Astaxanthin bioszintézis genetikai befolyásolása Phaffia rhodozyma-ban = Genetic influence on biosynthesis of astaxanthin in Phaffia rhodozyma

Az astaxanthin (3,3¢-dihydroxy-b,b-carotene-4,4¢-dione) termelő élesztők nagy biotechnológiai jelentőségűek. RAPD analízisen alapuló csoport analízist végrehajtva igazoltuk , hogy az astaxanthin-termelő izolátumok két fajba (Xanthopyllomyces dendrorhous és Phaffia rhodozyma) tartoznak. Különböző mutációs eljárásokat - gamma-, UV-sugárzás és kémiai mutagenezis, illetve ezek kombinációi - alkalmazva auxotróf és színmutánsokat izoláltunk mindkét élesztőfajból. Pigment- illetve astaxanthin túltermelő mutánsokat, melyek színanyag profilja jelentősen eltért hoztunk létre. Protoplaszt fúziós kísérleteket végeztünk és fúziós hibrideket izoláltunk és jellemeztünk. In vivo EPR vizsgálatokkal jellemeztük a különböző pigment-profilú mutánsok plazmamembránjának szerkezeti és dinamikus sajátosságait a hőmérséklettel összefüggésben. Meghatároztuk a X. dendrorhous 3-hydroxy-3-methylglutharyl coenzyme A reductase (HMG-CoA reductase) génjének részleges génszekvenciáját. Felfedeztük, hogy mind a P. rhodozyma és a X. dendrorhous képes lebontani az ochratoxin A-t ochratoxin alfává, feltehetően egy sejthez kötött karboxipeptidáz A aktivitás révén. | Astaxanthin (3,3¢-dihydroxy-b,b-carotene-4,4¢-dione) - accumulating yeasts are of great biotechnological interest. RAPD analysis involving astaxanthin-producing yeast strains was performed: cluster analysis based on RAPD markers differentiated isolates of Xanthopyllomyces dendrorhous and Phaffia rhodozyma (asexual) at an intraspecific level. Different mutation strategies, which involves *- and UV-irradiations, as well as chemical mutagenesis of cells was worked out to obtain auxotrophic and colour mutants from these astaxanthin-producing yeasts. Overproducer mutants exhibited different patterns of carotenoid production have also been isolated. Protoplast fusion experiment have been carried out and fusion hybrides have been isolated and characterized. Spin labelling methods were used to describe the structure and dynamic properties of various carotenoids containing X. dendrorhous’s plasma membranes in relation to temperature. A partial gene sequence of 3-hydroxy-3-methylglutharyl coenzyme A reductase (HMG-CoA reductase) of X. dendrorhous has been determined. Ochratoxin degrading activities of P. rhodozyma and X. dendrorhous isolates were discovered. P. rhodozyma is able to convert ochratoxin A to ochratoxin a (possibly mediated by a cell-bound carboxypeptidase A)

Effect of ambient temperature on the productive and carcass traits of growing rabbits divergently selected for body fat content.

Rabbits are particularly sensitive to heat stress which can affect productive performance, with rabbit breed/line possibly playing a role on the response to this condition. The study aimed at evaluating the effect of different ambient temperatures on the live performance and carcass traits of growing rabbits divergently selected for total body fat content. The two genetic lines (Lean and Fat) were selected based on the total body fat content estimated by computer tomography during five generations. From birth to slaughter (13 weeks of age), the rabbits were housed in two rooms where the temperature was controlled with air conditioners: in the control room the average ambient temperature was 20 °C and in the high temperature room it was 28 °C. After weaning (35 d), 60 Lean and 60 Fat rabbits/room were housed by two in wire-mesh cages and fed ad libitum with commercial pellets. The BW and feed intake (FI) were measured at 5, 7, 9, 11 and 13 weeks of age to calculate the daily weight gain (DWG) and feed conversion ratio (FCR). Mortality was recorded daily. At the end of the experiment, rabbits were slaughtered and carcass traits were measured. Mortality was independent of temperature and line. The temperature significantly influenced the FI, DWG, BW and the fat deposits: they were lower at higher ambient temperature. The effect of temperature differed according to the rabbits' total body fat content. At control temperature, the FI (165 vs 155 g/day; P < 0.05) and FCR (4.67 vs 4.31; P < 0.05) were higher in Fat rabbits, which also had more perirenal (36.2 vs 23.1 g; P < 0.05) and scapular fat (10.8 vs 7.1 g; P < 0.05). At high temperature, no differences in fat depots (14.5 vs 9.8 g; 5.3 vs 3.5 g) were found between the two lines. It can be concluded that temperature × genetic line interaction had an important role in productive and carcass traits, as the effect of temperature differs between Lean and Fat rabbits

Óvodából iskolába – tematikus rajzi foglalkozások 6-8 éveseknek

Kindergarten teachers and instructors have long been concerned with the question of how to facilitate the transition from kindergarten to school. Many methodological and ideological recipes from both sides can be found in specialized literature, both sides look for answers to the questions raised from their own point of view. In the study, from the teacher’s point of view, we try to present possible answers to the questions raised through a given segment not only for elementary school teachers, but also for kindergarten teachers.Mind az óvodapedagógusokat, mind a tanítókat régóta foglalkoztatja az a kérdéskör, hogy hogyan lehet megkönnyíteni az óvodából iskolába való átmenetet. Mindkét oldalról sokfajta módszertani, ideológiai receptet lehet fellelni a szakirodalomban, mindkét oldal a saját nézőpontjából keresi a válaszokat a felvetődött kérdésekre. A tanulmányban a tanár szemszögéből igyekszünk bemutatni lehetséges válaszokat egy adott szegmensen keresztül felvetült kérdéskörre nemcsak általános iskolai nevelőknek, hanem óvodapedagógusok részére is

Rabbits Divergently Selected for Total Body Fat Content: Changes in Proximate Composition and Fatty Acids of Different Meat Portions

The present research studied the potential of a four-generation divergent selection (Pannon maternal rabbit lines) based on the total body fat content to create two rabbit lines with different meat attributes: a Fat line to deliver greater amounts of healthy fatty acids for newborns and infants, and a Lean line intended to provide lean meat for everyday consumption. Selection was based on the fat index calculated in 10-week-old live rabbits by means of computed tomography (CT). For each generation, 60 rabbits/line were fed ad libitum with commercial pellet from weaning (5 weeks) to slaughter (11 weeks). A total of 15 rabbits/line were randomly selected for meat quality evaluations: the longissimus thoracis et lumborum muscles (LTLs), hind legs (HLs), forelegs (FLs) and abdominal wall (AW) were analyzed for their proximate composition and fatty acid (FA) profile. FA contents were also calculated. Results highlighted that it was possible to obtain leaner meat for everyday consumption in most meat portions starting from generation 4 (7.93 vs. 11.9, 5.10 vs. 5.98 and 7.26 vs. 10.9 g of lipids/100 g of meat in Lean and Fat groups for the FLs, HLs and AW, respectively). The sole exception was the LTLs, which were not affected by the divergent selection. The total PUFA amount increased in FL and AW (p < 0.05) portions of the Fat line only, attributable to a greater n-3 amount (151 vs. 216 and 73 vs. 143 mg/100 g of meat in Lean and Fat groups for the FLs and AW, respectively)

Egyedi elhelyezéssel kombinált csoportos tartás hatása az anyanyulak termelésére, helyválasztására és viselkedésére = Location preference, behaviour and performance of rabbit does in a pen system of combination of group and individual housing

The aim of the experiment was to test a special pen system of combination of group and individual housing, examination of production and preference of rabbit does. The experiment was conducted at Kaposvár University with pregnant and lactating Pannon White rabbit does (n=48). The 1.83 x 2.00 m open top pen consisted of four individual cages (0.5 x 0.91 m) which were connected to the 1.83 x 1.00 m common area throughout a 0.25 m long and 0.20 m wide lockable corridor. The rabbit does were randomly divided into three groups. The groups differed only in that the material of walls of the individual cages. Pen with solid wall cages (Solid, n=16); pen with wire-mesh wall cages (Wire, n=16) and pen with partly solid and partly wire-mesh wall cages (Mix, MP, n=16). Four rabbit does were placed to the closed individual cages 3 days before the expected parturition for 21 days. 18 days after kindling the entrances of the individual cages were opened, and the 21-day group-housing started. All 4 does and their kits could use all individual cages and the common area freely. The kits were weaned at 35 days of age. The injuries on ears, and body were checked on days 2, 4, 8, 14 and 22 after grouping the does. 24-h video recordings were made on days 1, 2, 3, 7 and 13 after opening the doors, and location of rabbits was registered at every 15 min. On day 1 rabbit does preferred to stay alone than together (Solid: 62.3%; Wire: 64.3%; Mix: 82.8%). Later on, less rabbit does located alone (on day 13: Solid: 30.8%; Wire: 51.0%; Mix: 39.2%). On day 1 in all pens the majority of the does located in the individual cages (Solid: 77.3%; Wire: 76.8%; Mix: 83.9%), however later the percentage of does in the individual cages decreased until day 13. At almost every day less rabbit does preferred the individual cages in the Solid than in Wire or Mix group. Rabbit does preferred their own cages, more rabbit does stayed in the own cages than the expected probability (25%) on all days (day 1: Solid: 64.6%; Wire: 68.4%; Mix: 74.6%; day 13: Solid: 28.0%; Wire: 38.0%; Mix: 34.5%). In Mix group rabbit does which were housed in solid wall cages before grouping preferred to stay in the solid wall cages in all days (day 13: 59.1%) and that of housed in wire-mesh cages before grouping preferred to stay in wire- mesh cages (day 13: 65.6%). No significant differences were found between the different types of pens in almost the all production traits. The productive performance fits to the results of Pannon Breeding Program. On the other hand in Wire and Mix groups the does mortality were 6.3% and 12.5% and the kindling rates were 62.5 and 68.8%. The ratio of injured rabbits was higher than 50% in each system. Based on the results it can be concluded that the main problems of group housing of does (aggressiveness, injuries) have not been solved with this system. Keywords: rabbit does, group housing, preference, aggressive behaviour, productive performanc