195
Strains of Chaetomium spp. and Trichoderma viride are well known for their cellulolytic ability. More recently, however, it has been shown that Pythium spp. could break down cellulose. For example, Park (1975) reported that cellulolytic species of Pythium can be isolated from organic debris in rivers and from river water, while Park & McKee (1978) reported that Pythium spp. were early and rapid colonizers of filter paper suspended in river water; they also demonstrated the importance of a source of combined nitrogen to support cellulolytic activity.
A total of 100 bacterial isolates were obtained from the surfaces of immersed leaves, and their characteristics are summarized in Table 4. Many of the isolates were pigmented, as is common among marine bacteria. The relative proportions of the various pigmented isolates changed during the period of immersion, suggesting that the bacterial flora was changing. Similarly, the proportion of isolates with particular biochemical characters changed during immersion, but the percentage with cellulolytic ability remained high throughout.
d) Changes in the Litter during Immersion
Leaves of Kandelia remained more or less intact for the first 28 days of immersion but thereafter breakdown proceeded quickly: by 56 days the leaves had broken down into thin, perforated fragments and by 168 days the material was not recognisable with the naked eye.
The main physical and chemical changes are shown in Figure 3. Over a period of some 50 days, the general pattern of change in the dry weight of the leaf tissue was a progressive decrease to about 35% of the initial weight. After an early rise, the hot-water-soluble carbohydrate also declined though in a rather irregular way. Concomitantly, the protein content rose to more than double the initial level by day 18 and then fluctuated about a level substantially higher than that before immersion.
e) Diet of Higher Trophic Levels
In addition to detritus and the red alga Ceramium sp., potential
195
Strains of Chaetomium spp. and Trichoderma viride are well known for their cellulolytic ability. More recently, however, it has been shown that Pythium spp. could break down cellulose. For example, Park (1975) reported that cellulolytic species of Pythium can be isolated from organic debris in rivers and from river water, while Park & McKee (1978) reported that Pythium spp. were early and rapid colonizers of filter paper suspended in river water; they also demonstrated the importance of a source of combined nitro- gen to support cellulolytic activity.
A total of 100 bacterial isolates were obtained from the surfaces of immersed leaves, and their characteristics are summarized in Table 4. Many of the isolates were pigmented, as is common among marine bacteria. The relative proportions of the various pigmented isolates changed during the period of immersion, sug- gesting that the bacterial flora was changing. Similarly, the propor- tion of isolates with particular biochemical characters changed during immersion, but the percentage with cellulolytic ability re- mained high throughout.
d) Changes in the Litter during Immersion
Leaves of Kandelia remained more or less intact for the first 28 days of immersion but thereafter breakdown proceeded quickly: by 56 days the leaves had broken down into thin, perforated frag- ments and by 168 days the material was not recognisable with the naked eye.
The main physical and chemical changes are shown in Figure 3. Over a period of some 50 days, the general pattern of change in the dry weight of the leaf tissue was a progressive decrease to about 35% of the initial weight. After an early rise, the hot-water-soluble carbohydrate also declined though in a rather irregular way. Con- comitantly, the protein content rose to more than double the ini- tial level by day 18 and then fluctuated about a level substantially higher than that before immersion.
e) Diet of Higher Trophic Levels
In addition to detritus and the red alga Ceramium sp., potential
No comments yet.
Private notes are available after approval.