Research On Deletion Of Alcohol Dehydrogenase â…¡ Gene From Pachysolen Tannophilus P-01 Capable Of Co-fermenting Pentose And Hexose Released From Lignocellulose

The characteristic of alcohol dehydrogenase II (ADHII) of Pachysolen tannophilus P-01 and Saccharomyces cerevisiae 1308 in the process of cultivation and fermentation were studied. The activities of ADH II, acidities and pH value in the fermentation broth of both strains were analyzed. The results showed that, the ADH II activities of P-01 was higher than that of 1308.Primer of homology were designed to clone adh2 of P-01 by blasting the adh2 of Saccharomyces kluyveri,Pichia stipitis alcohol,Candida albicans SC5314,Saccharomyces.cerevisiae from NCBI.A fragment of 340bp was cloned through polymerase chain reaction,and it is the fragment from the adh2 of P-01.Then the ORF of adh2 was cloned by RACE.The data was submitted to NCBI(EU570211,EU590042).Adh2 of P-01 were deleted by knock-out and recombinants were Validated by resistance to G418,PCR and Co-fermenting. The ethanol concentration of P-01,MC and ND reached 1.85%(v/v),2.0%(v/v),2.4 %(v/v). The ethanol concentration reached the theoretical value of 70.9% and 85.1%,5.2% and 19.4% higher than the parent strains P-01,65.7%.At last, we analyzed the fermentation activity of MC and ND in corn straw hydrolyzates. The ethanol concentration of P-01,MC and ND reached 0.95%(v/v),1.15%(v/v) and 1.25%(v/v). The ethanol concentration reached the theoretical value of 53.2% and 57.8%,9.3% and 13.9% higher than the parent strains P-01,43.9%.