Microbial Transformation Studies Of Cellulose Pyrolysis Products

Biomass is the most abundant renewable resource on earth.With increase of energy and resource problem,the conversion utilization of biomass has a great application value.Pyrolysis is a major method of biomass conversion.Pyrolysis liquid and levoglucosan is major product of cellulosic biomass pyrolysis.With the development of pyrolysis technology,the content of levoglucosan reached 40%.Therefore,the effective use of pyrolysis liquild and levoglucosan is notable.Three kinds of microorganisms(ZS2?FX and GT)were isolated from soil with levoglucosan as sole carbon source.The results showed that three kinds of new microorganisms could assimilate levoglucosan efficiently.ZS2 and FX were cultured for 5d in 2%levoglucosan medium,the utilization rates of levoglucosan were 100%respectively.GT were cultured for 7d in the same medium,and utilization rate of levoglucosan reached 100%.4 strains were identified as Penicillium pinophilum,Penicillium citrinum and Eurotium cristatum on the basis of morphology features and 18S rDNA sequence analysis.Pyrolysis liquid contains aldehyde ketones,which could inhibit the growth of microorganisms.The results showed three kinds of microorganisms could grow in pretreamented pyrolysis liquid(treated by 5%activated carbon+Ca(OH)2)and use levoglucosan in pyrolysis liquid.The assimilate levoglucosan efficiency of Penicillium citrinum was the highest(4d,100%),Penicillium pinophilum was secondly(5d,90%),Eurotium cristatum was only 91%for 7d.Then the components in pyrolysis liquid after pretreatment were analysised,which showed that Pyrolysis liquid contained a mount of aldehyde ketones(furfural 18.5%).Pretreatment had a notable influence on the components of pyrolysis liquid,and the removal rate of hexamethyl cyclotrisiloxane,1,2-Cyclopentanedione,5-methylfurfural,3-methyl-1,2-Cyclopentanedione and hydroxyl methylfuraneol were 100%respectively.The removal rate of furfural was 77%.Penicillium pinophilum could produce P-glucosidase with levoglucosan as carbon source(enzyme activity reached 341U/ml after 5d).?-glucosidase enzyme activity reached 559 U/m with pyrolysis liquild as carbon source.Eurotium cristatum was found to highly produce melanin with levoglucosan and pyrolysis liquild.The yield of melanin by E.cristatum used levoglucosan and pyrolysis liquild as carbon source was 2.7 g/L and 3.9g/L,respectively.The melanin was identified as eumelanin with full wavelength scan and IR spectrum methods.Saccharomyces cerevisiae could produce ethanol with levoglucosan as carbon source,the ethanol productivity content only 0.2%.Pyrolysis liquild come from microcrystalline cellulose and lignocellulose as materials were analysised.The results showed in the same pyrolysis conditions,the content of aldehyde ketones using microcrystalline cellulose as pyrolysis material was less than using lignocellulose.The content of levoglucosan has a noticeable difference,the former was 38%,the latter was only 3.6%.The influence of acidolysis on the components in pyrolysis liquild was studied.The results showed the yield of levoglucosan in pyrolysis liquild had a noticeable decline(only 0.22%).