Pseudomonas CY growth in the presence of benzene

Abstract

The objective of this research is investigation of Pseudomonas CY growth, isolated from kerosene, in the presence of benzene. Thanks to their high enzymatic activity, microorganisms can use different compounds as a sole sources of carbon and energy, or they can use them in cometabolic processes. Their growth was observed by spectrophotometry measuring optical density on 500nm, while Pseudomonas count was determined on TSA. The growth was observed during specific time period (i.e. in following order: 1, 2, 3, 4, 5, 6, 7, 9, 10, 11, 12 and 24h). There were used three concentrations of benzene. The results have shown that Pseudomonas population depended on benzene concentration and time. In the presence of benzene the bacterial growth was low, but after 24 hours the Pseudomonas count increased. These results indicate the possibility for Pseudomonas CY growth in the presence of benzene, but also the extension of adaptation phase comparing to normal growth curve. Therefore, the results show that using Pseudomonas population is a very feasible way for decreasing contamination level of soils and waters caused by certain organic compounds.

Cilj ovog rada je ispitivanje rasta Pseudomonas CY, izolovanog iz kerozina, u prisustvu različitih koncentracija benzena. Mikroorganizmi zahvaljujući svojoj velikoj enzimskoj aktivnosti mogu koristiti različita organska jedinjenja kao jedinstvene izvore ugljenika i energije ili ih koristiti u toku procesa kometabolizma. Rast je praćen metodom spektrofotometrije merenjem optičke gustine na 560 nm a brojnost Pseudomonas bakterija je određena na TSA. Rast je praćen od nultog vremena do 24 sata (l, 2, 3, 4, 5, 6, 7, 9, 10, 11, 12 i 24 h). U radu su korišćene tri koncentracije benzena. Rezultati pokazuju da je brojnost Pseudomonas populacije zavisila od koncentracije benzena ali i vremena. Rast bakterijskih populacija u prisustvu benzena je slabiji, ali nakon 24 sata brojnost se povećava. Ovi rezultati ukazuju da Pseudomonas CY može da raste u prisustvu benzena ali da je faza adaptacije produžena u odnosu na normalnu krivu rasta. Dobijeni rezultati ukazuju na mogućnost korišćenja Pseudomonas populacije za smanjenje stepena kontaminacije zemljišta i voda nekim organskim jedinjenjima.