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1

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.

2

Wybrane enzymy pochodzenia mikrobiologicznego stosowane w przemyśle spożywczym

Pytka Monika, Janas Piotr, Kordowska-Wiater Monika

Przemysł Spożywczy

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2019

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T. 73, nr 12

26--30

PL

W nowoczesnej produkcji żywności występuje duże zapotrzebowanie na białka enzymatyczne. Ich stosowanie ma na celu zwiększenie wydajności i efektywności ekonomicznej produkcji tradycyjnej oraz pozwala otrzymać nowe produkty o ciekawych właściwościach funkcjonalnych i sensorycznych. Enzymy występują powszechnie w środowisku naturalnym, gdzie są syntetyzowane przez różnorodne organizmy. Są niezbędnymi katalizatorami wszystkich przemian biochemicznych zachodzących w przyrodzie. Cechuje je wysoka specyficzność i selektywność substratowa, co gwarantuje wysoką jakość produktu. W branżach przemysłu spożywczego takich jak np.: gorzelnictwo, piwowarstwo, piekarnictwo, przemysł owocowo-warzywny, szczególnie potrzebne są enzymy hydrolizujące tanie surowce skrobiowe, celulozowe oraz pektyny i β-glukany. Produkcja biotechnologiczna, która gwarantuje szybką, tanią i bardzo wydajną biosyntezę enzymów, może zaspokoić zwiększone zapotrzebowanie na te preparaty.

EN

There is a high demand for enzymatic proteins in modern food production. They are used to increase the efficiency and profitability of traditional production, as well as to obtain new products with interesting functional and sensory properties. Enzymes are present in the natural environment, where they are synthesized by various organisms. They are necessary catalysts of all biochemical reactions. They are characterized by high specificity and substrate selectivity, which guarantees high product quality. The enzymes that hydrolysing cheap starch and cellulosic raw materials, pectins and β-glucans are particularly needed in some of food industry branches, e.g. brewing, baking, or fruit and vegetable industry. Biotechnological production, which guarantees fast, cheap and very efficient biosynthesis of enzymes, can meet the increased demand for enzymatic products.

3

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.

4

Oxidation of activated carbon fibre and its adsorption of amylase

Li Y., Hu S.

Materials Science Poland

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2009

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Vol. 27, No. 2

453--461

EN

Activated carbon fibre was oxidized by combustion of nitrocellulose and oxidation with nitric acid to introduce the nitrogen and oxygen groups on its surface. The pore structure and chemical groups were investigated by nitrogen adsorption and FTIR. The result showed that the pore structure and surface morphology were not much affected but amide and hydroxyl groups could be introduced after oxidation. The adsorption capacity of amylase was markedly increased, and the hydrolysis activity of starch was maintained after 3 runs.