کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9437737 | 1615787 | 2005 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Effect of surfactants on stability of Acinetobacter johnsonii S35 and Oligotropha carboxidovorans S23 coaggregates
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موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم محیط زیست
بوم شناسی
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چکیده انگلیسی
The effect of anionic (sodium dodecyl sulphate or SDS) and cationic (cetyltrimethylammonium bromide or CTAB) surfactants on the stability of binary bacterial coaggregates comprising Acinetobacter johnsonii S35 and Oligotropha carboxidovorans S23 (both sewage sludge isolates) was studied and compared with that on the complex sewage sludge flocs. Both SDS and CTAB enhanced the bacterial coaggregation at their lower concentrations of 0.2 and 0.07 mg mlâ1, respectively. However, complete deflocculation of coaggregates was observed at 1 mg mlâ1 SDS and 0.3 mg lâ1 CTAB concentrations. Further, sewage sludge flocs did not deflocculate in the presence of CTAB, although a concentration-dependent deflocculation was observed in the presence of SDS. A. johnsonii S35 and O. carboxidovorans S23 cells were separately pretreated (prior to coaggregation) with the surfactants. In spite of the partial (complete) loss of viability during SDS (CTAB) pretreatment, washed cells still retained hydrophobic character and displayed significant coaggregation (aggregation index ranging from 84% to 97% in comparison to 96% in the case of non-treated cells), demonstrating reversibility of the surfactant induced deflocculation. Further, when exposed to lower concentration of surfactants (0.2 mg mlâ1 SDS), coaggregates were more resistant (76% viability) as compared to the individual partner (S35: 52%; S23: 39% viability). Since the coaggregates are stable and provide protection from surfactants at lower concentrations (those normally expected in the sewage treatment plants), their presence as well as a sustained role in the sewage sludge bioflocculation is evident.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: FEMS Microbiology Ecology - Volume 51, Issue 3, 1 February 2005, Pages 313-321
Journal: FEMS Microbiology Ecology - Volume 51, Issue 3, 1 February 2005, Pages 313-321
نویسندگان
Anushree Malik, Phuong Kimchhayarasy, Kazuo Kakii,