| In the hot season, the high-density culture of Siniperca chuatsi and high feeding rate, making the bait and waste enrich in the pond, which organic matter is decomposed by microorganisms to produce large amounts of ammonia and other toxic substances, harm the healthy growth of the Siniperca chuatsi. The experiment study on microbes linked to film in Siniperca chuatsi culture ponds amond8,9,10month, by placed exogenous nitrification bacteria it hanging to bio-artificial carrier elastic filler with indigenous bacteria, to study the growth of the film, influence on the conventional indicators of water quality and phytoplankton growth in pond, the main finding as follows.The growth of the film in Sinipera chuatsi Pond:1. The time of forming a stabilized microorganisms film is20days, the order of magnitude can reach1X107per gram. Biofilm growth is not evenly distributed:with the deep of the water layer, the number of bacteria and fungi gradually increased, however nitrifying bacteria is easier to gather in rich dissolved oxygen upper water level.2. The total number of bacteria of the Biofilm area was significantly greater than the non-linked membrane area in water (P＜0.05), amount of the Biofilm area was3.2-4.6times greater than the non-linked membrane area. The total number of Biofilm area bacteria was7.8X106cfu/mL reached its peak in the September25, and the mean was6.9×106cfu/mL. The peak of non-linked membrane area was1.9×106cfu/mL, and the mean was1.8×106cfu/mL.3. The trend of fungi in water was similarly betweent the Biofilm area and the non-linked membrane area. With the breeding cycle prolonged the amout of fungi gradually increase. The total number of fungi of the Biofilm area was significantly greater than the non-linked membrane area in water (P＜0.05), amount of the Biofilm area was2.3times greater than the non-linked membrane area between August25to September25, but the difference was not significant (P>0.05) afer September25. The total number of experimental and non-linked membrane area reached its peak in the October were2.9×106cfu/mL and2.8×106cfu/mL, and the average were2.3×106cfu/mL and1.8×106cfu/mL4. The total number of nitrifying bacteria of the Biofilm area was significantly greater than the non-linked membrane area in water (P＜0.05), amount of the Biofilm area was1.5times greater than the non-linked membrane area between August25to October25. The total number of experimental reached its peak were1.3×106per milliliter in the September25and 0.9×106per milliliter in the October25, and the average were1.2×106per milliliter and0.7×106permilliliter.Immobilized microbial membrane influence on water quality:1. The value of COD in the biofilm area was less than the COD value in the non-linked membrane area in Agust25to Octorber18(P＜0.05). The Biofilm area was26.65%less than the non-linked membrane area.2. The non-linked membrane area of Ammonia nitrogen was62.25%higher than the Biofilm area. The Biofilm area of nitrate was22.22%more than the non-linked membrane area. The non-linked membrane area of nitrite was30.30%higher than the Biofilm area. The non-linked membrane area of total nitrogen was14.52%higher than the Biofilm area. The Biofilm area of Ammonia nitrogen, Nitrite nitrogen and total nitrogen were significant lower than the non-linked membrane area (P＜0.05).3. There was significant difference between the phosphate content of Biofilm area and non-linked membrane area (P＜0.05). There was significant difference between experimental total phosphorus content group and non-linked membrane area (P<0.05).Immobilized microbial membrane influence on phytoplankton and chlorophyll a:1. The dominant species of phytoplankton from the qualitative and quantitative results were as follows:the dominant species of phytoplankton in the control and Biofilm area were Merismopedia tenuissima and C. apiculata in August. The dominant species of phytoplankton in the non-linked membrane area were Merismopedia tenuissima and P. cylindrus, and the Biofilm areas were Merismopedia tenuissima, Scenedesmus quadricauda, P. cylindrus in September. The dominant species of phytoplankton in the non-linked membrane area were Cyclotella sp, S. minutum, C. tetrapedia, Scenedesmus quadricauda; and the Biofilm areas were Cyclotella sp, C. tetrapedia, S. minutum, Scenedesmus quadricauda in September.2. The biomass and density of phytoplankton increases from August to October. There was significant difference between the phytoplankton density in the Biofilm area and the non-linked membrane area. The density of phytoplankton in the Biofilm area was89.81X105ind/L, the non-linked membrane area was49.74×105ind/L, the Biofilm area was80.56%higher than that in non-linked membrane area. Chlorophyta phytoplankton has been always in a dominant position in the Biofilm area in8,9,10months. The Cyanophyta phytoplankton has been in a dominant position in non-linked membrane area in September, so the water quality of experimental is better than that in non-linked membrane area. There was significant difference between the phytoplankton biomass in the Biofilm area and the non-linked membrane area. The Biofilm area of phytoplankton biomass was9.8724mg/L, the non-linked membrane area was4.9029mg/L, so the phytoplankton biomass of Biofilm area was101.36%higher than that in non-linked membrane area. The result was consistent with the density of phytoplankton. The number of Bacillariophyta gradually increased from August to October.3. The Chl-a content of Biofilm area was significant greater than the non-linked membrane area (P＜0.05). The trend of Chl-a in Biofilm area was gradually increase in8,9,10months, the highest and average value was0.22mg/m3and0.11mg/m3. Chl-a content of the non-linked membrane area tends were decreased to the lowest in the9months then increased, the lowest value was0.031mg/m3, the highest was0.109mg/m3. Chl-a content of the highest values of the non-linked membrane area was89.35%lower than the Biofilm area, and the average of the non-linked membrane area was102.3%lower than the Biofilm area. The Chl-a content of Biofilm area was significantly greater than the non-linked membrane area, regardless of the minimum value average value and maximum value. |
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