The Research About Environmental Factor In Competitive Conditions Impact For M.aeruginosa

On the suitable common condition for training, temperature25℃, light intensity7500Lx, the nutrient formula BG-11, and researching the different starting density, micro bygroup of abundance, light intensity, temperature and other factors have an affect on thegrowth of M.aeruginosa which is a familiar advantage kind in the pond water hua.Theresults showed that different micro algae and micro by group of abundance have aremarkable differences impact on the growth of M.aeruginosa of (P <0.05); The micro algaegrowth situation between different starting density are also significant difference (P <0.05);And under the same training the micro by group of abundance and starting density haveinteraction effect of the M.aeruginosa; After study, the growth of M.aeruginosa under thecompetition condition have a significant different in different light intensity and thetemperature (P <0.05). Finally, make a conclusion abut the micro algae and environmentalfactors of the micro algae characteristics which is the effect factors on the growth ofM.aeruginosa in freshwater aquaculture ponds, for the probe of the freshwater pondenvironment for regulation of micro algae composition, the method of the replacement toprovide the theory basis.In this paper, comparing with the Micro algae growth under separate training in the sameperiod, five common microalgae in freshwater pond, such as C.vulgaris,S.quadricauda-FACHB-1297, K.lunaris, Anabaena Broy sp·-FACHB-1299and Oscillatoriasp·-FACHB-1120, as well as the concentrations of them affecting the growth ofM.aeruginosa were investigated by using repeat two factors completely random design. Theresults showed that the initial density of five microalgae have a significant effect on thegrowth of M.aeruginosa（P<0.05）. When the minimum initial density of M.aeruginosa was4.5×10~5cells/ml, it was showed that the more concentrations of five microalgae increased,the more significantly the growth of M. aeruginosa was suppressed. While the initialconcentration of M.aeruginosa was high, the suppression effect of the concentrations of fivemicroalgae increasing on the growth of M. aeruginosa was not significant. In addition, thegrowth of M.aeruginosa was significantly affected by its initial concentration（P<0.05）.Through the competition of parameters calculation, the several micro algae competitionsuppress strength from big t o small in turn is Anabaena Broy sp. Oscillatoria sp. C.vulgaris.S.quadricauda. K.lunaris. Learned that several micro algae and different starting dense have different effect onthe growth of M.aeruginosa, then,make the experiment about several micro by group ofabundance and start doing the population density of orthogonal test, that is6factors that4level orthogonal tests. The experiment of the four level respectively for the different microalgae starting density in Arabic numerals1(starting density of0),2(starting density of2.0x10~5cells/ml),3(starting density of4.0x10~5cells/ml),4(starting density of8.0x10~5cells/ml), and six factors for six micro algae. Through the homogeneous variance analysisthe conclusion, when in the condition of C.vulgaris, Anabaena Broy sp level2(2.0x10~5cells/mL), S.quadricauda level3(4.0x10~5cells/mL), K.lunaris and Oscillatoria sp, level4(8.0x10~5cells/mL) have the most obvious inhibition effect,and at the same time the growthrate of M.aeruginosa is minimum while the inflection point time is maximum, startingdensity and micro by group of abundance of M.aeruginosa growth have obvious interaction(P <0.05).Based on the results from the orthogonal experiment, the density of the fixed startingseveral micro algae, that is the C.vulgaris, Anabaena Broy sp level2(2.0x10~5cells/mL),S.quadricauda level3(4.0x10~5cells/mL), K.lunaris and Oscillatoria sp, level4(8.0x10~5cells/mL) in BG-11medium, temperature25℃, light intensity for7500Lx,according todifferent under abundance gradient do random experiment. To test the differentM.aeruginosa cell number in each group, make use of income data for its growthrate,inflection point time and maximum inflexion point biomass, and then take the minimumgrowth rate, the largest inflection point time group. The results is the ABCE group, that isthe collection group of M.aeruginosa, C.vulgaris, S.quadricauda, the Anabaena Broysp,which has the most obvious inhibition effect on the growth of M. aeruginosa.Finally, in the same experimental conditions, take the kind of micro algae which isM.aeruginosa, C.vulgaris, S.quadricauda, the Anabaena Broy sp, in accordance with theabove experiments, combining the start of the density, and set respectively five kinds of lightintensity level (500LX,2500LX,5000LX,10000LX,15000LX) and four temperaturelevel (15℃,25℃,30℃,35℃). The results showed that under the condition of competitionalgae biomass were all less than the single biomass of training, the maximum biomassacquire when the competitive conditions algae was in light intensity for10000LX andtemperature for35℃, and in the condition of500LX and15℃the growth of M.aeruginosa significantly inhibited, the experimental stage biomass little change in thewhole experiment. Different light intensity and temperature all have a significant differenton the growth M.aeruginosa (P <0.05), Each group under the competition condition thegrowth of the M.aeruginosa and separate training have notable differences (P <0.05).