| This study used the green tide macroalgae (Ulva), which occurs along China’s coast common in recent years, as raw material. Through the degradation of cellulase produced by the marine microorganisms which screened from the sea mud and decayed algae, Ulva biomass could transformed into some monosaccharides which can be used by yeast. It can be applied in microbial anaerobic fermentation for producing biofuels ethanol, and it explores the process of marine algae biomass for biofuels.We used the green tide algae Ulva which broke out large-scale in Qingdao sea in 2008 and 2009 as experimental material. After cleaning, comminuting and analyzing its nutrition composition, we found its basic nutrition composition contains water 8.053%, protein 24.21%, fat 1.09%, crude fiber 18.37%, ash content 37.41%; In its inorganic element content, there were sodium 0.625 muon g/mL, calcium 0.894 muon g/mL, potassium 0.643 muon g/mL, zinc 0.048 muon g/mL, magnesium 0.167 muon g/mL and iron 0.0047 muon g/mL; The amino acid content of the analysis showed that Ulva contains 17 kinds of amino acids which includes 38.57% essential amino acids of total amino acids. According to the amino acids composition, freshness amino acids was the highest, sweet amino acids in the next place; The fatty acid composition and content of Ulva analysis shows that there are 13 kinds of fatty acids in it which contains 56.47% unsaturated fatty acids of total fatty acids, in which the linolenic acid content is 18.26% and the oleic acids content is 6.39%. And through the carbohydrate component systematic analysis, we found that its total sugar content is 39.50%, cellulose content is 13.3%, hemicellulose content is 28.01% , starch content is 2.475%, water-soluble polysaccharide content is 11.503% irrigated, and water-soluble pentosan content is 11.25%. Theoretically, there are more than 55% of carbohydrates which can be degradated into monosaccharides which can be used in producing ethanol.Cellulose and hemicellulose is a kind of biomass which is difficult to use but the amount is huge. The degradation and transformation for cellulose by microorganisms is the key link of the carbon cycle in nature world, so we screened from the sea mud in nature and the decayed algae in laboratory to get marine microorganisms which can degradate Ulva. After the separation and purification, preliminary screening and second screening from sea mud, we got 6 strains which can produce cellulase. Through extracting the crude enzymes after cultivating to hydrolyze Ulva, the results show that the effect of mould is better than bacteria. It was identified that the bacteria is Bacillus subtilis, the moulds are Trichoderma, Rhizopus and Aspergillus niger; After the separation and purification, preliminary screening and second screening from decayed algae,we got 2 strains which have the best effect of degradation. Also, we use Ulva as the only carbon source choice medium for screening for the first time..We compared the activities and the effects of degradation of that 9 strains microbes which have higher activities, with the commonly used Trichoderma koningii and Aspergillus niger, and the commodity enzyme BG and Super. The results showed that in the 11 kinds of microorganisms, the activities of BG from N8 and Aspergillus niger is higher; the activities of EG from Trichoderma koningii is on the high side; Also the activities of CBH from N11 and HBB - 1 is higher; The activities of hemicellulase from Aspergillus niger is supreme; The effects of degradating Ulva leaves of Trichoderma koningii is the most obvious; BB - 2 worked well on the degradation of Ulva powder; In degradation process, the consumption of Ulva powder of Aspergillus niger is the most; The saccharification of Trichoderma koningii worked relatively obviously.Therefore, we can determine that the activity of cellulase from Trichoderma koningii and Aspergillus niger are relatively high, but the proportion of its various enzymes is to optimize for follow-up study.We researched on two fungus Trichoderma koningii and Aspergillus niger as the object to degrade the cellulose in Ulva, and to produce the cellulase. Except for single bacterium ferment to produce cellulase, we focused on improving the ability of producing enzyme by designing different experiments. In liquid medium, there were different proportion and times of inoculation, and mixed culture after separate culture. In solid mixed-medium, there were the choice of medium and the time of relative inoculation . We found: in single fungi culture , the enzyme production of Aspergillus niger is a dominant species compared to Trichoderma koningii; when mixed the two fungus at the proportion of 1:0.25, the activity of enzymes producing by mixed fungus reached the highest value, CMC activity,β-glucosidase activity, filter paper activity were: 2.5289 U / mL, 49.4696 U / mL and 6.2378 U / mL; at different inoculation time, inoculated Aspergillus niger in the first 3 days, the activity of enzymes producing by mixed fungus reached the highest value, CMC activity,β-glucosidase activity and filter paper activity were 38.1292 U / mL, 39.9300U/mL and 3.2529 U / mL, respectively; in different culture approach, cultured for 3 days in separate then mixed the two fungus, the activity of enzymes producing by mixed fungus reached the highest value, CMC activity,β-glucosidase activity and filter paper activity were 86.9945 U / mL, 95.7881U/mL and 4.2739 U / mL, respectively; In the study of solid culture medium options, we found the medium 1 (M1) is the best solid medium;When mixed fungus inoculated in solid medium, the relative time of inoculation time in 12h, the activity of enzymes producing by mixed fungus reached the highest value, CMC activity,β-glucosidase activity, filter paper activity were 34.6837 U / mL, 34.3933U/mL and 10.8376 U / mL, respectively. |
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