The objective of the present study was to evaluate heterotrophic bacteria capable of growth in the presence of different antibiotics and their mixture in such dynamic ecosystem as marine beach. Mixture antibiotics had the strongest inhibitory effect on the growth of bacteria inhabiting sand of studied beach. Culturable bacteria were more resistant to ampicillin than to novobiocin and tetracycline. Inhibitory influence antibiotics on growth bacteria inhabiting studied beach were in the following order: mixture antibiotics > novobiocin > tetracycline > ampicillin.
Background. Food spoilage is a process in which the quality parameters decrease and products are no longer edible. This is a cumulative effect of bacteria growth and their metabolite production, which is a factor limiting shelf life. Thus, the aim of the study was to evaluate whether microbiological growth models for total viable count (TVC) and Clostridium strain bacteria are reliable tools for prediction of microbiological changes in spreadable processed cheese. Material and methods. Investigations were conducted for two types of bacteria: TVC and Clostridium in following temperature: 8°C, 20°C and 30°C. A total number of aerobic bacteria was determined based on standard PN-EN ISO 4833:2004 and Clostridium was detected by using microbiological procedure for sulphite-reducing anaerobic spore-bacteria with a selective nourishment. During the analysis nonlinear regression and Baranyi and Roberts primary model were used. Results. For temperatures 20°C and 30°C, Baranyi and Roberts model, for total viable count showed determination coefficient of 70%. The models prepared for Clostridium, in these temperatures, showed much lower R2, respectively 25% and 30%. At the abovementioned temperatures also the expiration of product shelf life was much shorter and amounted 70 days at 20°C and 7 days at 30°C. For both types of bacteria incubated at 8°C the numbers of bacteria decrease until the expiration of product shelf life. Conclusions. Models used in the analyses, Baranyi and Roberts and nonlinear regression, poorly matched the experimental data, hence they are not reliable tools. Nevertheless, they gave information about dynamic of microbiological changes in spreadable processed cheese.
Heterocyclic aromatic amines (HCAs) ingested with heat-processed meat can contribute to colon cancer development. Those compounds interact with human intestinal microbiota. Under the research study, the effect was analyzed of IQ, MeIQx, or PhIP amines (each of them at 5 and 25 μg/ml concentration rates) on the growth (24 h cultivation in MRS broth) and survival (incubation for max. 120 h in a phosphate buffer) of four probiotic strains of Lactobacillus. It was found that no concentration level of the HCAs analyzed impacted the growth of bacteria. A higher concentration level of IQ (25 μg/ml) decreased the survival of Lb. casei 0900 after a 24 h period of incubation. MeIQx and PhIP also decreased the survival of Lb. paracasei 0919 after a 24 h period of incubation. Totally, the count of living cells decreased from 109 cfu/ml to 108 cfu/ml. Three strains were absolutely resistant to PhIP during a 120 h period of incubation. The results obtained prove that the probiotic bacteria studied maintain their high viability in the presence of the amines tested and, probably, they can bind together with them in human colon and, then, the aggregated particles are removed from the human body.
The atricle is devoted to the study of the cultivation of cyanobacteria Microcystis aeruginosa (Kützing) Kützing, Microcystis pulverea (H.C.Wood) Forti. in the presence of basalt tuff. The possibility of using basalt tuff as an adsorbing material for regulating the number of cyanobacteria and preventing toxic “water bloom” in fluid circuits. The study analyzes the change in the biomass amount and the dynamics of the proportion of dead cyanobacteria in response to the presence of basalt tuff in the culture medium. It is noted that the use of basalt tuff leads to a decrease in the growth activity of cultures of Microcystis aeruginosa, Microcystis pulverea, manifested in an increase in the number of dead cells and slowdown the accumulation of cyanobacterial biomass. These effects are the result of a decrease in the amount of available nitrogen in the nutrient medium.
Background. Prebiotics are a category of nutritional compounds grouped together, not necessarily by structural similarities, but by ability to promote the growth of specific beneficial (probiotic) gut bacteria. Fructooligosaccharides (FOS) and inulin are among the most famous prebiotic compounds. In order to improve viability of probiotic bacteria during storage, fermented food should be supplemented with prebiotics. Material and methods. Yoghurts were produced from skimmed milk powder and prebiotics (FOS, inulin or resistant starch), which were added at concentrations of 1%, 2% and 3%. Yoghurts were stored in +4°C for three weeks. Every week each kind of fermented drink was examined in order to check the growth of lactic acid bacteria. Apparent viscosity and texture of bio-yoghurt were determinated during refrigerated storage. Results. The FOS and inulin addition to yoghurt caused an increase in the numbers of all bacteria in comparison to control yoghurt obtained without addition of prebiotics. The vi- able counts of Str. thermophilus, Lb. acidophilus and Bifidobacterium sp. when 1% of FOS was added to yoghurt were about 9 log cfu/g, 7.8 log cfu/g and 7.7 log cfu/g, respectively. In the presence of 1% of inulin, streptococci and bifidobacteria reached the growth at the level 8.8 log cfu/g and 7.5 respectively. Hardness and adhesiveness of yoghurt obtained with addition resistant starch increased systematically during 21 days of refrigerated storage. Conclusions. The numbers of lactic acid bacteria in obtained bio-yoghurts were sufficient in 97% of samples (106-109 cfu/g) according to FAO/WHO protocols. Generally, viability of bacteria was sufficient for 14 days and then their numbers decreased but usually not below 106 cfu/g. Prebiotics as FOS and inulin added to bio-yoghurt exhibited stimulatory effect on growth Lb. acidophilus and Bifidobacterium sp. Addition of prebiotics caused an increase in apparent viscosity and hardness (in case of FOS) and decrease in syneresis of obtained bio-yoghurts.
Drinking water is acting as life line for living thing on the Earth, without that no life. Due to global industrialization availability of pure water is one of the major issues. The effluent are directly or indirectly discharge through the river stream, which affect the ground as well as sea water and climatically cycle water reach to us. In that condition medicine are required for quire purpose. In the world so many plants and herbs are available which are used as antimicrobial and sources of medicines. Today the large number of drugs in use is derived from plants. The important advantages for therapeutic uses of medicinal plants in various ailments are their safety besides being economical, effective and easy availability. In this regard’s herb plant Eucalyptus extracted oil is used as antibacterial agent to treat the drinking water.
Jeszcze 50 lat temu przed wprowadzeniem do masowej produkcji nowego materiału wybuchowego w ogóle nie brano pod uwagę jego potencjalnego oddziaływania na środowisko. Wzrost świadomości ekologicznej doprowadził do tego, że obecnie dysponujemy już danymi dotyczącymi toksyczności wobec organizmów żywych najszerzej stosowanych materiałów wybuchowych. W badaniach nad związkami wysokoenergetycznymi szczególnie dużo uwagi poświęca się solom azotetrazolu, ze względu na zawartość azotu w cząsteczce przekraczającą 80% masowych oraz wysoką stabilność termiczną. W prezentowanej pracy przedstawiono wyniki badań dotyczących wpływu azotetrazolanu amonu, azotetrazolanu di(guanidyny) oraz azotetrazolanu di(triaminoguanidyny) na wzrost bakterii Bacillus halodurans. W analizie parametrów biokinetycznych wzrostu bakteryjnego zastosowano model logistyczny, dzięki któremu wystarczająco precyzyjnie można opisać wzrost mikroorganizmów w układzie zamkniętym, jakim jest hodowla stacjonarna. Uzyskane wyniki badań wskazały na znaczne oddziaływanie azotetrazolanu di(triaminoguanidyny) oraz mniejsze azotetrazolanu di(guanidyny), na kinetykę wzrostu badanych bakterii. W toku badań stwierdzono jednak, że najprawdopodobniej zasadniczy wpływ na wzrost badanej bakterii w grupie testowanych związków ma raczej charakter chemiczny kationu związku, z którym azotetrazol tworzy sole niż sama obecność anionu azotetrazolanowego.
Iron-regulated outer membrane proteins (IROMPs) of P. multocida serotype A3, which function as receptors for complexes containing iron ions, are induced by iron deficiency in the bacterial growth environment. Analysis of an electrophoresis image of proteins isolated from bacteria grown on medium supplemented with 2,2'-dipyridyl revealed expression of 16 new proteins that were not noted in the case of the bacteria grown in standard conditions, with molecular weights from 30 to 160 kDa. Induction of IROMP expression occurred within 30 minutes after restricted iron conditions were established. In immunoblotting, distinct reactions were noted for proteins of molecular weight ranges of 25-49 kDa, 61-95 kDa, and 108-214 kDa. Proteins of the molecular weight of 68, 75 and 86 kDa were analysed using mass spectrometry and matched with the highest probability to proteins in the NCBI data base. Several dozen different proteins with similar amino acid sequences were matched to each sample.