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1

A Healthy Environmental Evaluation Study of the Antibacterial Activity of Polyethylene Oxide Against Some Bacteria Isolated from Azo Dyes

Abdulazeem Lubna, Ali Zainab Haider, Muttaleb Wurood Hamza, Kzar Mazin H., Naje Ahmed Samir

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 4

27--34

EN

The maintenance of the human body, including any actions that may be taken to keep it free from disease and intoxication and to facilitate access to treatment, are all part of good health. Having a wide variety of molecular weights, polyethylene oxide (PEO) is a hydrophilic, uncrosslinked, nonlinear system polymer. It’s made from ethylene oxide, which has a lot of advantages for medicine administration and antimicrobial purposes. Polyethylene oxide bactericidal activity at different PEO concentrations value (80, 40, 20 and 10 μg/ml) against five isolates of Bacillus cereus isolated and identification from azo dye is investigated in this work (random selection from total isolates). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of each isolate were calculated, and PEO’s antibacterial activity was evaluated using the disk diffusion test. 85 Bacillus cereus isolates were collected from total azo dyes, PEO has a broad-spectrum antibacterial effect against tested bacteria, with an inverse connection between inhibitory zone diameter and PEO concentration, also even exceeds the activity of some drugs. The MICs of PEO ranged from 10 to 20 μg/ml, with MBCs ranging from 20 to 80 μg/ml. In other trials, PEO was shown to be strongly attached to bacterial cells, which might explain its effect on bacterial inhibitory growth and their invasion. At an appropriate concentration, PEO significantly inhibited bacterial growth. To avoid the development of antibiotic-resistant bacterial strains, it is strongly recommended that PEO be used as a cost-effective antibacterial agent, particularly when mixed with deys used at home or in enterprises.

2

Study of the Fermentation Conditions of the Bacillus Cereus Strain ARY73 to Produce Polyhydroxyalkanoate (PHA) from Glucose

Yasin Akram R., Al-Mayaly Ithar K.

Journal of Ecological Engineering

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2021

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Vol. 22, nr 8

41--53

EN

Polyhydroxyalkanoates (PHAs) have gained much attention as biodegradable polymers, many efforts are being made to minimize the cost of PHAs by finding cheap carbon source depending on the type of microorganism and fermentation conditions. The aims of this study were to evaluate the effects of different glucose concentrations and other important conditions on the PHA production by Bacillus cereus isolated from soil. Polyhydroxyalkanoates PHAs accumulated by soil microorganisms were examined by screening the isolated bacteria using Sudan B Black and Nile Blue staining process. A Gram positive strain was identified using the 16s rRNA gene, deposited in the NCBI GenBank sequence database. Different growth conditions (favorite glucose concentrations 1-8 % (w/v), temperatures and pH) were tested and the growth parameters (sugar consumption, cell counting and Cell Dry Weight CDW) were studied. The extracted polymers were analyzed and characterized using an FTIR spectrophotometer followed by a GC-MS analysis. The pure bacterial strain isolated from soil was deposited in the NCBI GenBank database B. cereus strain ARY73, which showed significant black colored granules (or dark blue) using Sudan B Black stain, it also showed positive to Nile blue A as a high indicator stain for PHA accumulation. B. cereus ARY73 showed high production of PHA using (w/v): 2% glucose and 1% nitrogen source at 35 °C and pH7 yields 79% per Cell Dry Weight and 96 h of incubation. The extracted polymers were analyzed and characterized using an FTIR spectrophotometer confirming the PHA structure. The FTIR spectrophotometer, followed by a GC-MS analysis indicated the Scl-co-mcl PHA structure. This research demonstrates that the isolated strain B. cereus ARY73 was a good candidate for PHA production with a better quality for use in biomedical and other applications. The use of biopolymer in soil, enhanced the accumulation of the microorganisms (such as bacteria) capable of degrading biopolymer or biodegradation by-products yields by other species which were isolated in this study and demonstrated their efficiency in producing biopolymers.

3

Polycarbonate biodegradation by newly isolated Bacillus strains

Arefian Mojgan, Tahmourespour Arezoo, Zia Mohammadali

Archives of Environmental Protection

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2020

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Vol. 46, no. 1

14--20

EN

As polycarbonate is frequently used in many products, its accumulation in landfills is absolutely harmful to the environment. The aims of this study were the screening and isolation of polycarbonate-degrading bacteria (PDB) and the assessment of their ability in the degradation of polycarbonate (PC) polymers. Nine-month buried- -PC films were used for PDB isolation and identification. The biodegradation ability of the isolates was determined by growth curve, clear zone formation, lipase and amylase production, AFM and FTIR. Bacillus cereus and Bacillus megaterium were identified and considered as PDB. The degradation ability of B. megaterium was significantly higher than that of B. cereus. Both were lipase and amylase positive. AFM and FTIR results showed the initiation of bacterial attachment. The PC biodegradation ability of isolates can be very efficient. Finding such efficient isolates (which was less studied before) will promise a decrease in plastic contamination in the future.

4

Aktualne zagrożenia mikrobiologiczne – bakterie z grupy Bacillus cereus

Maćkiw Elżbieta, Kowalska Joanna, Stasiak Monika, Kucharek Katarzyna

Przemysł Spożywczy

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2019

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T. 73, nr 2

36--40

PL

Bacillus cereus należy do bakterii wywołujących zatrucia pokarmowe o charakterze biegunkowym oraz wymiotnym. Ze względu na powszechność występowania w środowisku oraz zdolności do tworzenia form przetrwalnych zwanych sporami B. cereus stanowi zagrożenie dla bezpieczeństwa produktów spożywczych. Bakterie z grupy B. cereus izolowane są głównie z ryżu, makaronów, mięsa, warzyw, produktów mlecznych, przypraw oraz żywności gotowej do spożycia. Ryzyko infekcji można zmniejszyć poprzez unikanie spożycia produktów poddanych obrobce cieplnej i pozostawionych w temperaturze pokojowej, sprzyjającej kiełkowaniu przetrwalników i produkcji termostabilnych toksyn.

EN

Bacillus cereus belongs to bacteria that cause food poisoning of diarrheal and emetic type. Due to the common occurrence in the environment and the ability to form resting structures called spores, B. cereus poses a threat to the safety of food products. Bacteria of the B. cereus group are mainly isolated from rice, pasta, meat, vegetables, dairy products, spices and ready-to-eat foods. The risk of infection can be reduced by avoiding consumption of the products which are subjected to heat treatment and left at a room temperature as it favours germination of spores and production of heat-stable toxins.

5

Enzymatic bioconversion of feather waste with keratinases of Bacillus cereus PCM 2849

Ciurko Dominika P., Łaba Wojciech, Piegza Michał, Juszczyk Piotr, Choińska-Pulit Anna, Sobolczyk-Bednarek Justyna

Polish Journal of Chemical Technology

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2019

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Vol. 21, nr 3

53--59

EN

Enzymatic preparation from culture of keratinolytic Bacillus cereus PCM 2849 was applied for hydrolysis of whole chicken feathers, after sulphitolytic pretreatment. This process was optimized using a three-factor Box-Behnken design, where the effect of substrate concentration, sulphite concentration during pretreatment and reaction temperature was evaluated on the release of amino acids. Obtained results revealed the highest impact of reaction temperature, followed by substrate content and sulphite during pretreatment. Optimal process conditions were established, i.e. temperature 44.4°C, feathers 4.7% and treatment with 25.3 mM sulphite. Amino acid composition of the obtained hydrolysate was analyzed. Glutamic acid (9.21 g·kg−1) and proline were dominant, however significant amount of branched-chain amino acids was also observed. The FTIR analysis of residual substrate revealed the cleavage of disulphide bonds in keratin through the presence of thioester residues. The absence of reduced cysteine residues was confirmed, along with minor changes in proportions of keratin substructures.

6

Aktualne zagrożenia mikrobiologiczne produktów spożywczych - bakterie Bacillus cereus

Sztucki Damian

LAB Laboratoria, Aparatura, Badania

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2019

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R. 24, nr 6

25--27

7

Isolation and Identification of Native Bacteria from Total Petroleum Hydrocarbon Polluted Soil in Wonocolo Public Oilfields, Indonesia

Sari Gina Lova, Trihadiningrum Yulinah, Ni’matuzahroh

Journal of Ecological Engineering

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2019

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Vol. 20, nr 8

60--64

EN

The presented study concerns on isolation and identification of indigenous bacteria in total petroleum hydrocarbon (TPH) polluted soil. The composite TPH polluted soil was collected from Wonocolo public oilfields, Indonesia. Pour plate and plate count techniques were used to bacterial population analysis and enumeration, respectively. Two dominant bacterial colonies were isolated from 4.06x107 CFU/g population in polluted soil, then morphologically and biochemically were characterized using Microbact Identification Kits (MicrobactTM GNB12A and 12B). The identification of isolated bacteria was performed using Bergey’s Manual of Determinative Bacteriology. The results showed that the strains of bacteria are Bacillus sp. and B. cereus with probability of 72.00 and 77.00%, respectively. These strains potentially acted as biosurfactant producers and hydrocarbon degraders. Thus, biostimulation could be implemented to reduce the TPH levels in polluted soil at Wonocolo public oilfields.

8

Physical factors affecting the production of amylase from Bacillus species isolated from natural environment

Grata K., Nabrdalik M.

Ecological Chemistry and Engineering. A

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2014

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Vol. 21, nr 1

51--60

EN

The influence of different factors on amylolytic activity Bacillus cereus (2 strains) and Bacillus mycoides (2 strains), isolated from soil samples and water of Turawa Lake has been studied. Effect of physiological (pH of reaction mixture in the range of 4.0–8.0, temperature of reaction from 30 to 60 oC) and nutritional parameters (the carbon sources and they concentration in medium) were examined spectophotometricaly for their effect on amylase production. The results obtained showed, that in view of all studied factors the least favorable value of pH was 5.0, while in most cases the most favourable for the process of amylase production were following values 7.0 and 8.0. Moreover, it has been stated that the lowest amount of amylase was noted at 30 oC, and the highest at 60 oC. In case of amylolytic activity, in view of all temperatures the most effective strain was B. mycoides A134 whereas the least B. mycoides G3. The best results of amylase production have been achieved for all remaining strains in two cases – on maltose and glucose medium at all tested temperatures. Additionally, soil occurring strains preferred lower concentration of potato starch (ie 1 %) when compared with water strains which favoured higher concentration (5 %).

PL

Celem badań była ocena wpływu różnych czynników na aktywność amylolityczną Bacillus cereus (2 szczepy) i Bacillus mycoides (2 szczepy) wyizolowanych z gleby i Jeziora Turawskiego. Metodą spektrofotometryczną badano wpływ pH mieszaniny reakcyjnej w zakresie od 5.0 do 8.0 i temperatury w zakresie od 30 oC do 60 oC oraz źródła węgla i jego koncentracji w podłożu na poziom produkowanych amylaz. Stwierdzono, iż najgorszą wartością pH do syntezy amylaz było 5.0, natomiast najlepszą, w większości przypadków pH 7.0. Uwzględniając zakres badanych temperatur, najwyższą aktywność uzyskano w temp. 60 oC, natomiast najniższą w temp. 30 oC dla wszystkich testowanych szczepów. Najbardziej aktywnym szczepem był B. mycoides A 134, natomiast najmniej B. mycoides G3.

9

Skuteczność wybranych związków dezynfekcyjnych wobec przetrwalników Bacillus

Olesiak P., Stępniak L.

Inżynieria i Ochrona Środowiska

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2012

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T. 15, nr 1

41-50

PL

Badano wpływ trzech często stosowanych w antyseptyce i dezynfekcji związków: kwasu nadoctowego, nadtlenku wodoru w stężeniu 5 i 30% oraz aldehydu glutarowego na przetrwalniki bakterii. Kwas nadoctowy stanowił główny składnik preparatu komercyjnego pod nazwą Steridial P. Natomiast aldehyd glutarowy stosowano w postaci preparatu handlowego o nazwie Lysoformin 3000. Skuteczność dezynfektantów badano wobec przetrwalników bakterii z rodzaju Bacillus: B.subtilis, B.mycoides oraz B.cereus. Endospory, czyli przetrwalniki, są formami bakterii, które pozwalają im przeżyć skrajnie niekorzystne dla nich warunki, takie jak: suszę, wysoką temperaturę czy działanie środków dezynfekcyjnych. Zawdzięczają to odmiennej od komórek wegetatywnych budowie. Wykazano, że testowane związki są bardzo silnymi biocydami. Działanie sporobójcze wobec badanych szczepów obserwowano po trzydziestominutowej ekspozycji na każdy z testowanych związków.

EN

The effect of three frequently used in antyseptic and disinfection of: peracetic acid, hydrogen peroxide at a concentration of 5 and 30%, and glutaraldehyde. Peracetic acid was the main ingredient Steridial P, in addition to acetic acid and hydrogen peroxide. Hydrogen peroxide in the form of 5% is much stronger than what we use hydrogen peroxide to antiseptic wounds in our homes. However, glutaraldehyde has performed under the trade name as Lysoformin 3000. Disinfecting measures are an especially important role in maintaining cleanliness in hospitals but also in our homes. Also are needed in the pharmaceutical and grocery industry. Thanks it did reduce the incidence of some diseases, and sometimes eliminate them. Disinfectants allow us to fight drug-resistant strains of bacteria, which occur in hospitals.The effectiveness of disinfectants affected by many factors. Their role in our lives is invaluable. Disinfectants were used against bacterial spores of the genus Bacillus: B.subtilis, B.mycoides and B.cereus. Bacillus-genus bacteria occur everywhere: in water, air and soil are transferred along with objects, and air movements on human hands. So it's easy to get infected. Endospores are forms of bacteria that allow them to survive extremely unfavorable to them, conditions such as drought, high temperatures or the action of disinfectants. Construction disputes differs significantly from the construction of cell vegetative. The most important part of sports is the cover phones, which represent up to 50% of the dry matter (d.m.) of the spore. It is the presence of these creations provides endosporom such "integrity". Guards are constructed primarily of proteins containing large amounts of cysteine. Endospores are forms very dehydrated, the water is only 15% of all cells. Compared with cell vegetative, spores have also about almost half proteins more and 75% carbohydrates less. They do not have beta-hydroxybutyrate, which is to 1/3 d.m. cells vegetative. In construction there are large quantities of endospores dipikolinic acid (DPA), associated mainly with calcium ions, but also other divalent elements. Complexes of Ca2+ - DPA may constitute up to 10% d.m. all disputes. DPA is the most frequently isolated from the mantle. This compound is not present in vegetative cells and spores is responsible for resistance to UV radiation from 5 to 50 times greater (depending on the strain) than vegetative forms. The lower sensitivity to ultraviolet radiation also correspond to protein family SASP (small amidesoluble proteins). They change the structure of DNA-stiffen and straighten - through the saturation of these biomolecules is on the outer side of the helix. These proteins are present only in disputes, and are destroyed during germination. Spore cell wall is much thicker, otherwise refracts light and is composed of many layers, so that is poorly permeable. It was shown that the tested compounds are very potent biocides. Sporicidial action against all tested strains was observed after a thirty-minute exposure to each of the tested.

10

Influence of the Culture Conditions on Lipolytic Activity of Bacillus cereus and Bacillus mycoides

Nabradalik M., Grata K.

Ecological Chemistry and Engineering. A

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2011

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Vol. 18, nr 12

1727-1736

EN

The aim of the research was the evaluation of lipolytic activity of B. cereus and B. mycoides strains, in reference to carbon source, pH and the temperature. In the research, two strains of Bacillus cereus and Bacillus mycoides each, isolated from the soil and water, were applied. The sources of carbon in culture media were fatty substrates: tributyrin, Tween 40, Tween 60, Tween 80 and glucose. The lipolytic activity was measured by means of titration at pH ranging from 5 to 8 and the temperature ranging from 30 oC to 60 oC. The results were presented in the units of lipolytic activity [U cm–3]. In the conducted research, the amount of liberated lipolytic activity depended on the type of fatty substrate in the medium, pH and the temperature. The strains under study showed the lowest activity at pH 5 and 6, and the highest at pH 7 and 8. In these conditions, most of the strains showed the lipolytic activity, even in case of the lack of fatty substrate in the medium. The highest amount of lipolytic activity was liberated at pH 8 in the medium with Tween 40, and the highest results (0.88 [U cm–3]) were noted for the soil strain B. cereus. When analysing the influence of the temperature on the lipolytic activity, it was stated that the highest amount of lipolytic activity was noted at 30 and 40 oC, and the lowest at 50 and 60 oC. The best results were obtained for most of the strains at 30 oC, in medium with Tween 40, and the most active was the soil strain of B. mycoides (0.88 [U cm–3]). The exception is B. cereus, as it liberated 1.38 [U cm–3], in the medium with glucose. Taking into account all analysed sources of carbon and parameters, it seems that the most active were B. mycoides strains.

PL

Celem podjętych badań była ocena aktywności lipolitycznej szczepów B. cereus oraz B. mycoides w zależności od źródła węgla, pH oraz temperatury. Do badań wykorzystano 2 szczepy Bacillus cereus oraz 2 szczepy Bacillus mycoides wyizolowane z gleby i wody. ródłem węgla w pożywkach były substraty tłuszczowe: tributyryna, Tween 40, Tween 60, Tween 80 oraz glukoza. Aktywność lipolityczną oznaczono w zakresie pH od 5 do 8 oraz temperaturach od 30 do 60oC metodą miareczkową, a wyniki podano w jednostkach aktywności enzymatycznej [U cm-3]. W przeprowadzonym doświadczeniu aktywność lipolityczna uzależniona była od rodzaju substancji tłuszczowej zawartej w podłożu, pH oraz temperatury. I tak, badane szczepy B. cereus oraz B. mycoides wykazywały najmniejsza aktywność przy pH 5 oraz 6. Natomiast największą aktywność stwierdzono przy pH 7 i 8. W tych warunkach większość szczepów wykazywała aktywność lipolityczną nawet przy braku substratu tłuszczowego w podłożu. Największe wartości aktywności lipolitycznej uzyskano przy pH 8 na podłożu z dodatkiem Tween 40, a największe wartości (0,88 U cm-3) uzyskano dla glebowego szczepu B. cereus. Analizując wpływ temperatury na aktywność lipolityczną stwierdzono, iż najwyższą aktywność odnotowano w temperaturze 30 i 40 oC, a najmniejszą w 50 i 60 oC. Największe wartości, dla większości szczepów, uzyskano w temperaturze 30 oC na podłożu z dodatkiem Tween 40, gdzie najbardziej aktywnym okazał się glebowy B. mycoides (0,88 U cm-3). Wyjątek stanowi glebowy B. cereus, dla którego wartość aktywności lipolitycznej na podłożu z dodatkiem glukozy wynosiła aż 1,38 U cm-3. Uwzględniając wszystkie analizowane źródła węgla i parametry, najaktywniejszymi były szczepy B. mycoides.

11

Proteolytic activity of Bacillus cereus strains

Nabrdalik M., Grata K., Latała A.

Proceedings of ECOpole

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2010

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Vol. 4, No. 2

273--277

EN

The aim of conducted research was to assess proteolytic activity of Bacillus cereus strains, depending on the source of proteins in a growth medium and temperature. Two Bacillus cereus strains: G10 and A96, isolated from soil and water respectively, were applied in the research. The source of carbon in the growth media was provided by the protein substrates as follows: albumin, casein and skimmed milk. The temperature ranged between 30 and 60ºC. The proteolytic activity was determined with the use of a spectrophotometric method with 2% casein as a substrate, at the wavelength λ = 560 nm. In the experiment, the proteolytic activity depended on the type of protein substrate in the growth medium and the temperature. B. cereus G10 strain showed the highest activity at 30ºC in case of albumin and the lowest in the growth medium with skimmed milk. At temperatures 40 and 50ºC the most favourable medium was with an addition of skimmed milk and the least favourable with albumin. Proteolytic activity was not recorded when the temperature was the highest and the medium contained skimmed milk, whereas at the same temperature the lowest activity was noted again in the medium with albumin. Bacillus cereus A96 strain showed, however, different activity. The highest activity was noted at tempertaures of 30 and 50ºC in the medium with skimmed milk, and the lowest in the medium with casein. The opposite was noted at 40ºC, as no proteolytic activity was recorded in the presence of skimmed milk while the highest was recorded in the presence of casein. When analysing the influence of the temperature on the proteolytic activity, it has been noted that strains of Bacillus cereus are the most vigorous at the temperature of 30 and 40ºC, and the least vigorous at 50 and 60ºC. The highest recorded values for the screened strains have been obtained at 30 and 40ºC in the medium with skimmed milk.

PL

Celem podjętych badań była ocena aktywności proteolitycznej szczepów Bacillus cereus w zależności od źródła białka zawartego w podłożu oraz temperatury. Do badań wykorzystano 2 szczepy Bacillus cereus G10 oraz A96 wyizolowane odpowiednio z gleby i wody. Źródłem węgla w pożywkach były substraty białkowe: albumina, kazeina oraz odtłuszczone mleko. Aktywność proteolityczną oznaczono w zakresie temperatur od 30 do 60ºC. Oznaczenia aktywności proteolitycznej przeprowadzono metodą spektrofotometryczną, używając jako substratu 2% kazeiny po 10-minutowej inkubacji, przy długości fali λ = 560 nm. W przeprowadzonym doświadczeniu aktywność proteolityczna uzależniona była od rodzaju substancji białkowej zawartej w podłożu oraz temperatury. I tak, badany szczep B. cereus G10 w temperaturze 30ºC największą aktywność proteolityczną wykazywał w obecności albuminy, a najniższą w obecności odtłuszczonego mleka. W temperaturach 40 i 50ºC najkorzystniejszym podłożem okazało się podłoże zawierające odtłuszczone mleko, a najmniej korzystne zawierające albuminę. W najwyższej temperaturze nie stwierdzono aktywności proteolitycznej w obecności odtłuszczonego mleka, zaś najniższą aktywność odnotowano ponownie w środowisku albuminy. Z kolei drugi z badanych szczepów, Bacillus cereus A96, charakteryzował się odmienną aktywnością. W temperaturach 30 i 50ºC najwyższą aktywność proteolityczną odnotowano w podłożu zawierającym odtłuszczone mleko, a najniższą w środowisku kazeiny. Natomiast w temperaturze 40ºC zaobserwowano odwrotną sytuację, gdyż nie stwierdzono aktywności proteolitycznej w obecności odtłuszczonego mleka, a najwyższą aktywność uzyskano w obecności kazeiny. Analizując wpływ temperatury na aktywność proteolityczną, stwierdzono, iż największą aktywność badane szczepy Bacillus cereus wykazują w temperaturach 30 i 40ºC, a najmniejszą w 50 i 60ºC. Najwyższe wartości dla badanych szczepów uzyskano w temperaturach 30 i 40ºC na podłożu z dodatkiem odtłuszczonego mleka.

12

Effect of different environmental factors on amylolytic activity of Bacillus cereus and Bacillus mycoides

Grata K., Nabrdalik M., Latała A.

Proceedings of ECOpole

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2010

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Vol. 4, No. 1

49--53

EN

The influence of different factors on amylolytic activity Bacillus cereus (2 strains) and Bacillus mycoides (2 strains), isolated from soil samples and water of Turawa Lake has been studied. Effect of physiological (temperature of reaction from 30 to 60 and pH of reaction mixture in the range of 4.0÷8.0) and nutritional parameters (the carbon sources and they concentration in medium) were examined spectophotometricaly for their effect on amylase production. The amylase activity was estimated on the basis of the reduction in blue colour intensity resulting from enzymatic hydrolysis of starch. The results obtained, that in view of all studied factors, the best pH level appear 7.0 or 8.0 and temperature 60ºC for all tested strains. Moreover amylase yield was the highest in media containing maltose or glucose as sole carbon source in all tested temperature.

PL

Celem badań była ocena wpływu różnych czynników na aktywność amylolityczną Bacillus cereus (2 szczepy) i Bacillus mycoides (2 szczepy), wyizolowanych z gleby i jeziora Turawa. Badano wpływ pH mieszaniny reakcyjnej w zakresie od 5,0 do 8,0 i temperatury w zakresie od 30 do 60°C oraz źródła węgla i jego koncentracji w podłożu na poziom amylaz. Na podstawie stopnia zmniejszenia się zabarwienia z jodem oznaczono ilość rozłożonej skrobi metodą spektrofotometryczną. Uzyskane wyniki badań wykazały, iż spośród przebadanych czynników dla wszystkich szczepów najlepszą wartością pH była 7,0 lub 8,0, a temperatura 60ºC. Ponadto najwyższy poziom amylaz uzyskano, hodując badane szczepy na podłożu z maltozą lub glukozą w zakresie badanych temperatur.

13

Jakość mikrobiologiczna rynkowych przypraw i ziół

Berthold-Pluta A., Kurzyńska D.

Postępy Techniki Przetwórstwa Spożywczego

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2010

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nr 2

42-46

PL

Celem zaprezentowanych w artykule wyników pracy naukowo-badawczej było określenie ogólnej jakości mikrobiologicznej oraz występowania Bacillus cereus w 30 próbkach rynkowych przypraw i ziół, a także określenie wybranych cech biochemicznych i fizjologicznych wyizolowanych szczepów B. cereus. Ogólna liczba drobnoustrojów w przebadanych próbkach wahała się od 1,5x102 do 7,9x105 jtk/g, przy czym liczbę ponad 104 jtk/g stwierdzono w 40% próbek. Obecność Bacillus cereus w 1 g potwierdzono w 63,3% próbek, przy czym w połowie z nich najbardziej prawdopodobna liczba B. cereus nie przekraczała 101, a tylko w jednej próbce wynosiła ponad 103 w 1 g. Wszystkie 46 wyizolowane szczepy B. cereus rozkładały kazeinę. Zdolności do fermentacji laktozy i galaktozy nie wykazywało 91,3% i 82,6% szczepów, odpowiednio. Właściwości lipolityczne i amylolityczne wykazywało 63,0% i 82,6% szczepów, odpowiednio. Wszystkie szczepy wykazywały wzrost w warunkach 20, 30 i 37st. C/24 h, 78,3% szczepów w 43st. C/48 h, a 71,7% szczepów w 12st. C/3 dniach. Zdolności psychrotrofowe posiadało 23,9% szczepów (8st. C/10 dni), 6,5% szczepów (6st. C/10 dni) oraz 2,2% szczepów (4st. C/10 dni). Wszystkie badane próbki przypraw i ziół spełniały wytyczne ICMSF odnośnie OLD tj. <106 jtk/g, a poziom zanieczyszczenia B. cereus nie stwarzał niebezpieczeństwa zdrowotnego dla konsumentów (<104 jtk/g).

EN

The aim of this work was to study the microbiological status of 30 retail samples of spices and herbs. The samples were examined among others for the presence of Bacillus cereus. The further aim of the study was to identify particular biochemical and physiological features of the isolated B. cereus strains. The total bacterial counts (TTC) for the samples ranged from 1.5x102 up to 7.9x105 cfu/g, however 40% of the samples had counts exceeding 104 cfu/g. The presence of B. cereus per 1g was detected in 63.3 % of the samples. However the most probable number of B. cereus population did not exceed 101 in half of the samples and the number exceeding 103 per 1 g was observed only in one sample. All 46 isolated B. cereus strains were capable of hydrolysing casein. It was also found that 91.3% and 82.6% of the strains did not exhibit the ability to ferment lactose and galactose, respectively. Furthermore, 63.0% and 82.6% of the strains respectively showed lipolytic and amylolytic activity. All the examined strains grew in the following conditions: 200, 300 and 37st. C/24 hr, 78.3% of the strains grew at 43 st. C/48 hr and 71.7% at 12 st. C/3 days. In this study 23.9% (8st. C/10 days) and 6.5% (6st. C/10 days) and 2.2% (4st. C/10 days) of the strains were identified as psychrotrophic. All the examined samples of spices and herbs conformed to the ICMSF specifications regarding TTC i. e. <106 cfu/g. It was concluded that the level of B. cereus contamination (<104 cfu/g) found in the samples did not pose any potential consumer health risk.

14

Bioleaching of metals from polish black shale in neutral medium

Farbiszewska-Kiczma J., Farbiszewska T., Bąk M.

Physicochemical Problems of Mineral Processing

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2004

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Vol. 38

273--280

EN

The black shale present in Polish ores (Lubin region) differs from others in mineralogical and chemical properties and in susceptibility to enrichment. The ores are characterized by high content of copper and others metals like silver. Some metals in the shale ore are present as bituminous organometallic compounds such as porphyrinus. The presence of these compounds, reduces metals recovery by classical acid bioleaching methods. This study has been undertaken in order to determine possibilities of metals bioleaching from the sandwich compounds occurred in black shale. The bioleaching process was carried out in neutral medium using Bacillus cereus and Bacillus amyloliquefaciens strains. The progress of this process was followed by analysis of copper, zinc and nickel bioleaching kinetics. The bioleaching experiments with copper suggest different organic forms of this metal in the shale ore. Some of them are highly susceptible to bioleaching by heterotrophic bacteria. Organic compounds of the nickel appeared to be more resistant to bioleaching than copper compounds. Bioleaching of zinc was negligible. Also, the bioleaching process was carried out on a batch scale using "Biomel" reactor.

PL

W artykule przedstawiono wyniki izolacji, z polskiego łupka miedzionośnego, autochtonicznych szczepów bakterii heterotroficznych oraz wyniki badań nad bioługowaniem tegoż łupka w środowisku obojętnym, przy współudziale wyizolowanych bakterii. Proces prowadzono w małej skali laboratoryjnej, w trzech różnych temperaturach. Dla porównania, proces bioługowania w większej skali został przeprowadzono w bioreaktorze. Proces prowadzony był w bioreaktorze przez 24 dni w temperaturze 250C.

15

Jakość mikrobiologiczna serów podpuszczkowych dojrzewających

Kazimierczak A., Molska I., Nowosielska R.

Przemysł Spożywczy

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1999

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T. 53, nr 5

18-20

PL

Oznaczono jakość mikrobiologiczną 101 próbek (64 - polskich, 37 - importowanych) różnych rodzajów serów dojrzewających dostępnych na rynku warszawskim. Oznaczono następujące grupy drobnoustrojów: bakterie z grupy coli, Escherichia coli, Staphylococcus aureus, Bacillus cereus, enterokoki, Clostridium, pleśnie i drożdże. Ogólny poziom zanieczyszczenia badanymi drobnoustrojami był wyższy w próbkach serów krajowych niż w serach z importu. W żadnej próbce nie stwierdzono obecności w 0,01 g Staphylococcus aureus.

EN

The microbiological quality of 101 samples (64 - Polish, 37 - imported) of different varietes of ripened cheese obtained from retail trade of Warsaw market was surveyed. The following groups of microorganisms were tested: coliform bacteria, Escherichia coli, Staphylococcus aureus, Bacillus cereus, enterococci, Clostridium, yeast and moulds. The overall level of tested microorganisms was higher in samples of Polish cheese than that in imported cheese. Staphylococcus aureus was not detected in 0,01 g of any of the tested samples.