Inhibitory effects of 2‐mercaptobenzothiazole on microbial growth in a variety of trophic conditions

Abstract

Abstract-2-Mercaptobenzothiazole (MBT) is found mainly in the wastewaters of its industrial production as a rubber vulcanization accelerator. Because this compound was found to be toxic to activated sludges and because it causes poor process performances, its impact on bacteria in particular was studied. 2-Mercaptobenzothiazole, but not other benzothiazoles, exerted mainly bacteriostatic effects towards Escherichia coli, Sarcina lutea, Staphylococcus aureus, and a 2-hydroxybenzothiazole-degrading isolate (OBT18). It caused membrane disturbance as measured by induced potassium effluxes from the cell. Emphasis was on the effects of MBT on growth of E. coli on different electron donor-electron acceptor combinations. Paracoccus denitrificans was grown in the presence of oxygen or nitrate and the yeast Saccharomyces cerevisiae was used under aerobic and fermentative conditions. In almost all conditions the growth was severely inhibited, indicating that MBT might interfere with a common oxidoreduction step in membranebound systems and probably also interferes with metabolic reactions not related to the respiratory chain.

Initial Transformations in the Biodegradation of Benzothiazoles by Rhodococcus Isolates

“…As a result of MBT manufacture, process waters originate which contain 2-hydroxybenzothiazole (OBT), benzothiazole (BT), and benzothiazole-2-sulfonate (BTSO 3 ), apart from MBT itself. A biological purification of such wastewaters is often considered to be problematic (1,12,13), probably due to the toxic effects ascribed to MBT (5,6,(13)(14)(15). This might explain why only a few benzothiazole-degrading organisms are reported in the literature and why information on benzothiazole degradation pathways is scarce.…”

Identification of selected microorganisms from activated sludge capable of benzothiazole and benzotriazole transformation

“…Among the identified bacterial strains capable of BT and BTA biotransformation, the most common bacteria were Rhodococcus sp., Enterobacter sp., and Arthrobacter sp. In other studies, Rhodococcus strain PA, Rhodococcus OBT18, Rhodococcus erythropolis strain BTSO 3 1, Rhodococcus rhodochrous and Pseudomonas putida strain HKT 554 were tested for BT biodegradation (Gaja & Knapp, 1997;De Wever et al, 1997, El-Bassi et al, 2010Chorao et al, 2009). Rhodococcus strains PA and OBT18 were capable of BT and 2-hydroxybenzothiazole (OBT) degradation, but they did not remove 2-mercaptobenzothiazole (MBT).…”

Quaternized and Thiazole‐Functionalized Free Radical‐Generating Organometallic Dendrimers as Antimicrobial Platform against Multidrug‐Resistant Microorganisms

“…Indeed, many reports attest to the antimicrobial activities of the quaternary ammonium groups [40,[44][45][46][47] and 2-mercaptobenzothiazole. [48][49][50][51][52] It is demonstrated that quaternary ammonium groups are membrane active [40,47] while 2-mercaptobenzothiazole are shown to function at the level of the cell membrane. [50,51] Previously, we proved that η 6 -dichlorobenzene-η 5 -cyclopentadienyliron(II) complexes are membrane active and also induce oxidative stress on microorganisms.…”

“…[48][49][50][51][52] It is demonstrated that quaternary ammonium groups are membrane active [40,47] while 2-mercaptobenzothiazole are shown to function at the level of the cell membrane. [50,51] Previously, we proved that η 6 -dichlorobenzene-η 5 -cyclopentadienyliron(II) complexes are membrane active and also induce oxidative stress on microorganisms. [42,43] Therefore, we expect these hybrids to function via multiple mechanisms that include generating oxidative stress and interacting with cell membrane and its functions in addition to other yet-to-be identified mechanisms.…”