ABSTRACT
In order to decrease the alkali and water consumptions in the sugarcane bagasse alkaline/oxidative pretreatment for ethanol production, an alkaline recycle process was carried out. Two recycles of NaOH/H2O2 pretreatment did not decrease the pretreatment and enzymatic hydrolysis efficiencies and the consumptions of NaOH and water would be saved by 26% and 40%, respectively. A simultaneous saccharification and fermentation (SSF) culture with pretreated bagasse as substrate was developed giving 25 g ethanol l(-1) with a yield of 0.2 g g(-1) bagasse and productivity of 0.52 g l(-1) h(-1).
Subject(s)
Cellulose/chemistry , Cellulose/metabolism , Ethanol/metabolism , Kluyvera/metabolism , Saccharum/chemistry , Saccharum/microbiology , Sodium Hydroxide/chemistry , Alkalies/chemistry , Hydrolysis , Oxidation-ReductionABSTRACT
In order to obtain resistant mutants to nystatin, ultraviolet radiation and LiCl were used to mutagenize the protoplasts of taxol-producing fungi NCEU-1, and four positive mutants with high yield of taxol were screened out on nystatin flat. After further screening experiments on fermentation, a mutant strain--UL04-5 which was able to produce taxol with high yield and could be stably passed on in genetics was eventually found, it's ability to produce taxol was improved from 314.07 microg/L (strain NCEU-1) to 418.24 microg/L (strain U04-5).
Subject(s)
Ascomycota/genetics , Ascomycota/metabolism , Mutagenesis , Paclitaxel/biosynthesis , Protoplasts/metabolism , Ascomycota/drug effects , Ascomycota/growth & development , Fermentation , Genetic Variation , Nystatin/pharmacologyABSTRACT
The breeding of high-yield strain of taxol was performed by protoplast mutagenesis of strain NCEU-1 using ultraviolet radiation and combined treatment of UV and LiCl. The mutants UV40-19 and UL50-6 were obtained, which raised the taxol yield from 314.07 microg/L to 376.38 microg/L and 392.63 microg/L respectively. Genetic differences between the mutants UV40-19, UL50-6 and their parent strain were primarily compared through random amplified polymorphic DNA (RAPD) and isozyme technique. The results showed that the genetic differences were very obviously between the parent strain and its mutants and between the two mutants, which laid foundation of molecular mechanism for the study of genes related to the taxol biosynthesis and mutants for raising the taxol yield.
