Sponges have traditionally been viewed as rather unselective filter feeders, and therefore as potential biofilters to remediate microbial water pollution. Here we show that the assumed connection between the ability of sponges to feed on microbes and the potential biotechnological use of such an ability to reduce microbial pollution is more complex than assumed. In a laboratory feeding experiment combined with a transmission electron microscopy study, we assessed the potential of the marine sponge Hymeniacidon perlevis to ingest and digest 3 common pathogenic microbes occurring in coastal waters: 2 bacteria (Escherichia coli and Vibrio anguillarum), and 1 marine yeast Rhodotorula sp. All 3 microbes were ingested by the sponge, but selectively, at different rates and following different cellular mechanisms. Yeast cells were processed very atypically by the sponge. Differences in the ingestion and digestion pathways led to large differences in the effectiveness of the sponge to remove the microbes. While sponge grazing reduced the concentration of E. coli and Rhodotorula sp. to levels far below the initial values, sponges were ineffective in abating concentrations of the most infective bacterium, V. anguillarum. This bacterium, which was digested more slowly than E. coli, proliferated in the experimental flasks at much higher rates than it was grazed. These findings raise the question whether sponges are suitable for bioremediation of microbial pollution, since selective or preferential ingestion of certain bacteria by sponges may end up fueling growth of those grazed less, such as Vibrio spp.

Sessile filter-feeding marine sponges (Porifera) have been reported to possess high efficiency in removing bacteria pollution from natural or aquaculture seawater. However, no investigation has been carried out thus far in a true mariculture farm water system. Therefore this study sought to investigate the ability of the marine sponge Hymeniacidon perlevis to bioremediate the bacteria pollution in the intensive aquaculture water system of turbot Scophthalmus maximus. Sponge specimens were hung in fish culture effluent at different temperature to investigate the optimal temperature condition for bacteria removal by H. perlevis. Turbots S. maximus were co-cultured with sponge H. perlevis in 1.5 m(3) of water system at 15-18 degrees C for 6 weeks to control the growth of bacteria. It was found that H. perlevis was able to remove pathogenic bacteria efficiently at 10-20 degrees C, with a maximal removal of 71.4-78.8% of fecal coliform, 73.9-98.7% of pathogenic vibrio, and 75.0-83.7% of total culturable bacteria from fish-culture effluent at 15 degrees C; H. perlevis continuously showed good bioremediation of bacteria pollution in the S. maximus culture water system, achieving removal of 60.0-90.2% of fecal coliform, 37.6-81.6% of pathogenic vibrio, and 45.1-83.9% of total culturable bacteria. The results demonstrate that H. perlevis is an effective bioremediator of bacteria pollution in the turbot S. maximus culture farm water system.

To resolve "the supply problem" in sponge-derived drug development and other biotechnological applications, current research is exploring the possibility of obtaining an alternative sustainable supply of sponge biomass through intensive aquaculture of sponges utilizing artificial seed rearing. This study aimed to investigate the technology of early juvenile sponge cultivation under controlled conditions. The effects of food, temperature, water flow, and light on the growth and survival of early juveniles of the marine sponge Hymeniacidon perlevis were examined. The concentrations of four types of food elements [microalgae (Isochrysis galbana), photosynthetic bacteria (Rhodopseudomonas), Fe(3+) (FeCl(3)), and Si (Na(2)SiO(3))] were investigated for early H. perlevis juvenile growth. Interestingly, temperature changes have striking effects on juvenile growth. Juvenile sponges grow faster when they are shifted to higher temperatures (18 degrees C to 23 degrees C) than when they are shifted to lower temperatures (18 degrees C to 4 degrees C to 23 degrees C) or kept at a constant temperature (18 degrees C). Periodic water flow and light cycles favor early juvenile sponge growth. Light was found to be a key factor in the color loss of early H. perlevis juveniles. Overall, size (area) increased as much as 29 times for H. perlevis juveniles under the tested controlled conditions.