THE EFFECT OF ORGANIC-MATTER AND OXYGEN ON THE DEGRADATION OF BACTERIAL-MEMBRANE LIPIDS IN MARINE-SEDIMENTS
THE EFFECT OF ORGANIC-MATTER AND OXYGEN ON THE DEGRADATION OF BACTERIAL-MEMBRANE LIPIDS IN MARINE-SEDIMENTS
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DOI：
10.1016/0016-7037(86)90355-8
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发表时间：
1986-05-01
影响因子：
5
通讯作者：
PATTON, JS
中科院分区：
文献类型：
--
作者：
HARVEY, HR;FALLON, RD;PATTON, JS
研究了产甲烷菌[Methanococcus pastae]和假单胞菌[Pseudomonasperfectomatinus]的放射性标记膜脂在红树林、海滩和高沼泽海洋沉积物中的好氧和厌氧降解。还通过向海滩沉积物中添加腐殖酸来研究有机物对降解量和速率的影响。在好氧沉积物中。CO2是脂质降解的主要产物，而在厌氧条件下，CO2和CH4都是主要的最终产物，总体速率相对于有氧条件降低（高达40%）。细菌总数增加，在所有的孵育过程中，最大的增加发生在厌氧沉积物中补充腐殖酸。在用甲醛或高压灭菌处理的好氧或厌氧沉积物中没有发生脂质降解。在低有机海滩沉积物中，假单胞菌的酯连接的磷脂比产甲烷菌的二植烷基甘油二醚降解得更快，在96小时内降解了69%的磷脂，而产甲烷菌脂质仅降解了4%。好氧和厌氧沉积物中的脂类降解与有机质含量高度相关，随着有机质含量的增加，脂类降解受到抑制。长时间孵育（75天）的diphytanyl甘油醚导致51%降解为CO2在低（0.5%）的有机红树林沉积物，而只有9%被矿化在高（10.8%）的有机沼泽沉积物。膜脂对有机基质的物理化学吸附被提出作为保护膜脂免受微生物攻击和降解的机制。
The biodegradation of purified radiolabelled membrane lipids from a methanogenic bacterium [Methanococcus voltae] and a pseudomonad [Pseudomonas perfectomatinus] were investigated in mangrove, beach and high marsh marine sediments under aerobic and anaerobic conditions. The effect of organic matter on the amount and rate of degradation was also examined by supplementing beach sediments with humic acids. In aerobic sediments. CO2 was the major product of lipid degradation while under anaerobic conditions both CO2 and CH4 were major end products and the overall rates were reduced (up to 40%) relative to aerobic conditions. Total bacterial numbers increased during all incubations with the largest increases occurring in anaerobic sediments supplemented with humic acids. No lipid degradation occurred in aerobic or anaerobic sediments treated with formaldehyde or autoclaving. In low organic beach sediments, the ester-linked phospholipid of the pseudomonad was degraded much more rapidly than the diphytanyl glycerol diether of the methanogen with 69% of the phospholipid degraded in 96 hours versus only 4% of the methanogen lipid. Lipid degradation in both aerobic and anaerobic sediments was highly correlated to organic matter content with increasing amounts of organic matter inhibiting degradation. Long incubations (75 days) of the diphytanyl glycerol ether resulted in 51% degraded to CO2 in low (0.5%) organic mangrove sediments while only 9% was mineralized in high (10.8%) organic marsh sediments. Physicochemical sorption of membrane lipids to the organic matrix is proposed as a mechanism which protects membrane lipids from microbial attack and degradation.