplankton communities have several vital functions within lake ecosystems including the transfer of energy and material from producers to secondary consumers. Its structure is potentially affected by both lake morphology and typology, as well as anthropogenic changes in lakes. These communities are also sensitive to various substances in the water column, including nutrient enrichment and pollutants. Thus, they have often been used as indicators to assess the condition and change of the freshwater environment. Our aim was to present first detailed data about the species composition of zooplankton communities in two understudied Bulgarian reservoirs, the Konush and Sinyata Reka. Samples were collected from several stations in spring and summer 2016. The qualitative analysis of the zooplankton revealed the presence of three main taxonomic groups: Rotifera, Cladocera and Copepoda. From these, rotifers were best represented as number of species and abundance, followed by cladocerans and copepods.
  • Item
    Differential glycation of arginine and lysine by glucose and inhibition by acesulfame potassium
    (Plovdiv University Press “Paisii Hilendarski”, 2018-11-06) Ahire, Komal; Kumar, Dinesh; Ali, Ahmad
    Glycation is a non-enzymatic process between the reactive carbonyl group of sugars and free amino groups of proteins especially arginine and lysine residues. This process leads to formation of a group of compounds called as Amadori products and advanced glycation products. These products have been implicated in many secondary complications of diabetes. In last few years the intake of sweetener has increased for various health reasons like control of hyperglycaemia and obesity. The present study was designed to evaluate the effect of Acesulfame-K, a well-known and widely used sweetener, on glycation system of arginine-glucose and lysine-glucose. The amount of glycation products generated in the presence and absence of acesulfame potassium was measured by established methods such as browning, Fructosamine assay, and determination of carbonyl content. The effect of acesulfame potassium was also checked on the glycation of DNA by agarose gel electrophoresis method. The results indicate that lysine is more potent in causing glycation as compared to arginine. Acesulfame potassium could significantly decrease the amount of glycation products in the glycation systems, arginine-glucose and lysine-glucose. It can be concluded that Acesulfame-K has anti-glycation potential as it decreased formation of Amadori products and AGEs. This study is significant in understanding the role of artificial sweetener in the process of glycation.
  • Item
    Enhancement of catalase and superoxide dismutase activities in transgenic Escherichia coli expressing rice metallothionein isoforms
    (Plovdiv University Press “Paisii Hilendarski”, 2018-11-06) Shahpiri, Azar; Deljoonia, Reza
    Metallothioneins (MTs) are small, ubiquitous Cys-rich proteins known to be involved in the homeostasis of essential metals, detoxification of toxic metals and protection against oxidative stress. In the present work transgenic E.coli overexpressing different rice MT isoforms including OsMT1, OsMT2, OsMT3 and OsMT4 showed higher tolerance against hydrogen peroxide stress. Moreover the enzymatic activity of catalase (CAT) and superoxide dismutase (SOD) in the transgenic strains were higher than that in control strain when they were grown in the medium containing hydrogen peroxide. To understand the mechanistic action of MT on the removal of reactive oxygen species, the activity of CAT and SOD in the E.coli protein extract were assayed after addition of pure Zn2+/MTs, Fe2+/MT and apo/MT. whereas the activity of CAT and SOD did not change by addition of apo/MT, the activity of CAT and SOD were increased after addition of Fe2+/MTs and Zn2+/MTs, respectively. These results open new insights into the role of MT as activator of CAT and SOD by supplying metals.
  • Item
    Developmental stability of the golden jackal (Canis aureus moreoticus) populations in its expansion range in Bulgaria
    (Plovdiv University Press “Paisii Hilendarski”, 2018-11-06) Markov, Georgi; Gospodinova, Milena; Kocheva, Maria; Dimitrov, Hristo
    The European golden jackal (Canis aureus moreoticus) is widespread in Bulgaria and it was assumed that the species had occupied almost the entire country with less manifested presence in highlands. The general aim of this investigation was to carry out comparative analysis at a population level of developmental stability of the jackal inhabiting in different habitats (POP_1, inhabiting Sakar-Strandzha region, POP_2 inhabiting the Upper Thracian Plain and POP_3 inhabiting the western part of the Sub-Balkan valleys), located along the presumable route of the species movement northwards and westwards in the country. The population levels of developmental stability were assessed through fluctuating asymmetry determined as minor non-directional deviations from bilateral symmetry in 10 morphological non-metric skull characters. Looking at the fluctuating asymmetry as an indicator of environmental and genetic stress, there is no evidence of genetic depression by reproductive isolation in the studied populations. Moreover, there is no indication of relatively reduced developmental stability in any of the analyzed populations. In general, the results from the comparative population analysis of the craniological epigenetic fluctuating asymmetry in Bulgarian golden jackal with regard to the population developmental stability provided a substantial biological basis for their interpretation as bio monitor characteristics in a future biological monitoring of this species in the country.
  • Item
    Halophytes and salt tolerant wild plants as a feedstock for biogas production
    (Plovdiv University Press “Paisii Hilendarski”, 2020-04-27) Kamel, Mohamed; Hammad, Sabah Ahmed; Khalaphallah, Rafat; Mousa, Mohamed Abdelazeem
    This paper describes the ability of wild plants to be investigated as feedstock in biogas production. Anaerobic degradation of four wild halophytes and salt-tolerant plants (Avicennia marina, Tamarix nilotica, Zygophyllum album, and Zygophyllum coccineum) collected from the red seacoast in Egypt was studied. Lab-scale reactors were fed with dried and milled plant biomass. Obtained results showed the highest biogas production result from A.marina 487.862 ml/VS (403.385 ml/TS) followed by T.nilotica 441.30 ml/VS (333.278 ml/TS) while 291.28 ml/VS (206.21ml/TS) and 127.923 ml/VS (81.272 ml/TS) for Z. album and Z. coccineum respectively. The chemical structure of these plants was the main factor controlling the variation in biogas production especially cations (Ca2+, Na+, K+, Mg2+) and organic fractions (volatile solids, crude fiber, crude protein). At high volatile solids with high protein content and low salt content, there was the highest biogas production in A.marina. on the other hand, increasing salt content decreasing biogas as Z. coccineum. That indicates the wild plants can represent a promising source for renewable energy and their solid digestate fraction can be used as bio fertilizer.
  • Item
    Inheritance of main quantitative traits in broad bean (Vicia faba L.)
    (Plovdiv University Press “Paisii Hilendarski”, 2020-04-27) Kosev, Valentin; Georgieva, Natalia
    The purpose of this study was to analyze the values of some genetic parameters of hybrid populations of Vicia faba, which would allow rational selection of desired genotypes in terms of main quantitative traits. The field trial was conducted during the period 2016-2018 at the Institute of Forage Crops (Pleven). Four cultivars (Fb 2481, BGE 002106, BGE 029055, BGE 032012) and their hybrids (Fb 2481 × BGE 002106, BGE 002106 × Fb 2481, BGE 029055 × BGE 032012, BGE 032012 × BGE 029055) were subjects of the study and their quantitative traits were observed in generations F1 and F2. Results showed that the plant height, seeds number and seed weight per plant in all crosses were inherited overdominantly. The alleles of the genes that determined more seeds per plant with an increased weight were dominant. The highest values of hypothetic and true heterosis in F1 were found in cross BGE 029055 × BGE 032012 regarding plant height (82.03%, 81.55%), in Fb 2481 × BGE 002106 – for 1st pod height (49.39%, 40.97%), in BGE 002106 × Fb 2481 – for pods number (36.05%, 32.95) and seed weight (225.47%, 161.36%), and in BGE 032012 × BGE 029055 – for seeds number per plant (117.77%, 96.89%). The coefficients of inheritance in all four crosses had medium to high values for the trait of seed weight per plant.
  • Item
    Legumes in soil surface maintenance system in mountain and biological fruit growing
    (Plovdiv University Press “Paisii Hilendarski”, 2020-03-06) Bozhanska, Tatyana; Georgieva, Maria; Georgiev, Diyan; Ivanov, Toshko; Naydenova, Galina
    The new methods of soil surface maintenance of the artificial grass establishment or growing of green manure crops applied in modern fruit-growing have been the subject of research in various Agra-ecological areas in Bulgaria but they are not yet implemented in the fruit-growing technology. Legumes are a basic element of these methods because of their nitrogen-fixing system. The present article summarizes our own and foreign results about the suitability of the different types of legumes in this trend. Bulgarian studies confirm the role of legumes in optimizing the nutritional and water regime of fruit crops in the conditions of mountain or biological fruit growing. In view of the fact that there are a wide variety of morphological and biological types of legumes in Bulgaria, it is reasonable to have a special selection of varieties for soil surface maintenance in orchards.
  • Item
    Correlation and regression dependences between quantity and quality indicators depending on fertilizing of bird's-foot-trefoil with humate fertilizers
    (Plovdiv University Press “Paisii Hilendarski”, 2020-02-18) Churkova, Boryana
    During the period of 2013-2015 in the experimental field of RIMSA-Troyan was conducted an experiment. The experimental design was a block with 4 replications with a plot size of 5 m2 of grassland with 'Targovishte 1' bird's-foot-trefoil cultivar. The following fertilizing variants were examined: control - null, phosphorus humate (3000 l'ha), boron humate (1600 l/ha) and molybdenum humate (1600 l/ha) and phosphorus humate (2500 l/ha) + boron humate (1000 l/ha) + molybdenum humate (1000 l/ha). On the basis of the data obtained from previous publications, correlation dependencies and regression equations are made between quantitative and qualitative indicators depending on fertilization with humate fertilizers. The crude protein content has been found to have high positive correlations with the percentage of leaves in the grassland (r = 0.8173) and the weight percentage of bird's-foot-trefoil (r = 0.7835), which allows the development of graphical regression models. There is a high correlation between the height of the plants and the relative share of the stems in the grassland (r = 0.8058), as well as between FUM and FUG (r = 0.9457). The high coefficient of determination between the percentage share of bird's-foot-trefoil and the quantity of the stems R2 = 0.9087 determines the equation of the regression dependence between these two components (y = 1.2167x-65,001).
  • Item
    Factors affecting population dynamic and preference of Acyrthosiphon pisum Harris in winter pea lines
    (Plovdiv University Press “Paisii Hilendarski”, 2020-02-18) Nikolova, Ivelina
    Population dynamics and preference of Acyrthosiphon pisum Harris on six winter pea lines in field condition were studied. Aphid number was recorded on marked plants by counting. The impact of several factors on the population growth and pea aphid choice during the period 2016-2018 was tracked. Weather condition strongly affected on the population dynamics of the pea aphid. The highest positive and significant effect on pea aphid infestation had the temperature (r = 6.748) followed by humidity (r =1.992). It was found that a peak in the aphid population density was reached in the sensitive stage of pod formation, as well as at flowering under a favorable weather condition. Among winter pea lines, lines 6 and 12A stood out with a significantly lower aphid density, nitrogen concentration and shorter generative period. They were much less preferred by aphids and defined as tolerant. Also, the interaction between aphid density and generative period as well as total nitrogen was positive and significant.
  • Item
    Effects of reuterin-producing Lactobacillus reuteri strain plus glycerol on the quality and aerobic stability of laboratory sorghum silage
    (Plovdiv University Press “Paisii Hilendarski”, 2020-04-27) González, Marcela J.; Olivera, Jorge; Chilibroste, Pablo; Reginensi, Stella
    Aerobic spoilage of silage is one of the main causes of economic losseses to the livestock industry. The objective of this study was to evaluate the effect of reuterin-producing L. reuteri SO23 plus glycerol on the aerobic stability of laboratory sorghum silage. Chopped sorghum was added with 2% glycerol and inoculated with L. reuteri SO23 and/or a commercial silage additive. Treated forage was packed in laboratory silos and stored for 90 days. Microbial inoculation did not affect the chemical parameters and all silages had low pH values (≤3.63). It was determined that silages inoculated with LAB strains were characterized by higher DM recovery (P<0.001) and aerobic stability (P<0.001), and lower mould and yeast counts (P=0.009). Aerobic spoilage began at day 7 for untreated control silage, and between day 12 and 15 for inoculated silages. Control and treated silages showed some differences in mould counts during the time of exposure to oxygen, but the extent of these differences was dependent on the inoculant applied. In conclusion, inoculation with L. reuteri SO23 plus glycerol improved aerobic stability of sorghum silage, retarded pH increase upon exposure to air, and slowed down the increase of moulds and yeasts populations from day 4 of aerobic exposure. The results also showed that the combination of L. reuteri SO23 and commercial additive is preferable because this combination reduced fermentation losses, mould and yeast counts, and improved silage aerobic stability.
  • Item
    Antimicrobial susceptibility and biofilm-forming ability of Enterococcus faecalis strains isolated from the urogenital tract of outpatients
    (Plovdiv University Press “Paisii Hilendarski”, 2020-02-18) Tsankova, Marinela; Marhova, Mariana; Kostadinova, Sonya; Iliev, Ivan
    Enterococci are increasingly associated with infections of urogenital tract. The two species Enterococcus faecalis and Enterococcus faecium are the third most commonly isolated pathogens in catheter-associated UTIs. Both species are capable of producing biofilms, with E. faecalis being more frequently isolated. This study explores the antimicrobial resistance and biofilm formation ability of 72 Enterococcus faecalis isolates, collected for one-year period from the urogenital tract of outpatients. The results showed that urinal tract infections (UTIs), caused by enterococci are more frequent among children up to 10 years of age, while genital tract infections (GTI) are most often observed in women in reproductive age. Antimicrobial resistance was low, with higher levels for UTI agents compared to GTI isolates. The results demonstrate 100% susceptibility to penicillins, which are the most effective agents for treatment of infections caused by Enterococcus faecalis. The resistance to fluoroquinolones was < 19%, with clearly defined cross-resistance. Biofilm formation was established for 26% of the tested strains after 24 h of cultivation on tryptic soy broth, with OD630 values for the biofilms in range 0.050-0.200. This categorizes the isolates as low-grade biofilm-forming strains. The susceptibility profile of strains in present study confirms need always to detect resistance of isolates before antibiotic prescriptions from physicians.
  • Item
    Evaluation the effects of Staphylococcus aureus Enterotoxin B on BAX, p53, Caspase3 and Bcl-2 genes expression in gastric cancer cell line
    (Plovdiv University Press “Paisii Hilendarski”, 2020-04-27) Shahrokhi, Matineh Rahmani Ghaleh; Doosti, Abbas
    Gastric cancer is known as the fourth cancer in the world and the second cause of cancer death. According to studies, Staphylococcus aureus (S. aureus) Enterotoxin B has a major role in inducing apoptosis in various cancers. The aim of this study was to evaluate the apoptosis gene expression after gastric cancer cell treatment with enterotoxin B. In this experimental study, the pcDNA3.1(+)–seb recombinant plasmid, after amplification in E. coli strain TOP10F and extraction was introduced into AGS cells by lipofection method. After 10 days of treatment with neomycin antibiotic, total cellular RNA was extracted and cDNA was constructed for real time PCR for apoptotic genes of p53, BAX, caspase3 and Bcl-2, as well as the GAPDH as a reference gene. The results showed an increase in the expression of BAX, and p53 genes and decreased Bcl-2 and caspase3 expression at a significant level. As compared to the AGS cell, which did not receive the seb gene, the cells containing the toxin gene had progressed more towards apoptosis. Enterotoxin B, expressed in gastric cancer cells, increases the expression of pro-apoptosis genes and reduces the expression of anti-apoptotic genes. According to evidence, this poison can act as an anticancer agent in the AGS cell line.
  • Item
    Microbiological, physicochemical and organoleptic characteristics of probiotic Bulgarian yoghurts obtained by an ultrafiltered whole cow’s milk
    (Plovdiv University Press “Paisii Hilendarski”, 2020-04-27) Dushkova, Mariya; Kodinova, Siyka; Yanakieva, Velichka; Denkova, Zapryana
    Ultrafiltration of whole cow’s milk with ultrafiltration polyacrilonitrile membrane with 10 kDa molecular weight cut-off at volume reduction ratios 2 and 3 was performed. The obtained ultrafiltration retentates were used for production of probiotic Bulgarian yoghurts with three different starters. A control sample was prepared using whole cow’s milk with the same starters. All yoghurts were analyzed according to the following parameters: titratable acidity, dry matter, organoleptic characteristics, concentration of specific microorganisms, Lactobacillus bulgaricus and Streptococcus thermophilus, as well as the total count of viable lactic acid bacteria for 28 days of storage. The results showed that the increase in the volume reduction ratio during ultrafiltration increased the titratable acidity, as well as the dry matter of all examined yoghurts. The level of ultrafiltration concentration led to an increase in the viable lactic acid bacteria in all tested yoghurts which improves their functional properties.
  • Item
    The cytotoxic and genotoxic effects of di-isononyl phthalate and di-(2-ethylhexyl) phthalate: An in vitro and in vivo approach on toxicological assessment
    (Plovdiv University Press “Paisii Hilendarski”, 2019-07-15) Revathy, Venugopal; Chitra, Kumari Chidambaran
    The aim of the present study was to analyze the cytotoxic and genotoxic effects of two selected phthalates, di-isononyl phthalate (DINP) and di-(2-ethylhexyl) phthalate (DEHP) in vivo and in vitro using fish model, Oreochromis mossambicus and cell lines as Chinese Hamster Ovary-K1 (CHO-K1) cells, TA97A, TA98 and TA100 strains of Salmonella typhimurium and human peripheral erythrocytes. In vivo toxicological assessment showed genotoxicity of DINP and DEHP at 300 ppm and 60 ppm concentrations exposed for 60 days, which was evident by the formation of micronuclei and other nuclear abnormalities in erythrocytes of the fish. However, comet analysis revealed no genotoxic effects of the phthalates in which tail length and percent tail DNA remained unchanged. In vitro analysis showed mutagenicity of DINP and DEHP in Salmonella typhimurium tester strains. Study on human peripheral blood lymphocytes showed the formation of micronuclei, nucleoplasmic bridges and nuclear bud. Exposure of phthalates in CHO-K1 cells showed significant (P<0.05) increase in the tail length and tail DNA percent in DEHP while DINP showed negative results. Cell viability test using MTT assay in CHO-K1 cells showed significant (P<0.05) decrease in cell viability while lactate dehydrogenase release test showed cytotoxicity of exposed phthalates. The study illustrated that DINP and DEHP exerted genotoxic effects both in vivo and in vitro could be relatively unsafe for the organisms. Further, the study can be used as a biomonitoring tool to alarm the risk of plasticizers that enter into the aquatic or nearby environment from the production or release sites.