Microbiological degradation of pentane by immobilized cells of Arthrobacter sp.

Abstract

The increasing production of several plastics such as expanded polystyrene, widely used as packaging and building materials, has caused the release of considerable amounts of pentane employed as an expanding agent. Today many microorganisms are used to degrade hydrocarbons in order to minimize contamination caused by several industrial activities. The aim of our work was to identify a suitable microorganism to degrade pentane. We focused our attention on a strain of Arthrobacter sp. which in a shake-flask culture produced 95% degradation of a 10% mixture of pentane in a minimal medium after 42 days of incubation at 20°C. Arthrobacter sp. cells were immobilized on a macroporous polystyrene particle matrix that provides a promising novel support for cell immobilization. The method involved culturing cells with the expanded polystyrene in shake-flasks, followed by in situ growth within the column. Scanning electron microscopy analysis showed extensive growth of Arthrobacter sp. on the polymeric surface. The immobilized microorganism was able to actively degrade a 10% mixture of pentane, allowing us to obtain a bioconversion yield of 90% after 36 h. Moreover, in repeated-batch operations, immobilized Arthrobacter sp. cells were able to maintain 85-95% pentane degradation during a 2 month period. Our results suggest that this type of bioreactor could be used in pentane environmental decontamination.

OPTIMASI PERTUMBUHAN BAKTERI LAUTSalinicola peritrichatus LBF-1-0025 DALAM SENYAWA ALKANA

“…Gambar 1A menunjukkan bahwa isolat LBF-1-0025 memiliki kemampuan optimal mendegradasi senyawa pentana pada konsentrasi 150 ppm dengan nilai OD 600nm sebesar 1,99. Konsentrasi optimal dalam pertumbuhan bakteri menunjukkan batas kemampuan bakteri yang dapat menggunakan senyawa pentana sebagai sum ber karbon dan energi untuk kegiatan metabolisme (degradasi substrat) (Ionata, Blasio, & Cara, 2005). Nilai OD 600nm sel isolat LBF-1-0025 meningkat dari 1,77 pada konsentrasi pentana 100 ppm menjadi 1,99 pada konsentrasi pentana 150 ppm.…”

Degradation of Alkane by Bacteria Immobilized on Polyurethane Foam

“…Pentane-degrading Arthrobacter sp. was immobilized on a macroporous polystyrene particle matrix by promoting flocculation with the addition of Ca 2 at the end of the growth phase 4) . Earlier studies in our lab for fatty-oil containing wastewater treatment have shown that a bacterial consortium in an activated sludge formed into a biofilm showed good physical adsorption on polyurethane foam even with large pore size 5) .…”