MICROBIOLOGICAL STUDY ON THE METHANE PRODUCTION IN MARINE

产甲烷细菌的膜脂由特殊的醚键糖脂组成，与大多数细菌不同。因此，通过测定海洋沉积物中的脂类组分来估算海洋产甲烷细菌的生物量及其活性是可行的。在东京湾、油坪湾和骏河湾等富营养化的近岸沉积物中，甲烷浓度为0.12-93 nmol/g，脂类浓度为17-152 ng/g。这些值在每个沉积物中密切相关。这些沉积物样品的培养实验表明，有几组产甲烷细菌在沉积物中，如乙酸，氢气+二氧化碳气体，和甲醇的利用者。它们的活性远高于从近海海岸沉积物中获得的产甲烷菌。在相模湾和骏河湾等离岸海岸沃茨的沉积物中，间隙沃茨中的甲烷浓度为0.32-0.65 nmol/g，脂质浓度为4.6-21 ng/g。在培养实验中观察到，与富营养化的沉积物相比，甲醇利用率低得多。研究了桡足类和磷虾等常见浮游动物肠道微植物群的产甲烷活性。在30个磷虾标本中，每粒粪粒的产甲烷活性为1.8微摩尔。在另一个实验中，在60天的培养过程中产生了615微摩尔/克的甲烷。微生物群落被观察到是甲醇利用者。

Membrane lipids of methanogenic bacteria are composed of special ether-linked glycerelipids, different from most of bacteria. So it is possible to estimate biomass of marine methanogenic bacteria and their activity by determining the lipid components in marine sediments. In the coastal eutrophicated sediments, such as Tokyo Bay, Aburatsubo Inlet and inner most part of Suruga Bay, methane concentrations were observed 0.12-93 nmol/g in the interstitial water samples, and lipid concentrations were 17-152 ng/g. These values were closely related in each sediment. Incubation experiments with these sediment samples showed that there are several groups of methanogenic bacteria in the sediments, such as utilizers of acetate, hydrogen+carbon dixide gasses, and methanol. Their activities were much higher than the mrethanogens obtained from off shore sediments. In the sediments of off shore waters like Sagami and Suruga Bays, methane concentrations were 0.32-0.65 nmol/g in the interstitial waters, and lipid concentrations were 4.6-21 ng/g. It was observed in the incubation experiments that methanol utilizers were much lower compared with eutrophicated sediments. Methanogenic activities of the intestinal micro flora of common zooplankton like copepods and euphausia were studies. Methanogenic activities were observed to be 1.8 micro mole per fecal pellets of 30 specimens of euphausia. In another experiment 615micro mols/g of methane were produced during 60 days of incubation. The microflora were observed to be methanol utilizers.