King G M
Darling Marine Center, University of Maine, Walpole 04573.
Appl Environ Microbiol. 1988 Dec;54(12):3079-85. doi: 10.1128/aem.54.12.3079-3085.1988.
Halophenols such as 2,4-dibromophenol (DBP) occur naturally in some marine sediments, as a consequence of various animal and algal activities. In an earlier study, DBP was observed in the burrow microenvironment of the hemichordate Saccoglossus kowalewskii. At the concentrations found in the burrow lining, aerobic respiration appeared to be inhibited significantly relative to anaerobic catabolism. This effect, as well as factors contributing to the degradation of DBP, has been documented further here. Results from the addition of radiolabeled DBP to oxic and anoxic sediment slurries and growth experiments with aerobic and anaerobic enrichments suggested that aerobes did not significantly metabolize DBP and that concentrations likely to be encountered on the inner surfaces of the burrow wall were inhibitory. In contrast, only minimal inhibition of growth occurred for anaerobes exposed to 1 mM DBP; in addition, DBP was substantially degraded in both enrichments and sediments under anaerobic conditions. Dehalogenation with the consequent production of phenol appeared to initiate anaerobic degradation. Sulfate-reducing bacteria did not dehalogenate DBP but appeared to degrade phenol. Decreased bacterial numbers and marked differences in the concentration and chemical speciation of iron in sediments from S. kowalewskii burrows may be attributed to toxic effects of DBP on aerobic bacteria.
诸如2,4 - 二溴苯酚（DBP）之类的卤代酚由于各种动物和藻类活动而天然存在于一些海洋沉积物中。在早期的一项研究中，在半索动物科瓦列夫斯基柱头虫的洞穴微环境中观察到了DBP。在洞穴壁衬里中发现的浓度下，相对于无氧分解代谢，有氧呼吸似乎受到了显著抑制。这种效应以及导致DBP降解的因素在此处得到了进一步记录。向有氧和无氧沉积物浆液中添加放射性标记的DBP以及进行有氧和无氧富集生长实验的结果表明，需氧菌不会显著代谢DBP，并且洞穴壁内表面可能遇到的浓度具有抑制作用。相比之下，暴露于1 mM DBP的厌氧菌仅出现了最小程度的生长抑制；此外，在厌氧条件下，DBP在富集物和沉积物中均被大量降解。脱卤作用随之产生苯酚，似乎启动了厌氧降解。硫酸盐还原菌不会使DBP脱卤，但似乎会降解苯酚。科瓦列夫斯基柱头虫洞穴沉积物中细菌数量的减少以及铁的浓度和化学形态的显著差异可能归因于DBP对需氧菌的毒性作用。
