Directed freeze-fracturing of Bacillus subtilis biofilms for conventional scanning electron microscopy

2018 ◽  
Vol 152 ◽  
pp. 165-172 ◽  
Author(s):  
Felix M. Fuchs ◽  
Gudrun Holland ◽  
Ralf Moeller ◽  
Michael Laue
2016 ◽  
Vol 82 (2) ◽  
Author(s):  
Irma KRESNAWATY ◽  
Agustin Sri MULYATNI ◽  
Deden Dewantara ERIS ◽  
Haryo Tejo PRAKOSO

AbstractThe difficulties in processing of petroleum-based plastic waste had encouraged the development of biodegradable plastics polyhydroxyalkanoate (PHA). Researchers isolated the PHA-producing microorganisms from various sources to obtain new species with high PHA production capability. In addition, the high cost of PHA production might be overcome by using carbon-rich waste, such as palm oil mill effluent (POME). This research conducted characterization of produced PHA and optimization of PHA production in POME. In previous research, three potential isolates were obtained, which are one Pseudomonas aeruginosa isolate and two Bacillus subtilis isolates. Analysis of Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) showed the presence of PHA accumu-lation within the bacterial cell. The results of Spectra of Fourier Transform Infra Red Spectroscopy (FT-IR) revealed differences in C-C and C-H alipathic regions of PHA produced by Pseudomonas aeruginosa and Bacillus subtilis. Optimum production of PHA was obtained using POME at concentration of 50-25% during 6 days of incubation time in an enriched media pretreatment.Abstrak Sulitnya pengolahan limbah plastik berbasis minyak bumi mendorong pengembangan plastik biodegradable poli-hidroksialkanoat (PHA). Beberapa peneliti mengisolasi mikroorganisme penghasil  PHA dari berbagai sumber karena diharapkan akan diperoleh spesies baru dengan kemampuan produksi PHA yang tinggi. Selain itu kendala tingginya biaya produksi PHA dapat diatasi dengan peman-faatan limbah yang kaya akan  karbon, seperti limbah cair pabrik kelapa sawit (LCPKS). Pada penelitian ini dilakukan karakterisasi PHA yang dihasilkan dan optimasi produksi PHA pada LCPKS. Pada penelitian sebelumnya telah diperoleh  tiga isolat potensial, yaitu : satu isolat  Pseudo-monas aeruginosa dan dua isolat  Bacillus subtilis.  Analisis Scanning Electron Microscopy (SEM) dan Transmission Electon Microscopy (TEM) menunjukkan adanya akumulasi PHA di dalam sel bakteri. Dari hasil analisis FT-IR disimpulkan bahwa senyawa PHA yang dihasilkan Pseudo-monas aeruginosa  berbeda dengan  Bacillus subtilisyang ditandai   perbedaan   pada  spectra   gugus  C-C  dan   C-H alifatik.  Produksi optimum PHA diperoleh pada konsentrasi LCPKS 50-25%, waktu inkubasi  enam hari dan optima-lisasi pertumbuhan pada media kaya di awal untuk mening-katkan populasi mikroba.


2016 ◽  
Vol 82 (2) ◽  
Author(s):  
Irma KRESNAWATY ◽  
Agustin Sri MULYATNI ◽  
Deden Dewantara ERIS ◽  
Haryo Tejo PRAKOSO

AbstractThe difficulties in processing of petroleum-based plastic waste had encouraged the development of biodegradable plastics polyhydroxyalkanoate (PHA). Researchers isolated the PHA-producing microorganisms from various sources to obtain new species with high PHA production capability. In addition, the high cost of PHA production might be overcome by using carbon-rich waste, such as palm oil mill effluent (POME). This research conducted characterization of produced PHA and optimization of PHA production in POME. In previous research, three potential isolates were obtained, which are one Pseudomonas aeruginosa isolate and two Bacillus subtilis isolates. Analysis of Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) showed the presence of PHA accumu-lation within the bacterial cell. The results of Spectra of Fourier Transform Infra Red Spectroscopy (FT-IR) revealed differences in C-C and C-H alipathic regions of PHA produced by Pseudomonas aeruginosa and Bacillus subtilis. Optimum production of PHA was obtained using POME at concentration of 50-25% during 6 days of incubation time in an enriched media pretreatment.Abstrak Sulitnya pengolahan limbah plastik berbasis minyak bumi mendorong pengembangan plastik biodegradable poli-hidroksialkanoat (PHA). Beberapa peneliti mengisolasi mikroorganisme penghasil  PHA dari berbagai sumber karena diharapkan akan diperoleh spesies baru dengan kemampuan produksi PHA yang tinggi. Selain itu kendala tingginya biaya produksi PHA dapat diatasi dengan peman-faatan limbah yang kaya akan  karbon, seperti limbah cair pabrik kelapa sawit (LCPKS). Pada penelitian ini dilakukan karakterisasi PHA yang dihasilkan dan optimasi produksi PHA pada LCPKS. Pada penelitian sebelumnya telah diperoleh  tiga isolat potensial, yaitu : satu isolat  Pseudo-monas aeruginosa dan dua isolat  Bacillus subtilis.  Analisis Scanning Electron Microscopy (SEM) dan Transmission Electon Microscopy (TEM) menunjukkan adanya akumulasi PHA di dalam sel bakteri. Dari hasil analisis FT-IR disimpulkan bahwa senyawa PHA yang dihasilkan Pseudo-monas aeruginosa  berbeda dengan  Bacillus subtilisyang ditandai   perbedaan   pada  spectra   gugus  C-C  dan   C-H alifatik.  Produksi optimum PHA diperoleh pada konsentrasi LCPKS 50-25%, waktu inkubasi  enam hari dan optima-lisasi pertumbuhan pada media kaya di awal untuk mening-katkan populasi mikroba.


Author(s):  
K. Tanaka ◽  
A. Iino

Until recently, a few reports have been published as to the methods for observing intracellular structure by means of scanning electron microscopy. Makita and Sandborn saw intracellular granules in the glands of the hen oviduct with tissue sections by means of Smith-Farquhar tissue sectioner. Geminario and McAlear applied the freeze-fracturing technique in order to ascertain the intracellular structure of retinas from mice.A new method, attempted by us, embedding the materials in epoxy resin and cracking it into two pieces after freezing, is described below with its application to cytology.1. The pieces of tissue are fixed in glutaraldehyde and osmium tetroxide.2. They are dehydrated by graded series of ethanol and propylen oxide.3. Then they are embedded in small gelatin capsules (size no. 2) which are filled with Cemedine 1500 (epoxy resin) without any catalysts (Epon 812 or Rigolac can be used but the temperature for hardening them is very low, -80°C).


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