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Diversity Analysis Of Microalgae And Mining Of Algal Species Resources In Daqing Area

Posted on:2017-12-19Degree:MasterType:Thesis
Country:ChinaCandidate:Q LiFull Text:PDF
GTID:2510304856478414Subject:Microbiology
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Fossil fuels have become indispensable parts of our life since the progress of industrial production technologies with the increasingly demand of human beings for oil,coal and other fuel resources year by year.However,it has become the key challenge for sustainable development future to look for renewable resources due to the fuel resources are non-renewable.Therefore,algae resources have been one of the renewable resources which can be the new generation biodiesel producer playing irreplaceable roles in modern air transport.In this context,microalgae resources collected from the natural environment are ideal biomass material for development of biodiesel in the sense of selecting high quality microalgae strains when the specialty and components of the microalgae are analyzed.First of all,the water samples in this paper were collected from Binzhou,Liming,Sabei and Lande lakes in Daqing district of Heilongjiang province.The phosphorus,TDS,conductivity,Mg2+,salinity,color,p H value,ammonia nitrogen,total nitrogen and nitrite nitrogen of them were detected by conventional analysis.Meanwhile,totally 8algae strains were isolated from the samples by Streak Plate Method and the morphological characteristics of them were determined according to Chinese fresh water algae-system,classification and ecology as well as molecular biological identification of 18Sr DNA and ITS squencing.The results illuminated that HDL01 is Chlorella vulgaris;HDL02 is Micractinium pusillum;HDL03 is Micractinium reisseri;HDL04 is Pectinodesmus pectinatus;HDL05 is Micractinium pusillum;HDL06 is Desmodesmus communis;HDL07 is Desmodesmus intermedius;HDL08 is Monoraphidium convolutum.Secondly,the species,concentrations,physical and chemical factors of the 8 strains were identified by redundancy analysis.The results showed that there was a positive correlation between the algal species HDL01 and HDL04 with environmental factors which were phosphorus,TDS,conductivity,Mg2+,salinity,color,p H value and ammonia nitrogen.The increasing of environmental factors concentration will lead to the rising density of algal HDL01 and HDL04.Furthermore,algae strains HDL05,and HDL07 were positively correlated with dissolved oxygen,Fe3+and temperature,indicating that these strains could be adapted to higher dissolved oxygen,Fe3+and temperature.Then,the biomass and lipid content of the 8 strains were tested.The highest growth rate was obtained by HDL01 reaching to 0.153±0.001/d which followed by HDL07 that was 0.133±0.004/d;the biomass growth rate of HDL01 reaching to 0.090±0.007 g/L/d was the fastest and followed by HDL08 which was 0.077±0.006 g/L/d;HDL01 was also with the highest lipid growth rate reaching to 6.440±0.003 mg/L/d and followed by HDL08(5.994±0.003 mg/L/d).Furthermore,the unsaturated fatty acid content of HDL04 was 30.46%which was the highest value followed by 25.47%of HDL05.Comprehensively considering the growth rate,biomass,lipid growth rate and fatty acid composition of the 8 algae species,HDL08 was the most appropriately test algae strain for biodiesel production.At last,the metabolites of the microalgaes were determined.The results showed that there were 8 unsaturated fatty acids in HDL08 while they were 7 in HDL05 and HDL06 respectively.The maximal astaxanthin and algal protein content of HDL01 and HDL08 reached to 0.156±0.014 mg/m L and 0.243±0.004 mg/m L respectively,which were followed by HDL07 and HDL01 that were 0.105±0.002 mg/m L and 0.195±0.002 mg/m L respectively.Similarly,the largest chlorophyll and carotenoid pigment content were achieved in HDL01 reaching to 10.79±0.563 mg/g,2.872±0.202 mg/g respectively followed by HDL06 and HDL07 that were 10.259±0.675 mg/g and1.953±0.132 mg/g.Comprehensively thinking of the 8 algae strains about the contents of unsaturated fatty acids,astaxanthin,algae protein,chlorophyll and carotenoid pigment,algal strains HDL01 could be engineered strain for biomass energy.The water samples were collected in the Daqing city in Heilongjiang province where is the high latitude alpine region of China with abundant oil and widely distributed lakes,which has significant importance to investigate microalgae types in alpine region.Meanwhile it is helpful to enrich our species resources and provide favorable guarantee for the production of bio-diesel in future.
Keywords/Search Tags:Microalgae, isolation, identification, lipid, astaxanthin, unsaturated fatty acid, carotenoids
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